75 results on '"Sfenthourakis S"'
Search Results
2. Terrestrial isopods (Crustacea: Oniscidea) from the remote Greek island Antikithira and its surrounding islets
- Author
-
Sfenthourakis, S and BioStor
- Published
- 1993
3. Annual cycle of mesozooplankton at the coastal waters of Cyprus (Eastern Levantine basin)
- Author
-
Fyttis, G, primary, Zervoudaki, S, additional, Sakavara, A, additional, and Sfenthourakis, S, additional
- Published
- 2023
- Full Text
- View/download PDF
4. Deterministic assembly and anthropogenic extinctions drive convergence of island bird communities
- Author
-
Triantis, K.A. Rigal, F. Whittaker, R.J. Hume, J.P. Sheard, C. Poursanidis, D. Rolland, J. Sfenthourakis, S. Matthews, T.J. Thébaud, C. Tobias, J.A.
- Subjects
geographic locations - Abstract
Aim: Whether entire communities of organisms converge towards predictable structural properties in similar environmental conditions remains controversial. We tested for community convergence in birds by comparing the structure of oceanic archipelago assemblages with their respective regional species pools. Location: Eighteen major oceanic archipelagos of volcanic origin with global distribution. Major taxa studied: Terrestrial birds. Methods: We compiled a comprehensive database of morphological trait and phylogenetic data for 6,579 bird species, including species known to have become extinct owing to human activities. We quantified morphological and phylogenetic dissimilarity among species between pairs of archipelagos, using a modified version of the mean nearest taxon distance. We tested for convergence by estimating whether overall mean turnover among archipelagos and pairwise turnover between archipelagos were lower than expected by chance. Results: For all land birds, we found that turnover in body plan, body mass and phylogeny among archipelagos was significantly lower than expected. Seventeen (of 18) archipelagos showed significant body plan and phylogenetic similarity with at least one other archipelago. Similar convergent patterns of community assembly were detected in different subsamples of the data (extant species, endemics, native non-endemics, and Passeriformes only). Convergence was more pronounced for extant species than for extant and extinct species combined. Main conclusions: Consistent convergence in phylogenetic and morphological structure among archipelagic communities arises through a combination of non-random colonization and in situ adaptation. In addition, by including data from extinct taxa, we show that community convergence both precedes and is accentuated by the anthropogenic extinction of endemic lineages. Our results highlight the potential role of non-random extinction in generating patterns of community convergence and show that convergence existed even before anthropogenic extinctions, owing to deterministic community assembly in similar environmental settings at the global scale. © 2022 John Wiley & Sons Ltd.
- Published
- 2022
5. The role of ecological specialization in shaping patterns of insular communities
- Author
-
Sfenthourakis, S. Triantis, K.A. Proios, K. Rigal, F.
- Abstract
Aim: Research on the response of species richness to area and environmental heterogeneity so far has not addressed possible effects of species’ differences in ecological specialization. Herein we provide a new metric, ‘ecorichness’, in an attempt to fill this gap. Location: Aegean islands (Greece). Taxon: Terrestrial isopods. Methods: ‘Ecorichness’ estimates an island's biodiversity by integrating species richness and the specialists-generalists spectrum. We calculated ‘ecorichness’ for terrestrial isopods from 43 Aegean islands based on the habitats they exploit. ‘Ecorichness’ then was regressed on area, habitat diversity and the K-parameter of the Choros model using linear and quadratic models, compared based on AICc. A reduced data set, without halophilous species and coastal habitats, as well as an alternative description of habitat diversity, also was explored. The small island effect (SIE) thresholds identified using both a path analysis approach and piecewise continuous linear models were compared to the area of maximum ‘ecorichness’. Results: ‘Ecorichness’ response to area and habitat heterogeneity was best fitted by quadratic models with peaks located at an area similar to the SIE threshold identified by path analysis. Different measures of habitat diversity produced similar patterns. Exclusion of coastal species and habitats shows that the response of ‘ecorichness’ to area is mostly shaped by the increasing contribution of specialists in the assemblages of larger islands. Main conclusions: ‘Ecorichness’ facilitates exploration of the role of ecological specialization in shaping community patterns. It can be applied to different community data sets, whenever habitat range exploitation can be quantified. Results from the case study accord with previous suggestions that the relative contribution of generalists and specialists differs between small and large island communities. © 2020 John Wiley & Sons Ltd
- Published
- 2021
6. Variation in breeding parameters of Eleonora’s falcon (Falco eleonorae) and factors affecting its reproductive performance
- Author
-
Xirouchakis, S. M., Fric, J., Kassara, C., Portolou, D., Dimalexis, A., Karris, G., Barboutis, C., Latsoudis, P., Bourdakis, S., Kakalis, E., and Sfenthourakis, S.
- Published
- 2012
- Full Text
- View/download PDF
7. Insights into how predator diversity, population density and habitat type may affect defensive behaviour in a Mediterranean lizard
- Author
-
Savvides, P. Poliviou, V. Stavrou, M. Sfenthourakis, S. Pafilis, P.
- Abstract
Various factors may alter anti-predatory responses among conspecifics. Here we assess some of these factors using three populations of a Mediterranean lizard (Acanthodactylus schreiberi) in Cyprus that differ in their habitat type, predator diversity and population density. We expected that predation would affect flight initiation distance (FID; the approach distance allowed to an observer before the lizard flees), escape distance (ED; the distance covered by the lizard from the point an escape attempt starts to the first place the lizard stops) and tail autotomy (autotomy rates, economy of autotomy, post-autotomy tail movement). We also predicted that juveniles, being more exposed to predators, would be more effective in their defensive responses. Our findings suggest that predation and population density appear to be associated with most autotomy traits but were not associated with FID and ED, which are better explained by refuge availability. The only ontogenetic difference was detected in the economy of autotomy: juveniles are more prone to autotomise, possibly because they do not experience such high costs as tailless adult individuals. Our results suggest that anti-predatory responses are influenced by a variety of factors. Unravelling the compound effects of all the factors involved should be the focus of future research. © 2018, © 2018 Dipartimento di Biologia, Università di Firenze, Italia.
- Published
- 2019
8. Substrate type has a limited impact on the sprint performance of a mediterranean lizard
- Author
-
Savvides, P. Georgiou, E. Pafilis, P. Sfenthourakis, S.
- Abstract
Environmental factors may affect animal performance in diverse ways, even among different populations of a single species. Here, we assess the impact of substrate type on the sprint performance (maximum speed and acceler-ation) of Schreiber’s fringe-fingered lizard (Acanthodactylus schreiberi). This species is a skillful runner that also bears micro spike-like protruding scales on its toepads (toe fringes), an adaptation for locomotion on sand. We worked with three populations living in habitats that differ in substrate type (sand, soil and rock). We measured sprint performance using a race-track with custom substrate platforms replicating the different substrate types. We formulated two hypotheses: first, we anticipated that the three populations would differ in their sprint performance due to the differences in substrate type; second, we expected that each population would perform better on its home substrate. Our results generally refuted the hypothesis that sprint performance would differ on different substrate types. Our results suggest that there is a restricted effect of substrate type on locomotion and indicate a multifactor interplay among alternative underlying parameters. © Firenze University Press.
- Published
- 2019
9. Modelling the role of alien species and fisheries in an Eastern Mediterranean insular shelf ecosystem
- Author
-
European Commission, Michailidis, N., Corrales, Xavier, Karachle, Paraskevi K., Chartosia, N., Katsanevakis, Stelios, Sfenthourakis, S., European Commission, Michailidis, N., Corrales, Xavier, Karachle, Paraskevi K., Chartosia, N., Katsanevakis, Stelios, and Sfenthourakis, S.
- Abstract
We developed a trophic mass-balance model to describe the structure and functioning of the insular shelf ecosystem of the Republic of Cyprus and assess the impact of fishing and alien species during the mid-2010s. A total of 40 functional groups were defined, ranging from producers and detritus to top predators and when possible, alien species were included in exclusively alien groups. All fishing activities in the area were considered. Input data were obtained from local surveys, fishery statistics, published data on stomach content analyses, other scientific and grey literature, as well as empirical equations. Results show that the ecosystem shares common structural and functional characteristics with other Mediterranean ones, especially those in the eastern basin. Fishing has noticeable impacts on the ecosystem and based on the results, 7.1% of the total primary production is required to sustain fisheries. The model predicts a strong negative impact of small-scale fisheries on small sharks and turtles, and of recreational fisheries on the large demersal and pelagic fishes. Our results also highlight the significant role of alien species within the ecosystem. Alien fish accounted for 29% of fish production. Negative impacts of alien fish were predicted, in particular by alien siganids on phytobenthos, and some alien demersal fishes on eels and morays. This is the first food-web model for Cyprus and results are discussed and compared to other Mediterranean models
- Published
- 2019
10. Environment shapes the digestive performance in a Mediterranean lizard
- Author
-
Karameta, E. Gourgouliani, N. Kouvari-Gaglia, D. Litsi-Mizan, V. Halle, S. Meiri, S. Sfenthourakis, S. Pafilis, P.
- Abstract
An efficient digestive system is of pivotal importance for survival as it governs the energy flow from the environment to organisms. Reptiles require relatively little energy, and their digestive system can readily respond to internal and external shifts. Ergo, reptiles can colonize even demanding habitats by improving digestive performance. Although many studies address lizard digestion, few examine geographical variation. Here, we examine how the digestion of a single lizard species (Stellagama stellio) differs along a latitudinal and climatic gradient, comprising mainland and insular populations. Apparent digestive efficiency (ADE, the percentage of ingested energy absorbed through the gut) for lipids, proteins and sugars was used to answer the main question: is digestive performance consistent across populations (one species, one pattern) or is it dependent on habitat features (different populations, different patterns). We expected that climate and insularity would affect ADE. Indeed, the northernmost populations, inhabiting colder, rainier, less seasonal regions, achieved the lower ADEs. Insularity, however, had no effect on digestive efficiency, indicating that insular (or mainland) habitats are not all the same and local particularities may play a role. These findings suggest that each population adjusts its physiological repertoire to the local conditions. © 2017 The Linnean Society of London.
- Published
- 2017
11. The Aegean archipelago: A natural laboratory of evolution, ecology and civilisations
- Author
-
Sfenthourakis, S. Triantis, K.A.
- Abstract
The Aegean archipelago, comprising numerous islands and islets with great heterogeneity in topographic, geological, historical and environmental properties, offers an ideal natural laboratory for ecological and evolutionary research, and has been the stage for a very long interaction between human civilizations and local ecosystems. This work presents insights that have been gained from past and current relevant research in the area, highlighting also the importance of the Aegean archipelago as a useful model to address many major questions in biogeography, ecology and evolutionary processes. Among the most interesting findings from such studies concern the role of habitat heterogeneity as the most important determinant of species richness, the development of a new model (Choros) for the species-area-habitats relationship, the mechanistic aspects of the Small Island Effect, the very high rates of species turnover, the lack of a role for interspecific competition in shaping species co-occurrence patterns in most cases, the importance of non adaptive radiation in diversification of several taxa, the insights into the relative roles of vicariance and dispersal in speciation, the understanding of the interplay between human presence and the establishment of exotic species and extinction of indigenous biotas. Concluding, the Aegean archipelago is an ideal stage for research in evolution, ecology and biogeography, and has the potential to become a model study area at a global level, especially for land-bridge, continental islands. © The Author(s) 2017.
- Published
- 2017
12. Tail autotomy affects bipedalism but not sprint performance in a cursorial Mediterranean lizard
- Author
-
Savvides, P. Stavrou, M. Pafilis, P. Sfenthourakis, S.
- Abstract
Running is essential in all terrestrial animals mainly for finding food and mates and escaping from predators. Lizards employ running in all their everyday functions, among which defense stands out. Besides flight, tail autotomy is another very common antipredatory strategy within most lizard families. The impact of tail loss to sprint performance seems to be species dependent. In some lizard species, tail shedding reduces sprint speed, in other species, increases it, and, in a few species, speed is not affected at all. Here, we aimed to clarify the effect of tail autotomy on the sprint performance of a cursorial lizard with particular adaptations for running, such as bipedalism and spike-like protruding scales (fringes) on the toepads that allow high speed on sandy substrates. We hypothesized that individuals that performed bipedalism, and have more and larger fringes, would achieve higher sprint performance. We also anticipated that tail shedding would affect sprint speed (though we were not able to define in what way because of the unpredictable effects that tail loss has on different species). According to our results, individuals that ran bipedally were faster; limb length and fringe size had limited effects on sprint performance whereas tail autotomy affected quadrupedal running only in females. Nonetheless, tail loss significantly affected bipedalism: the ability for running on hindlimbs was completely lost in all adult individuals and in 72.3% of juveniles. © Springer-Verlag Berlin Heidelberg 2016.
- Published
- 2016
13. PESI - A taxonomic backbone for Europe
- Author
-
de Jong, Y. Kouwenberg, J. Boumans, L. Hussey, C. Hyam, R. Nicolson, N. Kirk, P. Paton, A. Michel, E. Guiry, M.D. Boegh, P.S. Pedersen, H. Enghoff, H. von Raab-Straube, E. Güntsch, A. Geoffroy, M. Müller, A. Kohlbecker, A. Berendsohn, W. Appeltans, W. Arvanitidis, C. Vanhoorne, B. Declerck, J. Vandepitte, L. Hernandez, F. Nash, R. Costello, M.J. Ouvrard, D. Bezard-Falgas, P. Bourgoin, T. Wetzel, F.T. Glöckler, F. Korb, G. Ring, C. Hagedorn, G. Häuser, C. Aktaç, N. Asan, A. Ardelean, A. Borges, P.A.V. Dhora, D. Khachatryan, H. Malicky, M. Ibrahimov, S. Tuzikov, A. De Wever, A. Moncheva, S. Spassov, N. Chobot, K. Popov, A. Boršic, I. Sfenthourakis, S. Kõljalg, U. Uotila, P. Olivier, G. Dauvin, J.-C. Tarkhnishvili, D. Chaladze, G. Tuerkay, M. Legakis, A. Peregovits, L. Gudmundsson, G. ólafsson, E. Lysaght, L. Galil, B.S. Raimondo, F.M. Domina, G. Stoch, F. Minelli, A. Spungis, V. Budrys, E. Olenin, S. Turpel, A. Walisch, T. Krpach, V. Gambin, M.T. Ungureanu, L. Karaman, G. Kleukers, R.M.J.C. Stur, E. Aagaard, K. Valland, N. Moen, T.L. Bogdanowicz, W. Tykarski, P. Weslawski, J.M. Kedra, M. Martins, A.M.F. Abreu, A.D. Silva, R. Medvedev, S. Ryss, A. Šimic, S. Marhold, K. Stloukal, E. Tome, D. Ramos, M.A. Valdés, B. Pina, F. Kullander, S. Telenius, A. Gonseth, Y. Tschudin, P. Sergeyeva, O. Vladymyrov, V. Rizun, V.B. Raper, C. Lear, D. Stoev, P. Penev, L. Rubio, A.C. Backeljau, T. Saarenmaa, H. Ulenberg, S.
- Subjects
InformationSystems_INFORMATIONSTORAGEANDRETRIEVAL ,ComputingMethodologies_ARTIFICIALINTELLIGENCE - Abstract
Reliable taxonomy underpins communication in all of biology, not least nature conservation and sustainable use of ecosystem resources. The flexibility of taxonomic interpretations, however, presents a serious challenge for end-users of taxonomic concepts. Users need standardised and continuously harmonised taxonomic reference systems, as well as highquality and complete taxonomic data sets, but these are generally lacking for nonspecialists. The solution is in dynamic, expertly curated web-based taxonomic tools. The Pan-European Species-directories Infrastructure (PESI) worked to solve this key issue by providing a taxonomic e-infrastructure for Europe. It strengthened the relevant social (expertise) and information (standards, data and technical) capacities of five major community networks on taxonomic indexing in Europe, which is essential for proper biodiversity assessment and monitoring activities. The key objectives of PESI were: 1) standardisation in taxonomic reference systems, 2) enhancement of the quality and completeness of taxonomic data sets and 3) creation of integrated access to taxonomic information. New information This paper describes the results of PESI and its future prospects, including the involvement in major European biodiversity informatics initiatives and programs. © de Jong Y et al.
- Published
- 2015
14. The island rule is not valid in terrestrial isopods (Crustacea: Oniscidea)
- Author
-
Karagkouni, M., primary, Sfenthourakis, S., additional, and Meiri, S., additional
- Published
- 2016
- Full Text
- View/download PDF
15. PESI - a taxonomic backbone for Europe
- Author
-
de Jong, Y, Kouwenberg, J, Boumans, L, Hussey, C, Hyam, R, Nicolson, N, Kirk, P, Paton, A, Michel, E, Guiry, MD, Boegh, PS, Glöckler, F, Korb, G, Ring, C, Hagedorn, G, Häuser, C, Aktaç, N, Asan, A, Ardelean, A, Borges, PA, Dhora, D, De Wever, A, Khachatryan, H, Malicky, M, Ibrahimov, S, Tuzikov, A, Moncheva, S, Spassov, N, Chobot, K, Popov, A, Boršić, I, Sfenthourakis, S, Kõljalg, U, Uotila, P, Olivier, G, Legakis, A, Dauvin, JC, Tarkhnishvili, D, Chaladze, G, Tuerkay, M, Peregovits, L, Gudmundsson, G, Ólafsson, E, Lysaght, L, Galil, BS, Raimondo, FM, Domina, G, Stoch, F, Minelli, A, Walisch, T, Spungis, V, Budrys, E, Olenin, S, Turpel, A, Krpach, V, Gambin, MT, Ungureanu, L, Karaman, G, Kleukers, RM, Stur, E, Aagaard, K, Valland, N, Moen, TL, M de Frias Martins, A, Bogdanowicz, W, Tykarski, P, Węsławski, JM, Kędra, M, Abreu, AD, Silva, R, Medvedev, S, Ryss, A, Šimić, S, Marhold, K, Stloukal, E, Tome, D, Ramos, MA, Gonseth, Y, Valdés, B, Pina, F, Kullander, S, Telenius, A, Tschudin, P, Sergeyeva, O, Vladymyrov, V, Rizun, VB, Raper, C, Lear, D, Stoev, P, Penev, L, Rubio, AC, Pedersen, HÆ, Backeljau, T, Saarenmaa, H, Ulenberg, S, Ouvrard, DNM, Enghoff, H, von Raab-Straube, E, Güntsch, A, Geoffroy, M, Müller, A, Kohlbecker, A, Berendsohn, W, Appeltans, W, Arvanitidis, C, Vanhoorne, B, Declerck, J, Vandepitte, L, Hernandez, F, Nash, R, Costello, MJ, Bezard-Falgas, P, Bourgoin, T, Wetzel, FT, de Jong, Y, Kouwenberg, J, Boumans, L, Hussey, C, Hyam, R, Nicolson, N, Kirk, P, Paton, A, Michel, E, Guiry, MD, Boegh, PS, Glöckler, F, Korb, G, Ring, C, Hagedorn, G, Häuser, C, Aktaç, N, Asan, A, Ardelean, A, Borges, PA, Dhora, D, De Wever, A, Khachatryan, H, Malicky, M, Ibrahimov, S, Tuzikov, A, Moncheva, S, Spassov, N, Chobot, K, Popov, A, Boršić, I, Sfenthourakis, S, Kõljalg, U, Uotila, P, Olivier, G, Legakis, A, Dauvin, JC, Tarkhnishvili, D, Chaladze, G, Tuerkay, M, Peregovits, L, Gudmundsson, G, Ólafsson, E, Lysaght, L, Galil, BS, Raimondo, FM, Domina, G, Stoch, F, Minelli, A, Walisch, T, Spungis, V, Budrys, E, Olenin, S, Turpel, A, Krpach, V, Gambin, MT, Ungureanu, L, Karaman, G, Kleukers, RM, Stur, E, Aagaard, K, Valland, N, Moen, TL, M de Frias Martins, A, Bogdanowicz, W, Tykarski, P, Węsławski, JM, Kędra, M, Abreu, AD, Silva, R, Medvedev, S, Ryss, A, Šimić, S, Marhold, K, Stloukal, E, Tome, D, Ramos, MA, Gonseth, Y, Valdés, B, Pina, F, Kullander, S, Telenius, A, Tschudin, P, Sergeyeva, O, Vladymyrov, V, Rizun, VB, Raper, C, Lear, D, Stoev, P, Penev, L, Rubio, AC, Pedersen, HÆ, Backeljau, T, Saarenmaa, H, Ulenberg, S, Ouvrard, DNM, Enghoff, H, von Raab-Straube, E, Güntsch, A, Geoffroy, M, Müller, A, Kohlbecker, A, Berendsohn, W, Appeltans, W, Arvanitidis, C, Vanhoorne, B, Declerck, J, Vandepitte, L, Hernandez, F, Nash, R, Costello, MJ, Bezard-Falgas, P, Bourgoin, T, and Wetzel, FT
- Published
- 2015
16. Species richness can decrease with altitude but not with habitat diversity
- Author
-
Hortal, J. Carrascal, L.M. Triantis, K.A. Theb́ault, E. Meiri, S. Sfenthourakis, S.
- Published
- 2013
17. Island biogeography is not a single-variable discipline: The small island effect debate
- Author
-
Triantis, K.A. Sfenthourakis, S.
- Abstract
In some island systems, an 'anomalous' feature of species richness on smaller islands, in comparison with larger ones, has been observed. This has been described as the small island effect (SIE). The precise meaning of the term remains unresolved, as does the explanation for the phenomenon and even whether it exists. Dengler (2010; Diversity Distrib, 16, 256-266.) addresses a number of conceptual and methodological issues concerning the nature and the detection of the SIE but fails to settle conclusively most of the issues he raises. We contend that his approach is theoretically flawed, especially in its treatment of habitat diversity. We offer a few suggestions of what is needed to advance understanding of the SIE. © 2011 Blackwell Publishing Ltd.
- Published
- 2012
18. Increased molecular divergence of two endemic Trachelipus (Isopoda, Oniscidea) species from Greece reveals patterns not congruent with current taxonomy
- Author
-
Parmakelis, A. Klossa-Kilia, E. Kilias, G. Triantis, K.A. Sfenthourakis, S.
- Abstract
In the present study, we employed three mitochondrial DNA genetic markers in a phylogenetic analysis aiming at the delineation of the relationships amongst nominal Trachelipus kytherensis populations, as well as between populations of this species and of Trachelipus aegaeus and a new form, occurring syntopically with the latter. Both the phylogenetic analysis and the genetic distances separating populations, show the presence of several distinct and well differentiated clades that undermine the monophyly of T. kytherensis. On the other hand, despite the insular distribution of T. aegaeus populations, their divergence is low and the monophyly of this taxon can be rescued by the inclusion of two more insular populations previously assigned to T. kytherensis. The patterns of genetic divergence among clades are only partially congruent with the geographic distribution of populations. The validity of taxonomic characters used so far in the genus appears to be questionable; therefore, a more comprehensive phylogenetic study at a population level is deemed necessary for understanding the divergence of Trachelipus lineages. © 2008 The Linnean Society of London.
- Published
- 2008
19. The island rule is not valid in terrestrial isopods (Crustacea: Oniscidea).
- Author
-
Karagkouni, M., Sfenthourakis, S., and Meiri, S.
- Subjects
- *
BODY size , *ISLAND animals , *INVERTEBRATES , *ISOPODA , *WOOD lice (Crustaceans) - Abstract
The island rule posits that small animals grow larger on islands, whereas large-bodied ones are expected to dwarf, but remains largely unexplored in invertebrates. We tested the rule at an inter-specific level on terrestrial isopods (Oniscidea). We also tested the influence of island area on body size variability. We assembled female size and distribution data from the literature for 901 species of Oniscidea. We compared lengths of insular endemics ( N = 296 species) and congeneric or confamilial mainland species ( N = 605). We repeated the same analyses for species within climatic zones. We found that isopods do not follow the island rule in either the family or genus level, either globally or within climatic regions. While sizes of island isopods are often different than those of their mainland kin, they show no overall tendency towards dwarfism or gigantism on islands. Island area has no discernible effect on body size. Size variation is similar among insular and mainland species, but the size range is greater in insular species. Globally, the island rule is not supported. Oniscidea are phytosaprophagous feeding on a wide variety of plant material and are preyed upon by a wide range of predators, so that island environment does not exert strong selection pressures on their body size. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
20. Altitudinal terrestrial isopod diversity
- Author
-
Sfenthourakis, S. Anastasiou, I. Strutenschi, T.
- Abstract
We have assessed the diversity of terrestrial isopods across an elevational and habitat gradient on Mt. Panachaiko (NW Peloponnisos, Greece). Previous knowledge on the biodiversity of this mountain was restricted to very few records of individual species, and no systematic sampling had ever been applied for any animal taxon. We selected the most representative habitat types within an altitudinal range from 750 to 1700 m a.s.l., where we applied qualitative and quantitative monthly sampling using hand collecting and pitfall traps for 6 months during the snow-free period (June-November). We sampled three sites with maquis vegetation, one site with fir forest, one with sparse hawthorn vegetation and two at a highland meadow, and we compared the distribution and abundance patterns of isopod species among these habitat types. Overall, 13 isopod species were found, seven of which were also captured in pitfall traps. One species, Armadillidium lobocurvum, was extremely abundant at the most elevated sites, resulting in very uneven patterns of abundance. The habitat types with higher diversity of isopod species were the sparse hawthorns and the open maquis, and the richest month was July. We also discuss the phenology of the most abundant species at the highland meadows. © 2005 Elsevier SAS. All rights reserved.
- Published
- 2005
21. From sampling stations to archipelagos: Investigating aspects of the assemblage of insular biota
- Author
-
Sfenthourakis, S. Giokas, S. Tzanatos, E.
- Abstract
Aim To investigate the formation of nestedness and species co-occurrence patterns at the local (sampling station), the intermediate (island group), and the archipelago scale. Location The study used data on the distribution of terrestrial isopods on 20 islands of the central Aegean (Greece). These islands are assigned to two distinct subgroups (Kyklades and Eastern islands). Methods The Nestedness Temperature Calculator was used to obtain nestedness values and maximally nested matrices, the EcoSim7 software and a modified version of Sanderson (2000) method were used for the analysis of species co-occurrences. Idiosyncratic temperatures of species and the order of species placement in the maximally nested matrices were used for further comparisons among spatial scales. The relationships of nestedness values with beta-diversity, habitat diversity and a number of ecological factors recorded for each sampling station were also investigated. Results Significant nestedness was found at all spatial scales. Levels of nestedness were not related to beta-diversity or habitat diversity. Nestedness values were similar among spatial scales, but they were affected by matrix size. The species that contributed most to the nested patterns within single islands were not the same as those that produce nestedness at the archipelago scale. There was significant variation in the frequency of species occurrence among islands and among spatial scales. There was no direct effect of ecological factors on the shaping of patterns of nestedness within individual islands, but habitat heterogeneity was crucial for the existence of such patterns. Positive associations among species prevailed at all scales when species per station were considered, whi1e negative associations prevailed in the species per island matrices. All associations resulted from the habitat structure of sampling stations and from particularities of geographical distributions. Conclusions There was no clear-cut distinction between nestedness patterns among spatial scales, even though different species, and partially different factors, contributed to the formation of these patterns in each case. There was a core of species that contributed to the formation of nested patterns at all spatial scales, while the patterns of species associations suggested that biotic interactions are not an important causal factor. The results of this study suggest that locally rare species cannot be widespread at a higher spatial scale, while locally common species can have a restricted distribution. © 2004 Blackwell Publishing Ltd.
- Published
- 2004
22. Hotspots of endemic terrestrial invertebrates in southern Greece
- Author
-
Sfenthourakis, S. Legakis, A.
- Abstract
In the present paper we identify biodiversity hotspots of endemic terrestrial invertebrates in southern Greece, using four different criteria and five taxonomic groups. The hotspots identification procedure was facilitated by the use of the MaplnfoPro G.I.S. software. We mapped the known distribution of 424 endemic species on a digital map of southern Greece in 548 10 × 10 km2 grids. The total number of registrations (records per grid) is 3826 in 465 grids. Registrations are unevenly distributed in the five sub-regions of the study area, a fact that results from both the unequal collecting effort applied in each sub-region and their different levels of endemism. We first identified the hotspots for each individual taxonomic group, and then for the total species pool. Finally, we analyzed the species saturation pattern in order to find the minimum number of grids needed for the inclusion of 85% of the total number of species. The most important hotspots are mostly at the higher mountains of the study area, especially on Taygetos and Idi Mts. We also give a brief evaluation of the performance of the four criteria used in the case of endemic species analyses.
- Published
- 2001
23. Island Species Richness Increases with Habitat Diversity
- Author
-
Hortal, J., Triantis, K.A., Meiri, S., Thebault, E.M.C., Sfenthourakis, S., Hortal, J., Triantis, K.A., Meiri, S., Thebault, E.M.C., and Sfenthourakis, S.
- Abstract
Species richness is commonly thought to increase with habitat diversity. However, a recent theoretical model aiming to unify niche and island biogeography theories predicted a hump-shaped relationship between richness and habitat diversity. Given the contradiction between model results and previous knowledge, we examine whether the relationship between species richness and habitat diversity is consistently monotonically increasing and under which circumstances, if at all, such relationships could be hump shaped. We review the empirical evidence about the shape of such relationships and show that species richness on islands usually increases with habitat diversity and that it never decreases. We also critically examine the assumptions of the theoretical model and modify them to incorporate a less restrictive definition of niche width. The modified assumptions lead to simulations that better capture real patterns, using either simple parameters or observed distributions of niche breadth. Further work is needed to incorporate ecological interactions and metacommunity dynamics if the aim is to merge niche and island biogeography theories in a realistic modeling framework.
- Published
- 2009
24. Does by-catch pose a threat for the conservation of seabird populations in the southern Ionian Sea (eastern Mediterranean)? A questionnaire based survey of local fisheries
- Author
-
KARRIS, G., primary, FRIC, J., additional, KITSOU, Z., additional, KALFOPOULOU, J., additional, GIOKAS, S., additional, SFENTHOURAKIS, S., additional, and POIRAZIDIS, K., additional
- Published
- 2013
- Full Text
- View/download PDF
25. Increased genetic diversity in Greek populations of the genus Ligidium (Crustacea: Isopoda: Oniscidea) revealed by RFLP analysis of mtDNA segments
- Author
-
Klossa-Kilia, E., Kilias, G., Sfenthourakis, S., Klossa-Kilia, E., Kilias, G., and Sfenthourakis, S.
- Abstract
We investigated mtDNA genetic differentiation and the phylogenetic relationships of 11 populations of the oniscidean genus Ligidium. We studied nine populations from Greece, assigned to three nominal species (L. euboicum, L. germanicum and L. beieri), and two from central Europe (L. germanicum and L. hypnorum), applying RFLP analysis of two mtDNA segments (12S rDNA and 16S rDNA) amplified by PCR. The analysis revealed seven monomorphic and four polymorphic populations, and 17 different haplotypes, each one present in one population only. Several restriction enzymes produced population specific patterns, enabling discrimination among the different populations. The estimated net nucleotide divergence between populations ranges from 1.06 to 16.52%, while the high NST value (0.96) indicates the existence of increased interpopulation genetic differentiation that can be attributed to the extreme isolation among Ligidium populations. The relationships between haplotypes and populations are not congruent with their geographical distribution and the established taxonomy within the genus.
- Published
- 2005
26. Variation in breeding parameters of Eleonora’s falcon (Falco eleonorae) and factors affecting its reproductive performance
- Author
-
Xirouchakis, S. M., primary, Fric, J., additional, Kassara, C., additional, Portolou, D., additional, Dimalexis, A., additional, Karris, G., additional, Barboutis, C., additional, Latsoudis, P., additional, Bourdakis, S., additional, Kakalis, E., additional, and Sfenthourakis, S., additional
- Published
- 2011
- Full Text
- View/download PDF
27. Use them or lose them: the need to make collection databases publicly available
- Author
-
Legakis, A., Sfenthourakis, S., Polymeri, R., Thessalou-Legaki, M., Froese, Rainer, Reyes Jr., R., Legakis, A., Sfenthourakis, S., Polymeri, R., Thessalou-Legaki, M., Froese, Rainer, and Reyes Jr., R.
- Published
- 2003
28. From scientific natural history to ecosystem research: changing roles of the animal in the history of animal ecology
- Author
-
Legakis, A., Sfenthourakis, S., Polymeni, R., Thessalou-Legaki, M., Jax, Kurt, Legakis, A., Sfenthourakis, S., Polymeni, R., Thessalou-Legaki, M., and Jax, Kurt
- Published
- 2003
29. A morphometric approach to the geographic variation of the terrestrial isopod speciesArmadillo tuberculatus(Isopoda: Oniscidea)
- Author
-
Kamilari, M., primary and Sfenthourakis, S., additional
- Published
- 2009
- Full Text
- View/download PDF
30. Terrestrial isopods (Crustacea: Oniscidea) from the remote Greek island Antikithira and its surrounding islets
- Author
-
Sfenthourakis, S, primary
- Published
- 1993
- Full Text
- View/download PDF
31. A morphometric approach to the geographic variation of the terrestrial isopod species Armadillo tuberculatus (Isopoda: Oniscidea).
- Author
-
Kamilari, M. and Sfenthourakis, S.
- Subjects
- *
ISOPODA , *WOOD lice (Crustaceans) , *POLYMORPHISM (Zoology) , *FOURIER analysis , *POPULATION genetics - Abstract
The terrestrial isopod species Armadillo tuberculatus Vogl, 1876 (Crustacea, Isopoda, Oniscidea) is a widely polymorphic species distributed in the south-central Aegean region (Greece) with a different morph on each island. Variation consists in coloration, size of cuticular tubercules, shape of telson and the shape of the male first pleopod exopodite (secondary sexual character of taxonomic importance). We studied the allometric growth of a cuticular tubercule in 17 populations (for both male and female individuals) and the shape variation of the first male pleopod exopodite in 10 populations using Elliptic Fourier Analysis, in order to test for patterns of intraspecific variation and possible relationships between morphs. In addition, Thin Plate Spline analysis was used for the calculation of the minimum bending energy between different exopodite shapes, which was then used for estimating the minimum spanning network (MSN) connecting them. The different allometric growth rates of the tubercule among island groups were significantly related to island latitude and climatic factors. On the other hand, the clustering of islands and the MSN based on male exopodite shape differences were not related to the palaeogeography of the Aegean region or to the present geographic distances of islands. These results are interpreted as evidence for non-adaptive radiation of the morphs. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
32. Testing for nestedness in the terrestrial isopods and snails of Kyklades islands (Aegean archipelago, Greece)
- Author
-
Mylonas, M., Giokas, S., and Sfenthourakis, S.
- Subjects
LANDSCAPE ecology ,PHYTOGEOGRAPHY ,SNAILS - Abstract
Most insular communities exhibit nestedness, with the species assemblages of the more depauperate islands constituting subsets of those of the richer. Several methods for the estimation and evaluation of nestedness have been developed during the last fifteen years. In the present paper we use two of the more recent and elaborate methods, namely the 'temperature' method of Atmar and Patterson and the 'departures' method of Lomolino, in order to investigate patterns of nestednessin the distribution of two well studied and speciose animal groups, terrestrial isopods and land snails, in the Kyklades archipelago (Aegean Sea, Greece) that lies between two continental regions. Significant nestedness is present in both species assemblages and, surprisingly, each method gives almost identical levels of nestedness for the two animal groups. Isolation has been found to be more important in producing nestedness in both groups than area, which does not seem to bean important explanatory factor. However, the role of isolation in this case is better understood under an historical perspective, takinginto account the complex palaeogeography of the region and the differential departmentalisation of distinct island groups. Additionally, certain metrics of habitat diversity that were included in the analysis were the best explanatory factors of nestedness, indicating a morecomplex causal pattern that also involves extinction. Since the two methods used are based on different assumptions and have different scopes, their results do not converge. The 'temperature' method finds the maximum possible nestedness in an island sorting, which does not necessarily lead to plausible biogeographical explanations, while the 'departures' method, although more useful in detecting causality, fails to fully evaluate levels of nestedness. Nevertheless, both methodsare valuable tools in the exploration of interesting distributional patterns, when this effort is accompanied by a good understanding of histo [ABSTRACT FROM AUTHOR]
- Published
- 1999
33. Testing for nestedness in the terrestrial isopods and snails of Kyklades islands (Aegean archipelago, Greece)
- Author
-
Sfenthourakis, S. Giokas, S. Mylonas, M.
- Abstract
Most insular communities exhibit nestedness, with the species assemblages of the more depauperate islands constituting subsets of those of the richer. Several methods for the estimation and evaluation of nestedness have been developed during the last fifteen years. In this paper we use two of the more recent and elaborate methods, namely the 'temperature' method of Atmar and Patterson and the 'departures' method of Lomolino, in order to investigate patterns of nestedness in the distribution of two well studied and speciose animal groups, terrestrial isopods and land snails, in the Kyklades archipelago (Aegean Sea, Greece) that lies between two continental regions. Significant nestedness is present in both species assemblages and, surprisingly, each method gives almost identical levels of nestedness for the two animal groups. Isolation has been found to be more important in producing nestedness in both groups than area, which does not seem to be an important explanatory factor. However, the role of isolation in this case is better understood under an historical perspective, taking into account the complex palaeogeography of the region and the differential departmentalisation of distinct island groups. Additionally, certain metrics of habitat diversity that were included in the analysis were the best explanatory factors of nestedness, indicating a more complex causal pattern that also involves extinction. Since the two methods used are based on different assumptions and have different scopes, their results do not converge. The 'temperature' method finds the maximum possible nestedness in an island sorting which does not necessarily lead to plausible biogeographical explanations, while the 'departures' method, although more useful in detecting causality, fails to fully evaluate levels of nestedness. Nevertheless, both methods are valuable tools in the exploration of interesting distributional patterns, when this effort is accompanied by a good understanding of historical, ecological and idiosyncratic properties of each particular data set.
34. Synchronous parallel composition in a process calculus for ecological models
- Author
-
Mauricio Toro, Philippou, A., Kassara, C., and Sfenthourakis, S.
35. Ontogenetic shifts in the digestive efficiency of an insectivorous lizard (Squamata: Agamidae)
- Author
-
Karameta, E., Mizan, V. L., Sagonas, K., Sfenthourakis, S., Valakos, E. D., and Panayiotis Pafilis
36. A biogeographical analysis of Greek Oniscidean endemism
- Author
-
Sfenthourakis, S. and Sinos Giokas
37. PESI - a taxonomic backbone for Europe
- Author
-
Güntsch, A., de Jong, Y., Kouwenberg, J., Boumans, L., Hussey, C., Hyam, R., Nicolson, N., Kirk, P., Paton, A., Michel, E., Guiry, M. D., Boegh, P. S., Pedersen, H., Enghoff, H., von Raab-Straube, E., Geoffroy, M., Müller, A., Kohlbecker, A., Berendsohn, W., Appeltans, W., Arvanitidis, C., Vanhoorne, B., Declerck, J., Vandepitte, L., Hernandez, F., Nash, R., Costello, M. J., Ouvrard, D., Bezard-Falgas, P., Bourgoin, T., Wetzel, F. T., Glöckler, F., Korb, G., Ring, C., Hagedorn, G., Häuser, C., Aktaç, N., Asan, A., Ardelean, A., Borges, P. A. V., Dhora, D., Khachatryan, H., Malicky, M., Ibrahimov, S., Tuzikov, A., De Wever, A., Moncheva, S., Spassov, N., Chobot, K., Popov, A., Boršic, I., Sfenthourakis, Spyros, Kõljalg, U., Uotila, P., Olivier, G., Dauvin, J. -C, Tarkhnishvili, D., Chaladze, G., Tuerkay, M., Legakis, A., Peregovits, L., Gudmundsson, G., ólafsson, E., Lysaght, L., Galil, B. S., Raimondo, F. M., Domina, G., Stoch, F., Minelli, A., Spungis, V., Budrys, E., Olenin, S., Turpel, A., Walisch, T., Krpach, V., Gambin, M. T., Ungureanu, L., Karaman, G., Kleukers, R. M. J. C., Stur, E., Aagaard, K., Valland, N., Moen, T. L., Bogdanowicz, W., Tykarski, P., Weslawski, J. M., Kedra, M., Martins, A. M. F., Abreu, A. D., Silva, R., Medvedev, S., Ryss, A., Šimic, S., Marhold, K., Stloukal, E., Tome, D., Ramos, M. A., Valdés, B., Pina, F., Kullander, S., Telenius, A., Gonseth, Y., Tschudin, P., Sergeyeva, O., Vladymyrov, V., Rizun, V. B., Raper, C., Lear, D., Stoev, P., Penev, L., Rubio, A. C., Backeljau, T., Saarenmaa, H., Ulenberg, S., University of Amsterdam [Amsterdam] (UvA), University of Oslo (UiO), The Natural History Museum [London] (NHM), Royal Botanical Garden Edinburgh, Royal Botanical Garden, Royal Botanic Gardens, Herbarium, National University of Ireland [Galway] (NUI Galway), Danish Meteorological Institute (DMI), International Oceanographic Data and Information Exchange (IODE) of the Intergovernmental Oceanographic Commission of UNESCO, Oostende, Hellenic Center for Marine Research (HCMR), Aquatic and Terrestrial Ecology, Operational Directorate Natural Environment, Royal Belgian Institute of Natural Sciences (RBINS), Institute of Oceanology of Bulgarian Academy of Sciences (IO-BAS), Bulgarian Academy of Sciences (BAS), National Museum of Natural History, University of Tartu, Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Icelandic Institute of Natural History, Israel Oceanographic and Limnological Research - IOLR (ISRAEL), Dipartimento di Scienze Ambientali, Università degli Studi dell'Aquila (UNIVAQ), Department of Biology, Universita degli Studi di Padova, Klaipėda University [Lituanie] (KU), Department of Natural History, NTNU University Museum [Trondheim], Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology (NTNU), Muzeum i Instytut Zoologii Polskiej Akademii Nauk, Institute of Oceanology, Polish Academy of Sciences (IO-PAN), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Instituto Superior de Engenharia de Lisboa (ISEL), Centre for Earth Evolution and Dynamics [Oslo] (CEED), Department of Geosciences [Oslo], Faculty of Mathematics and Natural Sciences [Oslo], University of Oslo (UiO)-University of Oslo (UiO)-Faculty of Mathematics and Natural Sciences [Oslo], University of Oslo (UiO)-University of Oslo (UiO), Institute of Botany, Universität für Bodenkultur Wien [Vienne, Autriche] (BOKU), Tachinidae Recording Scheme, Sfenthourakis, Spyros [0000-0003-3213-2502], European Commission, Experimental Plant Systematics (IBED, FNWI), de Jong, Y, Kouwenberg, J, Boumans, L, Hussey, C, Hyam, R, Nicolson, N, Kirk, P, Paton, A, Michel, E, Guiry, MD, Boegh, PS, Pedersen, HA, Enghoff, H, von Raab-Straube, E, Guntsch, A, Geoffroy, M, Muller, A, Kohlbecker, A, Berendsohn, W, Appeltans, W, Arvanitidis, C, Vanhoorne, B, Declerck, J, Vandepitte, L, Hernandez, F, Nash, R, Costello, MJ, Ouvrard, D, Bezard-Falgas, P, Bourgoin, T, Wetzel, FT, Glockler, F, Korb, G, Ring, C, Hagedorn, G, Hauser, C, Aktac, N, Asan, A, Ardelean, A, Borges, PAV, Dhora, D, Khachatryan, H, Malicky, M, Ibrahimov, S, Tuzikov, A, De Wever, A, Moncheva, S, Spassov, N, Chobot, K, Popov, A, Borsic, I, Sfenthourakis, S, Koljalg, U, Uotila, P, Olivier, G, Dauvin, JC, Tarkhnishvili, D, Chaladze, G, Tuerkay, M, Legakis, A, Peregovits, L, Gudmundsson, G, Olafsson, E, Lysaght, L, Galil, BS, Raimondo, FM, Domina, G, Stoch, F, Minelli, A, Spungis, V, Budrys, E, Olenin, S, Turpel, A, Walisch, T, Krpach, V, Gambin, MT, Ungureanu, L, Karaman, G, Kleukers, RMJC, Stur, E, Aagaard, K, Valland, N, Moen, TL, Bogdanowicz, W, Tykarski, P, Weslawski, JM, Kedra, M, M de Frias Martins, A, Abreu, AD, Silva, R, Medvedev, S, Ryss, A, Simic, S, Marhold, K, Stloukal, E, Tome, D, Ramos, MA, Valdes, B, Pina, F, Kullander, S, Telenius, A, Gonseth, Y, Tschudin, P, Sergeyeva, O, Vladymyrov, V, Rizun, VB, Raper, C, Lear, D, Stoev, P, Penev, L, Rubio, AC, Backeljau, T, Saarenmaa, H, and Ulenberg, S
- Subjects
Fauna Europaea ,EU-nomen ,ZooBank ,computer.software_genre ,Index Fungorum ,ComputingMethodologies_ARTIFICIALINTELLIGENCE ,Floristics & Distribution ,PESI, Euro+Med PlantBase, Fauna Europaea, European Register of Marine Species, Index Fungorum, International Plant Names Index (IPNI), AlgaeBase, ZooBank, European taxonomic backbone, EU-nomen, Taxonomic indexing, Authority File, Taxonomy, Nomenclature, Global Names Architecture, INSPIRE, LifeWatch, EUBON ,Arctic Ocean ,European register of marine species ,European taxonomic backbone ,Plantae ,Faunistics & Distribution ,Atlantic Ocean ,Global Names Architecture ,Biodiversity assessment ,PESI ,Euro+Med PlantBase ,European Register of Marine Species ,International Plant Names Index (IPNI) ,AlgaeBase ,Taxonomic indexing ,Authority File ,Taxonomy ,Nomenclature ,INSPIRE ,LifeWatch ,EUBON ,Ecology ,Settore BIO/02 - Botanica Sistematica ,Global names architecture ,Europe ,Nature Conservation ,General Research Article ,Taxonomy (biology) ,Data mining ,Neogene ,European register of marine specie ,InformationSystems_INFORMATIONSTORAGEANDRETRIEVAL ,Index fungorum ,Biodiversity informatics ,Biology ,Animalia ,Ecology, Evolution, Behavior and Systematics ,Fungi ,15. Life on land ,Data science ,Settore BIO/03 - Botanica Ambientale E Applicata ,Sustainability ,Authority file ,Catalogues and Checklists ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,computer - Abstract
Reliable taxonomy underpins communication in all of biology, not least nature conservation and sustainable use of ecosystem resources. The flexibility of taxonomic interpretations, however, presents a serious challenge for end-users of taxonomic concepts. Users need standardised and continuously harmonised taxonomic reference systems, as well as highquality and complete taxonomic data sets, but these are generally lacking for nonspecialists. The solution is in dynamic, expertly curated web-based taxonomic tools. The Pan-European Species-directories Infrastructure (PESI) worked to solve this key issue by providing a taxonomic e-infrastructure for Europe. It strengthened the relevant social (expertise) and information (standards, data and technical) capacities of five major community networks on taxonomic indexing in Europe, which is essential for proper biodiversity assessment and monitoring activities. The key objectives of PESI were: 1) standardisation in taxonomic reference systems, 2) enhancement of the quality and completeness of taxonomic data sets and 3) creation of integrated access to taxonomic information. New information This paper describes the results of PESI and its future prospects, including the involvement in major European biodiversity informatics initiatives and programs., PESI was funded by the European Commission under the Seventh Framework Program (project reference: RI-223806), contributing to the FP7-INFRASTRUCTURES 'Capacities' sub-program under the Coordination and Support Actions (CSA) funding scheme (call: FP7-INFRASTRUCTURES-2007-2).
- Published
- 2015
38. Time synchronisation for millisecond-precision on bio-loggers.
- Author
-
Wild TA, Wilbs G, Dechmann DKN, Kohles JE, Linek N, Mattingly S, Richter N, Sfenthourakis S, Nicolaou H, Erotokritou E, and Wikelski M
- Abstract
Time-synchronised data streams from bio-loggers are becoming increasingly important for analysing and interpreting intricate animal behaviour including split-second decision making, group dynamics, and collective responses to environmental conditions. With the increased use of AI-based approaches for behaviour classification, time synchronisation between recording systems is becoming an essential challenge. Current solutions in bio-logging rely on manually removing time errors during post processing, which is complex and typically does not achieve sub-second timing accuracies.We first introduce an error model to quantify time errors, then optimise three wireless methods for automated onboard time (re)synchronisation on bio-loggers (GPS, WiFi, proximity messages). The methods can be combined as required and, when coupled with a state-of-the-art real time clock, facilitate accurate time annotations for all types of bio-logging data without need for post processing. We analyse time accuracy of our optimised methods in stationary tests and in a case study on 99 Egyptian fruit bats (Rousettus aegyptiacus). Based on the results, we offer recommendations for projects that require high time synchrony.During stationary tests, our low power synchronisation methods achieved median time accuracies of 2.72 / 0.43 ms (GPS / WiFi), compared to UTC time, and relative median time accuracies of 5 ms between tags (wireless proximity messages). In our case study with bats, we achieved a median relative time accuracy of 40 ms between tags throughout the entire 10-day duration of tag deployment. Using only one automated resynchronisation per day, permanent UTC time accuracies of ≤ 185 ms can be guaranteed in 95% of cases over a wide temperature range between 0 and 50 °C. Accurate timekeeping required a minimal battery capacity, operating in the nano- to microwatt range.Time measurements on bio-loggers, similar to other forms of sensor-derived data, are prone to errors and so far received little scientific attention. Our combinable methods offer a means to quantify time errors and autonomously correct them at the source (i.e., on bio-loggers). This approach facilitates sub-second comparisons of simultaneously recorded time series data across multiple individuals and off-animal devices such as cameras or weather stations. Through automated resynchronisations on bio-loggers, long-term sub-second accurate timestamps become feasible, even for life-time studies on animals. We contend that our methods have potential to greatly enhance the quality of ecological data, thereby improving scientific conclusions., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
39. Seasonal Variation in the Thermoregulation Pattern of an Insular Agamid Lizard.
- Author
-
Karameta E, Gavriilidi I, Sfenthourakis S, and Pafilis P
- Abstract
Ectotherms, including lizards, rely on behavioral thermoregulation to maintain their body temperature within an optimal range. The benign climate of islands is expected to favor the thermoregulation efficiency of reptiles throughout their activity period. In this study, we investigated the seasonal variation in thermoregulation in an insular population of the roughtail rock agama ( Laudakia stellio ) on Naxos Island, Greece. We measured body, operative, and preferred temperatures across three seasons (spring, summer, and autumn), and we evaluated the effectiveness of thermoregulation, using the Hertz index (E). Our results revealed that the effectiveness of thermoregulation was significantly influenced by seasonality. E was quite high in summer (0.97) and spring (0.92), and lowest in autumn (0.81). Accordingly, the quality of the thermal environment was significantly low during autumn, and maximum during summer. However, despite the environmental temperature fluctuations, lizards exhibited remarkable stability in body temperatures. They also adjusted their preferred temperatures seasonally and doubled the thermal niche breadth they occupied during summer, thus enhancing thermoregulation efficiency. Whether or not these adjustments are plastic or fixed local adaptations remains to be explored in further research across multiple years and seasons, including additional insular populations.
- Published
- 2023
- Full Text
- View/download PDF
40. Intra-island patterns of cryptic diversity within an oceanic island: Insights from the differentiation of Schizidium Verhoeff, 1901 (Oniscidea, Armadillidiidae) within Cyprus, with descriptions of two new species.
- Author
-
Dimitriou AC, Soares Campos-Filho I, Georgiou A, Taiti S, and Sfenthourakis S
- Abstract
Cyprus is a Mediterranean island of volcanic origin isolated for at least 5.3 Myr from surrounding continental areas. The present study focuses on the diversification of the isopod genus Schizidium within the island, including also specimens from surrounding continental areas. The genus Schizidium sensu lato is probably non monophyletic, comprising 26 species distributed from Greece to Iran. Up to date the only representative of the genus reported from Cyprus was Schizidium fissum. Aiming to investigate the patterns of genetic diversity within the focal island, to evaluate the morphology-based taxonomy of the species in the genus, and at the same time to explore phylogenetic relationships with mainland populations, we applied genome-wide ddRADseq as well as Sanger sequencing targeting three mitochondrial (16S, COI and 12S) and the nuclear NaK loci. Results of phylogenetic analyses support the existence of two distinct epigean Schizidium clades with well-defined geographic boundaries that conform to the known paleogeography of Cyprus, plus one endogean clade with restricted distribution within the island. Genetic data and morphology corroborate the assignment of this latter endogean clade to a new species, Schizidium myrrae n. sp. The two epigean clades are also considered as distinct species, one corresponding to the known S. fissum at the eastern part of the island (Pentadaktylos massif) and the other to the newly described S. christosi n. sp. distributed along the western part of the island (Troodos massif). Even though detailed examination of many specimens could not retrieve any morphological differences among representatives of these two clades, clado-chronological analysis indicates a long isolation between them, estimated at ∼ 9 Mya, as well as the sharing of a common ancestor with S. tiberianum from Israel at ∼ 15 Mya. Hence, we can consider these epigean Schizidium species as one more case of cryptic diversity on Cyprus, exhibiting similar patterns with the recently described case in the genus Armadillo., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
41. The genus Armadillo Latreille, 1802 (Oniscidea, Armadillidae) from Cyprus, with descriptions of two new species.
- Author
-
Campos-Filho IS, Dimitriou AC, Taiti S, and Sfenthourakis S
- Subjects
- Animals, Cyprus, Microscopy, Electron, Scanning, Species Specificity, Male, Female, Phylogeny, Isopoda classification, Isopoda ultrastructure
- Abstract
The present work aims to morphologically characterize the species of Armadillo from Cyprus. Moreover, two new species of the genus are described, A. konstantinoui sp. nov. from several places along the island, and A. karametae sp. nov. from Pafos region. The circum-Mediterranean species A. officinalis is also redescribed.
- Published
- 2023
- Full Text
- View/download PDF
42. Diversification within an oceanic Mediterranean island: Insights from a terrestrial isopod.
- Author
-
Dimitriou AC, Antoniou A, Alexiou I, Poulakakis N, Parmakelis A, and Sfenthourakis S
- Subjects
- Animals, Biological Evolution, DNA, Mitochondrial genetics, Gene Flow, Genetic Variation, Genetics, Population, Humans, Phylogeny, Isopoda genetics
- Abstract
Understanding intra-island patterns of evolutionary divergence, including cases of cryptic diversity, is a crucial step towards deciphering speciation processes. Cyprus is an oceanic island isolated for at least 5.3 Mya from surrounding continental regions, while it remains unclear whether it was ever connected to the mainland, even during the Messinian Salinity Crisis. The terrestrial isopod species Armadillo officinalis, that is widespread across the Mediterranean, offers the opportunity to explore intra-island divergence patterns that might exhibit geographical structure related also to the region's known paleogeography. Genome-wide ddRADseq, as well as Sanger sequencing for four mitochondrial and three nuclear loci data were generated for this purpose. In total, 71 populations from Cyprus, neighbouring continental sites, i.e., Israel, Lebanon and Turkey, and other Mediterranean regions, i.e. Greece, Italy, and Tunisia, were included in the analysis. Phylogenetic reconstructions and population structure analyses support the existence of at least six genetically discrete groups across the study area. Five of these distinct genetic clades occur on Cyprus, four of which are endemic to the island and one is widely distributed along the circum-Mediterranean countries. The sixth clade is distributed in Israel. The closest evolutionary relationship of endemic Cypriot populations is with those from Israel, while the evolutionary clade that is present in countries all around the Mediterranean is very shallow. Cladochronological analyses date the origin of the species on the island at ∼6 Mya. Estimated f4 and D statistics as well as F
ST values indicate the genetic isolation between the populations sampled from Cyprus and surrounding continental areas, while there is evident gene flow among populations within the island. Species delimitation and population genetic metrics support the existence of three distinct taxonomic units across the study area, two of which occur on the island and correspond to the endemic clade and the widespread circum-Mediterranean one, respectively, while the third corresponds to Israel's clade. The islands' paleogeographic history and recent human activities seem to have shaped current patterns of genetic diversity in this group of species., (Copyright © 2022. Published by Elsevier Inc.)- Published
- 2022
- Full Text
- View/download PDF
43. An all-inclusive approach: A universal protocol for the successful amplification of four genetic loci of all Onscidea.
- Author
-
Dimitriou AC and Sfenthourakis S
- Abstract
Accounting more than 3,700 described species, Oniscidea is the largest and at the same time the only terrestrial isopod suborder inhabiting almost all terrestrial biomes. Despite the great effort dedicated on describing taxonomic diversity of Oniscidea, mainly employing morphology, there is still a considerable number of species/genera of uncertain generic/familiar assignment. Based on different morphological characters, alternative evolutionary relationships have been proposed to describe the diversity of Oniscidea at different phylogenetic levels. Accumulating morphological and genetic data are repeatedly challenging the monophyly of established taxa, undermining the validity of several morphological characters traditionally used in terrestrial isopod taxonomy, leading to often revisions of the current taxonomy of the Oniscidea . The use of genetic data facilitates the efforts to reconstruct the complex evolutionary history of the focal group by providing important data for the identification, delimitation, and description of species. The proposed protocol with universal PCR conditions and primers was used to successfully amplify COI, 16S, 28S and NAK loci in diverse Oniscidea taxa. The application of this protocol is anticipated to facilitate the generation of new genetic data and hence promote scientific research in Isopoda taxonomy, evolution, ecology, and other related fields., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
44. Preface - 11 th ISTIB: Facets of terrestrial isopod biology.
- Author
-
De Smedt P, Taiti S, Sfenthourakis S, and Campos Filho IS
- Published
- 2022
- Full Text
- View/download PDF
45. Are terrestrial isopods able to use stridulation and vibrational communication as forms of intra and interspecific signaling and defense strategies as insects do? A preliminary study in Armadillo officinalis.
- Author
-
Cividini S, Sfenthourakis S, and Montesanto G
- Subjects
- Animals, Insecta physiology, Vibration, Animal Communication, Isopoda physiology
- Abstract
The capability of producing sounds and vibrations is well known in insects and is thought to be a form of intra- and interspecific communication. Sounds and vibrations are used and modulated for several aims such as interacting with conspecifics, getting information from the environment, and defending against predators. This phenomenon is less known but also present in other arthropods, including a few roller-type terrestrial isopods. In this study, we used a Y-shape test apparatus to investigate the behavior of adult individuals of Armadillo officinalis Duméril, 1816 (Crustacea: Isopoda: Oniscidea) when exposed to two particular vibrational stimuli, namely species-specific stridulations and non-specific substrate-borne vibrations. Our results showed that adults of A. officinalis significantly react to the presence of both types of vibrational stimuli, by moving away from the vibrational source as if they experienced these vibrations as a sign of danger or disturbance. A. officinalis can produce stridulations only when it rolls into a ball during the so-called conglobation, a possible defense mechanism against predators. Stridulation might thus be a secondary form of defense used during conglobation to deter a predator following contact with it and might be experienced as an alert by conspecifics nearby. The high sensitivity to non-specific substrate-borne vibrations might provide A. officinalis with the possibility to anticipate dangers and adverse conditions, giving it a better chance of survival.
- Published
- 2019
- Full Text
- View/download PDF
46. Genetic evidence against monophyly of Oniscidea implies a need to revise scenarios for the origin of terrestrial isopods.
- Author
-
Dimitriou AC, Taiti S, and Sfenthourakis S
- Subjects
- Animals, Bayes Theorem, Biological Evolution, DNA, Mitochondrial genetics, Female, Likelihood Functions, Male, Mutation, Sodium-Potassium-Exchanging ATPase genetics, Isopoda classification, Isopoda genetics, Phosphoenolpyruvate Carboxykinase (ATP) genetics, Phylogeny
- Abstract
Among the few crustacean taxa that managed to inhabit terrestrial environments, Oniscidea includes the most successful colonizers in terms of species richness and abundance. However, neither morphological traits nor molecular markers have definitively resolved phylogenetic relationships among major Oniscidea clades or established the monophyly of the taxon. Herein, we employed the highly conserved, nuclear protein-coding genes Sodium-Potassium Pump (NAK) and Phosphoenolpyruvate Carboxykinase (PEPCK), along with the traditionally used 18 s and 28 s ribosomal RNA genes, in an attempt to clarify these questions. Our dataset included sequences representing all major Oniscidea clades and closely related aquatic taxa, as suggested by previous studies. We applied Bayesian Inference and Maximum Likelihood methods and produced a robust and fully resolved phylogenetic tree that offers strong evidence against the monophyly of Oniscidea. The amphibious genus Ligia appears to be more closely related to representatives of marine suborders, while the phylogenetic pattern of the remaining Oniscidea implies a complex history of the transition from the marine environment to land. With the exception of the basal clade, all other established major clades have been recovered as monophyletic, even though relationships within these clades call for a revised interpretation of morphological characters used in terrestrial isopod taxonomy.
- Published
- 2019
- Full Text
- View/download PDF
47. Response of the temperate scleractinian coral Cladocora caespitosa to high temperature and long-term nutrient enrichment.
- Author
-
Hadjioannou L, Jimenez C, Rottier C, Sfenthourakis S, and Ferrier-Pagès C
- Subjects
- Adaptation, Physiological, Animals, Anthozoa growth & development, Anthozoa metabolism, Carbon metabolism, Chlorophyll analysis, Global Warming, Hot Temperature, Nitrogen metabolism, Nutrients, Proteins analysis, Symbiosis, Anthozoa physiology
- Abstract
Anthropogenic nutrient enrichment and increased seawater temperatures are responsible for coral reef decline. In particular, they disrupt the relationship between corals and their dinoflagellate symbionts (bleaching). However, some coral species can afford either high temperatures or nutrient enrichment and their study can bring new insights into how corals acclimate or adapt to stressors. Here, we focused on the role of the nutrient history in influencing the response of the Mediterranean scleractinian coral Cladocora caespitosa to thermal stress. Colonies living naturally in nutrient-poor (<0.5 µM nitrogen, <0.2 µM phosphorus, LN) and nutrient-rich (ca. 10-20 µM nitrogen, 0.4 µM phosphorus, HN) locations were sampled, maintained under the right nutrient conditions, and exposed to a temperature increase from 17 °C to 24 °C and 29 °C. While both HN and LN colonies decreased their concentrations of symbionts and/or photosynthetic pigments, HN colonies were able to maintain significant higher rates of net and gross photosynthesis at 24 °C compared to LN colonies. In addition, while there was no change in protein concentration in HN corals during the experiment, proteins continuously decreased in LN corals with increased temperature. These results are important in that they show that nutrient history can influence the response of scleractinian corals to thermal stress. Further investigations of under-studied coral groups are thus required in the future to understand the processes leading to coral resistance to environmental perturbations.
- Published
- 2019
- Full Text
- View/download PDF
48. Promoting evolution: the brand new Hellenic Evolutionary Society (HEVOS) .
- Author
-
Abatzopoulos TJ, Giokas S, Pafilis P, Poulakakis N, Sfenthourakis S, and Zouros E
- Abstract
Herein we present the recently founded Hellenic Evolutionary Society (HEVOS) that has been recently instituted to promote evolution and scientific thinking among the Greek-speaking public. HEVOS is a timely initiative, given the low levels of acceptance of evolution by Greek society and the almost complete lack of evolution teaching in primary and secondary education in Greece. Herein, the main aims of the Society are presented., Competing Interests: Competing interestsThe authors declare that they have no competing interests.
- Published
- 2019
- Full Text
- View/download PDF
49. Isopod distribution and climate change.
- Author
-
Sfenthourakis S and Hornung E
- Abstract
The unique properties of terrestrial isopods regarding responses to limiting factors such as drought and temperature have led to interesting distributional patterns along climatic and other environmental gradients at both species and community level. This paper will focus on the exploration of isopod distributions in evaluating climate change effects on biodiversity at different scales, geographical regions, and environments, in view of isopods' tolerances to environmental factors, mostly humidity and temperature. Isopod distribution is tightly connected to available habitats and habitat features at a fine spatial scale, even though different species may exhibit a variety of responses to environmental heterogeneity, reflecting the large interspecific variation within the group. Furthermore, isopod distributions show some notable deviations from common global patterns, mainly as a result of their ecological features and evolutionary origins. Responses to human disturbance are not always traceable, but a trend towards community homogenisation is often found under strong global urbanisation processes. In general, even though it is still not clear how predicted climate change will affect isopod distribution, there is evidence that mixed effects are to be expected, depending on the region under study. We still lack robust and extensive analyses of isopod distributions at different scales and at different biomes, as well as applications of distribution models that might help evaluate future trends.
- Published
- 2018
- Full Text
- View/download PDF
50. A molecular phylogeny of Porcellionidae (Isopoda, Oniscidea) reveals inconsistencies with present taxonomy.
- Author
-
Dimitriou AC, Taiti S, Schmalfuss H, and Sfenthourakis S
- Abstract
Porcellionidae is one of the richest families of Oniscidea globally distributed but we still lack a comprehensive and robust phylogeny of the taxa that are assigned to it. Employing five genetic markers (two mitochondrial and three nuclear) we inferred phylogenetic relationships among the majority of Porcellionidae genera. Phylogenetic analyses conducted via Maximum Likelihood and Bayesian Inference resulted in similar tree topologies. The mtDNA genes cytochrome oxidase I (COI) and 16s rRNA (16s) were used for clade dating using previously published mutation rates. Our results provide evidence against the monophyly of both Porcellionidae and the largest genus of the family Porcellio . These results are compared to previous published work based on morphological evidence. The genera Leptotrichus and Brevurus are not grouped with the rest of Porcellionidae whereas Agnaridae are grouped with part of Porcellionidae. Armadillidium and Schizidium (Armadillidiidae) occupy a basal position on the phylogenetic tree. Even though the African genera Tura and Uramba (distributed in East Africa) are grouped together there is no general geographical pattern in other sub-clades. Additional taxonomic issues that arise in this work such as the assignment of the recently described genus Levantoniscus , arealso discussed. The status of Porcellionidae should be further revised and morphological characters traditionally used in Oniscidea taxonomy should be reconsidered in view of molecular evidence. The origin of the monophyletic clade within Porcellionidae as indicated in the present work is dated back to the Oligocene (~32 mya).
- Published
- 2018
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.