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Genetic information is crucial for the proper exploitation of Octopus vulgaris, the most commercially valuable octopus species worldwide. The main aim of the present study was to investigate genetic structure, with the intent to inform effective management of the common octopus in Sardinia (western Mediterranean Sea), one of the most productive areas within Italian waters. Patterns of population structure were assessed in 246 specimens from seven population samples. Variation in five nuclear-encoded microsatellites and sequences of two mitochondrial genes (COI and COIII) highlighted high variability and low but significant genetic differentiation among populations, which clustered into four groups corresponding to the north, northwest, south, and east coasts of Sardinia. Secondarily, the sequence data from Sardinia were compared with GenBank data from other areas. AMOVA and Bayesian analyses supported the occurrence of significant differences within the Mediterranean Sea, and between Eastern Atlantic and Mediterranean samples. The described genetic differentiation at a regional geographical scale could be determined by a combination of historical and/or current events restricting gene flow. The occurrence of significant genetic structuring at different spatial scales is an important piece of information to define the most appropriate conservation strategies in the area, both at the local and regional level.

The movements of Octopus vulgaris were investigated by a mark–recapture study (1604 specimens tagged), carried out during a commercial octopus traps fishery, at a depth of 20–50 m, over a rocky substrate area of the Sardinian Sea (central western Mediterranean Sea). Overall 87 specimens (56 males and 31 females) were recaptured after 4 and 63 days from the tagging. The difference between the depth at release and recapture varied up to 5.0 m but in 100% of males and in 80% of females the variation was less than 3.0 m. Theoretical straight distances travelled by recaptures ranged from 9 to 5800 m in males and from 9 to 1700 m in females, regardless of the days of freedom. There was no correlation between distances and sex or body size and no marked orientation was found except for medium males that move preferentially in the south western direction. The movements of O. vulgaris , generally linked to the availability of food, partners and/or shelters, in this study were limited within 1 km in most of the recaptures (84–86%). This high site fidelity, within the rocky area investigated, could represent useful information for management plans of this species like the creation of small no-take areas.

International audience; Cephalopod assemblages at the scale of the entire Mediterranean Sea were analysed using information from 2 decades of standardized scientific bottom trawl surveys. Western and eastern assemblages (6 yr of data) were compared using a combined approach of multivariate ordination techniques and non-linear regressions. These methods enabled us to distinguish assemblages and simultaneously analyse the influence of geographic, bathymetric and environmental (sea surface temperature and chlorophyll a concentration) gradients on observed community patterns. Despite few differences in species composition between sub-basins, the relative contribution of species differed. Bathymetry was the primary structural driver for the cephalopod communities of both basins, and contributed to 3 assemblages (shallow water, upper slope and middle slope). Winter temperature influenced community assemblages more strongly in the western than in the eastern basin, in contrast to a small but consistent winter productivity influence on community assemblages in both basins. Thus, the environmental parameters analysed did not cause an immediate change in cephalopod assemblages, but rather an effect lagged by several months. Differences in the relative importance of environmental drivers show that different processes operate in the 2 basins. These results demonstrate similarities and differences between Mediterranean basins regarding important cephalopod functional groups. This information should help integrative ecosystem management approaches currently used in fisheries and conservation management.

The precious coral Corallium rubrum is one of the most vulnerable resources in the Mediterranean Sea because of the high levels of human-related and natural mortality rates. The aim of the present study was to document the diversity and connectivity patterns among Sardinian Corallium rubrum populations focusing, in particular, on deep populations (>80 m depth) where the commercial exploitation is concentrated. Microsatellite markers revealed high levels of inbreeding, heterozygote deficits, and significant genetic differentiation between and within areas at different depths, with an associated ‘isolation by distance’ pattern. These results indicated that for precious coral populations in Sardinia the ‘deep reef refugia hypothesis’, that envisages the capacity for deep corals to act as seed banks for the shallower impaired (over-harvested) populations, is not supported. The highest genetic diversity recorded in Sardinia for all areas and depths with respect to other Mediterranean areas indicates that the strict local management has been effective, since harvesting has not yet led to a substantial erosion of the genetic pool. Possible causes for the high levels of observed diversity in Sardinia are discussed in relation to hydrological conditions, its geographical position and its proximity to some putative glacial refugia. Thus, given the occurrence in Sardinia of highly diverse and differentiated deep-water populations of C. rubrum whose genetic diversity are important for the long-term resilience of the species, the results of the present study strongly support the close monitoring of harvesting, along with the maintenance or even strengthening of the current management and conservation measures (no-take protected areas) already in place in the area. Copyright © 2014 John Wiley & Sons, Ltd.

Coleoid cephalopods go through a single breeding period in their life cycle, i.e., they are semelparous, although a great flexibility has been observed in their reproductive strategies, which range from simultaneous terminal spawning over a short period at the end of the animal׳s life to continuous spawning over a long period of the animal׳s life. So far, the information available on deep-sea species reproductive strategies is still poor and most of our knowledge about squid reproduction relates to females. In particular, not much is known on what strategy male squids have evolved to store sperm into spermatophores and adapt to semelparity. In this study an investigation of male reproductive strategy of the deep-sea umbrella squid Histioteuthis bonnellii (Ferussac, 1835) is presented. The reproductive system was examined in 119 males caught in the Sardinian waters (Central Western Mediterranean) and is described for the first time. Results indicate that this species produces and stores spermatophores over a considerable period of time. The total number of spermatophores found in the reproductive system ranged between 12 and 3097 and the size of spermatophores stored by a single individual varied greatly, up to over 300%. Spermatophore length (SpL) gradually decreased towards the distal end of the reproductive system, so that spermatophores found in the proximal part of Needham׳s Sac were larger than those found in the terminal organ. Body size and SpL of spermatophores from the proximal part of Needham׳s Sac were positively correlated. Both indices of the sperm mass and of the ejaculatory apparatus decreased with the increase of SpL, while the cement body index increased, indicating that larger spermatophores contain less sperm and are equipped with larger cement bodies. Up to 64 spermatangia were found, exclusively in the terminal organ. The large size range of mature males (ML: 60.0–198.0 mm; TW: 113.50–2409.00 g) and the variation in spermatophore number and size indicate that in H. bonnellii males the allocation and storage of sperm start early in the individual life and extends in time, while animals continue to grow and produce spermatophores presumably more successful in attaching to female tissues. This pattern enlarges the time window available for reproduction and likely maximizes the percentage of mating success as the animals grow older and chances of mating events become comparatively lower, due to the basic low density of specimens in the deep-sea environment. Both aspects are potentially indicative of adaptation to the deep sea.

The Mediterranean Sea is characterized by large scale gradients of temperature, productivity and salinity, in addition to pronounced mesoscale differences. Such a heterogeneous system is expected to shape the population dynamics of marine species. On the other hand, prevailing environmental and climatic conditions at whole basin scale may force spatially distant populations to fluctuate in synchrony. Cephalopods are excellent case studies to test these hypotheses owing to their high sensitivity to environmental conditions. Data of two cephalopod species with contrasting life histories (benthic octopus vs nectobenthic squid), obtained from scientific surveys carried out throughout the Mediterranean during the last 20 years were analyzed. The objectives of this study and the methods used to achieve them (in parentheses) were: (i) to investigate synchronies in spatially separated populations (decorrelation analysis); (ii) detect underlying common abundance trends over distant regions (dynamic factor analysis, DFA); and (iii) analyse putative influences of key environmental drivers such as productivity and sea surface temperature on the population dynamics at regional scale (general linear models, GLM). In accordance with their contrasting spatial mobility, the distance from where synchrony could no longer be detected (decorrelation scale) was higher in squid than in octopus (349 vs 217 km); for comparison, the maximum distance between locations was 2620 km. The DFA revealed a general increasing trend in the abundance of both species in most areas, which agrees with the already reported worldwide proliferation of cephalopods. DFA results also showed that population dynamics are more similar in the eastern than in the western Mediterranean basin. According to the GLM models, cephalopod populations were negatively affected by productivity, which would be explained by an increase of competition and predation by fishes. While warmer years coincided with declining octopus numbers, areas of high sea surface temperature showed higher densities of squid. Our results are relevant for regional fisheries management and demonstrate that the regionalisation objectives envisaged under the new Common Fishery Policy may not be adequate for Mediterranean cephalopod stocks., SI

Ecological theory predicts that heterogeneous habitats allow more species to co-exist in a given area, but to date, knowledge on relationships between habitat heterogeneity and biodiversity of coral forests in the outer shelf and upper slope along continental margins is rather limited. We investigated biodiversity of coral forests from 8 sites spread over two different geomorphological settings (namely, pinnacles vs . canyons) in the outer shelf along Sardinian continental margin. Using a combination of multivariate statistical analyses, we show here that differences in the composition of coral assemblages among contrasting geomorphological settings were not statistically significant, whereas significant differences emerged among sites within similar geomorphologies (i.e. among pinnacles and among canyons). Our results reveal that environmental and bathymetric factors such as sediment coverage, slope of the substrate, terrain ruggedness, bathymetric positioning index and aspect were important drivers of the observed patterns of coral biodiversity, in both settings. Spatial variability of coral forests' biodiversity is affected by environmental factors that act at the scale of each geomorphological setting (i.e. within each pinnacle and canyon) rather than by the contrasting geomorphological settings themselves. This result allows us to suggest that simple categorization of benthic communities according topographically defined habitat is unlikely to be sufficient for addressing conservation purposes.

The Mediterranean red coral, Corallium rubrum, is one of the most precious corals worldwide. Below 50 m depth, C. rubrum populations are generally characterised by large and sparse colonies, whereas shallow populations (above 50 m depth) show high densities of small colonies. We show here instead that populations dwelling between 80 and 170 m depth exhibited a continuous range of population density (from 2 to 75 colonies per 0.25 m2), with less than 1% of variance explained by water depth. An inverse relationship between maximum population density and mean colony height was found, suggesting that self-thinning processes may shape population structure. Moreover, demographically young populations composed of small and dense colonies dominated along rocky vertical walls, whereas mature populations characterised by large and sparsely distributed colonies were found only in horizontal beds not covered by sediment. We hypothesise that, in the long term, shallow protected populations should resemble to present deep populations, with sparsely distributed large colonies. Since the density of red coral colonies can decay as a result of self-thinning mechanisms, we advise that future protection strategies should be based also on a measure of red coral spatial coverage instead of population density.

An assessment is made of the reserve's benefits within the no-take area of Su Pallosu (Western Mediterranean) and in its neighbouring fishing ground in the 12 years since its establishment. Using tag recapture data, Palinurus elephas were found up to 50 km from the centre of the reserve. Experimental CPUE inside the no-take area indicated significant increases over time in both abundance and biomass. The percentage increase in biomass from 1997, the year before all forms of fishing were banned, to 2009 was about 500%. Commercial surveys performed in 2008–2009 in the surrounding areas showed a negative gradient of lobster CPUE with increasing distance from the border of the MPA. The most productive zone was located within about 6 km from the reserve boundary. The results show that, to date, adult spillover has aided local fishing. The small size of the study area makes it easy to record a significant biological response after the first year of protection. However, for a long-lived species such as P. elephas, a 12 year horizon can provide only partial evidence of these benefits. Copyright © 2011 John Wiley & Sons, Ltd.

A sample of 360 Bathypolypus sponsalis from the central western Mediterranean Sea (the Sardinian Channel and the Tyrrhenian Sea) was analysed in order to describe size, depth distribution and reproductive data. The first record of the species in the Tyrrhenian Sea and of a spent female are reported in this paper. The size-structure of the sample was in between values of documented data from the western and eastern Mediterranean basins and the minimum mature sizes in both sexes and spermatophore length were similar to previous data from the eastern Mediterranean Sea. Low values of gonadosomatic index and fecundity, the asynchronous ovulation, in addition to an extended reproductive period, have been associated with an intermittent spawning strategy.

The contribution that a small restocking area (central western Mediterranean) has made to the Palinurus elephas (Fabr., 1787) population was examined by comparing the abundances recorded inside and outside the area before (1997) and after the establishment of the reserve (1998–2005). From 1998 to 2002 a progressive percentage increase of P. elephas biomass values was recorded both inside the area and in the surrounding zones. The total mean abundance within the reserve (CPUE=0.23±0.10 kg/50 m/boat) was 7.5 times greater than that for the neighbouring zone (CPUE=0.03±0.07 kg/50 m/boat). The inter-annual analysis of lobster size inside the area also showed a progressive increase of adults and juveniles. The results high-lighted the effectiveness of fishing restrictions in rebuilding the lobsters population and suggest that small MPAs should be set up.

WOS: 000382753200012, The genus Octopoteuthis includes squids inhabiting meso-and bathypelagic waters worldwide. Of the seven presently named species distributed in the world's oceans, only Octopoteuthis sicula has been reported for certain in the Mediterranean Sea to date. However, mixed and confusing descriptions of the systematic characters useful for identifying the species occur in the literature. Similarly, molecular analysis results available for the genus are contradictory and inconsistent. The research herein was undertaken firstly to clarify the systematic status of the genus in the Mediterranean Sea and confirm the presence of a single species, namely O. sicula. Additional goals were the assessment of the validity of systematic characters to identify the species and the analysis of beak morphology to provide useful tools in prey-predator relationship studies. Octopoteuthis specimens from various areas of the Mediterranean Sea and the Atlantic and Pacific oceans were compared, and the analysis of traditional morphological characters was combined with molecular genetics and the study of beaks. Molecular genetics and beak morphology results support the existence of a single species in the Mediterranean Sea. Additional evidence would suggest that this species is also distributed in the north-eastern Atlantic. The morphological characters reported in the literature to identify O. sicula did not identify Mediterranean specimens, with the exception of the two tail photophores. All information collected supports the need for a reconsideration of morphological characters used to identify Octopoteuthis species., David and Lucile Packard FoundationThe David & Lucile Packard Foundation, We heartily thank Jonathan Ablett for his kind assistance in loaning the holotype of Octopoteuthis sicula and providing photographs and related information. We also want to thank the David and Lucile Packard Foundation for the support given to part of the research at the base of this work. Angel Guerra provided positive criticism and constructive suggestions which greatly improved the quality of this document, for which we are deeply grateful. We also wish to thank our friend and colleague Louise Allcock for her critical reading of the manuscript and helpful suggestions. Last but not least, we feel grateful to the reviewers for their suggestions and their much appreciated supportive attitude and useful comments.

Growth of spiny lobsters Palinurus elephas was investigated using tagging data. A total of 4044 lobsters were tagged and released between 1997 and 2004 in an area off central‐western Sardinia, Italy, where fishing is banned. The growth increments of 248 lobsters, recaptured inside the no‐take area and in the surrounding zones, were recorded and analysed with two different procedures, and von Bertalanffy growth parameters were estimated for each sex. Males showed a higher asymptotic carapace length than females (167.9 versus 120.2mm). Growth increments recorded inside and outside the no‐take area did not reveal any density‐dependent effects on females. Small but non‐significant differences were evident for males, showing faster growth in lobsters caught outside the no‐take area.

First observations on reproduction of Neorossia caroli from the southern Sardinian sea are reported, based on the analyses of an egg clutch and specimens collected by bottom trawl on sandy and muddy grounds. The egg clutch, consisting of 13 white eggs of 9 mm length with embryos at an advanced developmental stage, was found at 1200 m depth, attached to a piece of hard substrate. Adult specimens were collected in a depth range between 400 and 1600 metres. DNA sequences indicated that embryos, spermatangia and adults belonged to the same species, the carol bobtail squid, N. caroli. Fecundity analysis made on 40 females showed a variable number of eggs (20–611) in the ovaries, with the combined presence of advanced and developing oocytes, and few smooth eggs ready to be spawned in the oviducts of mature females. Several sperm reservoirs (spermatangia) were embedded in the mantle of some of the females, in the anterior ventral area overlying the oviduct.

This study describes the results obtained by applying the Arnason Schwartz multistate mark-recapture model to eight years of data collected in and around a small no-fishing marine protected area (MPA; 4 km2) in the central western Mediterranean. From 1997 to 2004, a total of 4044 specimens of Palinurus elephas (Fabr., 1787) were tagged and 317 recaptured. The most parsimonious model which best explained the data variability was that of a temporally constant rate of apparent survival and movement in each of the two strata. The absence of any temporal influence in the apparent survival rate inside the no-take area suggested that spillover and mortality are constant for each period of the study. The lower apparent survival rate in surrounding zones than inside the MPA (0.26 ± 0.04 (SE) vs 0.94 ± 0.03 (SE)) is presumed to be a function of fishing effort. A continuous movement of P. elephas across the boundary of the small MPA was also tested. This information on retention of lobsters in the MPA contributes to our understanding of the effect of introducing MPAs into a managed commercial fishery system.

In this paper we report information about the sexual maturity process of 245 Octopus vulgaris specimens (75 females and 170 males) from the Mediterranean Sea. For both sexes, six stages of sexual maturity (immature, developing, maturing, mature, spawning, and spent) are identified on the basis of macroscopic and microscopic observations of the reproductive system and linked with some reproductive indices. A good correspondence between gonad appearance and its histological structure is observed, highlighting, in females, how oviducal gland morphology plays a crucial role in the macroscopic evaluation of maturity. The Gonadosomatic and Hayashi indices, in the two genders, and the Oviducal Gland index in females alone do not allow distinguishing all the stages in an irrefutable way. Data on the potential fecundity, oocyte and spermatophore size are reported and compared with literature. In addition, spermatophore components are also computed. The results reported in this paper lead to easy identification of the different phases of sexual maturation of O. vulgaris and could constitute an important tool for defining assessment models in view of sound management of this species.

Species diversity is widely recognized as an important trait of ecosystems’ functioning and resilience. Understanding the causes of diversity patterns and their interaction with the environmental conditions is essential in order to effectively assess and preserve existing diversity. While diversity patterns of most recurrent groups such as fish are commonly studied, other important taxa such as cephalopods have received less attention. In this work we present spatio-temporal trends of cephalopod diversity across the entire Mediterranean Sea during the last 19 years, analysing data from the annual bottom trawl survey MEDITS conducted by 5 different Mediterranean countries using standardized gears and sampling protocols. The influence of local and regional environmental variability in different Mediterranean regions is analysed applying generalized additive models, using species richness and the Shannon Wiener index as diversity descriptors. While the western basin showed a high diversity, our analyses do not support a steady eastward decrease of diversity as proposed in some previous studies. Instead, high Shannon diversity was also found in the Adriatic and Aegean Seas, and high species richness in the eastern Ionian Sea. Overall diversity did not show any consistent trend over the last two decades. Except in the Adriatic Sea, diversity showed a hump-shaped trend with depth in all regions, being highest between 200–400 m depth. Our results indicate that high Chlorophyll a concentrations and warmer temperatures seem to enhance species diversity, and the influence of these parameters is stronger for richness than for Shannon diversity, SI

The homing and orientation skills of Palinurus elephas were investigated in three no-take areas of the central-western Mediterranean in order to inform future reserve design. In general, P. elephas did not show a particular ability to orient homeward. A considerable portion of tagged lobsters were recaptured in the same direction as the capture point but, the points of capture and recapture were at such a distance from each other as to exclude any possible return to the original den. Homing ability seemed to be constrained to where lobsters were only displaced a short distance. For distances longer than 0.5km, the lobster movements seem to become nomadic, without a particular direction. The movement pattern suggests that it will be important that any restocking of marine reserves must be performed with lobsters collected in adjacent zones at distance more than 0.5km. Lobsters captured in a fishing zone