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The Haemaphysalis genus (Acari, Ixodidae) in Senegal is reviewed. This embodies a summary of specimens collected from vertebrate hosts over three decades. 454 collections were performed over this period (408 from mammals and 46 from birds), representing a total of 5752 ticks in different developmental stages. Seven Haemaphysalis spp. were collected, identified, and inventoried including: H. (Kaiseriana) rugosa, H. (Ornithophysalis) hoodi, H. (Rhipistoma) houyi, as well as four other species belonging to the leachi group, namely H. (Rhipistoma) leachi, H. (Rh.) moreli, H. (Rh.) muhsamae and H. (Rh.) spinulosa. Vertebrate hosts of Haemaphysalis species were identified and listed in different ecological zones of Senegal. An identification key of the haemaphysalids of Senegal is proposed, which is also applicable to the haemaphysalid fauna of the Occidental sub-region of the Afrotropical zoogeographical region. The role of these species as potential vectors of zoonotic diseases in Senegal is also discussed., Acarologia, 58, 928-945

International audience; This study assesses changes in subtidal benthic communities on the largest reef flat in Reunion, Saint-Gilles La Saline, using several types of surveys. Temporal and spatial trends are documented over a 22 year period (1987-2009), thus spanning the 1998 and 2000s bleaching events. The most plausible explanations for the observed trends are proposed. We chose two sites that are characterized by two types of community and metabolism: (1) an oligotrophic site dominated by Acropora corals (Site-Toboggan), where sea-urchins are numerous and macroalgae rare and (2) a dystrophic site dominated by non-Acropora corals, mostly massive and submassive, where macroalgae abound and sea-urchins are almost absent (Site-Planch'Alizés). Results are presented in three parts : Part 1 : general trends of the communities, part 2 : primary producers, part 3 : living corals. Part 1 presents three surveys. Survey 1 reports status and trends across the reef flats in 1993, 1996, and 2002, with all attached benthic components reported at the level of the species where possible. Survey 2 reports composition and changes in associated sedentary organisms such as sea urchins, holothurids, and the Pomacentridae fish Stegastes. Survey 3 focuses on the period 1998 to 2009 on permanent transects established in 1987 and monitored periodically, partly as a contribution to the Global Coral Reef Monitoring Network (GCRMN). In general, community structures at both locations remained stable, with primary producer coverage around 5% at Toboggan (T) and around 60% at Planch'Alizés (P). Living coral coverage averaged around 17% at both sites, but it was dominated by Acropora on Site-T (68%) and by massive corals on Site-P (88%). Regular echinoids were very abundant at T but almost absent from P, while the opposite was true for holothurids. The territorial damselfish Stegastes was of comparable abundance at both sites (

Cyanobacteria have dominated marine environments and have been reef builders on Earth for more than three million years (myr). Cyanobacteria still play an essential role in modern coral reef ecosystems by forming a major component of epiphytic, epilithic, and endolithic communities as well as of microbial mats. Cyanobacteria are grazed by reef organisms and also provide nitrogen to the coral reef ecosystems through nitrogen fixation. Recently, new unicellular cyanobacteria that express nitrogenase were found in the open ocean and in coral reef lagoons. Furthermore, cyanobacteria are important in calcification and decalcification. All limestone surfaces have a layer of boring algae in which cyanobacteria often play a dominant role. Cyanobacterial symbioses are abundant in coral reefs; the most common hosts are sponges and ascidians. Cyanobacteria use tactics beyond space occupation to inhibit coral recruitment. Cyanobacteria can also form pathogenic microbial consortia in association with other microbes on living coral tissues, causing coral tissue lysis and death, and considerable declines in coral reefs. In deep lagoons, coccoid cyanobacteria are abundant and are grazed by ciliates, heteroflagellates, and the benthic coral reef community. Cyanobacteria produce metabolites that act as attractants for some species and deterrents for some grazers of the reef communities.

International audience; Coral reef growth and development depend on several environmental factors, including tectonic and climatic parameters and local ecological drivers. Reef growth is especially sensitive to sea-level variations. Paleo-water depth reconstructions are essential tools used to determine reef growth patterns during different periods of reef growth. Assemblages of corals and/or coralline algae have been commonly used in such paleodepth reconstructions. This study shows that using microendolith ichnocoenoses can sometimes provide better accuracy than traditional coralgal analyses, particularly in the depth-range 0-10 m where coralgal assemblages usually show broad distribution ranges. Holocene and Pleistocene cores from two barrier reef sites on the west coast of Grande Terre in New Caledonia are examined here. Holocene reef development at these sites feature examples of microendolith ichnocoenoses that document rapid environmental changes and small sea-level variations of about 2-5 m in amplitude, and record these changes with more accuracy than coral and coralline algae assemblages which are highly dependant on the hydrodynamic energy of the setting. During the Pleistocene, which was less chronologically constrained, the microendolith ichnocoenoses also reflect paleo-water depths and reef-growth patterns at different periods of reef history.

A previous study of the spatial patterns of Borassus aethiopum (a humid savanna palm tree) led to the following predictions: H I. Trees and termite mounds positively influence all developmental stages; H2. There is intense competition between B. aethiopum juveniles; H3. Juvenile and seedling survival and growth rates are higher away from mother plants; H4. Mound positive effect overwhelms the effect of intraspecific competition for very young B. aethiopum individuals, the reverse applies to older, non-reproductive individuals. To test for these hypotheses the potential positive and negative neighbourhood effects were analysed. Progression of seedlings into the juvenile stage and juvenile growth were analysed through logistic regression models including the effects of four neighbourhood indices designed to model the respective influence of B. aethiopum juveniles and adults, trees and termite mounds. Statistical results explain the observed spatial pattern and reveal two main neighbourhood effects that influence both B. aethiopum juveniles and seedlings: a positive effect of mounds due to the fact that they constitute nutrient-rich soil patches, and a negative effect of juveniles due to intraspecific competition. Seedlings would be mostly affected by the mound positive effect, whereas juveniles would be mostly affected by competition.

The coralgal framework within the outer reef margin of many Indo-Pacific reefs exhibits three main shallow-water communities, the environmental significance of which can be inferred by comparison with their modern counterparts. A community dominated by tabular Acropora gr. hyacinthus/cytherea with branching Pocillopora damicornis, P. eydouxi, Montipora digitata, occasional domal faviids and mm-thick crusts of the coralline algae Lithophyllum and Mesophyllum (mainly), typical of the 6 – 15 m paleodepth range; a community including robust-branching Acropora gr. danai/robusta, A. humilis, A. digitifera and subordinate Favia stelligera, Echinopora gemmacea, associated to vermetid gastropods and thick coralline crusts of Hydrolithon cf. onkodes and Neogoniolithon cf. fosliei flourishing in depths less than 6 m; in medium-to-high water-energy settings, a community composed of domal Porites cf. lutea and P. cf. lobata with occasional Acropora gr. danai/robusta and cm-thick crusts of coralline algae in sheltered habitats in depths less than 10 m. These biological assemblages allow us to determine relationships between reef growth and paleobathymetry and, consequently, to reconstruct regional relative sea-level curves. High water-energy reefal assemblages provide stronger evidence for reconstructing sea-level curves than low-energy buildups, because they have generally been controlled by a keep-up growth mode. Subsiding reef sites seem to be more reliable indicators of sea-level variations because they usually present expanded reef sequences.

Tsetse fly guilds usually comprise two or three species. However, the presence of only one species often indicates that anthropic modifications have occurred in the habitat. On the other hand, more than three species are seldom observed in the same zone and the presence of five is extremely rare. Previous detailed studies have always focused on a single species, without taking into account interactions between species. The authors present the results of observations carried out in Cote d'Ivoire on a guild consisting of Glossina palpalis, G. pallicera, G. nigrofusca, G. longipalpis and G. fusca. Glossina have unusual physiological characteristics: both sexes feed exclusively on blood, they have a highly developed larviparity associated with a slow rhythm of reproduction (one larva about every ten days) and a long life expectancy (up to nine months). The authors report on the size of the flies, the hosts, feeding habits, ecodistribution, resting-places, flying heights, circadian activity and seasonal dynamics of tsetse fly populations in order to understand the organization of this guild. Each species feeds indiscriminately on a wide spectrum of hosts without a particular preference. Different species shared habitat (ecodistribution) and time (circadian and annual cycles). Thus, during an annual cycle, there is always a slight time-lag between the density peaks of G. palpalis and G. pallicera, the peak of the dominant species immediately preceding that of the dominated species. In a village area, 77% of the variations in density of G. pallicera were accounted for by the previous variations in density of the dominant species (G. palpalis). Experiments show that G. pallicera and G. nigrofusca immediately invade anthropic areas from which G. palpalis has been partially removed by trapping. These species thus appear to confront each other in a global dynamic equilibrium. This suggests that there is a ‘conflicting coexistence’ between the cohabiting species. Whereas the reason for such a process is quite obvious, how it occurs still remains to be explained. Other observations may provide a clue. For example, the sex ratios of both the main species fluctuate in opposite phases during the annual cycle. This strongly suggests that interspecific interactions occur through sexual mediation. Finally, the authors discuss the consequences of dynamic cohabitation on disease systems (trypanosomes, tsetse flies, hosts) and on control possibilities.

The effect of marine reserve protection on coral reef fish communities was studied on five islands located in the southwest lagoon of New Caledonia. Commercial fish communities and Chaetodontidae, sampled before fishing prohibition and after five years of protection, were compared. Reference stations were also sampled to assess variability in unprotected communities on the same time scale. The hypothesis that marine reserves protect and develop fish stocks was confirmed. Species richness, density and biomass of fish on the protected reefs increased respectively by 67%, 160% and 246%. This increase was statistically significant, whereas the reference stations showed only a small increase in density. There were significant increases in the species richness, density and biomass of the major exploited fish families (Serranidae, Lutjanidae, Lethrinidae, Mullidae, Labridae, Scaridae, Siganidae and Acanthuridae) and also of the Chaetodontidae. No significant increase in the mean lengths of fishes was noted among the main species, with the exception of one species of Siganid. Size structure changed for most of the main species, as the proportion of small individuals increased after five years of protection. Detrended correspondance analysis indicated that marine reserve protection was the most important determinant of the fish community structure. The second determinant was the position along an inshore-offshore gradient. Marine reserve protection resulted in an increase in the relative abundance and species richness of large edible species within the assemblages.

Coculture of a sulfate-reducing bacterium, when grown in the absence of added sulfate, with Methanobacterium bryantii , which uses only H 2 and CO 2 for methanogenesis, degraded formate to CH 4 . A pure culture of Desulfovibrio vulgaris JJ was able to produce small amounts of H 2 . Such a syntrophic relationship might provide an additional way to avoid formate accumulation in anaerobic environments.

In the tropical African region the entire drosophilid genus Lissoceplzala and Drosophila $mu species group have evolved a close association with endemic figs (Ficus spp., Moraceae). We previously described the biology of a few of these figdependent drosophilids (Lachaise, 1977). We report here on a further investigation in evergreen rainforests, mainly in western Africa, that has yielded information bearing on 19 fig species harboring 35 figbreeding drosophilids. The information shows that these fig-dependent drosophilids represent a major evolutionary pathway of the tropical African drosophilid

The phanerogamic vegetation of the lake was studied by Leonard (1969, 1974) during two surveys carried out in December 1964 and January–February 1968. The species composition and the location of the populations were determined and some observations on the aquatic vegetation of the then reduced lake area were made by Chouret and Lemoalle (1974), Fotius (1974), Fotius and Lemoalle (1976). These observations follow the changes in the lake basin which are related to the continuing slow recession of water since 1968. Due to travelling difficulties in the marshy or recently dried zones, the last surveys were made only in the south basin, while only some aerial surveys of the north basin could be made.