This article summarizes the latest knowledge on the ecology of three gobies. The authors compile data published by various scientists who carried out their research under different conditions, using a variety of methods for collecting data and processing the results. The relationship between population structure and different environmental conditions was considered for three goby species Pomatoschistus minutus (Pallas, 1770), l? microps (Kroyer, 1838) and Gobius niger Linnaeus, 1758, in different geographical areas, notably the Mediterra.nean (Gulf of Lions and Adriatic) and cold temperate Atlantic (north of the English Channel) parts. In the three species, the life cycles in the Mediterranean, favoured by the local hydroclimate, are "contracted" (growth is rapid and reproductive effort emphasized) whereas, in the Atlantic, life cycles are "protracted" with growth and reproduction equivalent or less intense. Irrespective of the geographical location Iof the species, its reproductive success is very much same. 0 Elsevier, Paris gulf of Lions I Atlantic I life cycle I occupying strategy I Gobiidae R&urn4 .-Comparaison biogkographique des parami?.tres biotiques de trois GobiidCs (Teleostei). Cet article resume les connaissances sur l'ecologie de trois gobies. Les auteurs compilent les donnees publiees par divers chercheurs qui ont entrepris leurs etudes sous differentes conditions en utilisant une vari6tC de methodes d'echantillonnage pour la recolte et le traitement des don&es. Les interrelations entre les variables et les processus demographiques des espbces Ctudiees, Pomatoschistus minutus (Pallas, 1770), I? microps (Kroyer, 1838) et Gobius niger Linnaeus, 1758, et les conditions environnementales des milieux qu'elles occupent sur la majeure partie de leurs aires de repartition biogtographique sont considerees; les secteurs Mediterranee (golfe du Lion, Adriatique) et Atlantique temper6 froid (au nord de la Manche) sont plus particulierement pris en compte. Les populations des trois especes, favorisees par l'hydroclimat local, presentent en Mediterranee un cycle vital tendant vers sa << contraction >> durant lequel la croissance est rapide et l'effort reproducteur accentue, alors que celui-ci est plutot << dilate >> chez celles vivant en Atlantique, avec une croissance et une reproduction relativement Cgales ou moins intenses. Quelle que soit la position gtographique de l'espbce, le sucds reproductif reste t&s voisin. Q Elsevier, Paris golfe du Lion I Atlantique I cycles vitaux I strategies d'occupation I Gobiidae

The role played by a southwestern Atlantic mangrove in the breeding activity of estuarine fishes was evaluated. This fish assemblage represented 85 % of the total catches of the experimental fishery surveyed between 1993 and 1997. To evaluate the maturation and spawning processes, qualitative (macroscopic stages of maturation) and quantitative (gonadosomatic index) attributes were considered which were combined in a reproductive activity index. Four types of occupation were found in the mangrove, according to the reproductive patterns presented by each species. It was estimated that the Guaratuba mangrove is used as a spawning site-either regularly or occasionally-by about 40 % of the species, that make up 41 % to 46 % of the total abundance of this fish assemblage. However, besides the spawning species, the mangrove attracts other species at advanced stages of maturation. The use of mangrove habitat for reproductive activity by the species is 52 to 57 % of the total fish abundance. Spring and summer are the seasons most associated with the maturation and spawning processes. Although most of the assemblage is formed by species that do not permanently inhabit the system, the Guaratuba mangrove is a significant site for the life cycle of estuarine and marine species occupying this coastal region. © 2000 Ifremer/CNRS/IRD/É ditions scientifiques et médicales SAS reproduction patterns / mangrove / fish assemblage / migrant and resident species Résumé-Rôle de la mangrove pour la reproduction des poissons dans la baie de Guaratuba, Brésil. Le rô le joué par la mangrove d'une baie de l'Atlantique sud-ouest dans l'activité reproductive de la communauté de poissons a été étudié. Ces espèces représentent 85 % de l'abondance totale des pêches expérimentales entreprises de 1993 à 1997. Pour évaluer les processus de maturation et de ponte, les stades macroscopiques de maturation des gonades et l'indice gonadosomatique ont été considérés puis combinés en un indice d'activité reproductrice. Quatre modes d'occupation de la mangrove ont été répertoriés selon les modalités de reproduction de chaque espèce. La mangrove de Guaratuba est considérée comme un site de ponte, de façon régulière ou temporaire, pour environ 40 % des espèces constituant 41 à 46 % de l'abondance totale de l'assemblage. Cependant, à côté des espèces effectuant leur ponte dans la mangrove, ce milieu attire d'autres espèces dont le degré de maturation sexuelle est avancé. La contribution de la mangrove à l'activité reproductrice du peuplement de poissons s'élève à 52 et 57 % de l'abondance totale. Les processus de maturation et de ponte s'expriment principalement au printemps et en été. Bien que de nombreuses espèces n'occupent pas en permanence la mangrove de Guaratuba, celle-ci constitue un site d'accueil important pour les espèces habitant la région estuarienne et littorale. © 2000 Ifremer/CNRS/IRD/É ditions scientifiques et médicales Elsevier SAS modes de reproduction / mangrove / assemblage de poisson / espèces migrantes et résidantes

Biodiversity and dynamics of icbtbyic communities in the mangrove of Guaratuba, Brazil. The Bay of Guaratuba, whose area is approximately 45 km', is a basin, situated to the south of Brazil (25" 52' S; 48" 39' W) and connected to the Atlantic ocean. In its northern part, a region of mangrove is found, under the influence of seasonal fluvial contributions, dominated by Lugunculuria racemosa. The depth exceeds 6 m in some places. According to the period of the year, salinity varies between 3 and 37, and temperature between 15 and 28 "C. Several of the present fish species are exploited by commercial and recreational fisheries. This work describes characteristics of the fish populations occupying this mangrove, and temporal and spatial evolution of populations of the main species from available data on their biology. Between September 1993 and August 1996, fish samplings have been undertaken monthly by trawl, according to the same fishing effort (20 min), in channels of this ecosystem. Size, numerical abundance and weight of each individual of species were measured, as well as surface and bottom temperatures and bottom salinity. Species richness, Shannon-Weaver's diversity index were calculated and abundances were processed by the multivaried analysis. The global species richness is 61 species, distributed in 28 families; the better represented species are Sciaenidae (lo), Gerreidae (5), Carangidae (5), Ariidae (4), Haemulidae (3), Serranidae (3), Bothidae (3). Each year, the number of species varies between 41 and 44, and a group of eight species represents between 80 to 90 % of the density and 75 % of the biomass. The constancy of this dominance is the main characteristic of this fish assemblage. The most represented species in abundance is Pomadusys corvinaefonnis is the first two years, then Stellifer rastrifer. The group of eight main species is shared by 15 species in total, of which 13 for the density and 14 for the biomass. The most important monthly catches take place in winter season, during which one observes a decrease of water temperature and an increase of salinity. These species, however, being likely to be replaced by others according to the year or the season; one never finds the same composition in the assemblage which preserves always the same structures. Seasonal differences between seasons under marine (winter) and continental (summer) influences play a major role on the dynamics of fish in the Guaratuba mangrove. This ecosystem plays a functional role in the achievement of the life cycle of many permanent or temporary species. Those having succeeded to reach high levels of abundance are not represented in a uniform way in the course of the year, even when they reside permanently in the ecosystem. Periodic displacement strategies for self regulation of stocks abundance, are necessary mechanisms for these populations, which thus success to coexist in occupying the mangrove. 0 Elsevier, Paris / Ifremer / Cnrs / Ird Pisces I organisation I paralic realm I mangrove I Western AtlanticR&urn6 -a parti...

The growth of Epinephelus marginatus living in the Natural Marine Reserve of the Lavezzi Islands was studied using the von Bertalanffy model. The growth parameters of this model were: L ∞ =135.9 cm, K=0.08, to=-0.80 years. The relationship between length and weight was W=12.5 10-2 TL 2.60. Grouper lengths were similar in the Lavezzi Islands and in North Tunisia. The relative abundance of trophic resources in the Lavezzi Islands, due to a positive "reserve" effect and enhanced by a small population density of groupers, has great consequences on growth, compensating the effect of lower water temperature. A plausible explanation for the similarity between these two populations is that they belong to a single metapopulation.