Patterns of community structure in the marine environment are strongly influenced by population relationships to biotic and physical gradients. The aim of this work is to explore the relationships of tropical rocky reef fish assemblages to wave exposure and benthic coverage in a gradient of distance from the coast. The study was conducted on the Guarapari Islands, southeastern Brazilian coast. Fish were sampled by underwater visual census (166 transects) and benthic cover was estimated with quadrats (223 replicates). Two main kinds of habitats were found to be derived from the close interrelation between exposure and benthic coverage: (1) exposed areas subjected to major hydrodynamic forcing, and (2) sheltered or moderately exposed areas. The first group is associated with mid-water schooling species like planktivorous labrids and Chromis, piscivorous Caranx, as well as gregarious omnivores like Abudefduf and Diplodus. In terms of benthic composition, macroalgae and encrusting calcareous algae prevail in this highenergy habitat. The second group is characterized by site-attached and reef associated species like territorial pomacentrids, invertebrate feeders such as Halichoeres poeyi and Chaetodon striatus, and small cryptobenthic fishes (e.g. blenniids and labrisomids). Turf algae, zoanthids and massive corals dominate this environment. Environmental plasticity is also common with some genera showing high abundances in all habitats (e.g. Holocentrus, Haemulon, Acanthurus). Examples of the coupling of food availability and fish abundance were found. Planktivores, territorial herbivores, macroalgae browsers and spongivores were positively related with the abundance of their preferred food items along the exposure gradient. Within-family analyses of Pomacentridae and Labridae showed that niche partitioning is likely occurring and seems to be mediated by swimming 'ability' and associated feeding performance.

ABSTRACT. Structure and composition of fish community from a sandy beach on Ilha do Frade, Vitória, Espírito Santo.

A B S T R A C TThe northern coast of Rio de Janeiro State lacks natural consolidate substrates, making it a proper environment to the development of researches using artificial structures. After studies about the type of substrate, concrete seems to be the most appropriate for studying fouling community development. This research was carried out to investigate the functional role of biofouling in the development of the ichthyic community in the north of Rio de Janeiro State. Percentage data of the epibenthic organisms' coverage and samples of the fish community with gillnet and visual census showed that biofouling in artificial reefs might have more than one functional role, acting as a facilitator in the recruitment of fish species and as a link in the trophic marine chain. Through the increase of localized structural complexity provided by the reef itself and by the fouling organisms which act as "engineering species", additional protection options are offered to the ichthyic community, especially recruits. Also, the epibiont biomass represents an important link in the food web, acting either as a direct source or in the transference of energy to higher trophic levels. Through the relationship between the ichthyic and fouling communities we concluded that the functional role of the latter in artificial reef habitats could be characterized mainly as shelter and feeding grounds for few fish species. R E S U M OO litoral norte do Estado do Rio de Janeiro possui uma escassez de substrato consolidado natural tornando o ambiente propício para o desenvolvimento de pesquisas com estruturas artificiais. Após estudos conclusivos sobre o tipo de substrato, o concreto parece ser o mais apropriado para o desenvolvimento da comunidade incrustante. Novas pesquisas foram realizadas para investigar o papel funcional da bioincrustação no desenvolvimento da comunidade íctica no norte do Estado do Rio de Janeiro. Dados de porcentagem de cobertura dos organismos epibênticos e amostragens da comunidade nectônica com rede de espera e censo visual, evidenciaram que a bioincrustação em recifes artificiais pode assumir mais de um papel funcional, como facilitadora no recrutamento de espécies de peixes e como elo na cadeia trófica marinha. Através do incremento da complexidade estrutural fornecida pelo próprio recife e pelos organismos incrustantes que atuam como "espécies engenheiras", opções adicionais de proteção são oferecidas para a comunidade íctica, principalmente recrutas. Além disso, a biomassa epibionte representa um importante elo na cadeia alimentar, atuando como fonte direta de alimento e/ou transferência de energia para níveis tróficos superiores. Através da relação entre as comunidades íctica e incrustante, conclui-se que o papel funcional desta última em habitats recifais artificiais caracteriza-se principalmente como abrigo e para algumas espécies também como alimentação.

Stationary visual census surveys were performed on an experimental artificial reef (21º29'S, 41º00'W) to clarify the role of structural complexity and benthic community as fish community modeling agents. Concrete modules of four types were grouped according to the combination of structural complexity through the presence/absence of holes and favourable/unfavourable surface for benthic colonization by anti-fouling painting. The survey (December 2002 to March 2003) showed higher abundance, richness and diversity in the complex modules. The same habitat usage pattern was observed according to vertical position and bottom type categories: demersal, hard-bottom and habitat generalist fishes preferred the complex ones. A higher number of juveniles occurred at those modules. It is assumed that trophic relationships and different habitat selection related to ontogenetic stages are also important modeling agents to the fish community structure since juvenile fish seem to actively seek the experimental complex modules.
Censos visuais estacionários foram realizados em um recife artificial (21º29'S, 41º00'W) para determinar o papel da complexidade estrutural e da comunidade bêntica como agentes modeladores da comunidade íctica. Módulos de concreto foram agrupados de acordo com a combinação do fator complexidade estrutural através da presença/ausência de cavidades internas nos módulos e de superfícies favoráveis/desfavoráveis à colonização da comunidade bêntica através de tinta anti-incrustante. De dezembro de 2002 a março de 2003, foram registrados maiores valores de abundância, riqueza e diversidade nos módulos complexos. Padrões de uso de habitat similares foram observados de acordo com a posição vertical na coluna de água e tipo de fundo: peixes demersais, de fundo consolidado e habitat generalista preferiram módulos complexos. Os resultados indicam que relações tróficas e seleção de habitat relacionada ao estágio ontogenético são também importantes agentes modeladores da comunidade íctica, uma vez que peixes juvenis buscam ativamente os módulos experimentais estruturalmente mais complexos

ABSTRACT

The fishery on Penaeidae shrimp is done all over the Brazilian coast, especially the seabob shrimp (Xiphopenaeus kroyeri). It is captured in large quantities in the Southeast and Southern Brazil. In order to study the population structure of X. kroyeri from Anchieta Municipality, Espírito Santo State, during the period from January to December 2008, monthly samplings with one-hour-long were conducted to verify the number of individuals, biomass, sex, total length and gonad maturity stage. The specimens had total length ranging from 2.96 to 9.96 cm, and females were larger than males. It is suggested that the population of X. kroyeri presents patterns of recruitment and reproduction similar to those of the Northeast region. The estimated size of first gonadal maturation was 4.5 and 6.9 cm for males and females, respectively. The fishing operates on a stock composed of predominantly adult males and juveniles and adult females. The mesh size of the nets and the high plant biomass in the fishing areas may be contributing to the increased catch of juveniles, undermining the recruitment of X. kroyeri.

One of the main issues regarding artificial reef fish evaluation is the performance of an efficient visual census sampling. An experimental artificial reef made of four different types of concrete modules was implanted on the north coast of Rio de Janeiro (21º29'S, 41º00W). Two interval-sampling periods using a visual census method were performed in the summer of 2003 (N = 6) and 2004 (N = 6), weekly and daily, respectively. The longer interval-sampling period showed twice of species with eight exclusive ones. Total fish abundance was higher during the shorter interval-sampling period, due to the presence of large shoals of Chloroscombrus chrysurus (Linnaeus, 1766) and Haemulon aurolineatum (Cuvier, 1829) especially at the complex modules. Fish abundance according to vertical position and feeding habits in the two interval sampling-periods showed a clear association to the structural complex modules, reinforcing the shelter influence on local fish assemblage structure and composition. The second survey showed quite different diversity and taxonomic results and highlighted the impossibility of obtaining several independent samples in a short period.of time.

ABSTRACT. Talitroides topitotum (Amphipoda) was introduced in Brazil by silviculture activities. Currently the species is distributed in the states of Paraná, Rio de Janeiro and São Paulo. This paper describes the species' occurrence in the state of Espírito Santo. The objective of this study was to determine the interference of the edge effect on community structure of macroinvertebrates associated with leaf litter, where a T. topitotum female specimen was observed in coffee cultivations in March 2008.