Growth and reproduction of Hyale media Dana (Amphipoda, Gammaridae, Hyalidae) associated to Sargassum cymosum C. Agardh

The post-marsupial growth, sexual differentiation, fecundity and reproductive biology of Hyale media Dana, 1853 living on Sargassum cymosum C. Agardh, 1820 are described. The growth was continuous througth 12 stages for males and 9 for females. The sexual differentiation occours at 2th or 3th moult and was demonstrated by the enlargment of the gnatopod II propod. Number of eggs increased with the female head length. Observations of courtship behavior, incubation, moult processes, emergence of juveniles and brood caracteristics were made. The precopula courtship continued for two days, the eggs were incubated for six days and the juveniles, that stay until three days in the marsupium, moult every day.597606Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Temporal variation in Sargassum Biomass, Hypnea epiphytism and associated fauna

Studies were carried out to investigate the temporal variation in Sargassum biomass, Hypnea epiphytism and associated fauna. There was a marked variation in the biomass of Sargassum and Hypnea among various sampling periods. Low values for Sargassum were recorded in August and November, while the lower value for Hypnea biomass was recorded in August. An inverse relationship was found between Sargassum biomass and the intensity of Hypnea epiphytism. The density of the total fauna associated to Sargassum showed a marked reduction in May. This variation was influenced by the variation patterns of the dominant faunistic groups (Gastropoda, Gammaridea, Isopoda and Caridea). Significant positive relationships were found between the biomass of Sargassum and Sargassum+Hypnea with the total density of all faunistic groups (per macroalgae biomass unit). However, the influence of Hypnea epiphytism on the phytal organisms was not evidenced.Sargassum cymosum é uma alga muito freqüente e abundante no sudeste do Brasil a qual apresenta uma fauna associada muito diversificada e freqüentemente epifitada pela alga vermelha Hypnea musciformis. Foram realizadas quatro amostragens na Praia do Lamberto, litoral norte do Estado de São Paulo, para observar a variação temporal da biomassa de Sargassum, do epifitismo de Hypnea e da fauna associada. Observou-se uma marcada variação da biomassa de Sargassum e Hypnea entre os períodos de amostragem. Os menores valores para Sargassum foram obtidos em agosto e novembro, enquanto o menor valor para Hypnea foi obtido em agosto. Relação inversa foi observada entre a biomassa de Sargassum e o epifitismo de Hypnea. A densidade da fauna total associada a Sargassum também mostrou variação significativa entre os períodos de amostragem, com marcada redução em maio. Este padrão foi influenciado pela variação dos grupos taxonômicos dominantes (Gastropoda, Gammaridea, Isopoda e Caridea). Observou-se uma forte relação positiva entre a biomassa of Sargassum e Sargassum+Hypnea com a abundância de todos os grupos taxonômicos. Contudo, não ficou evidenciada a influência do epifitismo de Hypnea sobre os organismos do fital.665671Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Hourstonius wakabarae sp. nov. (Amphipoda, Amphilochidae) from the southeastern coast of Brazil

A new species of Hourstonius is described from the northern coast of São Paulo State. Hourstonius wakabarae sp. nov. is distinguished from the other species of the genus by the morphology and the size of the accessory flagellum of antenna 1, the articles of antennae 1 and 2, the mandibular molar, and the telson. The new species H. wakabarae lives associated with macroalgae growing on rocky shores, especially the brown alga Sargassum, at depths up to 2-3 m. This is the first species of the genus Hourstonius recorded from Brazilian waters.195204Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

El papel de las algas epífitas y diferentes especies de sargassum en la distribución y alimentación de anfípodos herbívoros

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The presence of particular algal species can directly influence the distribution and abundance of mesoherbivores. The aim of this study was to answer the following questions: Do Sargassum beds of different localities show variation in the load of epiphytic algae? Do Sargassum beds of different localities show variation in the density of herbivore amphipods? Does the density of these amphipods in the same algal bed vary with epiphyte load? Are species of Sargassum and their epiphytes equally consumed by amphipods? The collections were carried out in three infralitoral algal beds in southeastern Brazil. Fronds of Sargassum were collected at each algal bed and the associated ampithoid and hyalid amphipods were separated, identified and counted. Sargassum fronds and epiphytes were identified, dryed and weighted. Experiments were carried out to determine the consumption of Sargassum species and epiphytes by amphipods. The weight of the epiphytes Hypnea musciformis and Dyctiopteris delicatula and the density of amphipods were different among sampling sites. There was a relationship between amphipod density and epiphyte weight at two sampling sites. The four amphipod species tested consumed algae, but showed different patterns of consumption. Despite consuming the epiphytes, the ampithoids preferentially feed on the three species of Sargassum, while Hyale nigra had a preference for Hypnea musciformis.The presence of particular algal species can directly influence the distribution and abundance of mesoherbivores. The aim of this study was to answer the following questions: Do Sargassum beds of different localities show variation in the load of epiphyti422353363FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)99/11325-9La presencia de determinadas especies de algas puede influir directamente en la distribución y abundancia de mesoherbívoros. El objetivo de este estudio fue responder a las siguientes preguntas: ¿Los bancos de Sargassum de diferentes localidades muestranWe thank D.F.C. Jacobucci and A. Turra for helping in the field. This work was partially funded by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (Process 99/11325-9) and Fundo de Apoio ao Ensino, à Pesquisa e à Extensão da Universidade Es

Efeito da variação temporal e do tamanho de anfípodes herbívoros nos níveis de consumo de Sargassum filipendula (Phaeophyta, Fucales) e sua principal epífita, Hypnea musciformis

The impact of herbivorous amphipods on a community of macroalgae does not depend only on the species present. Two equally important factors are the relative abundance and potential consumption of herbivorous species. The aim of this study was to determine the role of temporal and size variation of herbivorous amphipods in the consumption of Sargassum filipendula and their main algal epiphyte Hypnea musciformis. Monthly collections of 15 fronds of S. filipendula were carried out between June 2000 and May 2001 at Fortaleza beach, north coast of the state of São Paulo, Brazil, to evaluate the size structure of the herbivorous amphipods of the families Hyalidae and Ampithoidae and the occurrence of epiphytic algae associated with S. filipendula. Ampithoidae and Hyalidae amphipods were identified, separated in size classes and counted. Choice consumption assays were performed to estimate the grazing rates of amphipods of different size classes on S. filipendula and Hypnea musciformis. The amphipods showed temporal variation in abundance and recruitment in all sampling periods. Algal consumption varied among species and size of amphipods with a tendency for increased consumption with size (from a mean daily value of 0.143 g/frond for 0.75 mm Hyale nigra to 6.757 g/frond for 4.0 mm Cymadusa filosa). Consequently, the contributions of each species for the removal of the algae were different along the year. Our results indicate that amphipod algal herbivory should be evaluated at fine taxonomic resolution considering the individual contribution of different size classes. Key words: Amphipoda, herbivory, phytal.O impacto de anfípodes herbívoros em uma comunidade de macroalgas não depende somente das espécies presentes. Dois fatores igualmente importantes são a abundância relativa e o consumo potencial de espécies herbívoras. O objetivo deste estudo foi determinar o papel da variação temporal e de tamanho de anfípodes herbívoros no consumo de Sargassum filipendula e sua principal alga epífita Hypnea musciformis. Coletas mensais de 15 frondes de S. filipendula foram realizadas entre junho de 2000 e maio 2001 na praia da Fortaleza, litoral norte do estado de São Paulo, Brasil, para avaliar a estrutura de tamanho de anfípodes herbívoros das famílias Hyalidae e Ampithoidae e a ocorrência de algas epifíticas associadas a S. filipendula. Anfípodes ampitoídeos e hialídeos foram identificados, separados em classes de tamanho e contados. Ensaios de consumo com escolha foram realizados para estimar as taxas de herbivoria de anfípodes de diferentes classes de tamanho em S. filipendula e Hypnea musciformis. Os anfípodes mostraram variação temporal na abundância e recrutamento em todos os períodos de amostragem. O consumo das algas variou entre espécies e tamanho dos anfípodes com uma tendência de aumento de consumo com o tamanho (de um valor médio diário de 0,143 g/fronde para Hyale nigra com 0,75 mm a 6,757 g/fronde para Cymadusa filosa com 4,0 mm). Conseqüentemente, as contribuições de cada espécie para a remoção das algas foi diferente ao longo do ano. Nossos resultados indicam que a herbivoria por anfípodes deve ser avaliada com elevada resolução taxonômica, considerando-se a contribuição individual das diferentes classes de tamanho. Palavras-chave: Amphipoda, herbivoria, fital

Morphological development and ovary histology of Kalliapseudes schubarti Mañe-Garzon (Crustacea, Tanaidacea) from São Sebastião channel, São Paulo, Brasil

The morphological stages of the Kalliapseudes schubarti Mañe-Garzon, 1949 females were easily determinated and they were similar, but the male stages show distint forms probably due to the ambient stimuli. The description of the male stages demonstrate that K. gianucai (Bacescu, 1979) is another male stage of K. schubarti, probably a secondary copulatory stage. The morphology and development of the ovary is related both with the maturity and with the morphological modifications of females stages.675683Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Efeito da variação temporal e do tamanho de anfípodes herbívoros nos níveis de consumo de Sargassum filipendula (Phaeophyta, Fucales) e sua principal epífita, Hypnea musciformis

The impact of herbivorous amphipods on a community of macroalgae does not depend only on the species present. Two equally important factors are the relative abundance and potential consumption of herbivorous species. The aim of this study was to determine the role of temporal and size variation of herbivorous amphipods in the consumption of Sargassum filipendula and their main algal epiphyte Hypnea musciformis. Monthly collections of 15 fronds of S. filipendula were carried out between June 2000 and May 2001 at Fortaleza beach, north coast of the state of São Paulo, Brazil, to evaluate the size structure of the herbivorous amphipods of the families Hyalidae and Ampithoidae and the occurrence of epiphytic algae associated with S. filipendula. Ampithoidae and Hyalidae amphipods were identified, separated in size classes and counted. Choice consumption assays were performed to estimate the grazing rates of amphipods of different size classes on S. filipendula and Hypnea musciformis. The amphipods showed temporal variation in abundance and recruitment in all sampling periods. Algal consumption varied among species and size of amphipods with a tendency for increased consumption with size (from a mean daily value of 0.143 g/frond for 0.75 mm Hyale nigra to 6.757 g/frond for 4.0 mm Cymadusa filosa). Consequently, the contributions of each species for the removal of the algae were different along the year. Our results indicate that amphipod algal herbivory should be evaluated at fine taxonomic resolution considering the individual contribution of different size classes. Key words: Amphipoda, herbivory, phytal.O impacto de anfípodes herbívoros em uma comunidade de macroalgas não depende somente das espécies presentes. Dois fatores igualmente importantes são a abundância relativa e o consumo potencial de espécies herbívoras. O objetivo deste estudo foi determinar o papel da variação temporal e de tamanho de anfípodes herbívoros no consumo de Sargassum filipendula e sua principal alga epífita Hypnea musciformis. Coletas mensais de 15 frondes de S. filipendula foram realizadas entre junho de 2000 e maio 2001 na praia da Fortaleza, litoral norte do estado de São Paulo, Brasil, para avaliar a estrutura de tamanho de anfípodes herbívoros das famílias Hyalidae e Ampithoidae e a ocorrência de algas epifíticas associadas a S. filipendula. Anfípodes ampitoídeos e hialídeos foram identificados, separados em classes de tamanho e contados. Ensaios de consumo com escolha foram realizados para estimar as taxas de herbivoria de anfípodes de diferentes classes de tamanho em S. filipendula e Hypnea musciformis. Os anfípodes mostraram variação temporal na abundância e recrutamento em todos os períodos de amostragem. O consumo das algas variou entre espécies e tamanho dos anfípodes com uma tendência de aumento de consumo com o tamanho (de um valor médio diário de 0,143 g/fronde para Hyale nigra com 0,75 mm a 6,757 g/fronde para Cymadusa filosa com 4,0 mm). Conseqüentemente, as contribuições de cada espécie para a remoção das algas foi diferente ao longo do ano. Nossos resultados indicam que a herbivoria por anfípodes deve ser avaliada com elevada resolução taxonômica, considerando-se a contribuição individual das diferentes classes de tamanho. Palavras-chave: Amphipoda, herbivoria, fital

Sperm Ultrastructure Of Mytella (bivalvia) Populations From Distinct Habitats Along The Northern Coast Of São Paulo State, Brazil.

Ultrastructural analyses of bivalve spermatozoa are relevant in studies that aim to identify taxonomic traits for the purposes of discriminating species and conducting phylogenetic studies. In the present work, spermatozoa of mussel specimens of the genus Mytella, collected from two populations living in distinct habitats, were examined by electron microscopy. The objective was to identify sperm ultrastructural taxonomic traits that could be used to differentiate Mytella species. The specimens were from populations that live in intertidal zones on the southeast coast of Brazil, either buried in muddy-sand sediment or anchored to rocky substrates. The acrosomal vesicle was conical and long, the axial rod extended from the nucleus to the acrosome, the nucleus was an oblate spheroid with a condensed chromatin, the intermediate portion contained mitochondria encircling a pair of centrioles, and there was a single flagellum. The sperm was of a primitive type. The spermatozoon ultrastructure did not distinguish the specimens buried in muddy-sand sediment from those anchored to rocky substrates. The data suggest that the specimens analyzed, despite living in distinct habitats, belong to the same species, which conchological analyses identified as M. charruana. The presence of an axial rod in their sperm cells supports the inclusion of M. charruana in the subfamily Mytilinae.34103-1