Pteropoda (Gastropoda, Thecosomata e Gymnosomata) coligidos ao largo dos arquipélagos de São Pedro e São Paulo, costa nordeste, Brasil

Abstract

ABSTRACT. Pteropoda (Gastropoda, Thecosomata and Gymnosomata) collected along the northeast coast of the archipelago of São Pedro and São Paulo, Brazil. Pteropoda studies were carried out offshore São Pedro and São Paulo Archipelago (0056'2"N e 29OZ0'6"W) to assess biodiversity and spatial distribution. A Bongo net (mesh size 300 micrometer) was hauled obliquely from a depth between O and 50 m and O and 100 m by the REVIZEE-SCOREINE I oceanographic expedition on board of the Brazilian Navy Oceanographic Ship Antares. Samples were collected at 16 stations from Septemberto October 1995. A total of880 organisms distributed in 20 species, 14 genera and 9 families were identified. At the layer O-50 m, Creseis virgula (Rang 1828) was the most frequent species (71.43%), followed by Lil1lacina infla/a (Orbigny , 1836) and Cavolinia inflexa (Lesueur, 1813) (64.28%, each).ln terms ofrelative abundance outranked L. inflara (varying between 57.5 and 92.24%) and C. virgula (varying between 60.0 and 72.73%). At the layerO-lOO m, C. virgula was very frequent (80%), L. infla/a (70%) and Cuvierilla colul1lnella (Rang 1827) (40%) were frequent, other species had less than 30% of frequency. L. infla/a varied from 37.5 to 100% and C. virgula from 42.42 to 100% of relative abundance. Species diversity varied from medium to low « 2.0 bits.ind o !) in both layers. At the layer O-50 m C. virgula was directIy correlated to temperature and salinity, while at the layer O-I 00 m L. inflara was correlated to these parameters, showing that these species are Tropical Water indicators. KEY WORDS . Pteropoda, Diversity, Spatial distribution, North-east, Brazil Os pterópodos são pequenos moluscos pelágicos adaptados à vida planctônica. Devido a diferenças morfológicas, os Pteropoda são separados em duas ordens: Thecosomata e Gymnosomata. Os primeiros possuem concha espiralada, plana ou cônica, enquanto que os Gymnosomata caracterizam-se por sua ausência (MAGALD I 1981).Conhecidos desde o século XVII, apresentam uma ampla distribuição oceânica, sendo assim de grande interesse para o conhecimento dos ecossistemas marinhos (LALLI & WELL 1973). A importância desse grupo está relacionada com sua posição na cadeia trófica, tanto como consumidores do micro e nanoplâncton , como alimento para espécies de peixes forrageiros. Quando ocorrem em grandes concentrações, constituem uma parcela significativa na biomassa zooplanctônica (RESGALLA & MONTÚ 1994). Algumas espécies são consideradas como excelentes

Macrozooplâncton da Zona Econômica Exclusiva do Nordeste do Brasil (segunda expedição oceanográfica - REVIZEE/NE II) com ênfase em Copepoda (Crustacea)

“…Os estudos sobre a fauna da referida região não têm sido intensivos, observando-se, no entanto, esforços isolados para o seu conhecimento. Estudos desenvolvidos por: PARANAGUÁ (1970), GUSMÃO et al (1997), BOLTOVSKOY (1981BOLTOVSKOY ( , 1999, NEUMANN-LEITÃO et al (1999), OLIVEIRA & LARRAZÁBAL (2002), LARRAZÁBAL & OLIVEIRA (2003), entre outros, são os mais conhecidos. A grande maioria dos estudos existentes refere-se, sobretudo aos ecossistemas costeiros.…”

Thecosomata e Gymnosomata (Mollusca, Gastropoda) da cadeia Fernando de Noronha, Brasil

“…Uma dessas influências relatadas pelos autores é que muitas espécies do Atlântico SulOcidental são euritérmicas em outras regiões de sua área de dispersão, sendo exemplo L. helicina, espécie rara para Fernando de Noronha, esta, caracterizada como região tropical. OLIVEIRA & LARRAZÁBAL (2002) estudando os Pteropoda do arquipélago São Pedro e São Paulo encontraram esta espécie, no que se refere à abundância relativa, como sendo pouco abundante a rara nas estações prospectadas, em ambos estratos e malhas coletoras, o que coincide com os resultados obtidos em Fernando de Noronha.…”

Characterization of the geographical distribution pattern of the family Limacinidae Gray, 1840 (Mollusca - Gastropoda) in the waters of Northeastern of Brazil

“…Comparing such data with those obtained in the present study, in which H. inflatus was predominant in waters with temperatures ranging from 25.07 to 27.546C and salinity from 35.37 to 37.12, it is evident that this species is well adapted to temperate-cold to tropical waters, which helps to explain its wide distribution in oceans. Oliveira & Larrazá bal (2002) and Larrazá bal & Oliveira (2003), in studies conducted in 1996 with material of REVIZEE NE-I, considered H. inflatus to be a very abundant and frequent species in waters surrounding the São Pedro and Sã o Paulo Archipelago, being dominant and very frequent in the region of Fernando de Noronha. The results by the authors regarding the abundance and frequency of H. inflatus were similar to the results for REVIZEE NE-IV.…”

“…Resgalla Jú nior (1993) recorded L. trochiformis in the waters of Southern Brazil, considering the species to be epiplanktonic, with higher concentrations of individuals in the surface layers at night, common in tropical waters with temperatures ranging from 19.3 to 23.76C and salinity between 35.7 and 36.4. Oliveira & Larrazá bal (2002), studying the frequency of occurrence of Pteropoda from the Sã o Pedro and Sã o Paulo Archipelago and the surrounding areas, considered the species to be sporadic and rare. For the oceanic region of the Fernando de Noronha Island, Larrazá bal & Oliveira (2003) described L. trochiformis as being a not very frequent and not very abundant species, corroborating the results for waters of Northeastern Brazil, which are the object of this study.…”

“…Resgalla Jú nior (1993) established the pattern of spatial and temporal distribution of Pteropoda, Cladocera, and Chaetognatha at the South Brazil shelf, stating that, for Pteropoda, the family Limacinidae is distinguished by the dominance of Limacina retroversa (Fleming, 1823) and L. inflata. Oliveira (2002) described the ecology and distribution of the group in relation to the waters of Northeastern Brazil, highlighting Limacina inflata as the dominant species; Oliveira & Larrazá bal (2002) and Larrazá bal & Oliveira (2003) described the ecology of Thecosomata and Gymnosomata at the waters of the Sã o Pedro e Sã o Paulo Arquipelago and the Fernando de Noronha chain.…”