Antonia Cecília Zacagnini Amaral

Araçá: biodiversidade, impactos e ameaças

Araca Bay (Sao Sebastiao, State of Sao Paulo), within one of Brazils most beautiful coastlines, has small relict mangrove stands and a very diverse marine ecosystem. As such, the bay is a natural laboratory as well as important for local small scale fishing. In this study we summarize the large literature base to comprehensibly list the flora and fauna as a preliminary biodiversity inventory of Araca Bay. We place this in the historical context of human impact on the environment of the bay and we emphasize new, introduced and threatened species as bioindicators and natural resources. With this information, we provide a basis to inform conservation decisions as well as data for conservation management plans and call attention to the urgent need to protect this fragile environment and biota. We also emphasize that this small and uniquely biologically rich bay should be preserved, revitalized and integrated into the growing urban environment.

Feeding behavior of Scolelepis sp. (Polychaeta: Spionidae)

and may be part of a species complex, because some morphological variations (probably induced by changes in environmental factors such as salinity, temperature, or different sediment types) can be found in individuals from the same locality. Individuals can reach lengths of about 80 mm. The acuminate prostomium has 4-5 eyes arranged in a row, a prominent caruncula, and two long tentacular palps which are occasionally lost. According to Dauer (1983), who studied

Structure of molluscan assemblages in sheltered intertidal unconsolidated environments

A malacofauna de 13 ambientes oceânicos, protegidos, entremares e nao-consolidados e sua relacao com os fatores abioticos foram estudados com o intuito de conhecer a riqueza de especies e compreender o papel dos fatores abioticos na estruturacao das associacoes. Quatro tipos distintos de ambiente entremares foram reconhecidos com base nos descritores da comunidade (diversidade, riqueza e densidade) e nas caracteristicas abioticas. O tamanho medio do grao de areia (em phy) e a inclinacao da praia mostraram uma relacao negativa com a diversidade, riqueza e densidade. Sedimentos grossos foram favoraveis a fauna de moluscos nas areas estudadas, contrastando o bem conhecido efeito negativo deste tipo de areia sobre a fauna em praias oceânicas tipicas. Os terracos de mare baixa, tipicos de areas dominadas pela mare, e a presenca de estruturas biogenicas, tais como fragmentos rochosos e cascalho, estiveram tambem associados aos altos valores de riqueza. O grande numero de especies registrado na area estudada como um todo parece ser uma consequencia direta desta heterogeneidade ambiental, uma vez que esta e composta por tipos de ambientes altamente distintos.

The diet of Ophionereis reticulata (Echinodermata: Ophiuroidea) in southeastern Brazil

The ophiuroid Ophionereis reticulata (Say, 1825) occurs in the sediment-rocky shore interface, under small stones. Its diet is analyzed in this short communication. Specimens were collected at the Praia Grande beach, located on the northern coast of the state of Sao Paulo, Brazil, in July, 2002 and January, 2003. The animals were fixed in 70% ethanol and dissected to obtain their stomach contents. Of the total (35), 77.1% (27) had ingested some kind of food and, among those, 81.4% (22) had more than one item. The mean number of food items per stomach was 1.9. Ophionereis reticulata is an omnivorous species, consuming sediment, green and red algae, and polychaetes.

Morphometric study of the nereidid Laeonereis acuta (Annelida: Polychaeta)

In order to find the most suitable parameter for measuring the nereidid Laonereis acuta , correlations between total length or weight and eight morphological measurements: width of prostomium and 2nd, 6th, 13th and 19th setigers, length of the prostomium, length through segment 6th and length through segment 13th, were established. The width measurements showed the highest values of r , and were the most reliable indicators of size. Comparisons between weight and morphological measurements showed a similar pattern as well as negative allometric growth.

Mangrove vegetation decreases density but does not affect species richness and trophic structure of intertidal polychaete assemblages

The positive influence of mangrove vegetation on macrobenthic communities has been widely investigated, but studies mainly focused on epibenthic assemblages. Given the contrasting characteristics between epifauna and infauna, we expected that mangrove vegetation would not exert the same positive effect on infaunal assemblages. To test this hypothesis, we investigated polychaete assemblages in mangrove stands in a tidal flat in Southeast Brazil. Specifically, we focused on (a) whether polychaete assemblages (i.e., density, richness, community, and feeding guild composition) are different inside and outside mangrove stands, and (b) if changes are related to root biomass. Our results showed that mangrove areas have lower polychaete density than that of adjacent sandflats, and polychaete density is negatively related to root biomass. Species richness was not affected by the presence of vegetation, but the number of exclusive species was higher inside the mangrove. Changes in composition of polychaete assemblages were mainly attributable to reductions in species density rather than species replacement. Trophic structure was not influenced by mangrove vegetation, as subsurface-feeders dominated inside and outside mangrove zones. Our results contrast with the richness enhancement found for epibenthic fauna inside mangroves, and highlight that mangrove vegetation does not exert the same influence on epibenthic as that on infaunal assemblages.

Glyceridae Grube 1850 (Annelida: Polychaeta) from Southern and Southeastern Brazil, including a new species of Glycera

Rizzo, A.E., Steiner, T.M. & Amaral, A.C.Z. Glyceridae Grube 1850 (Annelida: Polychaeta) from Southern and Southeastern Brazil, including a new species of Glycera. Biota Neotrop. Sep/Dez 2007 vol. 7, no. 3 http:// www.biotaneotropica.org.br/v7n3/pt/abstract?article+bn00407032007. ISSN 1676-0603. This systematic study of the polychaete species of the family Glyceridae is part of a broader program to inventory and determine parameters for conservation and sustainable use of the marine biodiversity off the southeastern and southern coast of Brazil. The material studied was collected from intertidal sandy beaches, the inner continental shelf (<50 m depth) off the northern coast of the state of Sao Paulo, and the outer continental shelf and part of the continental slope (depths from 60 to 808 m) off the state of Rio de Janeiro south to Rio Grande do Sul (22° S - 34° 40’ S). The descriptions of several species were improved, adding new and important taxonomic characters, mainly related to proboscideal papillae. A key for identifi cation of the glycerid species from southeastern and southern Brazil is also provided. Eight species of Glyceridae were identifi ed: Glycera americana Leidy 1855; Glycera brevicirris Grube 1870; Glycera dibranchiata Ehlers 1868; Glycera lapidum Quatrefages 1866; Glycera oxycephala Ehlers 1887; Glycera tesselata Grube 1863; Hemipodia californiensis (Hartman 1938); Hemipodia simplex (Grube 1857); and a previously unknown species of Glycera.

Storm effects on intertidal invertebrates: increased beta diversity of few individuals and species

Climate change is predicted to lead to more extreme weather events, including changes to storm frequency, intensity and location. Yet the ecological responses to storms are incompletely understood for sandy shorelines, the globe’s longest land-ocean interface. Here we document how storms of different magnitude impacted the invertebrate assemblages on a tidal flat in Brazil. We specifically tested the relationships between wave energy and spatial heterogeneity, both for habitat properties (habitat heterogeneity) and fauna (β-diversity), predicting that larger storms redistribute sediments and hence lead to spatially less variable faunal assemblages. The sediment matrix tended to become less heterogeneous across the flat after high-energy wave events, whereas β-diversity increased after storms. This higher β-diversity was primarily driven by species losses. Significantly fewer species at a significantly lower density occurred within days to weeks after storms. Negative density and biomass responses to storm events were most prominent in crustaceans. Invertebrate assemblages appeared to recover within a short time (weeks to months) after storms, highlighting that most species typical of sedimentary shorelines are, to some degree, resilient to short-term changes in wave energy. Given that storm frequency and intensity are predicted to change in the coming decades, identifying properties that determine resilience and recovery of ecosystems constitute a research priority for sedimentary shorelines and beyond.

Allometric growth of a common Nassariidae (Gastropoda) in south-east Brazil

The allometric growth of two groups of Nassarius vibex on beds of the bivalve Mytella charruana on the northern coast of the State of Sao Paulo, was evaluated between September 2006 and February 2007 in the bed on Camaroeiro Beach, and from March 2007 to June 2007 at Cidade Beach. The shells from Camaroeiro were longer and wider and had a smaller shell aperture than those from Cidade; a principal components analysis also confirmed different morphometric patterns between the areas. The allometric growth of the two groups showed great variation in the development of individuals. The increase of shell width and height in relation to shell length did not differ between the two areas. Shell aperture showed a contrasting growth pattern, with individuals from Camaroeiro having smaller apertures. The methodology based on Kullback-Leibler information theory and the multi-model inference showed, for N. vibex, that the classic linear allometric growth was not the most suitable explanation for the observed morphometric relationships. The patterns of relative growth observed in the two groups of N. vibex may be a consequence of different growth and variation rates, which modifies the development of the individuals. Other factors such as food resource availability and environmental parameters, which might also differ between the two areas, should also be considered.

Arabella aracaensis, a new species with growth rings on its mandibles, and some remarks on the endoparasitic Labrorostratus prolificus (Polychaeta: Oenonidae) from southeast Brazil

The family Oenonidae is composed of 12 genera, some of which are exclusively parasitic in the body cavity of other polychaetes, as well as bivalves and echiurans. One of these is the genus Labrorostratus, with six described species. Labrorostratus prolificus Amaral, 1977 is known only from Brazil, as a parasite in the body cavity of Perinereis cultrifera (Grube, 1840), and in a species of Eunicidae. The genus Arabella has about 20 described species, three of which occur on the Brazilian coast. This study describes the first growth stages of L. prolificus, and adds new information to the original description. The new species Arabella aracaensis is described, with remarks on the presence of growth rings on its mandibles.