Basicladia emedii (Cladophorales, Chlorophyta): a new freshwater epilithic species from Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variação sazonal da abundância de Ecballocystis pulvinata Bohlin em um riacho da região centro-sul do estado do Paraná

Seasonal variation of abundance of Ecballocystis pulvinata Bohlin in a stream of central-southern region of Parana State. The temporal dynamics of E. pulvinata and its relation to abiotic variables were evaluated monthly during January to December 2007 in a stream located in the central-southern part of Parana State (25 degrees 11'16 '' S - 51 degrees 021'25 '' W). The abundance of the population in terms of percentage cover was obtained by means of the quadrat technique and the following stream water variables were measured: current velocity, irradiance, depth, substrate type, temperature, oxygen saturation, conductivity, pH and turbidity. The abundance of E. pulvinata was considered high (X = 26.7%), with more development (22-46%) during autumn/winter. The low values (0-0.08) of niche width and the few associations with environmental variables shows that the population evaluated is a generalist with regards to the environment in which it occurs. Factors most strictly related were the water flow and the particle size of the substrate, which positively correlated to the seasonal pattern of the population investigated.

Post-larval morphology, growth, and development of Uca cumulanta Crane, 1943 (Crustacea, Decapoda, Ocypodidae) under laboratory conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The megalopa and juvenile development of Pachygrapsus transversus (Gibbes, 1850) (Decapoda, Brahyura) compared with other grapsid crabs

Megalopae were reared in the laboratory to the 7(th) crab stage. The megalopa and 1(st) crab stage are described and juvenile development was studied with emphasis on pleopodal differentiation. The megalopal phase, is easily identified, and shares with those of other Grapsinae and Plagusiinae big size, the presence of many natatory setae, and a series of conspicuous teeth on the inner margin of the dactyli from the 2(nd) to 4(th) walking leg. These features are regarded as adaptive for settlement in a wave-swept environment, such as the rocky marine intertidal where most of those species live. Fast development of juvenile pleopods is another characteristic of these subfamilies. In Pachygrapsus transversus, the sexes can be distinguished from the 2(nd) crab stage. Gonopod differentiation in males and the basic segmentation of all four pleopod pairs in females are already concluded at the 5(th) instar. A review of the available information indicated that settlement of large megalopae and fast juvenile development, preceding a precocious sexual maturity, are trends in Grapsinae and Plagusiinae. on the other hand, the Sesarminae pass through a more extensive juvenile instar sequence and presumably a delayed maturity.

Larval stages of Stenocionops furcatus (Olivier, 1791) (Decapoda : Brachyura : Majoidea) and a reappraisal of larval morphological characters for Mithracidae

Stenocionops furcatus is a spider crab found in the western Atlantic, from Georgia, USA to Rio Grande do Sul, Brazil, on sand, coral, rocks or mud bottoms from the intertidal zone to 180 m. We describe all laboratory-reared larval stages of S. furcatus obtained from the northern coast of São Paulo State, Brazil, and compare our data with existing larval descriptions for the genus and other mithracids. The larval development of S. furcatus consists of two zoeal stages and one megalopa. The durations of the first and second zoeal stage were similar to4 and 5 days respectively, the megalopa appearing 10-18 days after hatching. Our results show that the zoeae of S. furcatus differ from those of other Mithracidae by possessing four setae on the proximal lobe of the coxal endite of the maxilla, instead of five, and by the presence of mid-dorsal setae on the third abdominal somite in the second zoeal stage, which are lacking in other mithracids. Larval descriptions for Stenocionops in two previous publications were attributed to the subspecies S. furcatus coelatus from the Caribbean. Larvae from Brazilian waters closely resemble one of these accounts, suggesting that this taxon extends beyond the West Indies and that the other description represents larvae of S. furcatus furcatus. Additional morphological details, not available previously, are provided.

On the population biology of the mottled shore crab Pachygrapsus transversus (Gibbes, 1850) (Brachyura, Grapsidae) in a subtropical area

The mottled shore crab P. transversus is probably the most common brachyuran crab living in the marine rocky intertidal of southeastern Brazil. However, its biology is largely unknown. In this study, some aspects of the population biology of this species are investigated. Distribution of individuals in the intertidal range is heterogeneous. Sabellariid worm reefs and mytilid mussel beds can be considered as nursery grounds retaining most part of juveniles, while the rocky surface is mostly inhabited by adults, which find safety shelters in rock crevices. Annual size frequency distributions revealed clues of population stability and indicated that young individuals reach the adult habitat in a gradual process. Sex-ratio follows the 1:1 proportion in smaller size classes but is biased towards males in larger ones. Higher mortality in larger females is indicated as a possible cause of this pattern. Ovigerous ratio shows a remarkable seasonality in which highest percentages of ovigerous females occur during summer months, while recruitment of young is more intense from April to July, suggesting a very extensive larval development. Once established in the intertidal zone, young recruits will develop to mature individuals in late spring, when molting crabs become scarce and proportion of breeding females increases. Therefore, growth and reproduction are in a great part temporally separated, allowing an annual life cycle in which settlement, growth and breeding may take place within a I-yr period.

Biology and shell relationship in Clibanarius vittatus (Bosc, 1802) (Crustacea, Diogenidae) from Sao Vicente, SP, Brasil.

This study aimed to characterize the populational structure of Clibanarius vittatus (Bosc, 1802), as well as to determine the morphometric relations between the animal's size and the variables: length of their chelar propodus and the size of the shell opening. C. vittatus is a relatively abundant pagurid on the west Atlantic coast, it occurs in the intertidal region from 38 degrees N to 28 degrees S. The animals in this study were randomly sampled every month on the Paranapu (a) over tilde Beach (46 degrees 23' S e 23 degrees 59' W), S (a) over tilde $ o Vicente (SP), Brazil. The biometrics data were adjusted to the power equation (y = ax(b)), by means of the minimum square method. A total of 427 individuals were collected. The size of the cephalothoraxic shield ranged from 2.5 to 12.7 mm, evidencing a representative sample of the population. The of most commonly genus of Gastropoda shells occupied by the hermits was Thais (97,26%). In relation to the morphometric analyses performed, it was observed a positive correlation between the animal size and the variables length of the chelar propodus and the size of the shells.

Reproductive output of the spider crab Epialtus bituberculatus (H. Milne Edwards, 1834) (Crustacea, Decapoda, Brachyura) associated with beds of the alga Sargassum cymosum (C. Agardh, 1820) on the southeastern Brazilian coast

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Population features of the spider crab Acanthonyx scutiformis (Dana 1851) (Crustacea, Majoidea, Epialtidae) associated with rocky-shore algae from southeastern Brazil.

Acanthonyx scutiformis, an endemic species in the Brazilian coast, is commonly found in intertidal rocky-shore algal communities. This study analyzes the population biology of A. scutiformis from Ubatuba region. A total of 371 specimens were collected over one year. Size range was 4.2[long dash]12.7 mm CW (carapace width) for females and 3.7[long dash]15.8 mm CW for males. Females predominated in intermediate size classes, whereas males prevailed in the largest ones. The estimated size when 50% crabs were mature was 10.7 mm CW for males and 8.9 mm CW for females. Sex ratio varied among the demographic groups. The processes that influence A. scutiformis population structure can be related to the different times males and females reach sexual maturity and probably to the distinct predation pressures on each sex during the adult phase.

Diversity and distribution of crustaceans from 13 sheltered sandy beaches along Sao Sebastiao Channel, south-eastern Brazil

The crustacean species composition in the intertidal zones of 13 sheltered unconsolidated marine beaches in south-eastern Brazil is described. Fifty-three crustacean species were collected, adding 46 species to the total reported by previous studies in the same region. Decapods dominated the community, in contrast to exposed sandy beaches where peracarids normally predominate. The species were distributed irregularly among the beaches. Richness varied markedly among sites, and was positively related to a combination of factors such as fine sand grains, high organic matter content, and relatively low silt-clay content. The presence of rock fragments enabled both rocky shore and sandy beach crustaceans to occur oil the same beaches. Richness and abundance of crustaceans showed no clear relationship to sediment grain size and slope, in contrast to the norm for exposed sandy beaches. The dominance of the tanaid Kalliapseudes schubarti in sonic areas may be a result of organic matter pollution in the region. These beaches showed higher species richness than typical sheltered and exposed sandy beaches, indicating that this sheltered, highly heterogeneous seascape is an important area for conservation.

Tributyltin in Crustacean Tissues: Analytical Performance and Validation of Method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Branch formation in Pulvinularia suecica (Nostocales, Cyanoprokaryota) and considerations on the classification of dichotomously and pseudodichotomously branched genera

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Macroalgas em nascentes e arredores de riachos na região noroeste do estado de São Paulo

Macroalgas são organismos tipicamente bentônicos, constituídos por um talo maduro, discreto e reconhecível a olho nu, cuja identificação microscópica é necessária. Diversos estudos foram realizados visando o conhecimento taxonômico em riachos brasileiros, no entanto, são raros os trabalhos que abordam as algas que se desenvolvem nas nascentes destes riachos. de fevereiro a setembro/2007 coletas mensais foram realizadas em nascentes e em suas imediações (solos úmidos dos afloramentos d'água) de quatro riachos na região noroeste do estado de São Paulo. O levantamento taxonômico resultou na identificação de 13 espécies, sendo 54% dos táxons pertencentes a Cyanophyta e 46% a Chlorophyta. Cylindrospermum gorakhpurense, Mougeotia gotlandica, Spirogyra gallica e S. taftiana são registradas pela primeira vez para o Brasil. A flora aquática encontrada diferiu da regional devido à presença de organismos da família Zygnemataceae (Chlorophyta) em estágio reprodutivo. Este tipo de hábitat mostrou-se especialmente favorável à reprodução das Zygnemataceae.

Distribuição ecológica de comunidades de macroalgas de ambientes lóticos do Parque Nacional de Itatiaia (RJ, MG), Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Short-term successional dynamics of a macroalgal community in a stream from northwestern São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)