Zafira da Silva de Almeida

Carcinofauna bêntica estuarina de dois manguezais da costa amazônica maranhense, Brasil

This study aimed to characterize the diversity of crustaceans in two mangroves (Buenos Aires and Tronco) in the Bay of Sao Marcos, Maranhao Amazon coast, Brazil. Four samples were taken quarterly between September 2011 to June 2012. In each survey, three regions were analyzed (zone 1, zone 2 and zone 3), yielding 24 samples. The biological material was collected manually. Environmental parameters such as salinity, temperature and dissolved oxygen were collected in each sampling area. In order to evaluate the similarity between the mangrove zones, a cluster analysis and consecutive development of dendrograms were used. A total of 873 individuals were collected, representing nine families and 21 species, of which the Ocypodidae and Penaeidae had the largest number of individuals. It was observed that Clibanarius vittatus (Bosc, 1802), Clibanarius tricolor (Gibbes, 1850), Clibanarius foresti Holthuis, 1959 and Uca maracoani (Latreille, 1802) were restricted to the first zone of the two mangroves, while other 10 species were observed throughout the mangroves, which may be closely related to their life habit. In general, the Buenos Aires stream recorded the greatest number of species in relation to the Tronco stream. However, a great similarity of the number of species and individuals of decapod crustaceans was found between the two sampled areas.

A new species of Paraonis and an annotated checklist of polychaetes from mangroves of the Brazilian Amazon Coast (Annelida, Paraonidae)

Abstract The polychaete fauna from the mangroves of the Amazon Coast in Maranhão state, Brazil, is reported in this study. Fourteen species are listed, namely Alitta succinea (Leuckart, 1847); Arabella (Arabella) iricolor Montagu, 1804; Capitella capitata (Fabricius, 1780) complex; Exogone (Exogone) breviantennata Hartmann-Schröder, 1959; Heteromastus filiformis (Claparède, 1864); Isolda pulchella Müller, 1858; Mediomastus californiensis Hartman, 1944; Namalycastis fauveli Nageswara Rao, 1981; Namalycastis geayi (Gravier, 1901); Namalycastis senegalensis (Saint-Joseph, 1901); Nephtys simoni Perkins, 1980; Paraonis amazonica sp. n.; Sigambra bassi (Hartman, 1945); and Sigambra grubii Müller, 1858. Among them, Namalycastis fauveli and Namalycastis geayi are recorded for the first time in Brazil. Paraonis amazonica sp. n. is a new species for science, characterized by a rounded prostomium, 4–8 pairs of foliaceous branchiae, absent eyes, and two types of modified neurochaetae, acicular and hook-shaped.

Patterns of mollusc distribution in mangroves from the São Marcos Bay, coast of Maranhão State, Brazil

The diversity and distribution of molluscs from the Amazon Coast of Maranhao State, Brazil, are poorly understood. The aim of this study was to investigate how molluscs in two mangrove creeks (Buenos Aires and Tronco) at the Sao Marcos Bay, coast of the Maranhao State, respond to spatial and temporal variations in the environment. Sampling was performed in the intertidal area along three zones established using a straight line transect of 100 m. Abiotic variables of water and sediment were measured at each creek. We found 5,912 specimens belonging to 23 species and 15 families of epifaunal and infaunal molluscs. The patterns of their distribution in the two creeks were different. Salinity, dissolved oxygen, and rainfall were the main variables that affected the temporal distribution of molluscs. We found low species richness in the overall mollusc composition. Diversity in the Buenos Aires Creek was lower than that observed in the Tronco Creek, possibly because of activities of a port located in proximity to the former. The spatial distribution of molluscs along the zones followed an abundance and diversity gradient, mainly influenced by exposure time during low tide. Port activities may influence the patterns of mollusc distribution in the surrounding mangroves, and we thus highlight the importance of management and monitoring of these areas.

New species of Grubeulepis Pettibone, 1969 (Eulepethidae, Annelida) from northern Brazil

Eulepethidae is one of the least diverse families of scale polychaetes, with only 23 species described thus far. In this study we describe an additional species of Grubeulepis from unconsolidated substrata from Maranhão, tropical Brazil (ca. 2°S). Grubeulepis serrata sp. nov. differs from other species of the family due to the presence of one pair of eyes, 14 pairs of branchiae, posterior lamellae beginning in the 27th segment, with hooked upper notochaetae and serrated outer edge acicular neurochaeta in the 3rd segment. The diagnosis of the genus formerly included species with 10-13 pairs of branchiae, and thus is modified to accommodate the 14 pairs of branchiae from the new species described here. Grubeulepis serrata sp. nov. shares with Grubeulepis mexicana (Berkeley Berkeley 1939) the number of lateral processes of the 12th elytra, the segment of the foliaceous lamellae and the presence of acicular neurochaeta in the 3rd segment, but they differ in the number of branchiae pairs, eyes and the notochaetae shape. Grubeulepis serrata sp. nov. shares with Grubeulepis geayi (Fauvel 1918) the spiny notochaetae with spoon-shaped distal end, but differ in the hooked upper notochaetae, amount of lateral processes, and elytra articulation.

Biologia reprodutiva do Hassar affinis (Pisces: Siluriformes, Doradidae), Lago de Viana, Baixada Maranhense, Maranhão, Brasil

The study of reproductive biology is important to determine protective measures for the maintenance of fish stocks. Thus, this study aimed to determine some aspects of the reproductive biology of Hassar affinis in the Lake of Viana, at the Baixada Maranhense, Maranhao, Brazil. A total of 147 specimens were used in the study. They came from commercial fishing, collected in the period between February 2012 and January 2013. In the laboratory, they were weighed and body traits measured. A longitudinal incision was made ventrally in order to macroscopically observe the gonads. After that, they were fixed in Bouin solution for microscopic analysis and Gilson solution for analysis of fertility. Negative allometry was recorded for both genders, indicating greater increase in length than by weight. The sex ratio for the entire period was 3.4 females per 1 male. There was a greater reproductive activity in the bimesters February/March and April/May, which indicates that the reproductive period of this species occur in these months. The average absolute fecundity is estimated in 47,211 oocytes. The first sexual maturity is reached at 11.52 cm. Based on these data, management measures are suggested, defining the reproductive for this species from February to May, and setting minimum catching size of 11.5 cm and, furthermore, it is suggested the development of other work at monthly intervals.