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The present study describes the ovarian development stages of wild Farfantepenaeus paulensis (Pe¤ rez-Farfante) through the combined observation of histological and visual characteristics. Twenty-¢ve females (61.872.4 g) were captured in 35^40-m deep waters o¡ southern Brazil (271S). The females were grouped according to the size and shape of their ovary and then killed. The colour of the fresh ovary was compared with a chromatic scale catalogue. Analysis of the histological sections of each ovary determined the morphological characteristics, size and frequency of the di¡erent oocyte types. Based on these characteristics, four distinct stages of ovarian maturation are proposed: stage I (immature), characterized by the presence of small basophilic oocytes (52.1719.9 mm) and ovary colour ranging from translucent to creamy; stage II (developing), with yolky oocytes (YOs) (144.2726.1 mm) and a light green colour; stage III (mature), presenting largeYOs but with cortical rods (235.0730.2 mm) and an olivebrown colour; and stage IV (spent), with atretic oocytes and the same ovary colour pattern as stage I. The gonadosomatic index ranged from 1.6 (stage IV) to 13.7% (stage III) and was closely related to the different ovarian maturation stages. The observation of visual features coupled with histological characteristics was found to represent a reliable procedure to evaluate the ovarian maturation of F. paulensis.

Kalliapseudes schubartii (Crustacea: Tanaidacea) is a tube dwelling invertebrate living in estuarine soft bottoms with distribution along the south-east and southern Brazilian and Uruguayan coasts. Individual growth, and reproduction were examined by taking samples for a year in the estuarine region of the Lagoa dos Patos (southern Brazil). The von Bertalanffy model described growth of K. schubartii (K=4.54 y−1, L∞=13.22 mm). Reproductive activity was observed in spring and summer. No relationship was observed between total length of females and brood size. Eggs, embryos, and mancas were often observed in a marsupium. Relative growth analysis showed two levels of allometry in the growth of chelipeds of males.

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ABSTRACT. Natural diet of the blue crab Callinectes sapidus (Decapoda, Portunidae) in the Patos Lagoon estuary area, Rio Grande, Rio Grande do Sul, Brazil. The Southern Brazil blue crab Callinectes sapidus Rathbun, 1869 is the most abundant crab of the genus Callinectes in Patos Lagoon estuary. Although this species is widely distributed throughout the Patos Lagoon estuary area, there is little information about its natural diet. This species is an important predator and has a significant influence on its prey populations. The aim of this study was to check the natural diet of blue crab through the foregut contents analysis. Crabs were collected using an otter trawl net from March 2003 to March 2004. After collected, crabs were preserved immediately in 10% formaldehyde. The carapace width, weight and sex were measured for each individual. The foregut of each crab was removed and stored in 70% ethanol. Blue crab feeds on a wide variety of sessile and slow moving invertebrates. The main item was Detritus, followed by the suspension-feeder mollusk Erodona mactroides Bosc, 1802 (Erodonidae). Sand grains and the small crustaceans of class Ostracoda, were an important component of the foregut contents, but sand grains were not considered food. Setae and pieces of Polychaeta and some seeds of submersed higher vegetation of Ruppia maritima L. (Potamogatonaceae) (beaked tasselweed), and Zannichellia palustris L. (Potamogatonaceae) (homed pondweed), were also found. This study has as purpose to provide information for a long-term protection and conservation of blue crab population and also to characterize its relationship with the macrobenthic communities in the Patos Lagoon estuary. RESUMO. Na região estuarina da Lagoa dos Patos, o siri-azul Callinectes sapidus Rathbun, 1869 é o mais abundante dentre as espécies do gênero. Apesar do siri-azul exercer influência sobre as comunidades bentônicas, por ser considerado um predador do topo da cadeia alimentar, não existem muitos estudos sobre aspectos ecológicos, inclusive sobre a composição e variabilidade sazonal de sua dieta natural, neste estuário. O objetivo principal deste estudo foi investigar a composição da dieta do siri-azul, evidenciando possíveis relações com a comunidade bentônica da região estuarina da Lagoa dos Patos. O período de estudo foi de março de 2003 a março de 2004, com coletas bimestrais. Os organismos foram coletados com auxílio de rede de arrasto de fundo, com malha de 13 mm entre nós opostos. Ainda em campo os animais foram fixados em formol 10%. Após a coleta os animais foram separados quanto ao sexo, medidos (largura e comprimento da carapaça -cm) e pesados (peso -g). Após a triagem, os animais foram dissecados e os intestinos retirados e pesados. As análises dos conteúdos alimentares dos siris demonstraram que os hábitos alimentares são diversificados, constituindo-se principalmente de invertebrados bentônicos. O item encontrado com maior freqüência foi Detrito, seguido pelo molusco filtrador Erodona mactroides Bosc, 1802 (Erodonidae). Crustáceos ...

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We evaluated the population dynamics of Acetes americanus Ortmann, 1893 focusing on sex ratio, individual growth, longevity, and the juvenile recruitment period. Samples were collected monthly from January 2006 to June 2007 in the bay of Ubatuba, Brazil. Specimen growth was identified for each gender, and the chosen cohorts were fitted in a von Bertalanffy Growth Model (VBGM); longevity was estimated by the von Bertalanffy inverse equation, considering 99% of the asymptotic length. A total of 6881 individuals (2343 males and 4538 females) were captured. On average the body size (total length) was greater in females (14.64 ± 3.34 mm) than in males (12.27 ± 1.86 mm). The mean growth curves (obtained by grouping the cohorts for each sex), provided estimates of TL ∞ = 19.33 mm, k = 0.02 and t 0 = −0.12 days for females and TL ∞ = 15.13 mm, k = 0.03 and t 0 = −0.07 days for males, where TL ∞ is the asymptotic length, k is coefficient of growth and t 0 is the theorical age when the size is equal to 0. Longevity was estimated at 0.61 years for females and 0.50 years for males. The sex ratio tended to favor females, which corroborates with others studies of sergestids. Our finding that males of A. americanus have higher values of k and therefore achieve a smaller size relative to females has been observed in other penaeids. We concluded that this differential growth pattern between the sexes is found across Dendrobranchiata. The life cycles of penaeids have an average duration of approximately 1-2 years, but our results corroborate other studies that estimate a shorter longevity for Acetes, as species of this genus are typically smaller in size. We found continuous recruitment with two main peaks observed during the study period, corroborating previous studies of Acetes.