This study aimed to describe the gonadal histology and the reproductive cycle of Crassostrea brasiliana in the mangroves of Guaratuba Bay in southern Brazil. Adults were collected monthly from January 2010 to April 2011 from three sampling sites in intertidal oyster beds. The animals were evaluated using biometric and histological analyses of the gonads. The gonadal tissue samples were processed according to the standard histological procedures, and permanent slides were prepared using Harris' haematoxylin and eosin. The oysters were identified at the species level using a molecular protocol. Females (69%) predominated over males (26%), with 4% indeterminate and 1% hermaphroditic. Mature females were more prevalent in February, March and December 2010 and in March 2011. Mature males were more prevalent in February and April 2010 and in March 2011. The presence of hermaphroditic individuals was sporadic, and oysters in immature stages or sexual repose were observed in only a few collections between the months of May and October 2010. The reproduction of C. brasiliana in Guaratuba Bay occurs intermittently, but with greater intensity during the summer, with a larger number of females produced.

Ucides cordatus is a species of considerable ecological and socioeconomic importance. The goal of this study is to contribute to the understanding of the reproduction biology of this species by describing the macroscopic anatomy, the histology of the female reproductive system and the reproductive cycle of U. cordatus. A total of 367 females were obtained from October of 2002 to March of 2005 during monthly collections in the Baía de Antonina, Paraná, Brazil. Specimens were submitted to necropsy and their reproductive systems (ovary and spermathecae) were analysed histologically. Permanent slides were stained with Harris' hematoxylin and eosin, Mallory's trichromic and the periodic acid‐Schiff reaction. Ovarian analysis allowed for the determination of five developmental stages based on the prevalence of oocytes in different phases of vitellogenesis. During stage V, when ovaries recover from spawning, the presence of oocytes in advanced stages of vitellogenesis was detected, suggesting that there could be more than one spawning in a single reproductive period. Females in stage IV were most common in the spring (November through February), whereas females with their egg mass exposed were most frequent from November through March. The reproductive period of U. cordatus in mangroves of the study region occurred from October to March. The reproductive events observed in the present study suggest that spermatophores acquired during copulation, which takes place during the ‘andada’, are only used in the reproductive period of the following year.

R RE ES SU UM MO OPertencente a Ocypodidae, o caranguejo-uçá, Ucides cordatus, é uma espécie endêmica da costa atlântica do Continente Americano. Possui grande importância econômica, principalmente para populações de baixo poder aquisitivo, que dependem de sua captura como fonte de renda e alimento. U. cordatus é considerado um dos componentes biológicos mais importantes do ecossistema dos manguezais por seu papel na ciclagem de matéria orgânica. Possivelmente, em virtude do intenso esforço de captura somado à destruição de seus habitats -os manguezais -e a uma enfermidade específica (Doença do Caranguejo Letárgico), têm-se observado uma tendência de redução dos estoques pesqueiros de caranguejo-uçá no litoral brasileiro. Porém, a despeito de sua importância cultural, ecológica e sócio-econômica, o número de pesquisas científicas desenvolvidas com a espécie ainda é limitado. O objetivo deste trabalho foi identificar e apresentar os principais estudos publicados sobre a espécie até o ano de 2007. Palavras-chave: crustáceo; Ocypodidae; Brachyura; caranguejo; manguezal. A AB BS ST TR RA AC CT TA member of Ocypodidae, the mangrove land crab, Ucides cordatus, is endemic to the Atlantic Coast of the Americas. It has considerable economic value mainly to underpriviledged communities, which depend on it as a source of income and food. U. cordatus is considered as one of the most important biological components of mangrove ecosystems, particularly due to its role in the cycling of organic matter. Possibly as a consequence of the intense harvesting, the destruction of its habitats -the mangrovesand disease, there has been a decrease in the fishery stocks of the mangrove crab throughout the Brazilian coast. However, in spite of the cultural, ecological, and socioeconomic importance of the species, the number of scientific studies on the mangrove land crab is still limited. The aim of the present study is to identify and relat the main studies published on the species until 2007.

Among oysters, species of Crassostrea (Sacco, 1897) are the most attractive to aquaculture. In Brazil, the genus is represented by C. rhizophorae (Guilding, 1828) and C. brasiliana (Lamarck, 1819). Because the maturation and breeding technology is not well developed for these species, aquaculturists need a reliable method to decide the correct time to place spat collectors in the field, and to identify both species, which are morphologically similar. In this study a specific Multiplex PCR protocol was developed, using one pair of universal primers from 18S rDNA as a positive control and a pair of specific primers for each target species. The sensitivity and specificity of the protocol was evaluated. It detected C. rhizophorae DNA in low concentrations, and C. brasiliana DNA in even lower concentrations. Further, the Multiplex PCR proved efficient in detecting DNA in concentrations equivalent to that of a single larva of each species, either separated or combined, when mixed with total DNA extract of a plankton sample representing 1000 L of filtered water. Field tests confirmed the applicability of the protocol, which holds the promise to become an important tool for aquaculture or conservation programs, allowing for the continuous monitoring of the life cycle of C. brasiliana and C. rhizophorae, by detecting the right periods of larval release and settlement

Water salinity is among the most important factors influencing the distribution, abundance, growth, and survival of Crassostrea gasar, an important aquaculture resource grown in estuarine environments in diverse regions of the world. The goal of the present work was to evaluate the effects of different salinities on survival and the tissues of C. gasar under laboratory conditions. Two experiments were performed using adult oysters from five marine farms located in the bay of Guaratuba, Brazil. In Experiment 1, the daily survival rates were evaluated after the oysters were submitted to gradual acclimatization at salinities ranging from 0 to 65 gL -1 and maintained in the laboratory without feeding for up to 365 days. In Experiment 2, the oysters were exposed to salinity from 0 to 50 gL -1 for up to 30 days without feeding and possible histological alterations caused by salinity were assessed. Three tolerance ranges of C. gasar to salinity were identified: "Optimal" (between 4 and 40 gL -1 ), "Tolerable" (between 2.1 and 3.9 and between 41 and 50 gL -1 ) and "Intolerable" (less than 2 and greater than 50 gL -1 ). No evidence of histological alterations was observed in oysters exposed to the different salinities.