This study aimed to analyze the carcino-bycatch of seabob shrimp (Xiphopenaeus kroyeri) in Macaé/RJ, a region influenced by the Cabo Frio upwelling. Samples were collected monthly with a shrimp fishing boat, from July/2010 to June/2011. The carcino-group bycatch was represented by 15 families, 24 genera and 30 species. The families with the highest number of species were Portunidae (7) and Penaeidae (5), representing 23.33% and 16.66% of the total catch, respectively. For each seabob shrimp captured, 2.94 bycatch individuals were caught on average, with the largest discrepant values in summer (1: 4.82) and autumn (1: 5.76). The main components of this carcinofauna (Artemesia longinaris and Pleoticus muelleri) are species with increasing importance as a fishery resource in the region due to their abundance, and need to be continuously studied over diverse aspects of population biology, aiming to improve conservation actions.

A B S T R A C TLuciferid shrimps have short life spans and a rapid turnover of generations, engage in sequential spawning, and protect their eggs during incubation. This study investigates the ecology of Lucifer faxoni in the littoral zone, Ubatuba region, São Paulo. Sampling was conducted monthly from July 2005 to December 2006 using a Renfro net trawled over a distance of 50 m for a total sampling effort of 50 m² at each station. Nine stations were sampled, ranging from 1 to 15 m deep. Three stations each were grouped into zones 1, 2 and 3 (Z1, Z2 and Z3). Monthly values of salinity, temperature and rainfall were recorded at each station. The pre-buccal somite length (SL) of each specimen was measured. The results showed that in shallower zones (Z1 and Z2), 6306 individuals were captured, whereas in the deeper zone (Z3), 3808 specimens were captured, but no significant differences in SL was detected between the specimens from Z1 and Z2 and those from Z3 (ANOVA, p=0.25). The abundance of shrimps did not differ significantly between seasons (Tukey's test, p=0.02) except in the spring. The sex ratio differed significantly over the seasons (χ², p<0.05). The results were closely associated with environmental factors with respect to the spatial and seasonal distribution of L. faxoni. Rainfall affected salinity directly, and contributed to the displacement of these shrimps to deeper areas. R E S U M OEste estudo analisa a ecologia de Lucifer faxoni Borradaile, 1915 em Ubatuba, São Paulo. Os indivíduos foram coletados mensalmente de julho de 2005 a dezembro de 2006, com uma rede de Renfro, arrastada por uma distância de 50 m, totalizando um esforço amostral de 50 m² em cada ponto de coleta. Nove pontos foram amostrados, variando de 1 a 15 m de profundidade. Cada 3 pontos foram agrupados em 3 zonas (Z1, Z2 e Z3). Os valores de salinidade, temperatura e pluviosidade foram registrados mensalmente em cada transecto. Os espécimes foram medidos quanto ao comprimento do somito pré-bucal (SL). Os resultados mostram que nas zonas mais rasas (Z1 e Z2) foram coletados 6306 indivíduos, enquanto que na mais profunda (Z3) obteve-se 3808 espécimes, não havendo diferença estatística entre as zonas (ANOVA, p=0.25). A abundância não diferiu estatisticamente entre as estações do ano (Tukey, p=0.02), exceto para a primavera. Em todas as estações amostradas, o sex ratio diferiu estatisticamente (χ², p< 0.05). Os fatores ambientais aqui analisados apresentaram relação estreita com a distribuição espaço-temporal de L. faxoni. A pluviosidade influenciou diretamente a salinidade, que provocou o deslocamento dos camarões L. faxoni para áreas mais profundas.

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The taxonomic status of the sergestid shrimp, Acetes americanus, has been questioned for several decades. No specific study has been performed thus far to resolve the incongruences. This species has a wide geographical range in the western Atlantic and is represented by two formally accepted subspecies: Acetes americanus carolinae, distributed in North America, and Acetes americanus americanus, present in South America. However, there are regions where the coexistence of both subspecies has been reported, such as Central America. This study aimed to genetically compare specimens of A. a. americanus collected in South America with A. a. carolinae sampled in North America to check for possible differences and the existence of more than one subspecies of A. americanus on the Brazilian coast. Based on the sequences of two informative markers, the cytochrome oxidase I region (COI) and 16S rRNA, phylogenetic reconstruction demonstrated well-defined clades with high support values, reinforcing the idea that A. a. americanus is genetically different from A. a. carolinae. Our hypothesis was corroborated as the specimens collected in Brazil were divided into two distinct lineages: the first composed of A. a. americanus sensu stricto (Brazil 1) and the second by Acetes americanus (Brazil 2). The three groups evidenced in the haplotype network were the same as those observed in the phylogenetic tree. The morphometric character (height/length of the thelycum) was effective in distinguishing A. a. Brazil 1 from A. a. carolinae. However, more detailed and conclusive studies comprising other characteristics to propose and describe a possible new entity are necessary. To the best of our knowledge, for the first time, the results of this study provide some insights into the taxonomic status of the sergestid shrimp A. americanus in the western Atlantic.