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The shorthead drum Larimus breviceps has an important role in the subsistence of local communities. However, studies addressing the trophic ecology of this species are still scarce. Here we present further information on the trophic ecology and ecomorphology of L. breviceps, including dietary analyses, carbon and nitrogen stable isotopes compositions (δ13C and δ15N), and morphometric measurements on a seasonal basis. Specimens were captured in the Northeastern Brazil from February to November 2017 by the local artisanal shrimp fisheries. A total of 46 individuals (27 juveniles and 19 adults) were randomly subsampled for ecomorphological analysis. Significant differences in the ecological attributes between ontogeny were found for peduncle and body flatness indexes. A total of 479 stomachs of L. breviceps were analyzed. The fish total length ranged from 6.3 to 19.2 cm. Nine prey categories were defined for L. breviceps. Sergestidae shrimps were the main prey. The diet composition from the multivariate technique of non-metric multidimensional scaling ordination displayed a different pattern for juveniles and adults. A subsample of 40 individuals (dry season = 20; rainy season = 20) were selected for stable isotope analysis. Mean values of δ13C and δ15N were different by size in the dry season. This information improves the general knowledge and ecological data on bycatch species, as well as may give support to management initiatives, potentially associated to trophic models, or may be considered into the design of Bycatch Reduction Devices (BRD), taking into account the current paradigm of the Ecosystemic Approach to Fishery (EFA).

Mycteroperca bonaci (black grouper) is one of the most sought species of grouper along its entire distribution, being a prime target for demersal line fisheries because of its high commercial value. Nonetheless, because of population declines the species is considered near threatened according to the IUCN red list. The present study aimed to determine the population parameters of M. bonaci, including growth, reproduction and mortality, and thus contributes to measures towards its conservation and management in the southwestern Atlantic. The sampling area is in the North Brazil Shelf, off Maranhão State, an area of intense fisheries development and yet poorly known. The large continental shelf harbours unique coral reef formations and has been declared an ecologically or biologically significant marine area (EBSA). Sampling on landing sites was carried out monthly between May 2017 and January 2019. A total of 137 black grouper specimens were sampled from commercial landings of artisanal fisheries. The size of the specimens ranged from 44 to 157 cm, and the weight varied from 0.976 to 54 kg. The length-weight was established: log(TW) = -11.26 + 3.01log(TL). Histological analysis of the gonads confirmed only the presence of female individuals, and the occurrence of individuals in the sexual transition was not recorded. Higher GSI values and higher frequency of spawning capable staged individuals occurred during the months of June to August, indicating spawning peaks. The estimated age of sexual maturity A50 for females was 4.62 years (

Tilapia culture presents high potential for income generation and hunger alleviation in developing countries. Suitable culture planning can help achieve such goals sustainably. This work aimed to comparatively evaluate the influence of semi-intensive and intensive cultivation systems of O. niloticus on condition factor, its derivatives and established growth models (Von Bertalanffy - VBGF, sigmoid Logistic - SLogistic, Brody and Gompertz) as well as on two proposed models (Michaelis-Menten hyperbolic growth – MMHG and hyperbolic Logistic - HLogistic). A linear estimation of VBGF parameters was also proposed. Weight-length relationships of tilapia were not significantly altered by the systems. Relative weights from the present study were higher in 9 out of 14 comparisons with tilapia from other natural environments and cultivations. Condition factor (K), Kmean, Krel and relative weight (Wrm) proved to be useful tools when assessing growth. In size-at-age analyzes (total length), VBGF and MMHG were the best models for intensive system whereas Gompertz and VBGF were selected for semi-intensive. Although length-at-age analyzes did not show significant differences between the systems and the growth indexes (o and P) were slightly higher in cages than in ponds, the comparison between VBGF and Gompertz (best models for weight datasets) - connected to the condition factor investigation and to the importance of natural food - suggested that semi-intensive system specimens would reach commercial size earlier based on weight in the present conditions. The adoption of MMHG model when indicated suggests a wide field of research that could allow making inferences expanding the amplitude of growth studies.

O objetivo do presente estudo foi estimar os primeiros parí­¢metros de crescimento e mortalidade de Biquara Haemulon plumierii no estado de Pernambuco, Brasil. Os otólitos sagittae foram coletados mensalmente de maio de 2013 a abril de 2014 a partir de desembarques da pesca comercial ao longo da costa de Pernambuco. O total de 333 indiví­­duos medindo 10,5 a 32,2 cm foram capturados. As distribuições de frequência de comprimento foram diferentes entre as áreas. Consequentemente, as relações peso-comprimento foram diferentes entre as áreas, bem como os parí­¢metros de von Bertalanffy. A relação peso-comprimento indicou crescimento alométrico negativo. Portanto, a equação de von Bertalanffy para sexos agrupados foi TLt = 31.1[1-e-0.1 (t +4.57)]. A idade máxima observada foi 21 anos e a mortalidade total foi 0,21 ano-1. As análises conduzidas indicam uma espécie com ciclo de vida longa e crescimento lento. Pequenos peixes recifais de pouca movimentação, como a biquara, são susceptí­­veis ao esforço pesqueiro, fatores ambientais e degradação, que afetam o crescimento e a mortalidade. Portanto, sugerimos uma avaliação do status atual do estoque.