Cytogenotoxicity biomarkers in fat snook Centropomus parallelus from Cananeia and Sao Vicente estuaries, SP, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Size-related shifts in dietary composition of Centropomus parallelus (Perciformes: Centropomidae) in an estuarine ecosystem of the southeastern coast of Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of seasonality and pollution on the hematological parameters of the estuarine fish Centropomus parallelus

This study investigated the hematological parameters of the tropical estuarine fish Centropomus parallelus and their use as a non-destructive biomarker for aquatic pollution. Individuals were collected, in summer and winter, at two estuaries, Cananéia (CAN) and São Vicente (SVE), and blood was extracted by caudal puncture. The evaluated parameters were hematocrit (Ht), red blood cells (RBC), Mean Corpuscular Volume (MCV), and the leukocyte (WBC) and thrombocyte counts. Fishes from CAN showed higher values of absolute number of thrombocytes in the summer. The fishes from SVE presented lower values of Ht and MCV in winter. Comparing the hematological parameters of fishes from these two sites, Ht, MCV, WBC and RBC were higher in fishes from SVE in the summer, whereas during the winter, Ht and thrombocytes were higher in animals from SVE. The results allow attributing the changes in the blood of fishes to seasonality and the presence of contaminants.

Lipidic and proteic absorption in digestive tract of tropical fat snook (Centropomus parallelus, POEY 1860)

The tropical fat snook Centropomus parallelus is a species of recognized ecological importance and with a high economical potential for fisheries and aquaculture. The investigations of digestive tube morphology in association with their feeding abilities are fundamental to improve techniques for aquaculture feeding procedures. Sudan black staining and Perl`s method were used to evaluate their absorption capacity of fat and protein respectively. The Sudan black stain was performed 12 h after the ingestion of lipids. The lipids are intensely absorbed in the ceca epithelium and less intensely in the intestine and rectum. The Perl`s method was performed 12 h after the ingestion of ferritin. The proteins are absorbed only in the rectum. This is the first description of fat and protein absorption ability by the digestive tube of fat snook. These data enhance the possibility of the addition of macromolecules in rations that can show a diversity of physiological effects. The histological implications of each segment of the digestive tube in association with fish biology are further discussed. (C) 2010 Elsevier B.V. All rights reserved.

Hematological parameters and phagocytic activity in fat snook (Centropomus parallelus) bred in captivity

The objective of this work was to determine the hematological parameters and the phagocytic capacity of peritoneal macrophages of fat snook related to sex, stage of gonadal maturation and seasonal cycle. Blood was collected from 135 animals (78 females and 57 males) and used for determinations of: erythrocyte number, hematocrit, hemoglobin, erythrocyte indices mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC), total and differential leukocyte counts, and thrombocyte count. The phagocytic capacity and phagocytic index were determined after Saccharomyces cerevisiae inoculation in the peritoneal cavity of the animals. The hematological results according to sex showed that the erythrocyte, total leukocyte and thrombocyte counts were statistically higher in males than females, with the latter showing a higher MCV. Concerning to erythrocyte count, hematocrit and hemoglobin concentration analyzed separately by sex and stage of gonadal maturation, males were found to have significantly elevated values in the mature stage and decreased levels in the resting stage. The results of the erythrocyte and leukocyte series, thrombocytes and phagocytic activity related to seasonal cycle showed significant differences in both sexes, where hematocrit and hemoglobin concentration were lower in winter and higher in the other seasons, mean corpuscular volume was higher in the summer and lower in the winter and fall, total leukocytes and thrombocytes lower in the spring and higher in the fall, lymphocytes low in the winter and summer and high in the spring and phagocytic capacity and phagocytic index high in the summer and low in the winter and fall. The results showed that the hematological values in males are statistically higher than those in females, the erythrocyte values in males increase with the progression of gonadal maturation and that winter is the season of the year least favorable for hematological and phagocytic responses for survival of fat snook kept in captivity. The parameters studied could be utilized in the evaluation of the health status of this species in captivity. (C) 2012 Elsevier Ltd. All rights reserved.

Cytogenotoxicity biomarkers in fat snook Centropomus parallelus from Cananeia and Sao Vicente estuaries, SP, Brazil

The aquatic environment receives many contaminants that can induce damages at the molecular, biochemical, cellular and physiological levels. Centropomus parallelus, an important food resource for local populations, is a predator fish that feeds on small fishes and benthic invertebrates, thus being vulnerable to the bioconcentration and biomagnification processes. This study aimed to evaluate cytogenotoxic responses in erythrocytes from C. parallelus juveniles collected in the Cananeia and Sao Vicente estuaries, both in winter and in summer. After anesthesia, blood samples were collected by caudal puncture. Blood smears were prepared on glass slides and stained with May-Grunwald-Giemsa dye. Two thousand cells were analyzed per slide (1000x), and nuclear abnormalities (NA) and micronuclei (MN) were scored. The Sao Vicente sample showed MN and NA frequencies (%/1000 cells) of 0.325 and 3.575, in winter, and of 0.125 and 2.935 in summer respectively; the Cananeia sample showed frequencies of 0.0325 and 0.03, in winter, and of 0.065 and 0.355 in summer, respectively. The rates found in Sao Vicente were significantly higher than those found in Cananeia, evidencing that the levels of pollution in that estuary were high enough to induce genetic damages.

Size-related shifts in dietary composition of Centropomus parallelus (Perciformes: Centropomidae) in an estuarine ecosystem of the southeastern coast of Brazil

Size-related and seasonal evaluation of the dietary composition of fat snook (Centropomus parallelus Poey 1860) in the upper sector of an estuary of the southeastern coast of Brazil were carried out based on stomach analyses of specimens ranging from 40 to 170 mm standard length. Results reveal that C. parallelus is a carnivorous species feeding mainly on benthic crustaceans. Relatively high stomach replenishment suggests that this environment is an important feeding ground for fat snook juveniles. Multivariate analyses indicated that predator size effect is significantly more important than seasonal variation in determining dietary composition. Predator length was associated with increased consumption of palaemonid shrimps (Macrobrachium spp.) and grapsid crabs, and decreased foraging on tanaids (Kalliapseudes schubarti), thus showing a preference shift from smaller to larger prey. Predator length was also positively associated with an increase in the stomach repletion index. Additionally, allometric growth of both gape and head were consistently correlated with this ontogenetic dietary transition, suggesting that such changes might be related to an individual's ability to capture and consume larger, more elusive prey. The digestive tube is short and grows isometrically, which is in accordance with the carnivorous habit of this estuarine fish and its maintenance through ontogeny.

Recreational anglers and fishing guides from an estuarine protected area in southeastern Brazil: Socioeconomic characteristics and views on fisheries management

The Iguape and Cananéia Lagoon-Estuarine Complex is a biodiversity hotspot in southeastern Brazil. In recent decades, the region has become an important destination for recreational fishing. The objective of this study was to analyze the socioeconomic characteristics of visiting anglers and fishing guides working in the Cananéia-Iguape-Peruíbe Environmental Protected Area and their views on fisheries management. Data were collected through semi-structured interviews conducted between January 2009 and January 2010. We interviewed 278 anglers, who were predominantly male (93%) with a mean age of 47 years and from the state of São Paulo. The targeted species were snooks (Centropomus undecimales and Centropomus parallelus) and weakfishes (Cynoscion leiarchus and Cynoscion acoupa). Only half the anglers had the mandatory fishing license, and many of them lacked knowledge about catch quotas and minimum size requirements for specific species. The fishing guides (n = 80) were all male, with a mean age of 39 years and extensive experience. Most of the guides believe that the study area is somewhat degraded due to the removal of riparian vegetation, siltation, pollution, and especially the depletion of fish stocks. The opinions of the stakeholders (anglers and guides) converge on the high priority needs of the fishery and possible management actions regarding recreational fishing, such as improved fisheries enforcement (first in order of importance), proper training of fishing guides, zoning of fishing areas, and the definition of a maximum size limit. © 2013 Elsevier Ltd.

Caracterização morfológica e bioquímica do sistema digestório e identificação por isótopos estáveis de robalo peva e flexa selvagens e de cativeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Validação de espécies de Centropomus (Centropomidae, Perciformes) do litoral do Rio Grande do Norte através de caracterização citogenética e molecular

The Centropomidae family consists of three genera, Centropomus, Lates and Psammoperca. Centropomus is the most diverse group, with six Centropomus species occur in the Western Atlantic Ocean C. poeyi Chávez, 1961, C. parallelus Poey, 1860, C. mexicanus Bocourt, 1868, C. pectinatus Poey, 1860 and C. ensiferus Poey, 1860. Some of these species are considered cryptic, because of its morphological traits showed low resolution for identification purposes. Despite showing great interest as a natural resource and fish culture, aspects of their diversity and karyotypic patterns are poorly understood. In this work morphological identification and comparison of mitochondrial 16S gene sequence were used to identify the species of the genus Centropomus occurring in Rio Grande do Norte, northeastern Brazil. Two sepecies were identified, C. undecimalis and C. mexicanus, which had the chromosomal aspects analyzed, through Classical cytogenetic method analyzes (conventional staining, C-banding, Ag-NORs), fluorochrome staining AT- and GC-specific, replication bands by incorporating of the base analog 5-Bromo-2’-deoxyuridine (5-BrdU), in situ chromosomal mapping of (TTAGGG)n sequences and in situ chromosome mapping 18S and 5S rRNA genes. Both species show 2n=48 acrocentric chromosomes, with ribosomal sites (Ag-NOR/18S rDNA/ Mitramycin+) in second chromosomal pair, in telomeric position on the long arm in C. mexicanus and interstitial in C. undecimalis. The nuclear organization pair (pair 2) shown a resolutive cytotaxonomic marker for these two species. The generated data reveal a lower species diversity than previously believed, suggesting that greater attention should be paid in taxonomic identification of the species, in view of optimize commercial actions exploitation, biological conservation and cultivation.