Population genetic structuring in pacu (Piaractus mesopotamicus) across the Paraná-Paraguay basin: evidence from microsatellites

The Paraná-Paraguay basin encompasses central western Brazil, northeastern Paraguay, eastern Bolivia and northern Argentina. The Pantanal is a flooded plain with marked dry and rainy seasons that, due to its soil characteristics and low declivity, has a great water holding capacity supporting abundant fish fauna. Piaractus mesopotamicus, or pacu, endemic of the Paraná-Paraguay basin, is a migratory species economically important in fisheries and ecologically as a potential seed disperser. In this paper we employ eight microsatellite loci to assess the population structure of 120 pacu sampled inside and outside the Pantanal of Mato Grosso. Our main objective was to test the null hypothesis of panmixia and to verify if there was a different structuring pattern between the Pantanal were there were no physical barriers to fish movement and the heavily impounded Paraná and Paranapanema rivers. All loci had moderate to high levels of polymorphism, the number of alleles varied from three to 18. The average observed heterozygosity varied from 0.068 to 0.911. After the Bonferroni correction three loci remained significant for deviations from Hardy-Weinberg, and for those the frequency of null alleles was estimated. F ST and R ST pairwise comparisons detected low divergence among sampling sites, and differentiation was significant only between Paranapanema and Cuiabá and Paranapanema and Taquari. No correlation between genetic distance and the natural logarithm of the geographic distance was detected. Results indicate that for conservation purposes and for restoration programs small genetic differences detected in the Cuiabá and Paranapanema rivers should be taken in consideration.

Quantification and source identification of atmospheric particulate polycyclic aromatic hydrocarbons and their dry deposition fluxes at three sites in Salvador Basin, Brazil, impacted by mobile and stationary sources

The present work has aimed to determine the 16 US EPA priority PAH atmospheric particulate matter levels present in three sites around Salvador, Bahia: (i) Lapa bus station, strongly impacted by heavy-duty diesel vehicles; (ii) Aratu harbor, impacted by an intense movement of goods, and (iii) Bananeira village on Maré Island, a non vehicle-influenced site with activities such as handcraft work and fisheries. Results indicated that BbF (0.130-6.85 ng m-3) is the PAH with highest concentration in samples from Aratu harbor and Bananeira and CRY (0.075-6.85 ng m-3) presented higher concentrations at Lapa station. PAH sources from studied sites were mainly of anthropogenic origin such as gasoline-fueled light-duty vehicles and diesel-fueled heavy-duty vehicles, discharges in the port, diesel burning from ships, dust ressuspension, indoor soot from cooking, and coal and wood combustion for energy production.

O uso de praguicidas nas psiculturas e pesqueiros situados na bacia do rio Mogi-Guaçu

The use of pesticides has been the main strategy to prevent ectoparasites that threaten aquaculture productivity. The non regulated use of such chemicals may lead to damage in aquatic ecosystems that receive the ponds effluents, compromising environmental and consumers' health. With the aim of evaluate the use of pesticides in aquacultural practices developed in Mogi-Guacu catchment, fish farm and fee fishing owners were interviewed. Eighty-nine enterprises were visited, and was verified that about 40% uses pesticide during management practices in recent years. The diflubenzuron, methyl parathion, trichlorfon and triflumuron were the pesticides most used. In addition to the interviews, samples were taken in 3 enterprises localized in Socorro, SP (Peixe River sub-catchment) which had a pesticide usage history. It was not detected residues of the pesticides diflubenzuron, methyl parathion and dichlorvos in any water, sediments nor fishes samples from tow distinct seasons (lower and high fishing seasons). On fact, non-detected pesticides residues corroborate with the fish farmers statement to deny recently pesticide usage during management practices. Nevertheless, the lack of chemotherapeutics usage criteria and the potential hazardous due to these practices were discussed.

Caracterização físico-química e de frescor de filés de tilápia do Nilo (Oreochromis niloticus) oriundas da pesca extrativista no médio Rio Tietê/SP, Brasil

For increasing, the fish consumption in Brazil, is necessary offer products, with quality control to guarantee food safety to the consumers. The Medium Tiete river region is the largest producer of Nile tilapia (Oreochromus niloticus) from catching in the Sao Paulo state and, thus, the aim of this research was to evaluate the physical-chemical parameters (protein, moisture, lipid, ash and freshness (non-protein nitrogen, total volatile base nitrogen -TVB-N and pH) in fish fillets - Anhembi, Botucatu and Igaracu do Tiete. The data was examined further using random blocks design and submitted to test of variance analysis and Tukey Test for comparison of means. The data showed significant difference (5%) amont the places, for the centesimal composition and freshness, being found the following medium values: misture (77.9 to 81.69 g/100g), protein (13.72 to 18.25 g/100g), lipids (0.6 to 1.9 g/100g), ash (0.6 to 1.0g), NNP(61.6 to 78.0 mg/100g), pH (6.2 to 6.4) and TVB-N (5.0 to 10.5 mg/100g). The values found in the physical-chemical and freshness analysis are in according with brazilian's legislation, the processing of fish in the places studied are-irregular and cannot guarantee food safety to the consumers and the quality of the product.

Os conhecimentos tradicional e científico do Saco do Arraial, estuário da Lagoa do Patos (RS)

Ethno-sciences study the logical behind the traditional population knowledge about environmental process. This case study aims at describing the ethno-knowledge of artisanal fishermen on the hydrodynamics of the estuary around Coreia community (Saco do Arraial), located in Dos Patos Lagoon, in southern Brazil, from an ethnooceangraphic perspective. For this purpose, mental maps, open-ended and in-depth semi-structured interviewing and participative research have been used. As well as scientific knowledge, rains and winds were had main hydrodynamic effort of Saco do Arraial, although astronomic influence in located hydrodynamic has been just a perception of traditional knowledge. Soon, these data have shown another important way to perceive the Patos Lagoon.

Cultivo da microalga marinha Chaetoceros calcitrans (BACILLARIOPHYCEAE) utilizando diferentes tipos de água marinha artificial

The use of microalgae as live food to a wide variety of organisms is one of the most important aspects in aquaculture. Several commercial formulations have been available in the marine aquarium market in order to prepare artificial sea water (ASW). The present study accounted microalgae Chaetoceros calcitrans performance cultured using different ASW in comparison to natural seawater(NSW). it was carried out using red Sea, Coralife and oceanic, three different ASW brands and NSW as control. nonaerated cultures were grew in 400 mL with Conwy culture medium with five replicates each under defined conditions. All cultures began with an algal inoculum of 208.000 cells/mL. a 5-mL aliquot was removed daily from each culture for cells counts. data obtained using polynomial regression test demonstrated that all ASW brands reached higher algal density rates than the one with NSW, though the three ASW brands were significantly heterogeneous. C. calcitrans raised with oceanic and red Sea brands showed similar growth rates and both were higher than Coralife brand. the results suggest that all three ASW brands studied can be used in the culture of this microalgae specie.

Estrutura populacional do camarão-branco Litopenaeus schmitti nas regiões estuarina e marinha da baixada santista, São Paulo, Brasil

The white-shrimp Litopenaeus schmitti distributes in West Atlantic Ocean, occurring along all Brazilian cost. Population structure in the Baixada Santista region was identified from samples obtained from artisanal and industrial fishery between June of 2005 and May of 2006. A total of 2.912 specimens were collected, being 2.138 females (1.008 in the estuary and 1.130 in the marine region) and 774 males ( 334 in the estuary and 440 in the marine region). Environmental parameters were annotated together the sampling, allowing to identify that water temperature influences directly the catches. Catches variations, length composition of samples by sex and gonadal maturation of females allowed to identify that: (i) estuary is used as a nursery area by individuals with small lengths, most young; (ii) marine region is used by larger individuals ( adults) and the spawning period extend from June to February, mainly between November and January. It was verified that estuarine fishery ( artisanal) focuses immature and in development individuals, with small lengths and, the marine fishery ( industrial) focuses adults during the whole year and, only in the summer, youngling from spawn. The length of first gonadal maturation of females was estimated in 15,8mm. These results and diagnoses must be considered in the management of L. schmitti fishery in Baixada Santista region.

Traceability system in cod fishing

The objective of this research was to examine how various factors in Icelandic cod fishing can influence the quality of the raw material, using traceability systems to link these factors, and how transfer that knowledge and techniques to the Brazilian seafood industry. Data were collected in 2007 and analysed, to find a functional relationship between various quality factors. The analysis, showed, that there is a correlation between the number of parasites in the fillets and location of the fishing ground. It also showed that fishing ground and volume in haul can influence gaping, and that fillet yield differs between fishing grounds. These conclusions could only be drawn because of the ability to trace the fish from catch and all the way through processing. Recommendations drawn from this research to the Brazilian Competent Authority are to revise the countries fisheries legislation in order to enable the implementation of a traceability system that could be used as a tool to improve the quality of the raw material. (C) 2010 Elsevier Ltd. All rights reserved.

A new flat mite (Acari: Prostigmata: Tenuipalpidae) from date palm in the Sultanate of Oman

Tenuipalpus omani n. sp. (Acari: Tenuipalpidae) is described from the Sultanate of Oman, based on adults of both sexes collected on date palm, Phoenix dactylifera L. (Arecaceae). This new species is most similar to T. eriophyoides Baker, T. pareriophyoides Meyer & Gerson and T. yarensis Hasan, Bashir & Wakil, also collected from date palm.

Growth performance and body composition of pacu Piaractus mesopotamicus (Holmberg 1887) in response to dietary protein and energy levels

Improper dietary protein and energy levels and their ratio will lead to increased fish production cost. This work evaluated effects of dietary protein : energy ratio on growth and body composition of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5 +/- 0.4 g) were fed twice a day for 10 weeks until apparent satiation with diets containing 220, 260, 300, 340 or 380 g kg-1 crude protein (CP) and 10.9, 11.7, 12.6, 13.4 or 14.2 MJ kg-1 digestible energy (DE) in a totally randomized experimental design, 5 x 5 factorial scheme (n = 3). Weight gain, specific growth rate increased and feed conversion ratio (FCR) decreased significantly (P < 0.05) when CP increased from 220 to 271, 268 and 281 g kg-1 respectively. Pacu was able to adjust feed consumption in a wide range of dietary DE concentration. Fish fed 260 CP diets showed best (P < 0.05) protein efficiency ratio and FCR with 11.7-12.6 MJ kg-1; but for the 380 CP-diets group, significant differences were observed only at 14.2 MJ kg-1 dietary energy level, suggesting that pacu favours protein as energy source. DE was the chief influence on whole body chemical composition. Minimum dietary protein requirement of pacu is 270 g kg-1, with an optimum CP : DE of 22.2 g MJ-1.

Dietary Levamisole Influenced Hematological Parameters of Juvenile Pacu, Piaractus mesopotamicus (Holmberg 1887)

Diseases outbreaks are a major concern in intensive fish farming because fish are exposed to stressors which may negatively affect their physiology. This study set out to determine effects of dietary levamisole (Levamisole HCl; SIGMA (R)) on performance and hematology of pacu, Piaractus mesopotamicus, juveniles. Fish (55.94 g) were stocked into 24 plastic aquaria (500 L; 15 fish per aquarium) and fed for 30 d with a commercial diet with 0, 50, 100, 200, 400, and 800 mg/kg levamisole, and for an extra 15 d, with a control diet in a totally randomized design trial (n = 4). Biometrical and hematological data were collected. No significant differences in growth parameters were recorded for either control or supplemented diets. Hematological parameters, such as hemoglobin, plasma glucose, white blood count (WBC), and differential leukocyte count were influenced (P < 0.05) levamisole. WBC, lymphocytes, neutrophils, monocytes, eosinophils, and special granulocytic cell numbers decreased significantly after 15 d. Dietary levamisole at 100 mg/kg diet for 15 d increased leukocyte production in juvenile pacu. However, levamisole administration for more than 15 d presented toxicity to lymphopoietic tissues. Information about long-period administration, mode of action in weight gain, effects on hematology of levamisole in freshwater fish nutrition are scarce and necessary for its safe use in aquaculture.

Dietary lysine requirement of juvenile pacu Piaractus mesopotamicus (Holmberg, 1887)

Lysine is the reference essential amino acid in fish feeds and usually the most limiting amino acid in feedstuffs. The dietary lysine requirement of juvenile pacu Piaractus mesopotamicus (4.3 g) was determined using five isonitrogenous (32% CP) test diets containing graded levels of lysine (0.9, 1.17, 1.44, 1.69 and 1.96% of dry diet) fed three times a day to four groups of 18 fish for 74 days. Growth, body composition, nutrient retention and hematological parameters of pacu were analyzed. Analysis of variance showed that all growth performance parameters were significantly affected by dietary treatments. The lysine requirements estimated using regression analysis for maximum weight gain and feed efficiency were 1.45 and 1.51% of dry diet, respectively. Nitrogen retention efficiency increased with increasing levels of dietary lysine up to 1.43% (p<0.05). Whole-body protein increased (p<0.05) and whole-body lipid decreased (p<0.05) with increasing dietary lysine level. Thus, the lysine requirement of juvenile pacu was estimated as being 1.4-1.5% of dry diet or 4.4-4.7% of dietary protein. (c) 2009 Elsevier B.V. All rights reserved.

Intestinal morphology and histology of the striped catfish Pseudoplatystoma fasciatum (Linnaeus, 1766) fed dry diets

This study unveils histological features of the intestinal tract of juvenile striped catfish Pseudoplatystoma fasciatum (Linnaeus, 1776) in three size classes (weight, standard length): I - 36.84 +/- 10.19 g, 14.52 +/- 1.54 cm; II - 59.03 +/- 11.47 g, 17.17 +/- 1.06 cm; III - 89.72 +/- 18.70 g, 20.79 +/- 1.55 cm, respectively. Histological organization of the juvenile speckled catfish intestine bears features common to the carnivorous fish, but the organ presents some convolutions that indicate a certain degree of dietary flexibility, a surprising trend, common only to omnivorous Siluriforms. The architecture of the mucosa of the speckled catfish intestine indicates that the species concentrates digestion and absorption of nutrients in the medium intestine, a common feature among carnivorous Teleosts.

Estimating Amino Acid Requirement of Brazilian Freshwater Fish from Muscle Amino Acid Profile

Information on nutritional requirement of some Brazilian farmed fish species, especially essential amino acids (EAA) requirements, is scarce. The estimation of amino acids requirements based on amino acid composition of fish is a fast and reliable alternative. Matrinxa, Brycon amazonicus, and curimbata, Prochilodus lineatus, are two important Brazilian fish with potential for aquaculture. The objective of the present study was to estimate amino acid requirements of these species and analyze similarities among amino acid composition of different fish species by cluster analysis. To estimate amino acid requirement, the following formula was used: amino acid requirement = [(amount of an individual amino acid in fish muscle tissue) x (average totalEAA requirement among channel catfish, Ictalurus punctatus, Nile tilapia, Oreochromis niloticus, and common carp, Cyprinus carpio)]/(average fish muscle totalEAA). Most values found lie within the range of requirements determined for other omnivorous fish species, in exception of leucine requirement estimated for both species, and arginine requirement estimated for matrinxa alone. Rather than writing off the need for regular dose-response assays under the ideal protein concept to determine EAA requirements of curimbata and matrinxa, results set solid base for the study of tropical species dietary amino acids requirements.

Apparent digestibility coefficients of selected feed ingredients for dourado Salminus brasiliensis

The excellence of its flesh and fast growth makes the dourado, Salminus brasiliensis, a carnivorous fish native to the Prata basin, a potential candidate for intensive fish farming. This study evaluated the apparent digestibility coefficients (ADC) of energy and nutrients of animal and plant protein sources for the carnivorous Characin dourado S. brasiliensis. Fish (19.5 +/- 5.0 g) were stocked in plastic cages (80-L) and fed pelleted test diets containing 30% of the test ingredient [fish meal (FM), poultry by-product meal (PBM), soybean meal (SBM), and corn gluten meal (CGM) plus 70% of a reference diet (481.4 g kg(-1) of crude protein and 18.63 kJ of gross energy per gram]. After the last daily meal, cages were transferred to cylindrical, conical-bottomed aquarium (200-L) where faeces were collected by sedimentation in a refrigerated container. Except for ADC of protein and energy, all other ADC of nutrients showed significant differences (P < 0.01). ADC values were: 94.3%, 91.3%, 93.1%, and 93.5% for crude protein; 91.0%, 90.3%, 87.8%, and 88.8% for gross energy; 92.1%, 84.5%, 80.6%, and 79.3% for ash; 83.9%, 80.3%, 84.3%, and 84.6% for dry matter; 97.4%, 96.7%, 93.3%, and 91.5% for lipid for FM, PBM, SBM, and CGM, respectively. The average amino acid ADC was: 93.6%, 90.0%, 92.1%, and 92.5% of FM, PBM, SBM, and CGM, respectively. All test ingredients were efficiently used and can partially replace FM in diets for carnivorous dourado.