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São Paulo, Brazil

Dias D.C.,Aquaculture Center | Leonardo A.F.G.,Polo Regional Vale do Ribeira APTA | Tachibana L.,Fishery Institute APTA SAA | Correa C.F.,Polo Regional Vale do Ribeira APTA | And 3 more authors.
Journal of Applied Ichthyology | Year: 2012

Summary: The aim of the present study was to evaluate the influence of probiotics prepared from Bacillus subtilis (strain C-3102-Calsporin ®; Calpis, Tokyo, Japan) as a dietary supplement on several reproductive aspects of female 'matrinxã'(Brycon amazonicus), including hematological parameters, immunological characteristics and total lipid concentrations in muscle and liver tissue. The broodstock were kept in two ponds of 600m 2, at a density of 50 fish per pond, from March to November 2008. The fish were divided into two treatment groups: untreated control fish (T1), and fish fed with 10g of probiotics per kg of ration (T2). Fish were fed a diet containing 32% crude protein (CP), 7% crude fat (CF), and 6.5% ether extract (EE) twice daily at a rate of 1% of the total biomass per day during the coldest months (May through August) and 3% during the warm season (March, April and September through November). During the reproductive period, 20 individuals from each treatment group were selected for the experiments; two doses of crude carp pituitary extract were given to females in 10-h intervals, and one dose was given to the males at the same time the females were given the second dose. A total of 20 fish were used for the hematological analyses. After anesthetization, blood samples were withdrawn by caudal puncture to determine the total number of cells, differential and total leukocyte counts, thrombocyte count, hematocrit, hemoglobin rate and plasma cortisol and glucose levels. The hematimetric index mean corpuscular volume (VCM) and mean corpuscular hemoglobin concentration (MHCM) were calculated. Ten other 'matrinxãs' from the same groups were used to assess macrophage phagocytic activity and lipid levels. The results showed that females fed a probiotics-supplemented diet exhibited an increase in numbers of oocytes and, consequently, had higher rates of fertilization and hatching of larvae. Probiotic-treated fish also exhibited a significant increase in the phagocytic activity of macrophages, indicating an improvement in the immune system of breeders. Hematologic parameters were different in comparison to the time-zero group, and plasma cortisol and glucose levels were higher in the females. The total lipids levels in muscle and liver tissue were lower in B. amazonicus that received feed supplemented with probiotics. © 2011 Blackwell Verlag, Berlin. Source

Ibrahim F.S.,Aquaculture Center | Goddard J.S.,Sultan Qaboos University | Ambu Ali A.,Sultan Qaboos University | Rana K.J.,University of Stirling | Rana K.J.,Stellenbosch University
Journal of Applied Ichthyology | Year: 2010

The goldlined seabream Rhabdosargus sarba (Forskål, 1775) is farmed in several countries of the Western Pacific Rim and is a candidate species for aquaculture in the Gulf States of the Middle East. This study was undertaken to examine the onset and patterns of maturity in male goldlined seabream in support of the development of practical hatchery techniques. The testes of 337 male fish (0 + to 7 + , average FL 183 ± 20 to 315 ± 12 mm) collected from the Oman trap fishery (August 2001-April 2002; September 2002-2003) were classified into four stages, based on cell type (immature, developing, active or resting). Four spermatogenetic cell types were identified in the testes spermatogonia (types a and b), spermatocytes, spermatids and spermatozoa. Active testes appeared more regularly during the peak of the reproductive season in January and February. In March, resting testes were observed indicating the end of the reproductive season. There was clear evidence of protandry. Intersex gonads were observed in male fish from age 0 + to 7 + (33% at age 0 + to 75% at age 7 + with maximum 82% intersex frequency observed at age 5 + ). From the evidence presented, male fish age 1 + produced free-flowing sperm under slight abdominal pressure during the period November-March. © 2010 Blackwell Verlag, Berlin. Source

Salze G.,Virginia Polytechnic Institute and State University | Craig S.R.,Virginia Cobia Farms | Smith B.H.,University of Toronto | Smith E.P.,Virginia Polytechnic Institute and State University | Mclean E.,Aquaculture Center
Journal of Fish Biology | Year: 2011

The morphological development of larval cobia Rachycentron canadum from 3 days post hatch (dph) until weaning (27 dph) was examined using S.E.M. Two groups of fish were studied: a control group (CF), reared under standard feeding protocol, and a group in which prey items were enriched with supplemental taurine (4 g l-1 day-1; TF). TF fish grew faster (P < 0·001), attained greater size (mean ±s.e. 55·1 ± 1·5 v. 33·9 ± 1·0 mm total length) and had better survival (mean ±s.e. 29·3 ± 0·4 v. 7·1 ± 1·2 %) than CF fish. Canonical variance analysis confirmed findings with respect to differences in growth between the treatment groups with separation being explained by two cranial measurements. S.E.M. revealed that 3 dph larvae of R. canadum (in both groups) possess preopercular spines, superficial neuromasts on the head and body, taste buds in the mouth, an olfactory epithelium which takes the form of simple concave depressions, and primordial gill arches. Gill filaments start to form as early as 6 dph and lamellae buds are visible at 8 dph in both groups. In CF fish, the cephalic lateral line system continues its development at 12-14 dph with invagination of both supra- and infraorbital canals. At the same time, a thorn-like or acanthoid crest forms above the eye. At 14 dph, invaginations of the mandibular and preopercular canals are visible and around 22 dph enclosure of all cranial canals nears completion. In CF larvae, however, completely enclosed cranial canals were not observed within the course of the trial, i.e. 27 dph. In TF larvae, grooves of the cephalic lateral line system form 4 days earlier than observed in CF larvae of R. canadum (i.e. at 8 dph), with enclosure commencing at 16 dph, and completed by 27 dph. Along the flanks of 6 dph larvae of either treatment, four to five equally spaced neuromasts delineate the future position of the trunk lateral line. As myomeres are added to the growing larvae, new neuromasts appear such that at 16 dph a neuromast is associated with each myomere. By 27 dph, the trunk lateral line starts to invaginate in CF larvae, while it initiates closure in TF larvae. These findings elucidate important features of the larval development of R. canadum and show that dietary taurine supplementation benefits larval development, growth and survival in this species. Moreover, they suggest a conditional requirement for taurine in larval R. canadum. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles. Source

Sipauba-Tavares L.H.,Sao Paulo State University | Millan R.N.,Sao Paulo State University | Penariol I.C.,Sao Paulo State University | Penariol I.C.,Aquaculture Center
Limnetica | Year: 2015

The aim of this study was to investigate the effects of the aquatic macrophyte (Eichhornia crassipes) and periphyton communities on the neotropical fishponds water quality, and to determine the ability of such communities to remove potential pollutants from the fishponds, making them interesting tools for the maintenance of desirable water quality in aquaculture under continuous water flow. In general, the biological treatments used in this study showed a positive effect in reducing BOD5, orthophosphates, total phosphorus, conductivity and thermotolerant coliforms from the water column and also decreasing organic matter, Cu, Fe, Mn and Zn, from the sediment. The differences in physical and chemical properties of the water column and sediment between the treatments showed an improvement in the overall water quality when the treated fishponds are compared with the control fishpond. The best growth rate performance of Nile tilapia (Oreochromis niloticus) occurred in the fishpond with periphyton treatment. © Asociación Ibérica de Limnología, Madrid. Spain. Source

Gil Anaya M.C.,University of Extremadura | Calle F.,University of Extremadura | Perez C.J.,University of Extremadura | Martin-Hidalgo D.,University of Extremadura | And 4 more authors.
Andrology | Year: 2015

In this study a Bayesian network (BN) has been built for the study of the objective motility of Tinca tinca spermatozoa (spz). Semen from eight 2-year-old sexually mature male tenchs was obtained and motility analyses were performed at 6-17, 23-34 and 40-51 s after activation, using computer-assisted sperm analysis (CASA) software. Motility parameters rendered by CASA were treated with a two-step cluster analysis. Three well-defined sperm subpopulations were identified, varying the proportion of spermatozoa contained in each cluster with time and male. Cluster, cinematic and time variables were used to build the BN to study the probabilistic relationships among variables and how each variable influenced the final sperm classification into one of three predefined clusters. Both network structure and conditional probabilities were calculated based on the collected data set. Results shown that almost all the variables were directly or indirectly related to each other. By doing probabilistic inference we observed that the cluster distribution corresponded to the definition provided by the cluster analysis. Also, velocity and time variables determined the cluster to which each spermatozoon belonged with a high degree of accuracy. Thus, BNs can be applied in the study of sperm motility. The construction of a BN that include fertility data opens a new way to try to clarify the roles of motility and other sperm quality indicators in fertilization. © 2015 American Society of Andrology and European Academy of Andrology. Source

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