A reproductive analysis of 1225 specimens of Poeciliopsis gracilis obtained through monthly samples from Coatetelco, a tropical shallow lake in Central Mexico, was made. There was an evident sexual dimorphism, including a difference in body size at the onset of reproduction. Sex ratio deviated significantly from unity. Monthly variations in gonadosomatic (GSI), hepatosomatic (HSI) indexes and o...

A feeding trial was performed to evaluate the effects of dietary L-threonine supplementation on growth and body composition fingerlings Rhamdia quelen (initial weight: 4.47 ± 0.39 g). Five diets (370 g/kg crude protein 14.23 MJ / kg digestible energy) containing levels (16.0, 22.0, 28.0, 34.0, 40.0 g threonine/kg protein) were fed quadruplicate groups fishes for 10 weeks. The analysed variables...

The blue swimmer crab (BSC, Portunus armatus) is an economically and culturally important species distributed throughout the coastal waters of Indo-Pacific region. Reproduction BSC poorly understood in south-eastern Australia, a region that experiencing substantial tropicalisation from global warming. We examined gonadal development, egg–mass relationships, influence temperature on development ...

Abstract Lumpfish is used to control sea lice in open net-pen farming of Atlantic salmon, but little known about their nutritional requirements. The aim this study was investigate the effects replacing marine oil (MO) with rapeseed (RO), diets incorporating 50 % plant protein concentrates, on growth, chemical and fatty acid (FA) composition juvenile lumpfish. Four extruded diets, nearly iso-lip...

some biological characteristics and population dynamic of platycephalus indicus were studied during one year from may 2011 to march 2012 in the coastal waters of bandar abbas. a total of 1106 samples were collected. also, each month 35 fish was choosen and transferred to the laboratory for evaluation of spawning season.the ages of 279 specimens were determined by sectioned otoliths. the ages of...

The effects of replacing a digestible energy source from fat (fish oil) with carbohydrate (wheat starch) on performance, glycogenesis and de novo lipogenesis was examined in triplicate groups of juvenile gilthead sea bream (Sparus aurata), fed four extruded experimental diets. In order to trace the metabolic fate of dietary starch, 0.7% wheat starch was replaced with isotope-labelled starch (>9...

Effects of a high terbuthylazine concentration (3.3 mg/1) on Cyprinus carpio were studied using a commercial herbicide formulation Click 500 SC (terbuthylazine 500 g/l). The fish were exposed to the pesticide for 24 h and allowed to recover for 6 days. Biometric parameters, plasma biochemical parameters and biomarkers of oxidative stress as well as histopathological changes in selected tissues ...

1. Rainbow trout (Salmo gairdneri) of mean initial weight 15 g were given either a low-manganese or control diet containing 1.3 and 33 mg Mn/kg dry diet respectively. 2. Weight gains over a 24-week feeding period were the same for both groups of trout. 3. Hepatosomatic index, blood packed cell volume and haemoglobin concentration, plasma protein and the activities of aspartic aminotransferase (...

We analyzed the dietary copper effects in the estuarine crab Neohelice (Chasmagnathus) granulata and its interaction with water salinity. Crabs were maintained at 2 per thousand and 30 per thousand salinity for 5 weeks and they were fed with commercial food supplemented with the green alga Scenedesmus vacuolatus previously exposed to copper. No mortalities were observed, but crabs maintained at...

The present study investigated the ecological relationships between endoparasites and the host Potamotrygon falkneri from the upper Paraná River by using as indicators the host's relative condition factor (Kn), sex and hepatosomatic relation (HSR). Forty-seven specimens of P. falkneri were analyzed between March 2005 and September 2006. Statistical analysis showed that the Kn was positively cor...