Ž . The productivity of Nile tilapia Oreochromis niloticus L. broodfish, spawned in large hapas Ž 2. 120 m in ponds under different exchange and management strategies, was monitored over a 70-day period. Female fish were checked for eggs twice weekly and returned to the same Ž . spawning hapa throughout the experiment 0 day or exchanged for females maintained in separate Ž . Ž . single sex grou...

This study examined the effect of dietary carotenoid availability on carotenoid and retinoid concentrations in the flesh, plasma, skin and eggs of female Chinook salmon Oncorhynchus tshawytscha. Carotenoid concentrations in all tissues were closely related to dietary availability. Early in the breeding season, carotenoids were stored primarily in the muscle, with a flesh carotenoid concentratio...

During 1997 we evaluated reproductive success in colonial water birds nesting in the Lower Rio Grande Valley (LRGV), Texas, and correlated success with concentrations of contaminants in eggs. We also measured steroid hormones and gonadosomatic index (GSI) as biomarkers of endocrine effects in common carp (Cyprinus carpio). Nest and fledging success of green herons (Butorides virescens) and grea...

Odontesthes bonariensis is a freshwater teleost fish from the Pampean inland waters, with an important economic potencial. The conditions of its intensive culture systems favour the proliferation of pathogen agents. This work describes the ocurrence of Achlya racemosa Hildebrand on eggs, and of Saprolegnia ferax (Gruith.) Thuret on a juvenile of Argentinian silverside (Odonthestes bonariensis)....

background: fluoxetine (prozactm) is one of the most popular antidepressant that can be released to aquatic systems via sewage-treatment effluents. it is suspected to provoke substantial effects in the aquatic environment. methods: in spawning tanks, specimens were exposed to concentrations of 0 and 0.54 µgl-1 fluoxetine from male introduction until the larvae had hatched. prior to spawning, ne...

background: the use of chemical materials such as malachite green to disinfect fish eggs is banned in many countries due to its reversed environmental effects. objectives: the purpose of this study was to investigate the effect of metalonic sumac extract as antifungal agent on eggs of schizothorax zarudnyi during the incubation period and to compare its effects with malachite green. methods: 24...

In the ripe eggs of all species of marine teleost fish so far examined, retinal (vitamin A aldehyde) is the predominant form of vitamin A, and in some species it represents 90% of the total vitamin A-active material in the eggs (Plack, Kon & Thompson, 1959; Plack & Kon, 1961). Hen’s eggs also contain retinal and, for forty-one eggs from six hens on a diet of breeder’s mash, a value of 21.7 pg/e...

Fatty acid composition of eggs affects development, growth and ecological performance of fish embryos and larvae, with potential consequences for recruitment success. Essential fatty acids in eggs derive from the maternal diet, and the time between ingestion and deposition in eggs is ecologically important but unknown. We examined the dynamics of diet-egg transfer of arachidonic acid (ARA) in t...