The spatial variation of the spawning shoals of M. hubbsi in Patagonia during its reproductive peak (January) between 2001 and 2008 was analyzed. In 2001 and 2004 spawning of hake in the north-patagonian area was concentrated inshore between 50 m and 80 m depths, in coincidence with a bottom thermal front (9° 14° C). Since 2005 an expansion of spawning into deeper waters (near the 100 m isobath...

River thermal regime is a critical factor affecting the initiation of spawning and breeding success in freshwater fish species. The four main domestic carps (FMDCs) Chinese sturgeon are representative warm-water cool-water fishes with different requirements Yangtze Basin, China. This study focused on these two types species below Three Gorges Dam (TGD), response curves were constructed. daily s...

—Spawning date is a crucial life history trait in fishes, linking parents to their offspring, and it is highly heritable in salmonid fishes. We examined the spawning dates of coho salmon Oncorhynchus kisutch and chinook salmon O. tshawytscha at the University of Washington (UW) Hatchery for trends over time. We then compared the spawning date patterns with the changing thermal regime of the Lak...

Healthy specimens of Colisa fasciatus exposed to sub lethal concentration of hexavalent chromium (4.8 mg/L) for 15 days revealed no significant alterations in any testicular architecture during its different phases. However, 30 days exposure revealed distarded shape of lobule and lobular wall, scattered interstitial leydig cells during preparatory phase of testicular cycle where as during spawn...

Vert-pre et al. (1) identified regimes in productivity for marine fish stocks, with the goal of urging management to develop strategies that are robust to regime-like behavior. Identification of drivers of productivity [i.e., is the stock driven by spawning biomass (the abundance hypothesis in Vert-pre et al.’s analysis in ref. 1) or environment (the regimes, random, and mixed hypotheses)?] is ...

BACKGROUND Amphibian declines are now recognized globally. It is also well known that many anurans do not reproduce easily in captivity, especially when held over long periods, or if they require hibernation before breeding. A simple method to induce spawning and subsequent development of large numbers of healthy tadpoles is therefore required to meet research and conservation goals. METHODS ...

The out-of season induced spawning of the Cyprinus carpio was done during period October 2009 to February 2010 (Autumn and Winter), in hatchery Marin Science Center. brooders average weight 1.700-4.000 kg for females 1.500-1.800 males. were acclimated on 22 °C, a 10 days. photoperiod 12-14 hour/day. results showed that this regime only one female 3males had positive reaction pituitary gland hor...

—Throughout its native range, American shad Alosa sapidissima is thought to cease feeding during anadromous migration. We examined the feeding habits of American shad during spawning migration by documenting changes in diet composition and feeding that occur in mature fish in the York River, Virginia. American shad were collected prior to and after spawning at various locations on a gradient fr...

Information on the spawning migration, spawning ecology and life history of tropical eels in the Indo-Pacific region is very limited. The physiological and morphological characteristics of tropical freshwater eels, Anguilla bicolor bicolor and A. bengalensis bengalensis collected in Malaysia were examined in relation to their downstream migration patterns. A total of 455 eels were collected ove...

eurasian perch, perca fluviatilis l., is one of the most important species in european freshwater aquaculture and probably one of most important of cold freshwater species in nearest future. the aim of this study was to test the ovaprim in artificial reproduction in eurasian perch in two temperatures (12 and 14°c) with using new oocyte maturation stage system. the results obtained in present st...