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...

Background: Habitat is the foundation for healthy and productive fisheries. For substrate spawning fish, lack of appropriate spawning substrate is inherently limiting and a lack of access to suitable spawning habitat will lead to population collapse. When specific properties of a habitat (e.g., temperature, depth, vegetation composition) are matched to the species’ ecological niche, a spawning ...

The cues triggering large-scale broadcast-spawning events in marine invertebrates are not fully understood. Using the sea urchin Lytechinus variegatus, we tested the effectiveness of a variety of potential spawning cues in eliciting a spawning response. In the laboratory, during two consecutive spawning seasons, about 400 isolated sea urchins were exposed to phytoplankton, sperm, or eggs, singl...

Schizothorax prenanti is an endemic fish in the mountain rivers of southwestern China with unique protection value. To further explore the vortex motion of hydraulic habitats, which is closely related to the fish breeding process, the cross-sectional vorticity was used to evaluate the hydraulic conditions of the natural spawning habitat of S. prenanti. A coupled level-set and volume-of-fluid (C...

Fish reproducing in group-spawning aggregations face intense fisheries during spawning events due to increased ease of capture. Other traits often associated with group spawning, such as late sexual maturation and sequential hermaphroditism, cause group-spawning species to be especially vulnerable to population declines, either because fishermen target large, reproductively mature specimens or ...

Hatch date distributions, local spawning time and incubation temperatures at different spawning sites around Iceland were used to trace the most likely origin of 0-group cod. Length, age and hatch date frequency distributions were obtained from young larvae collected on the main spawning grounds off the south coast in 1995 and from pelagic 0-group cod captured in six nursery regions off the wes...

A shortage of salmonid spawning habitat on dammed and regulated rivers has led to the popularity of spawning habitat rehabilitation projects. Habitat heterogeneity is thought to be an important feature of aquatic ecosystems, but specific metrics for design and assessment are lacking. In August 2002, ~ 2,786 metric tons of spawning gravels and 7 large boulders were placed in a 155 meter reach on...