Background: Catecholamines and cortisol are stress hormones in teleosts secreted, respectively, by the adrenal homologs, chromaffin and interrenal tissues. It is well known that the stress hormones respond to a variety of stress stimuli, induced or natural. There is a cross-talk between the stress and reproductive axis but the physiological implications are debated. It is believed that breeding...

Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of...

studies on reproductive biology are essential to assess culture potential of a fish species. mystus tengara is a popular food fish as well as preferred as an ornamental fish in west bengal. till date detailed report on reproductive biology of this fish species in the agro-climatic context of west bengal is lacking. therefore, the present work was aimed to study the detailed reproductive biology...

The release of eggs and sperm into the environment for external fertilization is common (Giese & Kanatani 1987) and thought to be the ancestral mating strategy (Wray 1995). Most phyla have at least some species that release sperm into the environment (free spawning or spermcasting) and a majority have representatives that also release eggs (broadcast spawning) for external fertilization (Levita...

As the number of fish reproduction studies has proliferated, so has the number of gonadal classification schemes and terms. This has made it difficult for both scientists and resource managers to communicate and for comparisons to be made among studies. We propose the adoption of a simple, universal terminology for the phases in the reproductive cycle, which can be applied to all male and femal...

The metabolic peptide hormone nesfatin-1 has been linked to the reproductive axis in fishes. The purpose of this study was to determine how energy availability after spawning affects plasma levels of nesfatin-1, the metabolic peptide hormone ghrelin, and sex steroid hormones in rematuring female rainbow trout (Oncorhynchus mykiss). To limit reproductive maturation, a group of female trout was f...

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 2010 Deepwater Horizon oil spill impacted the northern Gulf of Mexico (GOM) during the spring spawning season of Atlantic bluefin tuna (BFT). Overlap between BFT spawning habitat and surface oil in the northern GOM was examined using satellite-derived estimates of oil coverage, and spawning habitat models. Results suggested that although eggs and larvae were likely impacted by oil-contamina...

This study aims at investigating the spawning migration of the endemic Labeobarbus species and C. gariepinus from Lake Tana, through Ribb River, to Welala and Shesher wetlands. The study was conducted during peak spawning months (July to October, 2010). Fish were collected through overnight gillnet settings. A total of 1725 specimens of the genus Labeobarbus (13 species) and 506 specimens of C....

To elucidate the reproductive cycle of any animal, it is first necessary to understand the development of the germ cells and how this process occurs throughout the reproductive tract. Thus, the aim of the present study was to understand the oogenesis and spermatogenesis, as well as the ovarian and testis maturation and type of spawning, of Haemulon plumieri. A total of 119 females and 136 males...