The study aimed to investigate the maturation process of ovarian follicles and ovary structure of migratory form of female Bulatmai barbel (Lucioarbus capito). The histology of oogenesis coincided with that known from most teleosts. The ovarian structure was found to be cytovarian. The development of the oocytes is started from early May along with spawning and the degeneration of matured oocyt...

The study aimed to investigate the maturation process of ovarian follicles and ovary structure of migratory form of female Bulatmai barbel (Lucioarbus capito). The histology of oogenesis coincided with that known from most teleosts. The ovarian structure was found to be cytovarian. The development of the oocytes is started from early May along with spawning and the degeneration of matured oocyt...

The accuracy of the habitat simulation method is often questioned due to limited simulated elements and indicator species. This study established an environmental flow assessment by coupling fish with hydrological reference system. obtained through was corrected statistical characteristics natural regime. Huayuankou section in Lower Yellow River assessed. results show that demand 7.9 - 15.4 bil...

Spawning periodicity of the green mussel, P. viridis (Linn. 1758), from Moheshkhali channel Bay Bengal, Bangldesh was determined by ‘larval abundance’ method for a period one year November 1990 and October 1991. Higher larval abundance recorded during pre-monsoon (January to April) post-monsoon (September December) months. Two significant peaks in spawning were recorded- major peak September (p...

A total number of 88 fishes Thai pangas were conducted for induced spawning experiments. Among them, 30 mature Pangasius sutchi were conducted for the length-weight relationship, 25 matured females for the fecundity and 33 fishes (12 males and 21 females) for induced spawning experiments. The total-standard length relationship curve shows a straight line with a strong correlation (r = 0.986 and...

A total number of 88 fishes Thai pangas were conducted for induced spawning experiments. Among them, 30 mature Pangasius sutchi were conducted for the length-weight relationship, 25 matured females for the fecundity and 33 fishes (12 males and 21 females) for induced spawning experiments. The total-standard length relationship curve shows a straight line with a strong correlation (r = 0.986 and...

In many seabird studies, single annual proxies of prey abundance have been used to explain variability in breeding performance, but much more important is probably the timing of prey availability relative to the breeding season when energy demand is at a maximum. Until now, intraseasonal variation in prey availability has been difficult to quantify in seabirds. Using a state-of-the-art ocean dr...

Analysis of fish movements has been an important area of study for fisheries ecology and population dynamics for decades. Pacific sardine, Sardinops sagax, along the west coast of the United States exhibit a well-defined large-scale seasonal migration. Larger and older fish are found in the northern reaches of their range during summer and contract to southerly offshore areas for spawning durin...

—The objective of the study was to evaluate the variation in embryo viability within a population of walleye Sander vitreus from an inland reservoir throughout the spawning season. Egg size, egg lipid content, and fatty acid composition were used as criteria to evaluate egg quality. Additionally, we sought to verify whether any particular size-class of females produces superiorquality eggs or w...

The spawning migration of the European eel (Anguilla anguilla L.) to the Sargasso Sea is one of the greatest animal migrations. However, the duration and route of the migration remain uncertain. Using fishery data from 20 rivers across Europe, we show that most eels begin their oceanic migration between August and December. We used electronic tagging techniques to map the oceanic migration from...