the present study was conducted to estimate correlations among performance and egg quality traits in iranian native fowl. data were collected from 21,679 birdsat the isfahan native fowl breeding center to derive genetic parameters for performance traits and egg quality traits were measured on eggs of 1,020 birds. genetic correlations of performance and egg quality traits were estimated with a b...

length- weight relationship and growth pattern, condition factor and length at first maturity of yellowfin seabream were investigated in the persian gulf by monthly sampling of 30 fish from september 2011 to august 2012. maximum (31.45± 4.32) and minimum (17.80± 1.85) values of fork length and maximum (720.46 ± 292.58 gr) and minimum (134.01± 45.62) values of body weight were in january and sep...

Offspring size can have large and direct fitness implications, but we still do not have a complete understanding of what causes offspring size to vary. Daphnia (water fleas) generally produce fewer and larger offspring when food is limited. Here, we use a mathematical model to show that this could be explained by either: (1) an advantage of producing larger eggs when food is limited; or (2) a l...

We formulate and analyze two dynamic energy budget models, a net assimilation model with constant allocation strategy and a net production model with a 2-stage allocation strategy, with the objective of determining strategies that maximize the expected lifetime reproductive energy. The per capita death rate depends on the organism's size, as for example when the main cause of death is predation...

Fish reproductive biology plays an important role for fishery management, especially in developing countries. The aim of this study was to compile all available information and analyze reproduction patterns of marine fishes in three Large Marine Ecosystems (LMEs): North, East, and South Brazil Shelves. We tested the hypothesis that the onset and duration of spawning season differ among these th...

Abstract The reproductive cycle of the crustacean family Portunidae on coast Pacific is not well known. Therefore, and size at first maturity brown crab Callinectes bellicosus its relationship with environmental factors in El Colorado Lagoon, Ahome, Sinaloa has been determined. A total 360 females were collected from March 2012 to 2013. gonads fixed 10% formalin, histological cuts made by paraf...