The relationships between fecundity and size of Atlantic herring (Clupea harengus) were estimated within five different spawning areas off the coast Nova Scotia in 2019 2020. Statistically significant differences relative to body weight observed among years. Fecundity-at-length on German Bank ground was 29%–36% 22%–28% lower than estimates from 2001 1970, respectively. Temporal changes weight- ...

Cobitis faridpaki Cobitis faridpaki (Mousavi-Sabet, Vasil'eva, Vatandoust and Vasil'ev, 2011) is found in streams of the Siahrud River in the southeastern Caspian Sea basin, and this is the first report on reproductive parameters of the newly described endemic loach. Reproductive conditions are key parameters of fish populations, and their assessment is very important for endemic fishes. To stu...

Dr. RAYMOND PEARL (1912) was the first worker to suggest that sexlinked factors were involved in the inheritance of fecundity. PEARL used as a measure of fecundity the eggs produced during the winter period. He proposed that two major dominant factors were responsible for high egg production, one of which resided in the sex chromosome. GOODALE (1919) and HURST (1921) each failed to confirm the ...

High mortality rates have been observed in Teleost during early developmental stages, as well as great variations in reproductive tactics, which are related to adaptations towards environmental conditions and ecological niches for which different species have a specific response. The objective of this study was to describe reproductive tactics related to the survival of Cichlasoma orientale off...

1. Plant fecundity and seed dispersal often depend on environmental variables that vary in space. Hence, plant ecologists need to quantify spatial environmental effects on fecundity and dispersal. 2. We present an approach to estimate and model two types of spatial environmental effects: source effects cause fecundity and dispersal to vary as a function of a source's local environment, whereas ...

1. Using information on the Doñana population of Spanish imperial eagles Aquila adalberti from 1959 to 2004, we present strong empirical support to theoretical models on the regulation of population trajectories by the relationships between breeder mortality and floater availability. 2. During the study period, the eagle population showed three distinct phases: (i) a population increase with ne...

The study of the influence selenium on regeneration and fecundity crab Sesarma boulengeri Calman has been conducted. results demonstrated: effect walking legs S. Calman. Morphology regenerated appendage was different from control specimen. speed growth in bud lower than it depended size class crab. Regeneration index (R) higher small crabs large ones single autotomy double autotomy. Fecundity v...

In this essay, I briefly summarise reproductive phenotypes associated withWolbachia in insects, present a model of the dynamics of infection frequency for maternally-inherited microorganisms and determine the effect of changing costs associated with incompatibility, infection-related fecundity loss and number of mates in ideal populations of social insects. The model predicts that infections of...

Male age influence on fecundity and fertility has been studied in monomorphic (inversion free) and polymorphic (with inversion) strains of Drosophila ananassae. It was noticed that in both monomorphic and polymorphic strains, females mated to old males showed greater fecundity and fertility than females mated to young or middle aged males. Thus, in D. ananassae male age effect on fitness is ind...

Sex ratio, size at maturity, maturity stages, fecundity and egg diameter of Oreochromis niloticus from Coatetelco Lake, Morelos State, Mexico, were studied from January to December 1993. Sex ratio (male:female) was approximately 1:1.02. Length at maturity was 117 mm (males) and 120 mm (females). The fecundity ranged between 104 and 709 eggs, with egg diameter from 1,000 to 3,000 microns. The go...