The activity of glycogen Phosphorylase and carbohydrate hydrolyzing enzymes α-amylase, glucoamylase, trehalase, and sucrase was studied in the development of the Carniolan honey bee, Apis mellifera carnica Pollman (Hymenoptera: Apidae), from newly hatched larva to freshly emerged imago of worker and drone. Phosphorolytic degradation of glycogen was significantly stronger than hydrolytic degrada...

Kutum, Rutilus frisii kutum, is an commercially important fish in the Caspian Sea. The fish enters the rivers leading to the Caspian Sea for spawning. One of these rivers is Shiroud River. In the artificial propagation process of Kutum, different factors are involved in quality and quantity of female broods eggs and also in the best temperature and migration time for spawning. The influence of ...

Direct costs and benefits to females of multiple mating have been shown to have large effects on female fecundity and longevity in several species. However, with the exception of studies examining genetic benefits of polyandry, little attention has been paid to the possible effects on offspring of multiple mating by females. We propose that nongenetic effects of maternal matings on offspring fi...

At the beginning of the breeding season, the outermost tail feathers of 31 male Barn Swallows Hirundo rustica were either shortened by 20 mm, elongated by 20 mm or left unmanipulated. In first broods, the number of feeding bouts (per nestling per hour) by males and females did not differ significantly among experimental groups. However, in second broods, males with elongated tails fed their nes...

In some birds, feather ornaments are expressed in nestlings well before sexual maturation, possibly in response to parental favouritism towards high-quality offspring. In species with synchronous hatching, in which nestling ornaments may vary more among than within broods, parents may use this information to adjust their parental allocation to the current brood accordingly. We tested this hypot...

The change in avian clutch size with latitude is a celebrated example of geographic variation in a vertebrate life-history trait. Alternative hypotheses for this pattern invoke nest predation, limited food for nestlings, or post-fledging juvenile mortality as selection pressures leading to small clutch size of tropical birds. We manipulated the clutch size of Spotted Antbirds (Hylophylax naevio...

The relationships between parental effort, offspring growth, and offspring blood parasitemias are poorly known. We examined the effect of parental effort on offspring size and prevalence of trypanosomes in peripheral blood of nestling Pied Flycatchers Ficedula hypoleuca aged 13 days. Trypanosome infections were likely to be shared by siblings, indicating the role of a common environment and/or ...

Abstract In cooperatively breeding species, the presence of male helpers in a group often reduces female’s fidelity to her social partner, possibly because there is more than one potential sire group. Using long-term study superb fairy-wrens (Malurus cyaneus) and records paternity 1936 broods, we show that effect on rates extrapair varied according helpers’ relatedness female. The unrelated inc...

kutum, rutilus frisii kutum, is an commercially important fish in the caspian sea. the fish enters the rivers leading to the caspian sea for spawning. one of these rivers is shiroud river. in the artificial propagation process of kutum, different factors are involved in quality and quantity of female broods eggs and also in the best temperature and migration time for spawning. the influence of ...