Rainbow trout, oncorhynchus mykiss is one of the most important cold water fishes in Iran. For successful artificial propagation of rainbow trout, the quality and quantity of brooders and sexual materials are key factors. In the present study, we investigated the age-dependent changes of reproductive efficiency. For this purpose, the brooders were divided into age classes and then three age gro...

Substratum quality and oxygen supply to the interstitial zone are crucial for the reproductive success of salmonid fishes. At present, degradation of spawning grounds due to fine sediment deposition and colmation are recognized as main factors for reproductive failure. In addition, changes in water temperatures due to climate change, damming, and cooling water inlets are predicted to reduce hat...

BACKGROUND In the present study, the detection of anthelmintic resistance to triclabendazole (TCBZ) in sheep infected by Fasciola hepatica was studied using an egg hatch assay (EHA). F. hepatica eggs were recovered from bile and faeces of infected animals by isolates with different grade of anthelmintic resistance to TCBZ: i) a resistant isolate (RT); ii) a susceptible isolate (ST); iii) natura...

One of the influencing factors in hatching is egg screening. This study aims to determine frequency turning increase hatchability, fertility, and mortality quail eggs. Completely randomized design (CRD) used this experiment which consisted 4 treatments 5 replications. The were: 1 screening/day for each replication (p0), 2 screenings/day (p1), 3 (p2), (p3). From results study, it was concluded t...

Four thousands and two hundred hatching eggs were obtained from Bandarah chicken to evaluate the effect of chemical and natural eggs disinfectants and fumigation on egg weight loss, embryonic mortality, hatchability, hatch time, chick weight, and chick weight loss. Three incubation trials were done, each one contained 1400 hatched eggs and divided into fourteen treatments (100 eggs per each). F...

The effect of 2-tridecanone vapor on the cowpea weevil (Callosobruchus maculatus) development was determined. Seeds of cowpea were infested with adults and exposed to different doses of 2-tridecanone isolated from Pilocarpus microphyllus Stapf ex Holm, a plant species native from northeastern Brazil. The pure monoterpene was evaluated both undiluted as well as in the dilutions 1:10, 1:100 and 1...

Sanitation of hatching eggs is an important area of research due to the need for an effective, economical, and safe method of egg sanitation. Improved hatching egg sanitation is an important part of an overall pathogen reduction program within integrated poultry operations. This must be accomplished without disturbing the cuticle of the egg, which can decrease hatchability. The ability of ultra...

I examined the role of vibrations in predator-induced early hatching of red-eyed treefrogs, Agalychnis callidryas. The arboreal eggs of A. callidryas hatch up to 30% early if attacked by egg-eating snakes. This induced hatching is a behavioural response that occurs once snakes begin physically disturbing the clutch, and is sufficiently rapid to allow most embryos to escape. Other intense but be...

In this study, the effects of abrupt temperature change on the hatching success and larval survival of eggs, yolk-sac larvae (YSL) and larvae above nest (LAN), for both largemouth bass Micropterus salmoides and smallmouth bass Micropterus dolomieu were quantified. Temperature had a significant effect on hatching success and time to 50% mortality, with large heat shocks causing accelerated morta...

Offspring size is a key characteristic in life histories, reflecting maternal investment per offspring and, in marine invertebrates, being linked to mode of development. Few studies have focused explicitly on intraspecific variation and plasticity in developmental characteristics such as egg size and hatching size in marine invertebrates. We measured over 1000 eggs and hatchlings of the marine ...