caspian kutum, rutilus frisii kutum, is one of the most commercially important fish species in the caspian sea, but there are few reports about the endocrinology of induced spawning in this fish. in the present study, 54 individuals of female broodstocks of kutum were studied for quantity and quality of propagation index, during march and april 2007. hormone treatments include: lhrh-a2 (1 ?g kg...

The purpose of this study is to investigate the differences fatty acids and hormonal parameters in the spawning and non-spawning season between the diploid and induced triploid Far Eastern catfish, Silurus asotus. The measured triploids were produced by cold shock for 50 min at 4℃ in May 2014, the spawning season of diploid was in May, and the non-spawning season was designated in January. Estr...

Sex steroids have long been known to exist in molluscs, but few studies have focused on the roles of these substances in molluscan reproduction. In this study, we demonstrate that injections of estradiol into ripe sea scallops induced spawning in both sexes, testosterone injections induced spawning in males only and progesterone blocked spawning in both sexes. We also show that injections of se...

The cues triggering large-scale broadcast-spawning events in marine invertebrates are not fully understood. Using the sea urchin Lytechinus variegatus, we tested the effectiveness of a variety of potential spawning cues in eliciting a spawning response. In the laboratory, during two consecutive spawning seasons, about 400 isolated sea urchins were exposed to phytoplankton, sperm, or eggs, singl...

Induced spawning of fish often requires hormone injections. Preparations used for hormone-induced spawning must be mixed properly, and the correct amount must be used to be effective. This publication describes common techniques used to calculate the hormone concentration and dose, prepare hormone solutions, and inject the fish for induced spawning. To calculate the proper dosage, 1) the recomm...

Sporadic outbreaks of the coral-eating crown-of-thorns starfish are likely to be due, at least in part, to spatial and temporal variation in reproductive and settlement success. For gonochoric and broadcast spawning species such as crown-of-thorns starfish, spawning synchrony is fundamental for achieving high rates of fertilization. Highly synchronized gamete release within and among distinct p...

The enhanced ability to direct sexual reproduction may lead to improved restoration outcomes for Acropora cervicornis. Gravid fragments of A. cervicornis were maintained in a laboratory for two sequential trials in the seven days prior to natural spawning in the Florida Keys. Ten replicates of five chemicals known to affect spawning in various invertebrate taxa were tested. Hydrogen peroxide at...

Most corals undergo spawning after a particular moon phase, but how moon-related spawning is endogenously regulated in corals remains unknown. The objective of the present study was to evaluate whether dopamine (DA) affects spawning in Acropora tenuis. When pieces of four A. tenuis colonies were reared under a natural photoperiod and water temperature, spawning was observed after the predicted ...