Several years of research on the gametic development and spawning of different species of holothurians have produced results that find applications in aquaculture and fisheries management programs. The first set of data shows that sea cucumbers secrete a biologically active chemical which allows gamete synthesis synchrony among conspecifics. Laboratory experiments have revealed that the gametic...

Reproductive activity of Red Snapper Lutjanus campechanus (Poey, 1860) at artificial reefs (ARs) are only recently being investigated. Yet, the management fishery differs on a regional basis with state and federal jurisdictions, reproductive differences among regions have not been To compare L. (inshore) (offshore) individuals were collected in northwestern Gulf Mexico from four ARs quarterly f...

We trialled the efficacy of various exogenous hormones to induce spermiation, courtship behavior, and spawning in the "endangered" southern bell frog, Litoria raniformis. Intralymphatic administration of Lucrin(®), a synthetic nonapeptide luteinizing hormone releasing hormone (LHRH), was used successfully to induce courting behaviors and ejaculation of spermatozoa in males. Various hormones, in...

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...

Hatch date distributions, local spawning time and incubation temperatures at different spawning sites around Iceland were used to trace the most likely origin of 0-group cod. Length, age and hatch date frequency distributions were obtained from young larvae collected on the main spawning grounds off the south coast in 1995 and from pelagic 0-group cod captured in six nursery regions off the wes...