Spawning Latency Period in Hormonal Induced Reproduction of Snow trout (Schizothorax zarudnyi (Nikolskii, 1897))

Abstract

Background: The breeding performance is an important parameter to evaluate the breeding success in captivity conditions. The optimum dose of hormone in combination with latency period is desirable for getting best breeding performance in fish. Objectives: The objective of the study was to find the spawning latency period in the hormonal induced reproduction of Snow trout with two inducers (Ovaprim and hCG) separately and in combination. Materials and Methods: The fish spawners were randomly divided into five groups and treated with Ovaprim, Ovaprim and high dose of hCG, Ovaprim and low dose ofhCG, hCG and saline water as control. Results: The results suggested that Ovaprim and high dose of hCG treatment lead to shorter latency time (40 hours and 40 minutes), but ovulation percent, percentage of live embryos in the eyed stage and ovulation synchronization were lower than treated groups with Ovaprim alone or Ovaprim and low dose of hCG. Females from the control and hCG groups did not spawn. Conclusions: The highest hormonal stimulation effectiveness was recorded in the group in which one hormonal substance (Ovaprim) was applied. Therefore the accurate ovulation time of snow trout, Schizothorax zarudnyi was difficult to be predicted.

Dose Optimization of Ovatide Hormone for Induced Breeding of Freshwater Gang Magur, Hemibagrus Menoda (Hamilton, 1822)

“…Irrespective of the dosage of Ovatide applied in different treatments, the time interval between the first hormonal injection of Ovatide extract and ovulation (latency period or response time) varied between 21 and 22 h and occurred within a temperature range of 26 -28 °C. The longtime of latency was attributed to lack of synchronization in achievement of readiness of spawning by the fish (Rahdari et al, 2014). Tan-Fermin and Emata (1993) recorded a latency period of 12-16 h when Clarias gariepinus and Clarias macrocephalus were induced to breed using pituitary and ovaprim which is lower than the present findings.…”

Variations in Gonadosomatic Index, Gonadal Development and Spawning Induction of Spotted Scat Scatophagus argus (Linnaeus, 1766)

“…The latency time (the time interval between the second injection and ovulation) varied from 24.7 ± 2.53 h to 36.6 ± 2.33 h. This period was much longer than the period reported by Su et al (2019). It could be related to water temperature, or to shorter latency periods in higher temperature conditions (Rahdari et al, 2014), or to the oocyte diameter of the females (Barry & Fast, 1988). The present study showed that the fertilization and hatching rates were significantly different among different doses of injection of LHRH-A2 (P < 0.05).…”

Gonadal Maturation and Spawning of Barred Loach (Nemacheilus fasciatus) Induced by Topical Gill Hormone Application

“…Indeed, Ovaprim™ topical gill induction had a negative relation to spawning latency periods in the present study where the highest dose induced the shortest latency (4.50 µL/g female and 2.25 µL/g male dosage), showing that it is an effective technique. Spawning induction via exogenous hormone therapy at an optimal dose also shortens the time of spawning latency in striped snakehead (Channa striata) (Marimuthu et al, 2007), snow trout (Schizothorax zarudnyi) (Rahdari et al, 2014), and Labeo rohita (Khan et al, 2006). Ovaprim™ application to the gills affected total fecundity, we suggest that T3 (3.00 µL/g female and 1.50 µL/g male dosage) is the optimal dose for efficacy as there was no difference between this and the highest test dose.…”