Embryonic and larval developments of brackish water catfish,Mystus gulio(Hamilton and Buchanan, 1822) induced with human chorionic gonadotropin and consequent larval rearing

Abstract

Mystus gulio, the long whiskers catfish, is a popular food fish and potential candidate species for aquaculture in Sundarban area of India and Bangladesh. Recently, catch of this species has declined due to overfishing and various ecological changes. In the present study, mature fish was induced to spawn in captivity through intramuscular injection of human chorionic gonadotropin at the doses of 10 IU/g to female and 5 IU/g to male. Photomicrographs of all developmental stages of live embryo and larvae were documented with the aid of a light microscope. Results demonstrated that morula, blastula, gastrula and neurula and organogenesis ended at 1:30‐, 3:00‐, 5:30‐, 7:30‐ and 17:15‐hour post‐spawning (hps) respectively. Heartbeat and muscular contraction of embryo commenced at 8:30 and 11.15 hps respectively. Hatching of embryo started after an incubation period of 17:30 hour at an ambient temperature of 29 ± 1°C. The newly hatched larvae measured 2.17 ± 0.29 mm in total length with a yolk volume of 0.165 ± 0.03 mm3 started feeding 36 hr after hatching. The present study, on induced breeding and chronological development of M. gulio embryo, will have significant implications on conservation and seed production for aquaculture.

The use of S-GnRHa (salmon gonadotropin releasing hormone analogue) in induced breeding and early embryonic development of Gulsha, Mystus cavasius

“…The artificial propagation of Gulsha involves the injection of sexually mature females and males with synthetic hormones, with modifications, that have been used to spawn an entire range of catfish. Generally, catfish are injected with hormones under the peritoneal cavity (Bhenila & Biswas, 2014;Kumar et al, 2018;Kumar et al, 2021). Different hormones are used in different doses for different catfish species, which might have resulted in lower hatching and survival rates, and poor-quality fry and fingerlings.…”

Observation of Embryonic and Larval Developmental Stages in Endangered Nona Tengra (Mystus gulio) Induced with S-GnRHa

“…Ferosekhan et al (2015) recorded this stage at 21:30 h post fertilization in P. pangasius, Rahman et al (2004) at 15:00 h post fertilization in M. cavasius, Khan and Mollah (1998) at 18-22 h post fertilization in Clarias gariepinus and Kohinoor et al (1997) at 14 h post fertilization in O. pabo. The morula, blastula, gastrula and neurula and organogenesis stages were found to be completed at 1:30, 3:00, 5:30, 7:30 and 17:15 h postspawning respectively for induced breeding of Mystus gulio using human chorionic gonadotropin (Kumar et al, 2018).…”

“…The diameter of egg was measured in mm scale by using live sample on "ImageJ" software. Embryonic stages were characterized by following the description of Kumar et al (2018).…”

“…I nduced breeding is a method whereby using pituitary hormone or any other synthetic hormone ripe fish breeders are induced to breed in captivity (Bailung and Biswas, The M. gulio contributes a lot to coastal fishery both in commercial aspects and in providing food and nutrition for local community (Kumar et al, 2018;Sakthivel et al, 2013). It is a popular and commercial small indigenous fish species, so now a days its demand is rapidly increasing in Bangladesh (Gupta, 2014;Sarker et al, 2002), but their seed is not available in anywhere.…”

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2014; Kumar et al, 2018). Induced breeding technique is advantageous because it provides pure good quality spawn as well as ensures availability of fish seed, whereas availability of seed from natural source is contingent and depends on several environmental factors (Wahab et al, 2003;Mollah et al, 2008).

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