OBSERVATION ON THE INDUCED SPAWNING PRACTICES IN THE HATCHERIES OF RAJSHAHI DISTRICT OF BANGLADESH
An investigation was conducted during the period from March to December 2009 to investigate the induced spawning practices in 22 hatcheries of 6 Upazilas of Rajshahi District of Bangladesh. It was observed that, 6 native fish species viz. rui ( Labeo rohita ), catla ( Catla catla ), mrigal ( Cirrhina mrigala ), calibaush ( Labeo calbasu ), bata ( Labeo bata ), gonia ( Labeo gonius ) and six exotic fish species such as silver carp ( Hypophthalmichthys moltrix ), bighead carp ( Aristichthys nobilis ), grass carp ( Ctenopharyngodon idella ), common carp ( Cyprinus carpio ), Thai pangus ( Pangasius sutchi ), rajputi ( Puntius gonionotus ) were used in the surveyed hatcheries for induced spawning purpose. The average length limit was 41.70±13.02 to 72.81±25.98 cm, average age limit was 1.96±0.75 to 3.08±0.90 years and average weight limit was 1.83±0.79 to 7.54±3.92 kg of the brood fish. Two types of hormone injections like PG (pituitary gland) and HCG (human chorionic gonadotropin) were used for induced spawning. The rate of 1st doses of injections of PG were from 1 to 4 mg/kg and HCG from 150 to 500 IU/kg and the rate of 2nd doses of injections of PG for native and exotic species were from 4 to 8 mg/kg and 4 to 10 mg/kg respectively. The incubation period and hatching rate in different fish species varied from 10 to 72 hours and 55% to 80%, respectively. DOI: http://dx.doi.org/10.3329/jles.v6i0.9723 JLES 2011 6: 65-68
BREEDING PERFORMANCE, SPAWNING AND NURSING OF BLACK CARP (MYLOPHARYNGODON PICEUS)
Successful induced breeding of black carp was performed by using Pituitary Gland (PG) extract and synthetic hormone Flash TM . For PG, the female received two doses at the rate of 2 mg/Kg and 8 mg/Kg body weight respectively; where male received only single dose at the amount of 2 mg/Kg body weight. For Flash, the male and female was received only one dose at the amount of 0.3 ml/Kg body weight for male and 0.25 ml/Kg body weight for female respectively. The ovulation period was 12 hours for PG and 11 hours for Flash after lost injection. In total 6.1 Kg of hatchling was obtained from 23 kg of female black carp under the two treatments. While, the ratio of hatchling and female fish body weight was 1 : 4.28 for PG and 1 : 3.34 for Flash. The study also indicates that the spawn Production of black carp and nursery operation ware profitable. In the spawn production, the profit rate was 872.76% ware observed and the cost benefit ratio recorded as 1: 8.72. In cases of profit from spawn production and nursery operation combined of black carp, the return was 247.95%. While, cost benefit ratio was 1 : 2.47. For income generation through hatchery and nursery operation for sustainable aquaculture extensive study is needed in this regards. Bangladesh J. Zool. 43 (1): 73-83, 2015
Orally induced spawning of Thai carp (Puntius gonionotus, Bleeker) following co‐administration of des Gly10 (D‐Arg6) sGnRH ethylamide and domperidone
Oral delivery of a salmon gonadotropin releasing hormone analogue (50–100 μg kg−1 B.W.) and domperidone (25–50 mg kg−1 B.W.) to Thai carp, induced ovulation in 83–100% of treated animals within 48 h of administration.