Induced Breeding Response of Two Synthetic Hormone Analogues In The Spawning of Indian Major Carp Labeo rohita (Hamilton-Buchanan) Under The Agro-Climatic Condition of Assam, India

B.J. Saud¹, R. Hazarika², V.K. Verma³ and M. M. Goswami⁴

^{1, 3} Central Inland Fisheries Research Institute, Regional Centre, Guwahati (India)

^{2, 4} Department of Zoology, Gauhati University, Guwahati — 14, Assam, India

¹Email: bhaskarjsaud@gmail.com

³Email: agnesv2008@gmail.com

Abstract

Six induced breeding exercises on the Indian Major Carp species Labeo rohita (Hamilton-Buchanan) were conducted in Chinese Circular Eco hatchery system during the period of May 08 to July 09. Two synthetic hormone analogues namely, Ovaprim and Ovatide were used to compare their efficiency. The egg output of 5,80,000 to 6,52,800 with Ovaprim and 6,78,000 to 8,26,000 with Ovatide was recorded during the breeding exercises. Spawning was observed after a latency period of 9-10 hours under an optimum temperature range of 27^o-30^oC. The fertilization rate was recorded between 75-85% and 71-78% in ovatide and ovaprim respectively and the hatching success in ovatide was recorded between 84-90% and in ovaprim between and 80-83%. In the prevailing climatic condition of Assam, the study shows that ovatide is more effective synthetic hormone analogue for induced spawning and seed production of Labeo rohita. Proper brooder stock management and water quality control were emphasized during the breeding exercises.

INTRODUCTION

Induce breeding is the highly reliable techniques to re-establish the declining natural stock as well as to meet the raising demand of seeds to the farmer. The Chinese eco hatchery system for induced breeding is considered to be the suitable for the production of quality seed of carps since 1957(Choudhury and Alikunih, 1957). Though a large number of ovulating agents for induced breeding is available now a day, the present paper is a review dealing with a comparative account on the effect of ovatide and ovaprim on spawning of Labeo rohita in Chinese eco hatchery system with a note on its early embryonic development.

MATERIALS AND METHODS

Prior to breeding season, brooders of Labeo rohita were kept under captivity for five months in advance in stocking tank. To ensure the growth brooders were regularly fed on oilcake and rice bran (1:1). All the breeding experiments were conducted using the Chinese Circular Eco Hatchery (CCEH) system which is based on continuous flow of water by gravity separately for ovatide and ovaprim. Males with freely milt oozing and female with soft bulging belly with reddish vent were selected for breeding trial. Breeding sets were constructed as 2:1 (Two males against one female). Fishes were injected intramuscularly with different dosage of ovatide and ovaprim at a single dose. The injected fishes were then released into the breeding pool of CCEH and continuous water current was maintained in the breeding pool.

The fertilization rate was determined by counting the number of fertilized eggs in 100 numbers of eggs in replicate egg samples. Some eggs were examined under microscope for their developmental study. CCD Camera fitted to compound binocular microscope was used to take the live photographs of developmental stages. Some physico-chemical parameters of water were monitored followed by APHA in the breeding pool as well as during hatching.

OBSERVATION

Different dosages of ovatide and ovaprim were used to induce spawning of Labeo rohita. Both the synthetic hormone analogues give satisfactory result (Table-2). However, the ovatide shows better results then ovaprim at a dose of 0.5 — 0.4 ml/kg of body weight in female and 0.2-0.3 ml/kg of body weight in male with an egg output of 6,78,000 to 8,26,000 and 84-90% hatching success. Water temperature was recorded as 27-31⁰C during the period of investigation. Fertilized eggs of the Labeo rohita were demersal and non adhesive in nature. Separations of vitelline membrane followed by cleavage, formation of blastomeres, germ ring formation, yolk plug stage, development of somites were clearly discernible under microscope. Hatching of the embryo was observed after 18 hours of fertilization and continued upto 19- 22 hours at a water temperature of 29-31⁰C.

Table 1- Physico-chemical parameters studied During Breeding and Hatching of

Labeo rohita

Table 2- Results of Induced Breeding of Labeo rohita

The result obtained in the present study clearly demonstrates that Labeo rohita response well to both the synthetic hormone analogues ovatide and ovaprim in Chinese circular Eco-hatchery system of induced breeding. However use of ovatide at a dose of 0.5 — 0.4 ml/kg of body weight in female and 0.2-0.3 ml/kg of body weight in male found more successful than the ovaprim. Earlier, Pandey et al. (2002) also found a rate of 95-100% fertilization and 90-98% hatching success in Labeo rohita using Ovatide at a water temperature ranging between 28^o-31^o C. Water temperature plays a crucial role in the breeding of carps. According to Dwivedi and Reddy (1986) 26^o-28.5^o C is suitable for breeding of Indian major carp. But in the present investigation 28^o-31^o C of water temperature is found suitable for Indian major carp species, Labeo rohita in the agro climatic condition of Assam. Choudhuri and singh (1984) reported that the optimum water temperature range is 24^o-31^o C for breeding of Indian and Exotic carp. Hatching of the fertilized eggs in this study occurred 18 to 22 hours after fertilization. From the present investigation it is clear that, successful spawning and hatching success can be achieved by inducing Labeo rohita with ovatide in Chinese Circular Eco-hatchery system in the agro-climatic condition of Assam.

APHA (1989) Standard method for the examination of water and wastewater. Washington D.C.

Choudhuri. H and K.H. Alikunhi . 1957. Observation on the spawning in Indian carp by hormone injection. Current Science, 26(12): 381-382

Chaudhuri, H and Singh, S.B.1984. Induced breeding of carps. Indian council of agricultural research, New Delhi.p.82

Dwivedi, S. N. and Reddy, A. K. 1986. Fish breeding in a controlled environment — Carp Hatchery CIFE-D81. Aquaculture, 5(4) : 27-36.

Pandey. A.K., Mahaptra. C.T., Kanungo. G., Sarkar. M., Sahoo. G.C and Singh B.N. 2002. Ovadite induced spawning in the Indian major carp, Labeo rohita (Hamilton-Buchanan). Aquacult. 3: 1-4

PHOTO PLATES

        MATURE LABEO ROHITA                                        FOR BREEDING SYNTHETIC HORMONE INDUCTION TO THE BROODERS

        FERTILIZED EGGS OF LABEO ROHITA                                NEWLY HATCHED LARVA OF LABEO ROHITA