Characterization, Production and Aquaculture Potentials of Fast Growing Intergeneric Hybrids

from Clariid species in Floating Net Bamboo Cage

BYAgbebi O.T., Alegbeleye W.O., Adebambo O.A., Agbaje M.,

Odulate D.O., Olaoye O.J

INTRODUCTION

• Aquaculture production in Africa is still insignificant at the global level and accounts for about 0.9 percent the total global aquaculture production in 2000 (FAO, 2003)

• Heterobranchus and Clarias species are leading freshwater candidates for aquaculture in Africa, similar in appearance but have differential growth performances in culture. There are many heteroclarias and Clariobranchus types being produced by aquacultural practitioners in Nigeria without paying attention to the type of hybrid fingerlings being released to the ponds or culture medium.

INTRODUCTION CONTD

• These F1 hybrids have been reported to be fertile (Aluko, 1998; Nwadukwe, 1995).

• The problem posed by this is the indiscriminate use of these fertile hybrids as broodstock for further propagation posing a serious threat to the purity of our indigenous Clariid species. Furthermore, there is need to harmonise the growth records of these hybrids and recommend the fastest growing hybrids. This study was therefore designed to determine the fastest growing F1 hybrids for culture using two Clariid species: H. bidorsalis, and C. gariepinus domesticated and wild strains

Objectives of the study• Morphological, meristic and molecular characteristics of

Clarias gariepinus and Heterobranchus bidorsalis of the parent stocks.

• Characterisation of the strains using microsatellite markers• Determination of suitable fish primer for successful

taxonomic study• To assess and harmonise various growth records of these

hybrids in order to recommend the fastest growing hybrids.

• To carry out comparative studies on the desirable characters and strains under the same environmental condition to determine characters that are superior to their parent strains.

MATERIALS AND METHODS

• Broodfish Selection and Collection (Wild & Domesticated)

• Molecular Characterization -DNA Extraction -Polymerase Chain reaction and -Agarose Electrophoresis• Injection, Fertilization and Incubation

Techniques

Experimental CrossesParental Group• Female H. bidorsalis X Male H. bidorsalis (Domesticated)• Female H. bidorsalis X Male H. bidorsalis (Wild)• Female C. gariepinus X Male C. gariepinus (Domesticated)• Female C. gariepinus X Male C. gariepinus (Wild)

Intergeneric Hybrid (Heteroclarias type)• Female H.bidorsalis (Domesticated) X Male H. bidorsalis (wild)• Male H. bidorsalis (Domesticated) X female H.bidorsalis (Domesticated) Intergeneric Hybrid (Clariobranchus type)• Female Clarias gariepinus (Domesticated) X male Clarias gariepinus (Wild)• Male Clarias gariepinus (Domesticated) X female Clarias gariepinus (Wild) Intergeneric Hybrid (Domesticated type)• Female Heterobranchus bidorsalis (Domesticated) X Male Clarias gariepinus (Domesticated)• Male Heterobranchus bidorsalis (Domesticated) X female Clarias gariepinus (Domesticated) Intergeneric Hybrid (Wild type)• Male Heterobranchus bidorsalis (Wild) X female Clarias gariepinus (Wild)• Female Heterobranchus bidorsalis (Wild) X male Clarias gariepinus (Wild)

Data collection and analysis

• Fecundity (total no of eggs) = 66.6 x female body weight

• % Hachability = No. Of hatched eggs x 100 -------------------------- No. Of fertilized eggs

• % larvae survival = No of normal larvae x 100 ------------------------- No. Of hatched eggs

• Larval Indoor Rearing• Larval Outdoor Rearing• Two different rearing medium will be used, namely

Earthen pond and Cage culture. • 6 Earthen ponds of 10 by 10 metres will be used for the

rearing• 12 Cage happas of one cubic metre (1m x1m x 1m) will

be constructed.• The cages will be mounted inside the earthen pond

simultaneously for growth comparison.• After seven months of rearing in these mediums the

skewed sex ratio will be determined to find out the potency of hybridization techniques.

RESULTS AND DISCUSSION

• The first grant was utilized only for the purchase of broodstocks and few equipments needed as shown below:

Fish Species (Broodstock)

Sex Total Kg Cost (₦) Total Cost (₦)

Heterobranchus bidorsalis (Domesticated)

5 males5 females

21.8Kg 2,000 43,600

Clarias gariepinus (Wild)

3 males5 female

8.0Kg 1,000 8,000

Heterobranchus bidorsalis (Wild)

2 males2 female

5.75Kg 2.200 13,800

Clarias gariepinus (Domesticated)

4 males3 females

6.50Kg 1,500 10,100

Total ₦75,500

Materials Bought Quantity Cost (₦)

Hatchery tank divider for Acclimitization

4 tanks 12,000 ₦12,000

Grand Total ₦87,500

• Grand Total = ₦87,500• Amount Received = ₦87,500• Amount Spent = ₦87,500• Balance = ₦00,000

RECOMMENDATION

I recommend that second to the fourth grant would be released in order to proceed on the

research work on the field.

THANK YOU