| BIG MOUTH BUFFALO INTRODUCED TO CENTRAL CHINA |
| CULTURING FRIES AND FINGERLINGS OF BIG MOUTH BUFFALO |
| EMBRYONIC DEVELOPMENT OF BIG MOUTH BUFFALO |
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Jiaxi Wang, Shaohua Hu, Zhen Huangand Daweng
Ma Hubei Fisheries Research Institute Wuhan, Hubei People’s Republic of China,430071 |
| Big Mouth Buffalo Ictiobus Cyprinellus(Valenciennes)were introduced into China by Hubei Province Fishery Research Institute in 1983.We studied extensively the biology of this species and its adaptation to the environment of central China.Big Mouth Buffalo has an olive head and a dark-green spindle-like body with cover-tile shaped scales.The dorsal fin is long whit a “V” shape and the rear fin is different from common carp with no barb in the head .The adaptable water temperature was from 0 to 41.5℃ with optimum growth within the temperature range between 18℃ and 32℃.The fish can also grow in the semi-salty water(2.1-7.2g/l NaCl).There is no particular need for light at the stage of the fry and fingerling .Newly hatched fish can reach a body weight of 135-605g in the first year,700-1500g in the second year,and up to 1500-2500g in the third year.Feeding habit changes as the fish grows.Larvae,1cm long ,feed mainly on chorella(56% of total diet)and zooplankton such as cladecora brachionus,irceis cyclops (accounting for 44%of the total diet).Firse,2-6cm long,feed mainly cladecora.Fries,3-6cm ffed mainly on zooplandton such as cladecora,which accounts for over 90% of teir total diet.Fingerling,7-9cm long,eat mainly cladecora and benthos.The adult fish feed mainly on zooplandton and benthos,and they also take beancake,peanut cake,and compound feed when provided.Male fish reached sexual maturity within 2 years with with body weight of 0.8-1.5kg,and female fish needs 3 years and body weights of 1-2.5kg.Mature female fish can spawn13,700-36,000eggs/kg body weight when spawning is induced artificially.Under natural conditions ,one fish of 66cm in length can spawn 750,000 eggs.Fertilized eggs hatched within 128 hours within the temperature range of 16-23℃.Our results demonstrated that big mouth buffalo can be cultured successfully in the environment of central China. |
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Jiaxi Wang, Shaohua Hu, Zhen Huangand Daweng
Ma Hubei Fisheries Research Institute Wuhan, Hubei People’s Republic of China, 430071 |
| The objective was to study the effects of several
culturing methods on the survival and growth of fries and fingerlings
of Big Mouth Buffalo. In experiment 1,fries, 0.7-0.83cm long, were
cultured for 12days in a trough, a cement pool, a net cage and a pond.
In the trough, fries reached1.1 to 1.4cm with a survival rate of 94.6-98.7%.
In the cement pool, fries reached 2.6-3.03cm in body length with a
survival rate of 94.1-97.3%. In the net cage (1.5m long, 1m wide and
0.8m deep), fries reached 3.2-3.4cm in body length with a survival
rate of 96.5-98.8%. In ponds (0.07-1.16ha in area) with stocking density
of 35205 fries/ha (1.5-1.65cm/ind), Fries became 4-5cm in body length
with survival rates of 84.5%to 91.7%.
In experiment 2, fingerlings of 11.6-11.9g were cultured for one month in cement pools (4 square meters in area) and earthen ponds. Fingerlings reached 37.4-42.74g in the cement pools, and 32.7g in the earthen ponds with a survival rate of 90-100%. Our results suggest that high survival rates can be achieved with
all the methods tested, but the growth rate may vary depending on
the methods used. |
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Jiaxi Wang, Shaohua Hu, Zhen Huang and Daweng
Ma Hubei Fisheries Research Institute Wuhan, Hubei People’s Republic of China, 430071 |
| The objective was to characterize the fertilized
eggs and the embryonic development of Big Mouth Buffalo. Eggs of Big
Mouth Buffalo was round in shape and sticky. The fertilized egg was
1-1.3mm in diameter before absorbing water and 1.4-1.75mm arter absorbing
water. The first cleavage occurs 110 minutes after fertilization,
followed by continuous division of blastodermal cells. Fourteen hours and 8 minutes after fertilization, the blastomere wraps down towards the equator of the egg, it came into gastrula stage .It reached neural plate stage 26 hours and 10 minutes after fertilization. Embryos began to break the membrane and came out 129 hours and 28 minutes after fertilization. The newly hatched fry was 4.9-5.1mm in length. Eighty three hours later, the yolk sac almost disappeared and the fries began feeding. Twelve days after hatching, it became the larva stage. Twenty days after hatching, it came to the naiad stage. Twenty-eight days after hatching, it looked like the adult in shape with completion of the external development. The time for the embryo to break the membrane was 18-20 hours longer and the time for the air bladder development was 38-40 hours longer for big mouth buffalo than for the common carp. |