Embryonic Development And Effects Of Different Baits On Growth Of Cherax Quadricarinatus

In recent years,due to frequent occurrence of diseases in marine shrimp culture,freshwater shrimp culture such as red claw crayfish and crayfish are gradually attracting attention.Since 2014,the red claw crayfish has been introduced in China.As of now,there are several breeding sites for red claw crayfish in Hainan province.But it is still faced with the selection of high quality bait for crayfish,and the domestic production is mainly fed with shrimp feed,corn,wheat,soybean,raw fish,pumpkin,papaya and so on.The growth rate and survival rate of red claw crayfish are very different,and there are different proportions of hermaphroditism.However,the crayfish itself still faces the problems of the unsynchronized eggs of the female prawns,the larvae of the shrimps,the rate of ovum holding and the low hatching rate,which seriously restricts the development of the crayfish crayfish industry.Based on this,the effects of different diets on growth parameters and traits of red claw crayfish were studied.The results show that:(1)a:the embryo development sequence of the outside pond and the controlled condition is the same as the fertilized egg period,cleavage and blastocyst stage,the proto intestinal stage,the unlarval stage,the compound eye pigment formation period and the hatching period.b:the young shrimps were found to undergo 2 times of discarding in the mother body and then disintegrated free living;c:the outer pond and the fertilized eggs under the controlled indoor conditions.The color is different,indoor is light yellow,outdoor mostly olive green or green,a few even black;d:under different conditions,the hatchability of young body hatchability is larger,indoor hatchability is 407.41,outdoor is 262.59,the difference is significant;e:to reduce the parent shrimp residue,experimental development of artificial early dislocation technology research research The results showed that there was no difference in survival rate between artificial and natural dissection.This experiment can provide an effective basis for the promotion and development of the red claw crayfish in China,and is of great significance for promoting the economic development of China’s aquaculture.(2)a:when feeding the feed shrimp 60 d,the sex reversal rate of Penaeus prawns was 34.1 + 6.9%,which was significantly higher than 9.8 + 4.1%(p<0.05)in the feed group of Marmara Roche;b:the weight gain rate and the specific growth rate of all the specifications of the feeding combined feed + fish + pumpkin were the highest,and the feed plus pumpkin were fed.The group and feeding combined with feed group were the slowest,and the weight gain rate and specific growth rate of c:9g Red Crayfish crayfish juvenile shrimp were significantly higher than that of feed plus pumpkin group(p<0.05),while 15 g and 21 g Red Crayfish juvenile shrimp were fed with two kinds of feed.There was no significant difference in length,suggesting that with the growth of individuals,the proportion of plant feed increased gradually.