Studies On Artificial Propagation Of Parapocryptes Serperaster And Bait Domestication Of Boleophthalmus Petinirostris

This thesis makes Parapocryptes serperaster and Boleophthalmus petinirostrisas the research objects, and has researched the reproductive biology and ArtificialPropagation of Parapocryptes serperaster, and also made a preliminary study on baitdomestication of Boleophthalmus petinirostris.The main findings are as follows:1. Reproductive biology indicators of Parapocryptes serperasterRandomly count115samples from brood stocks, and the result including60females,55males, male and female ratio of these brood stocks is1.09:1. From Aprilto June, to catch brood stock by cages and measure statistics of60Ⅳ or Ⅴ females.The results show: the average body length of these brood stock13.79±0.60cm,average body weight20.67±2.97g, mean weight of gonad0.77±0.20g, averageabsolute fecundity13746±3349tablets, average relative fecundity661.68±105.49tablets/g in weight or991.28±210.37tablets/cm in length, the average sexualmaturity coefficient was3.71±0.65%, egg diameter0.65±0.03mm.The absolute fecundity of Parapocryptes serperaster increases with the increasein their body weight and length, and appears the curve relation. The correlationequation of absolute fecundity （F） and body length （L）: F=0.4932L^3.8917（R²=0.5314）, relevance is very significant; the correlation equation of absolutefecundity （F） and body weight （W）: F=351.21W^1.2057（R²=0.5578）, relevance isalso very significant. Count the Parapocryptes serperaster per unit body weightrelative fecundity and body length, weight was a single line or curve relationshipParapocryptes serperaster count per unit length relative fecundity and body length,weight curvilinear relationship. the correlation equation: Fs=2959.4ln（L）-6770.8（R²=0.3901），Fs=986.35ln（W）-1985.8（R²=0.4739）, the both relevance arevery significant. The weight （W） of Parapocryptes serperaster increases with the growth of body length （L） and the correlation showed the curve. The correlationequations: W=0.0287L^2.5049（R²=0.5783）, correlation is very significant.2. The selection of initial feed and artificial propagation of ParapocryptesserperasterThe larvae caliber of Parapocryptes serperaster generally in the100-150μm, theinitial feed generally select some smaller particle size like algae powder, eel powder,the fortified material of rotifers， micro particle pellets and oyster eggs. Theexperimental result is that in the three experimental groups （algae powder, eel powderand the fortified material of rotifers）, throughout the stomach of larvae does notappear food, the stomach is empty all the time. Oyster eggs three beakers in theexperimental group, stomach of larval fish appear veliger; micro particles with thefeed in the experimental group, food concentration of10/ml beaker particle, larvalfish stomach, but very little.During the mid-April to mid-June, the Parapocryptes serperaster spawningperiod,is mainly concentrated in three times spawning peak.During this period, twoseeding experiment are made, the first seeding, only three days continuously detectlarvae. And during the second seeding,larvae detect in eight consecutive days, andfirst increased and then a downward trend in the number of larvae, the larvae ofParapocryptes serperaster increasing trend in the number is no more than one day.The larvae oil droplets gradually depleted, and found a large number of oyster veligerin the gastrointestinal of the larvae of Parapocryptes serperaste with no oil droplets,but found that the number of larvae which swallowed oyster veliger is low and thetwo groups of larvae ultimately failed to survive.3. Bait domestication of Boleophthalmus petinirostrisIn the cement pool with bedding mud bottom, juvenile fishes of mudskipperssurvive in good condition, there was no death phenomenon. In the concrete pondswithout bunk, juveniles appear a large number of deaths, and the continuity of thedeath, basically reduced by about10%of the daily mortality. With the reduction inthe total number of juveniles, the daily number of deaths also showed a decreasingtrend. Each suitcase simulation experiment, juvenile fish survival varies considerably,particularly low survival rate of young fish in not bedding group, and juvenile fish survival rate is relatively high in the initial working group with foundation. Sobedding the bottom is conducive to the survival of juvenile fish and the effect of claymud bottom is significant.After bait domestication, feeding habits of large mudskipper have some shift, thetransition from feeding red worms to red worms and eel powder mixed bait, thehighest proportion of eel powder in red worms up to80%, if it continues to increaseeel powder proportion, the juveniles feeding will be not ideal, bait appears mostremaining. Observations are as follows: during the process of eel powder share of baitproportion from20%to70%, juvenile fish feeding well, basically in the feeding of1h,can eat up the bait, no residual, the juveniles of large mudskipper can grow rapidly,the apparent increase in the growth indexes. When the proportion of eel powderincreased to80%,2h after feeding, there is more bait remaining, and the juvenilesbasically stopped growing.