| Sepia lycidas is an important economic cephalopod in the south china sea, it has a highbreeding prospect for its individual large and fast-growing advantages, its introduction to ZhejiangProcince for farming has become an important issue. In this paper, reproductive biology andartificial breeding technology of Sepia lycidas were preliminarily studied, main results as follows:The reproductive biology of wild Sepia lycidas which were in breeding migration period wasstudied by the methods of marine biological resources survey and statistical regression analysis.The results showed that body weight of male was (2.84±0.44) kg, mantle length was (31.25±1.80)cm, body weight of female was (1.20±0.36) kg, mantle length was (23.06±2.41) cm, gonadsomatic index was (7.87±1.62)%, fecundity was412~1011eggs, average was (626.77±122.52)eggs. There was a typical power function relation between body weight and mantle length,cuttlebone length was a linear function of mantle length and body weight, ovarian weight was alsoa linear function of nidamental gland weight, mantle length and body weight. Fecundity increasedwith body length and body weight, the body length relative fecundity was positively correlatedwith body length and body weight, the weight relative fecundity was positively correlated withmantle length and negatively correlated with body weight.The adhesion effects of artificial adhesion substrates was studied by single factorexperiments.The results showed that, whether nylon rope or polyethylene mesh, the larger ones hadthe better adhesion effects. The adhesion effect of polyethylene mesh (27mm) was best, theaverage number of attaching oosperms was193.4, the average adhesion rate was (32.51±0.55)%;Followed by polyethylene mesh(15mm), the average number of attaching oosperms was137.5, theaverage adhesion rate was (23.14±2.21)%; The adhesion effects of nylon rope (8mm and10mm)were better, the average number of attaching oosperms were119.6and120.0, the average adhesionrates were (20.09±1.74)%and (20.13±1.85)%; The adhesion effects of nylon rope (2mm and4mm)and polyethylene mesh (2.5mm) were attached few egges.The effects of transport density (100ind/L,200ind/L,300ind/L,400ind/L) and transport time(24h,30h,36h,42h) for the long-distance transport of the fertilized eggs were studied throughsingle factor test methods. The results showed that, the hatching rate, survival rate of larvae, theweight of newly hatched larvae and completely absorked rate of yolk sac all decreased as thedensity and time increased. The optimum transport density was100~300ind/L, hatching rate was71.51%~86.85%, completely absorked rate of yolk sac was77.51%~90.85%, the weight of newly hatched larvae was0.246g~0.263g, survival rate of larvae78.88%~90.62%. The optimumtransport time was24~36h, hatching rate was71.51%~85.85%, completely absorked rate of yolksac was77.51%~90.95%, the weight of newly hatched larvae was0.246g~0.269g, survival rate oflarvae78.88%~89.62%.The embryonic development of Sepia lycidas was observed by microscopic imaging system.The results showed that, when the water temperature was27℃, salinity was30, the oospermscould hatch after20days, the total sum of temperature was288.6℃·d. The embryonicdevelopments were compartmentalized into11periods, asoosperm,cleavage, blastula, gastrula, theoccurrence of embryonic primodium, the formation of organization, red-bead stage, occurrence ofheartbeat, pigment appearance, endoskeleton formation stage, hatching.Hatching and growth characteristics of larval were studied through single fator experiment andconventional biological methods. The results showed that, a quadratic function relationship existedbetween hatching rate and temperature: y=0.213x2-12.783x+208.517(R2=0.978), the optimumtemperature was24℃, hatching rate was (93.3±2.9)%, and the hatching peak period was23~24days. A cubic function relationship existed between hatching rate and salinity: y=-0.007x3+22.430x-393.010(R2=0.800), the optimum salinity was30, hatching rate was(93.3±2.9)%, and the hatching peak period was23~24days. There was a exponential functionrelationship between Larval body weight (BW) and age (D): BW=0.2901e0.0546D(R2=0.9885),mantle length (ML) and age (D): ML=0.9236e0.0262D(R2=0.9807); There was a power functionrelationship between mantle width (MW) and mantle length: MW=0.7216ML0.9326(R2=0.9813),Larval body weight and mantle length: BW=0.4372ML1.559(R2=0.9729).The effects of transport density (20ind/L,40ind/L,60ind/L,80ind/L)、transport time (3h,6h,9h,12h) and water temperature (20℃,22℃,24℃,26℃) to the survival rate of Sepia lycidasseedling were studied through single fator experiment. The results showed that, survival ratedecreased as the density, time and temperature increased. The optimum transport density was20~40ind/L, the survival rate reached98.33%~99.33%.The survival rate of simulate transportationwas higher than the actual transportation under the same transport time. There was higher survivalrate (96.67%~99.33%) when the simulate transport time was less than9h, and higher survival rate(95.13%~97.53%) when the actual transport time was less than6h. The optimum temperature was20~22℃, survival rate could reach more than90%. |
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