北方沿海四角蛤蜊人工育苗技术的初步研究

Artificial breeding technique of clam Mactra veneriformis in Northern coast in China

于2004年和2006年对四角蛤蜊Mactra veneriformis人工育苗技术进行了研究。2004年在4个100L塑料桶和30m^3水泥池中分别培育出2—3mm稚贝20万粒和3000万粒，2006年在2个100L塑料桶中育出2～3mm稚贝12万粒。结果表明：室外土池中培育的亲贝（壳长33．97mm±2．90mm）产卵量为（79．7±4．0）万粒／个，海区采集的亲贝（壳长为39．62mm±2．78mm）产卵量为13．2万粒／个；在水温为25．4℃、盐度为24、pH为8．0的条件下，受精卵经过20h 30min发育为D形幼虫；四角蛤蜊的卵径、D形幼虫、后期面盘幼虫、变态规格、单水管、双水管稚贝的大小分别为（50．93±0．49）、（70．96±0．92）、（164．00±3．54）、（186．00±4．22）、（212．00±5．46）、（496．00±9．87）um；壳顶前期生长速度为（7．83—8．83）um／d，壳顶中、后期为（11．38—14．99）um／d；存活率为（80．34±1．86）％。稚贝期（10-45日龄）四角蛤蜊壳长、壳高的比例接近成体；10—15日龄稚贝的生长速度为（32．15—36．82）um／d，存活率近100％；15—30日龄，生长速度达（71．20±9．91）um／d，存活率为（85．30±1．28）％；30～45日龄，生长速度为（49．30±7．12）um／d，存活率只有（14．10±1．61）％。

Artificial breeding of clam Mactra veneriformis Reeve was conducted in four of each 100 - 1 polyethylene buckets and a 30 m^3 concrete pond in 2004 and 2006, 200 and 120 thousands and 30 million of juveniles with shell length of 2 - 3 mm being obtained. The sex ratio of female to male 1 ： 1.05 and a fecundity of 797 ± 40/ind. was found in the broodstock reared in outdoor earthern pond and 132 thousand/ind for the broodstock collected in coast. The fertilized eggs developed into D larvae 20.5 hours after fertilization at water temperature of 25.4℃, salinity 24 and pH 8. 0. The egg, D - larvae, pediveliger larvae, metamorphosis, and single siphon, and double siphon juveniles was （50.93 ± 0.49 ） um, （ 70.96 ± 0.92 ） um, （ 164.00 ±3.54 ） um, （ 186. 00 ± 4.22 ） um, （212.00 ± 5.46） um, （496.00 ±9.87）um in size, respectively. The early umbo -veliger larvae had daily growth of 7.83 - 8.83um, and the middle and late urnbo - veliger larvae 11.38 - 14.99 um, with survival rate of above （80.34 ±1.86） % and the metamorphosis rate of （95.48 ± 3.64） % for pelagic larvae. The 10 - 45 day old juveniles had similar shell morphometry as adult. From day 10 to day 15, the daily growth was （32.15 -36.82）um, with survival rate of nearly 100% ; from day 15 to day 30, the daily growth of （71.20 ±9.91 ）um was observed with survival rate of about （85.30 ± 1.28）% ; from days 35 to day 40 the growth rate reached （49.30 ±7.12） um per day, the survival rate decreasing to （ 14.10 ± 1.61 ） %.