農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

本年度共採集諾亞硨磲蛤種貝20顆，進行四批次人工繁殖操作，迄本年度為止，成 功培育長硨磲蛤1公分稚貝800顆以上。以溫度刺激法可成功誘導生殖腺成熟種貝排 精排卵，在28度攝氏、33psu的培育條件下，受精卵約需11-12天可變態成為底棲稚 貝。成功設置中間育成場，供種貝及稚貝渡冬及中間育成使用。 重整建構種貝培育 模式在6月底前完成初步測試結果顯示，可誘發較多數量個體排精或卵，但在培育期 間及誘發操作結束前之死亡率偏高，個體誘發有排或未排之隔離蓄養死亡率亦偏高 。種貝培育池之天然餌藻量在短期強降雨後難以恢復而喪失效果，導致種貝嚴重死 亡。7月初以備用池本地種與死亡嚴重池仍存活日本種交替誘發，日本種精僅誘排出 一個本地種排卵。7月底誘發測試業者收成池文蛤亦可得大量個體排精或卵，但各別 卵量明顯較少，誘發操作結束及其後蓄養均無死亡。8、9月份不易誘發排精卵，各 別卵量亦少。10月份本地種繁殖季即將結束，日本種略晚，在10月3日淡水原生種雄 誘發一個本地種排卵之受精卵有少量發育至D形苗，本地種雄誘發一個日本種排卵之 受精卵，完全孵化成D形幼苗飼育3日後死亡。10月17日再各別交替誘發本地與日本 種，僅各2個產卵，日本雄誘發本地種受精卵發育略顯不良，僅有1個體子代培育至 第5天仍有存活D形苗可供量測。2個日本雌子代之發育體型大小仍略有差異。日本種 受精卵卵徑40～47μm，本地種60～77μm。2種之初期D形苗長徑略同在 110～120μm，5天後日本種略大144～158μm，本地種128～134μm之範圍，2種子代 D形幼苗在飼育期間數量明顯漸減，均未完全變態成稚貝前死亡。

Before the end of June the preliminary experiment results that reformed construction of the sandy filter pool to breeding hard clam broodstock showed that a large number of individuals could be induced to spawning, but the mortality rate during the acclimated period and the end of the induction operation was high, and the mortality rate of the broodstock had been induced to spawning or not is also high when they were planted with plastic basket back to breeding pond by sexually isolated or massstocking.The amount of natural microalgae in the breeding sandy filter pool is difficult to recover after short-term heavy rainfall and loses its acclimated effect, resulting in serious death of the broodstock. At the beginning of July, the Japanese species of survivors that suffering severe death had been induced only one local species spawned eggs. At the end of July, the induction of adult clams from the farmerharvesting pond had been obtained a large number of individuals spawning, but the amount of eggs from each individual was significantly less, and there was no death after the end of the induction operation and subsequent stocked in plastic basket.In August and September, it is not easy to induce spawning and the amount of eggs from each individual was less also. In October, the local species spawning season is coming to an end. But the Japanese species is slightly late. On October 3, the estuary of Tamsui River native males induced a local fertilized egg to develop a small amount of D-shaped larval. At the same time the local males induced a Japanese individual ovulation fertilized egg that almost complete hatching into Dshaped larval died after 3 days of rearing. On October 17th, local and Japanese species were alternately induced, and only 2 females were spawned. Japanese males induced local fertilized eggs to develop obviously not completely. Only one individual progeny were cultivated until the 5th day for measure. The other two Japanese females are also very different in their development.The fertilized egg diameter of Japanese species is 40-47μm, and the native species is 60-77μm. The lengths of the initial D-shaped larval of the two species were slightly the same at 110 to 120μm. After 5 days, the Japanese species were slightly larger than 144-158μm, and the native species were in the range of 128-134μm. The planktonic larval amount of two species significantly decreasing during the rearing period were not completely metamorphosed and died before the juveniles.20 mature giant clamsTridacna naoewere collected for artificial propagations.More than 800 juveniles reached >1 cm in shell length until the end of 2018.Spawning can be successfully induced by dry-out treatment combined with temperature fluctuation application.Fertilized eggs metamorphosed into settled juveniles with water conditions under 28℃ and 33psu within 11-12 days.The outdoor cage was established for broodstock and juveniles to escape low temperature during winter time and grow-out.