The studies on the breeding and hatching of the Tridacna maxima
| Autor: | Yue-Chuan Chen, 陳岳川 |
|---|---|
| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 The giant clam (Tridacna maxima) is the important economic shellfish of Penghu. Due to the fishing activities, the catch falls sharply in recent years. The calm was already prohibited to catch in the waters of Penghu since June of 2006. The artificial cultural technique was then expected to support the market demand and stock management in future. This study was tried to set up the cultural technique of clam's spawning and its most suitable bait at its early life stage. Four stimulate techniques including temperature, dry out, Tridacna maxima frozen gonad turbid liquid and oyster's gonad turbid liquid of ways were used in this study. Among them, the frozen Tridacna maxima gonad turbid liquid and oyster's gonad turbid liquid were significantly effective method for spawning. The 4 kinds of baits were tested for this species of Nannochloropsis oculata, Isochrysis galbana, Tetraselmis chui and Chaetoceros muelleri. The bait was casting for feeding after the clam larvae was becoming pediveliger larva abnormally on the third day. The survival rate was examined after the larvae was sinking to the bottom on the 8th day. The survival rate for feeding the bait Isochrysis galbana, Chaetoceros muelleri, Nannochloropsis oculata and Tetraselmis chui were varied about 11.56, 9.22, 6.11 and 5.22%, respectively. The species of Isochrysis galbana was used to investigate the effect of bait density to survival rate. The rates for bait density 5000 and 50000 inds/ml were varied about 11.89 and 12.67%, respectively. It shows that the density of bait between these two densities was insignificantly different for feeding of the clam. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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