Biological aspects and nte development of larvae and juvenile of the angelwing clam pholas orientaus (gmelin, 1791)
| dc.contributor.author | Bee Wah, Ng | |
| dc.date.accessioned | 2016-01-13T01:55:24Z | |
| dc.date.available | 2016-01-13T01:55:24Z | |
| dc.date.issued | 2009-01 | |
| dc.description.abstract | In the natural bed of Kuala Kedah, the quantitative distribution of Pholas orientalis was estimated (from July 2006 till July 2007) using quadrate of 1m2 P. orientalis were found most distributed and abundance in the lower intertidal zone, where the clams burrowed in compact muddy substrate to a depth of about 0.3m. The dams were found during July, August and September 2006 and the size of P. orientalis in this study ranged from 6. 1 to 13.0 em. The correlation results of the relationship between water quality, abundance and distribution of P. orienta/is were weak, indicating that water quality is not the major factor affecting the distribution of P. orienta/is in sampling site. In this study also, P. orienta/is was exposed to thermal shock to spawn in the laboratory and the larvae were successfully reared to juvenile stage. larval development in P. orienta/is from embryonic to settlement stages was described. The fertilized eggs developed into straight-hinge after 24h of fertilization. The larvae fed on diet of lsochrysis galbana reached the umbo . stage (Sl: 154.721.Jm, SH: 149.54 um) within 13 days and settling on a substratum as juvenile (Sl: 0.22 cm, SH: 0.14 em) within 27 days. The .. larvae showed an average specific growth rate of 58.59 % em day-1 . Shell length and width correlation of larval and juveniles were corresponded to the linear equations y = 0.5969x + 77.69, R2 = 0.9743 andy= 0.2854x- 0.0105, R2 = 0.9527, respectively. The difficulties in the identification of P. orienta/is planktonic larvae from plankton sample could be resolved by using light microscope and scanning electron microscope. This study provided morphological characteristics and diagnostic features of the larval and umbo which have led to the development of an identification method for separating P. orientalis larvae from those of other bivalves larvae occurring in plankton samples. Three species of microalgae and their combination were used to test the effect of diet on the growth and survival of the P. orienta/is juveniles. Results showed that mixed diets of /. galbana and C. gracilis or just l. galbana alone were suitable for hatchery rearing of juvenile Angelwing clam P. orienta/is. Tetraselmis sp. as a single diet is not suitable to feed the juveniles of P. orienta/is. Optimum growth and survival rate were observed in mixed diets of I. ga/bana and C. gracilis. In diet of Tetraselmis sp., 100% mortality was recorded on week five. The results were compared to those reported for other bivalve species; and the implication of these findings was discussed in relation to hatchery operations and development of P. orientalis culture in Malaysia. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/1540 | |
| dc.language.iso | en | en_US |
| dc.subject | Angelwing clam | en_US |
| dc.subject | Pholas orientaus (gmelin, 1791) | en_US |
| dc.title | Biological aspects and nte development of larvae and juvenile of the angelwing clam pholas orientaus (gmelin, 1791) | en_US |
| dc.type | Thesis | en_US |
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