Asian clam (Corbicula fluminea) is potentially reared as aquaculture species but feeding regimes and nutrition for this clam remain questioned. The growth and survival of C. fluminea were evaluated with the assessment of feeding regimes raised in captive rearing treatments (with substrates) fed with spirulina (Arthrospira platensis). Three feeding methods were applied, Treatment A: deposit-feeding, Treatment B: suspension feeding, and Treatment C: combination deposit and suspension-feeding. Shell length (SL) and weight of the individuals were taken every 7 d which last for 6 wk. Condition index (CI), instantaneous growth rates of weight (Kw), and SL (KL) were determined after the experiment ends. Water parameters such as temperature (°C), pH, ammonia (NH4), and dissolved oxygen (DO) also being monitored along the experimental period. Significant weight gained (Kw) and CI was found higher in C. fluminea fed in Treatment C, where the increment was recorded at 6.24x10-3±2.4x10-3gday-1 and 4.34 ±0.3 respectively. Whereas, the increment of SL (KL) was insignificant in all treatments. Survival rates (SR) were greater than 95% in all treatments. The rearing conditions are significant factors that affect the feed utilization for their growth. The growth and survival indicate the specific feeding methods for captive C. fluminea and spirulina feasibility as their feed.

The Corbicula taxonomy in Malaysia is equivocal and scarcely being reported. This study aims to characterise phenotype and genotype of the Asian clam of the genus Corbicula (Mergele Von Mühlfeld, 1811) from three locations in east coast of Peninsular Malaysia. The phenotypic characterisation of the three population of the clam was evaluated on the basis of morphometric characters, while mtDNA cytochrome b (cytb) was used to characterise the genotypes. Results of morphometric analysis showed a significant difference (p<0.05) in shell height (SH), shell width (SW) and umbo length (UL) among three locations between the evaluated population. Discriminant analysis also revealed significant difference of the characters among the study sites. However, cluster analysis revealed an overlapping of morphometric characters among evaluated C. fluminea intricate complete separation between populations. Besides, a comparison of the Corbicula with the morphotypes and holotypes had proposed the Corbicula in this region known as C. fluminea. The genotypes characterisation using mtDNA cytb verifies the existence of C. fluminea. Phylogenetic trees demonstrated polymorphism and low genetic variances although geographically separated which parallel to the phenotypic characterisation. Thus, these findings enhance the knowledge on geographical variation and elucidate the complexity of taxa.

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