The effect of fine sand sediment and feeding microalgae on Asian clam (Corbicula fluminea) juvenile production

In recent years, the state of Kelantan area has seen significant advances in Corbicula fluminea or etak, which is becoming a commodity species for the local economy because of its high demand as a snack in Malaysia. Asian clam (Corbicula fluminea) is a renowned freshwater clam in Kelantan and has been consumed by the locals for a long time ago. However, the exploitation of Corbicula fluminea could cause negative repercussions for stock availability in the natural population. Not only that, excessive sand mining activity and water pollution have worsened the situation. Thus, an effort to expedite the availability seed of Asian clam must be initiated to conserve the Asian clam (Corbicula fluminea) population in their habitat and at the same time to fulfil the market demand. The scientific goals in this study aim to propagate freshwater microalgae by using the indoor system for Asian clam feed as well as to evaluate the effect of fine sand sediment on the Asian clam juvenile growth performance. To answer this question, the comparison of the used medium control (water from etak habitat) and to additional bold basal for freshwater microalgae culture as well as comparing the fine sand sediment and control. The results showed the production of freshwater microalgae propagation, where the used bold basal medium was a higher abundance kind of microalgae, such as Closterium Nitzsche, Monoraphidium komárková-legnerová, and Chlorella beijerinck. The densities of two treatments varied between 1.114 x 105 ± 0.0120 cells/mm and 1.2 x 106 ± 0.1320 cells/mm while the growth of microalgae started from 2 x105 ± 1.399 cells/mm to 2.4 x 106 ± 11.234 cells/mm, which were insignificantly different (P>0.05). Meanwhile, the Asian clam adult produced the numerous larvae in Oct-Dec approximately 22350-22464 Ind/L. The fine sand sediment treatment enhances the average shell length (SL) 353 ± 2.65 μm to 617 ± 5.13 μm and shell height (SH) 274 ± 2 μm to 383 ± 11 μm of Asian clam larvae faster than control, which was significantly different (P>0.05). However, growth development in both treatments was significantly different (P>0.05). Survival rate juvenile in sediment treatment was found at 6.10 % while no survived on control treatment. The study concludes that the water with additional Bold’s basal medium is viable for the propagation of freshwater microalgae as feed for Corbicula fluminea. At the same time, Asian clam broodstock in December is the best time for the adult to produce larvae. Besides that, sediment could enhance the better mean SL as well as SH, and also survival larvae.