Trial on artificial breeding and laviculture of giant razor clams (Cultellus maximus Gmelin, 1791)

The study was carried out with the aim of determining the reproductive parameters and performing the rearing of giant razor clams (Cultellus maximus Gmelin, 1791) at larval stage and postlarval stage with different diets. The results showed that the spawning rate was 62.22 ± 3.85%, the fecundity was 7.98 ± 0.67 million eggs/female, the relative fecundity was 48,081 ± 5,826 eggs/g female, the fertilization rate was 42.67 ± 4.47%, and the hatching rate was 44.19 ± 4.02%. The rearing at larval stage with different diets of algae was investigated ((T1.1): Nanochloropsis oculata + Isochrysis galbana; (T1.2): N. oculata + Chaetoceros muelleri; and (T1.3): N. oculata + Isochrysis galbana + C. muelleri). The results showed that T1.3 gave the survival rate, length and width of larvae, reaching 5.3 ± 0.91%; 1525.60 ± 48.90 μm and 918.20 ± 28.00 μm, respectively. The parameters obtained from T1.3 was significantly higher (P < 0.05) than that of T1.1 and T1.2. The rearing at postlarval stage with different diets was also studied as follow: (T2.1): N. oculata + I. galbana + C. muelleri; (T2.2): using commercial feed (Lansy and Frippak); and (T2.3): combination of 50% of T2.1 + 50% of T2.2. The results showed that T2.1 gave the survival rate, growth in length and width of postlarvae, reaching 11.83 ± 3.89%; 5.72 ± 0.61 mm and 3.31 ± 0.14 mm respectively. Growth parameters of T2.1 were significantly higher (P < 0.05) compared to that of T2.2 and T2.3.