Effects of rearing density and sub-sand filters on growth performance of juvenile freshwater mussels (Chamberlainia hainesiana) reared under recirculating system conditions

Abstract

Chamberlainia hainesiana, a commercially valuable bivalve, is found in Thailand. Juveniles of C. hainesiana have been successfully cultured in sterilized artificial media for culturing glochidia (to bypass the parasitic stage) until they develop into the juvenile stage. The survival percentage of glochidia in standard tissue culture medium (M199) supplemented with common carp plasma and antibiotics/antimycotic was 97.2 2.5%. All surviving larvae (100%) ultimately transformed into juveniles within 8 days. Early juveniles (0-90 days old) were reared in recirculating systems and were cultured at three density levels (500, 1500, and 3000 per culture unit) in a laboratory. The density level of 500 per culture unit resulted in the highest and most significant (p < 0.05) growth rate, with an average shell length and shell height; the average survival was 71.3 0.4%. The 90-150-day-old juveniles were reared outdoors in two different systems (with and without a filter plate). They were fed by filtering phytoplankton from the water in an earthen pond. The filter-plate system produced the highest growth rate (p < 0.01), with an average weight gain and shell size; the average survival was 98.7 0.6%. A forecasting equation was used to describe the shell length of juveniles, i.e., the relationship between shell length (L, mm) and age (t, days). The equations for 0-90-day-old early juveniles cultured in the laboratory (500 per culture unit), and for 90-150-day-old juveniles cultured using system 1 were L = 0.5236 0.053t + 0.0023t 2 1 10 5 t 3 (r 2 = 0.956) and L = 51.302 + 0.6812t 5 10 6 t 3 (r 2 = 0.940), respectively.