Physiological energetics of mussel larvae (Mytilus edulis). I. Shell growth and biomass

Abstract

Development and shell growth of the larvae of the marine mussel Mytilus edulis L. were recorded in laboratory cultures. Experiments were conducted at 6, 12 and 18 "C and food concentrations of 1, 2, 5, 10, 20, and 40 Isochrysis galbana cells p1-l. After fertilization, the eggs developed to the D-shaped stage within 104 h at 6"C, 42 h at 12"C, and 32 h at 18'C. Rearing was not successful with 1 I. galbana cell pl-l. At other food conditions, growth rate increased with concentration of I. galbana up to a plateau at about 10 cells Growth curves (shell length vs. time) were sigmoidal at the lowest food concentrations at 6°C; in all other cases they were linear with a maximum rate of 3.4 @m d-' at 6"C, 8.1 pm d-' at 12"C, and 11.8 pm d-' at 18°C. Total dry weight and ash weight were estimated for various larval stages. Based on these data, tissue dry weight, tissue wet weight, total wet weight and shell weight were calculated. Eggs, trochophores and the food organism I. galbana were analysed for their elemental composition (CHN). Body growth was estimated by data on shell growth and body weight.