To define the body mass of each copepod accurately,
part of its homogenate was used for protein determination
according to the method of Bradford (Bradford,
1976). One thousand mircoliter aliquot of supernatant
of the homogenates were transferred to glass tubes and
dyed with 1000 mL of the Bradford Reagent (Sigma-
Aldrich B6919) at room temperature for 20 min. The
absorbance was measured on a spectrophotometer
(Hitachi, U1800) at 595 nm. Protein concentrations (mg
mL21) were computed from the standard curve of
protein concentration versus its absorption, using
bovine serum albumin (Sigma B2518) as standard.