Effect of broodstock diet on the fecundity and biochemical composition of eggs of the Patagonian red octopus (Enteroctopus megalocyathus Gould 1852)

Abstract

Twelve females of the Patagonian red octopus Enteroctopus megalocyathus, of 1.4 ± 0.2 kg, were maintained at 12 ºC under three conditioning treatments: T1 (F10%), frozen fish at 10% daily body weight (bwt d^–1); T2 (FC (3:1) 10%), mix (3:1) of frozen fish and fresh crab at 10% bwt d^–1; and T3 (F7.5%), frozen fish at 7.5% bwt d^–1. Egg laying was observed after four months of conditioning, when from 545 to 1100 ºC days had been reached, and when females had increased 1.5 times in body weight. Absolute fecundity reached 2129 eggs (±1182) per female in treatments T1 and T2, whereas in T3 fecundity reached only 56 eggs. The lowest values of perivitelline protein were obtained in T1 and T2, while total lipid content in the yolk was similar among treatments. The most frequent fatty acids in egg yolk were 16:0, 17:0, 17:1, 18:0, 20:1, 20:4n-6, 23:0, 20:5n-3, 22:5n-3, and 22:6n-3. Significant differences in fatty acid contents among treatments were observed only for 16:1 and 22:5n-3. The results showed that females can be conditioned for egg production even when fed a diet lacking crustaceans, and that a dietary reduction of 7.5% bwt d^–1 diminished fecundity without affecting egg quality in terms of their biochemical composition.