Effects of temperature on farmed marine polychaete Perinereis helleri and its fatty acid profile

Abstract

Abstract This study investigated short‐term effects of temperature on survival, body weight and the fatty acid profile of farmed marine polychaete Perinereis helleri—an excellent live feed maturation diet for penaeid shrimp broodstock. Two consecutive experiments were conducted to evaluate the effects of low temperature (4, 8, 12, 16 and 20°C) and high temperature (20, 24, 28, 32 and 36°C) on a 7‐month‐old population of P. helleri farmed at Bribie Island Research Centre, Australia. The experimental polychaetes were purged for 24 h at 20°C before being transferred directly into 500 ml glass chambers, sealed and submersed in different target temperature water baths. The jars were then kept for 3 or 6 h in the low‐temperature experiment and 1 or 3 h in the high‐temperature experiment, respectively. Results showed that mortality occurred only at 4°C and 8°C (p < 0.01). Weight loss occurred across all treatments of the low‐temperature experiment, but only at 36°C in the high‐temperature one. Analysis of lipid classes and fatty acids show that farmed P. helleri is rich in polyunsaturated fatty acids (PUFA, i.e. 37% of total fatty acids), especially arachidonic acid (ARA, 20:4n‐6). The total value of essential fatty acids was 15.8% of total fatty acids or 16.8 mg/g dry matter. The n‐3:n‐6 ratio was 1.07 ± 0.04. This study suggests that P. helleri can be transported at ambient temperature of 16–20°C and can be farmed in a tropical climate.

Keywords

• fatty acids
• marine polychaete
• Perinereis helleri
• survival
• temperature