The Nutritional Aspects of Cannibalism in Crustacean Aquaculture: With Emphasis on Cultured Tropical Spiny Lobsters

Abstract

Cannibalism in high-value crustacean species, such as mud crab, clawed lobster, and spiny lobster, is a major impediment to commercial aquaculture due to its significant impact on survival and, hence, production. Knowledge of the nutrition acquired from consuming conspecifics may inform whether nutrient limitation is a primary reason for cannibalism, and if so, assist with feed formulation to prevent cannibalism. While feed shortages are usually not a limitation in aquaculture, nutrient limitation due to inefficient feed intake should not be disregarded, especially with formulated feeds. Additionally, unique nutrients may be absent from formulated feeds, the deficit of which may play a role in triggering cannibalism. The reasons for cannibalism in crustacean aquaculture are still unclear and possibly involve several factors, including feed availability, population density, life stages, resource competition, and prey vulnerability. In general, various forms of cannibalism exist that may have multiple drivers, including nutritional (e.g., state of hunger and lack of specific nutrient), behavioral (e.g., mating and aggression), ecological (e.g., population structure) and environmental (e.g., space limitation). In crustaceans, cannibalism occurs generally when animals are vulnerable; this may coincide with moulting events or through the lack of habitat complexity or density restrictions. The simultaneous occurrence of multiple factors influencing cannibalism in crustacean culture constitutes a major challenge for evaluating the relative significance of nutrition to cannibalism. In this review, we examine cannibalism, its drivers, and its relationship to nutrition in numerous terrestrial and aquatic species, with emphasis on crustaceans, particularly the tropical spiny lobster, Panulirus ornatus.