Lobster Diet Research Articles

In search of a reference protein to replace "vitamin-free casein" in lobster nutrition studies

The possible nutritional value of proteins prepared by isopropanol extraction of soft flesh of the sea urchin (Strongylocentrotus drobachiensis), mussels (Mytilus edulis L.), crab (Cancer irroratus), and shrimp tails (Penaeus sp.) was compared with casein in semipurified diets for juvenile lobsters. So that results of the feeding trial could be compared with other nutrition studies, a standard casein–albumin diet and frozen adult brine shrimp (Artemia salina) were fed as reference diets. While diets containing crab, mussel, and sea urchin protein all resulted in significantly greater survival than the casein-based diet, the diet containing crab protein alone was superior in both growth and survival. The diet consisting of shrimp protein was inferior to casein in all respects. The possibility of replacing casein with a crab protein isolate in reference diets for lobster nutrition studies is discussed.

EFFECTS OF DIETS ON THE FATTY ACID COMPOSITION OF JUVENILE ATLANTIC SILVERSIDES (Menidia menidia)

AbstractJuvenile Atlantic silversides (Menidia menidia) were cultured for 24 days on a live 3‐day‐old brine shrimp nauplii (Artemia salina) diet as well as the following artificial diets: a Conklin modified lobster diet, a Tunison laboratory modified diet (pellet and flake forms), and a Meyers closed formula flake prawn diet. A combination diet of brine shrimp nauplii and the Meyers prawn diet was also evaluated. The total lipid level and fatty acid profile of the diets and cultured fish were compared to those of the wild fish. Growth and survival were used as indicators of the overall performance of the various diets.The greatest growth and survival was found in fish fed live brine shrimp. However, their fatty acid profile resembled their diet profile more than that of the wild fish. The combination diet produced nearly equal growth and survival compared to brine shrimp fed fish and gave a fatty acid profile more like the wild fish. Therefore, the combination diet sacrificed little overall performance but promoted a better lipid character. Although the Conklin modified lobster diet produced an acceptable survival (7851, no artificial diet promoted growth or survival which was equal to brine shrimp or the combined diet fed fish.The use of the brine shrimp‐artificial diet combination reduced, by 50%, the number of brine shrimp cysts required for the successful culture of silversides.

Growth of the rock lobster Jasus lalandii and its relationship to benthos

Growth increments of the male rock lobster Jasus lalandii vary systematically with location within a small (38 km2) fishing ground off the South African west coast. High growth rates were recorded from an area where the availability of benthos suitable as rock-lobster food was also high. Increments could also be shown to vary significantly in different years, but over the size range examined, growth did not appear to be a function of size. Benthic biomass was found to be inversely related to depth. However, comparisons between biomass values from the same depths in two different areas of the fishing ground suggested that biomass was higher in areas which were in proximity to shallow water, where extensive kelp beds were found. Mussels (Aulacomya magellanica) formed an important constituent of the rock lobster's diet; these were prevalent at depths between 20 and 40 m, and especially in areas where rock-lobster growth rates were high.