REPLACEMENT OF FISHMEAL WITH ALTERNATIVE PROTEIN SOURCES FOR AUSTRALIAN RED CLAW CRAYFISH Cherax quadricarinatus

The Australian red claw crayfish (Cherax quardicarinatus) has been gaining attention as an aquaculture species in the last few decades attributed to several positive characteristics for ease of production.  Their omnivorous feeding habits provide farmers with a unique position to lessen the dependence on fish meal as the primary protein source.  Red claw appear to be able to grow well when fed various plant proteins (soybean, wheat flour, milo, pea meal) as partial replacements for fishmeal.  Turning to locally available feed ingredients, farmers will be able to formulate healthy, high performance diets without the need to purchase traditional fish feeds.  This study investigates the growth performance, nutrient utilization, muscle composition, and digestive enzymes of juvenile crayfish when fed diets without fishmeal.

Six experimental diets formulated without fish meal were compared to 2 control diets, a commercial shrimp feed and a formulated fishmeal diet. Each of these diets were formulated to contain 35% crude protein and will be fed for 12 weeks.  The 6 experimental diets were composed of ingredients having potential for their incorporation into aqua feeds (e.g. black soldier fly larvae, brewer's grains with yeast, and distiller's grains with solubles); (See Table 1.).  Each experimental diet was formulated to incorporate these ingredients at 10 and 15% of the total protein content.  Twelve juvenile red claw crayfish with an average weight of 1.01 grams were stocked in 24, 90 liter aquariums.  Every 4 weeks, individuals will be counted and weighed to assess growth performance, size distribution, and survival.

Developing a more complete understanding of the nutrient requirements of juvenile red claw crayfish, while expanding the available options for terrestrial protein sources, will allow small-scale farmers greater opportunities to provide healthy diets that do not rely on fish meal as the primary protein source.  

After four weeks, there were no significant differences either in average weight (3.51 grams) or survival (80.2%) in all 8 diets.  Additional growth performance data and laboratory analysis are forthcoming and will be presented.