Experimental cultivation of freshwater prawns (Macrobrachium rosenbergii) in polyculture with Australian red-claw crayfish (Cherax quadricarinatus)

Abstract

Abstract
Background and Aim. Arthropod farming in ponds, tanks, and recirculating aquaculture systems (RAS) is becoming increasingly popular worldwide due to the high market value and consumer appeal of fresh or chilled arthropod products. Co-culture of the most popular freshwater arthropods, the giant prawn (Macrobrachium rosenbergii De Man, 1879) and the red-claw crayfish (Cherax quadricarinatus von Martens, 1868) may be a very promising approach to aquaculture, but has been little studied to date.
Materials and Methods. Freshwater prawns and Australian red-claw crayfish were co-cultured in a recirculating aquaculture system in five tanks, each with a capacity of 2.2m³. All aquatic organismsfrom each tank were collected weekly to determine growth rates and weight increments, as well as to adjust daily rations. A MASSA-K BK 600 scale with an accuracy of 0.1 g was used to determine the body
weight of the aquatic organisms. To determine the hydrochemical regime, dissolved oxygen and pH levels were measured daily, as well as water temperature, using a YSI EcoSense DO200A portable thermooxymeter and a Testo 206 pH meter. Nitrite and nitrate tests were performed weekly using Tetra drop test kits.
Results. The effects of varying the ratio of Rosenberg's freshwater prawns to Australian red-claw crayfish grown in polyculture were studied. Absolute growth in the second and fifth groups was 0.3 g and 0.8 g greater than in the control (first group), while in the third and fourth groups it was 1.7 g and 1.9 g less than the control. Relative growth was also higher in the second and fifth groups by 3% and
20%, respectively. The highest survival rate, excluding the control group, was also noted in the second and fifth groups – 90% and 87%, respectively, and the lowest in the third and fourth groups – 80% and 83%, respectively.
Conclusion. The highest growth rates were observed in groups with uneven aquatic organism ratios (the second and fifth groups), where absolute growth rates were 11g and 11.5 g, respectively.
This indicates more optimal conditions for rearing, with reduced interspecific competition. The experiment demonstrates significant potential for combined rearing of Rosenberg's freshwater shrimp and Australian red-claw crayfish at a ratio of 4:1.