Comparison of selected condition indices between intermolt and post-molt marron, Cherax tenuimanus, of different feeding status raised under intensive culture conditions

摘要

Mature marron, Cherax tenuimanus (mean weight 40.2±2.3 g), were raised in an intensive system to investigate changes in hepatopancreatic and tail muscle indices and total haemocyte counts in fed intermoult (stage C) and either fed or non-fed post-moult (stage AB) groups. Marron were raised in individual compartments in a recirculating system under controlled environment. Wet and dry somatic indices, tissue moisture of hepatopancreas and tail muscle, and total haemocyte counts were analysed in 10 marron in each group. The results showed no differences in hepatopancreatic indices between intermoult or post-moult fed marron, while food deprivation resulted in marron having smaller hepatopancreata with higher moisture content. Furthermore, fed intermoult marron had smaller tail muscle with lower moisture content compared to fed post-moult marron. Food deprivation resulted in this post-moult group having high muscle moisture content. The wet muscle index in non-fed post-moult group was comparable to that of the fed pre-moult group, while dry muscle index was comparable to that of the fed post-moult group. The total haemocyte counts were similar among all studied groups. It was concluded that moult stage affects the tail muscle indices and that the assessment of marron condition could be based on hepatopancreatic or tail muscle indices.