Feeding behaviour, efficiency and food preference in yabbies Cherax destructor

Abstract

The influence of body size on the consumption of live zooplankton (Daphnia spp.) by freshwater crayfish was examined using yabbies (Cherax destructor) ranging from 5 to 45 g. Food preference between live zooplankton and inert pellets was also assessed under experimental conditions. In experimental tanks, yabbies of four size classes (\15, 15-24.9, 25-34.9 and 35-45 g) were presented with live Daphnia. All yabbies were held in separate tanks with five animals per size class. In yabbies less than 15 g, the feeding mode on zooplankton involved rapid searching and probing with the first two pairs of walking legs. Once a prey was located, the chelae on the end of these walking legs would grasp the zooplankton and then rapidly move it towards the mouthparts. Yabbies larger than 25 g tended to use their walking legs to push the Daphnia nearer to their third maxilliped which would then force or scoop the zooplankton towards the mouthparts. A short-term feeding trial showed that there was no significant difference between size classes in regards to zooplankton consumption (P [ 0.05). Capture efficiency of live Daphnia by yabbies less than 15 g was significantly lower (76%, P = 0.008) than the three larger size classes (93.6%). Yabbies less than 15 g consumed a significantly (P \ 0.001) higher percentage (5.2%) of their body weight than the other size classes (1.1%, 0.8%, and 0.6%, respectively). In the presence of both live zooplankton and a pellet diet, yabbies spent significantly (P = 0.005) more time feeding on zooplankton (85%) than on inert pellets (15%). This was the first study to quantify zooplankton consumption by yabbies and the results provide insights into understanding the trophic role of freshwater crayfish in structuring zooplankton communities and the husbandry management of crayfish farming.

Effects of Different Diet Types on Growth and Survival of White-Clawed Crayfish Austropotamobius pallipes in Hatcheries

“…This is in contrast to a study on hatchling P. leniusculus, where no significant difference in survival between Artemia cysts and live Artemia nauplii was observed (González et al, 2009). When four age classes of yabby Cherax destructor were tested with live plankton versus pellet food, they spent 85% of their time feeding on live food and 15% feeding on the inert pellets (Meakin et al, 2008), demonstrating a preference for live food items. This was also observed in a study where juvenile hairy marron Cherax tenuimanus, when presented with both live Daphnia and pellet, showed a significant preference for feeding on the live food (Meakin et al, 2009).…”

Zooplankton Predation and Consumption by Freshwater Crayfish, Cherax tenuimanus, at Different Sizes and Light Conditions

“…Larger marron were, in fact, able to capture a greater number of zooplankters than smaller conspecifics within the same period of time. As Meakin et al (2008) found that yabbies (Cherax destructor) could easily capture live zooplankton well past the juvenile stage, post juvenile marron 0 4 1-2.9 3-7.9 8-1 5…”

“…However. Meakin et al (2008) recently found that the yabby is capable of consuming large quantities of live daphnids beyond the juvenile stage.…”

Effects of soluble dietary cellulose on specific growth rate, survival and digestive enzyme activities in three freshwater crayfish (Cherax) species

“…New freshwater crayfish culture industries are needed, therefore, to meet a growing demand for product. Three Cherax species (redclaw, C. quadricarinatus ; yabby, C. destructor ; and marron, C. tenuimanus ) have been identified as excellent candidate species for commercial culture (Lawrence & Jones ; Meakin, Qin & Mair ; Wingfield ), and farming systems have been developed for each species over the past two decades (Wingfield ).…”