Overview of redclaw crayfish, Cherax quadricarinatus, farming practices in northern Australia

Development and current status of the redclaw crayfish, Cherax quadricarinatus,farming industry in tropical and sub-tropical Australia are described. Industry development has occurred mainly adjacent to the eastern coastline close to support infrastructure, suitable water supply and within a temperature range that enables commercially acceptable growth. Area of pondage varies from 0.5 to 12 ha per farm. Australian production levels, as determined by survey, remain below 50 tonnes from approximately 90 ha for 1992/93. No more than 10 tonnes were added to this total in the two previous financial years. Stock and pond management practices vary considerably between farms and regions. Depressed marketable yields are attributed to excessive numbers of small crayfish in each crop. Implementation of management practices to overcome this include extensive use of habitat, selection of broodstock with suitable characteristics, improved nutrition, cull harvesting, supplementary aeration and (in smaller operations) manual sexing. Increased productivity and total production are anticipated as better management practices are employed. Most product is sold live to domestic markets. Increasing export of product is likely as production levels increase with coordinated marketing of quality assured product. This will be facilitated by the recent formation of a marketing company comprising the majority of active farmers as shareholders

Interpretations of Retrograde Amnesia: Old Problems Redux

Recent evidence indicates that an old memory reactivated by cueing becomes labile and vulnerable to an amnesic treatment. Although the \u27reconsolidation\u27 concept derived from these findings challenges the traditional consolidation theory, here we argue that the new concept suffers from some of the same limitations as the earlier model. We propose an alternative retrieval-based theory that accommodates the recent data, as well as other puzzling related observations.</p