scholarly journals Biology of the Blood Crayfish,Euastacus gumarMorgan 1997, a small freshwater crayfish from the Richmond Range, northeastern New South Wales

2011 ◽  
Vol 35 (3) ◽  
pp. 685-697 ◽  
Author(s):  
Jason Coughran
1977 ◽  
Vol 4 (1) ◽  
pp. 37 ◽  
Author(s):  
WJM Vestjens

Australian pelicans (Pelecanus conspicillatus) were studied in colonies at 2 lakes in New South Wales. Adults regurgitated food for the young. Those up to 2 weeks old took liquid food from inside the tip of the adult's upper beak. Older ones took solid food from the adult's gullet, to age of about 3.5 months. After being fed, the young had convulsions lasting about 1 min; that did not happen after a second feeding immediately after the convulsion. Where there were 2 young of different sizes, only the larger convulsed, and sometimes the smaller was prevented from feeding and died of starvation. The survivor continued to have convulsions after feeding, as did single young, when there was no competition for food. Food was mainly fish; the most abundant fish was goldfish (Carassius auratus); a minor item was perch (Perca fluviatilis). Fish were 60 to 247 mm long and weighed 17 to 320 g. Crustaceans were less important and included freshwater crayfish (Cherax destructor) and shrimp (Macrobrachius sp.).


1983 ◽  
Vol 34 (3) ◽  
pp. 407 ◽  
Author(s):  
RA Faragher

The freshwater crayfish C. destructor was a major dietary item for brown trout, Salmo trutta L., and rainbow trout, S. gairdneri Richardson, in Lake Eucumbene, New South Wales. The incidence of crayfish in the diet increased, particularly in brown trout, over the period 1972-1977. The proportion of the trout's diet comprising C. destructor increased with length of brown trout but not with length of rainbow trout. The size of crayfish ingested was postively correlated with fish length for both species of trout, although rainbow trout tended to ingest smaller crayfish than brown trout of equivalent size. Analysis of the crayfish's diet revealed predominantly plant material. Spawning by the crayfish was apparently confined to the period December-April. The abundance of C. destructor in Lake Eucumbene was apparently low until about 1970 but increased between 1972-1977. A decline in the average size of brown and rainbow trout in the angler catch occurred from 1959-1960 until 1977-1978. Hypotheses are suggested for the increase of the crayfish population since impoundment of the lake (1957). Factors considered include predation by trout and the biology of the crayfish, particularly related to its occurrence in this lake, which has fluctuating water levels and a short season suitable for growth and spawning.


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