Severe physiological stress associated with the annual breeding emigration of Panulirus ornatus in the Torres Strait

Abstract

Juvenile lobsters Panulirus ornatus in the Torres Strait emigrate once a year from the Torres Strait to the Gulf of Papua, several hundred kilometres to the northeast. They mature and spawn during this emigration. After spawning the lobsters disappear. It has been suggested that the combined stress of reproduction and emigration results in mass mortality. To test this hypothesis, lobsters were collected at several stages of the emigration and their condition defined by the water content and composition of the digestive gland and abdominal muscle. A cage experiment, with 2 feeding regimes, was conducted to examine the likelihood of post-reproductive mortality. Compared to lobsters in the Torres Strait, before emigration takes place, lobsters that had con~pleted the breeding emigration were in very poor condition. There were changes in the size and composition of both the digestive gland and abdominal muscle. Three stages of deterioration were recognised; in the final stage the digestive gland tissue was severely atrophied. The physiological characteristics identified in this study provide a quantitative basis for future work on the mortality rates of lobsters that have completed the emigration.

Biochemical composition of ovary, embryo, and hepatopancreas in the grapsoid crabs Armases cinereum and Sesarma nr. reticulatum (Crustacea, Decapoda)

“…During starvation or periods of nutritional stress the water concentration of the hepatopancreas increases (Dall, 1974;Trcndall and Prescott, 1989). During nutritional stress hepatopancreas C concentration decreases while N concentration increases (Trendall and Prescott, 1989). This is the same pattern we found for hepatopancreas tissue of varied color along the continuum from brown to cadmium-yellow.…”

Does Morning as Opposed to Night-time Feeding Affect Growth in Juvenile Spiny Lobsters, Jasus edwardsh?

“…Crear et al (2002) 7.75-17.5 Rayns (1991 0.842 Manuel (1991) 3.2-13.5 Hooker et al ( 1997) 60-1 17.6 Hooker et al ( 1997) 115.7-180 major storage site of energy reserves in decapod crustaceans (Gibson and Barker 1979;McLeod et al 2004 ). It is responsive to physiological stress (Trendall and Prescott 1989) and a good indicator of the condition of spiny lobsters (Glencross and Smith 1997;Musgrove 1997;Cockcroft 1997;Crear et al 2002;Ward et al 2003). The digestive gland index (DGI) recorded in this study at the start of the experiments (4.2) was similar to the 5% value previously recorded by Cockcroft (1997) for adult Cape rock lobsters J lalandii and juvenile J edwardsii .…”

Influence of physiological condition on cadmium transport from haemolymph to hepatopancreas inCarcinus maenas

“…protein, lipid and water concentrations in tissues and haemolymph and tissue proportions) have been used to describe the physiological condition of decapod crustaceans (Stewart et al 1967, Stewart and Li 1969, Trendall and Prescott 1989. Shore crabs exposed to cadmium in the laboratory show large individual differences in cadmium accumulation in various tissues, and correlations between cadmium concentrations in individual tissues are often seen (Bjerregaard 1982).…”