Influence of Starvation and Subsequent Feeding on Body Composition and Energy Reserves in the PrawnPandalus platyceros

Abstract

Biochemical composition of body segments and physiological condition of the spot prawn (Pandalus platyceros) were determined during 84 d of starvation and 21 d of subsequent feeding. Maximum molting frequency, 1.79%∙d−1, occurred from day 22 to 43 and mortalities peaked at 0.81%∙d−1 on resumption of feeding. Ratios of wet weight of hepatopancreas to abdomen or whole body decreased on starvation and increased on feeding, and so provided an index of physiological condition. Uptake of moisture and chlorides with loss of other halides in prawn tissue resulted from starvation. Resting oxygen consumption rate declined by 50% after 40 d of starvation. Lipid in the hepatopancreas increased during early inanition to become the major energy source. Lipid contributed 73.1%, protein 20.6%, and carbohydrate 6.3% of total metabolized reserves. Hepatopancreas, carcass, and abdominal muscle generated 49.1, 33.4, and 17.5% of energy utilized. On subsequent feeding, lipid, carbohydrate, and protein accounted for 73.8, 20.1, and 6.1% of total caloric uptake with energy assimilation by body sections similar to depletion values. Spot prawn have sufficient reserves to remain in good commercial condition for 40 d without food.

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

“…There are several studies which have defined the relationship between stress and physical condition in decapod crustaceans (Stewart et al 1967, Dall 1974, 1975b, Whyte et al 1986. In this study, measures of physical condition were used to determine the degree of physiological stress experienced by the lobsters.…”

“…There is no evidence that the lobsters can result in catabolism of both digestive gland and return to the Torres Strait or reappear at Yule Island in muscle (Heath & Barnes 1970, Dall 1974, 1975a, 1981, subsequent years. It has been suggested that the simul- Barclay et al 1983, Landau 1985, Whyte et al 1986). In taneous physical and physiological demands of reproPanulirus cygnus, starvation was accompanied by an increase in the water content of the abdominal muscle and digestive gland solids (Dall 1974).…”

“…The mass fractions of ash (W ash) that were used to correct the total carbon and nitrogen measurements in each sample were: Torres Strait Reef, 0.04; Torres Strait Trawl and Gulf of Papua, 0.045; Yule Early-season and Late-season, 0.08; Yule Mid-season, 0.085; High-food treatment, 0.05; Low-food treatment, 0.1. The values used for the elemental composition of the ash in the digestive gland were ash W(C) = 0.14 and ash W(N) = 0.045 (Gnaiger & Bitterlich 1984, Whyte et al 1986). …”

“…A mass fraction of W ash = 0.074 was used to adjust the total carbon and nitrogen values for lobsters from all san~ples except the Low-food cage treatment, for which a conservative correction of W ash = 0.09 was used. Values for the elemental composition of muscle tissue ash were ash W(C) = 0.002 and ash W(N) = 0.004 (Gnaiger & Bitterlich 1984, Whyte et al 1986.…”

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“…Whyte et al (1986) used the ratio of wet weight of hepatopancreas of whole body as an index of physiological condition in the prawn Pandalus platyceros and demonstrated that the ratio decreased on starvation and increased on re-feeding. Armitage and Wall (1982) suggested that changes in moisture content in the body tissue reflect physiological changes during starvation.…”