Physiological Studies on Cancer irroratus Larvae. III. Effects of Temperature and Salinity on the Partitioning of Energy Resources During Development

Abstract

Balanced energy budgets were estimated for larval stages of the rock crab Cancer irroratus cultured in 6 combinations of temperature and salinity. The energy consumed by larvae during developn~ent increased in all culture conditions although consumption in 10 'C -30% S was significantly lower than for larvae in other conditions (15 "C -25 ' %o S, 15 "C -30 %O S, 15 "C -35 %o, 24 "C -30%0 S). Maintenance costs for the entire developmental period were highest for larvae cultured at 10°C -30% S and 15°C -25% S. Larvae under these conditions had net growth efficiencies of only 32-34 %. In the other temperature and salinity conditions tested, the amount of energy expended for maintenance was generally equal to the amount of energy converted to new tissue with net growth efficiencies varying between 4 8 and 51 %. These data suggest that the larva's ability to acquire energy resources and effectively partition the energy obtained between maintenance and growth depends on environmental factors. Under certain conditions (lO°C -30% S, 15OC -25 % S ) larvae are unable to compensate physiologically for environmental changes. One consequence of incomplete physiological compensation is a reduced potential for growth and an overall reduction in the organism's ecological fitness within the zooplankton community.

Biochemical changes associated with embryonic and larval development in the American lobster Homarus americanus Milne Edwards

“…lipid was also a contributing factor as the increased levels in the fourth stage also contributed to the decrease in percent content of protein. (Johns, 1982).…”

Larval growth in the estuarine crab Chasmagnathus granulata: the importance of salinity experienced during embryonic development, and the initial larval biomass

“…Low salinities lead to a decrement in growth rates or even loss of weight in larval instars of several marine and estuarine crustaceans (Johns 1982;Pfaff 1997;Anger et al 1998Anger et al , 2000; instars with osmoregulatory abilities seem to be less sensitive to low salinity (G. Torres et al, in press). Effects of salinity on larval growth may also depend on initial larval reserves or acclimation history, especially in estuarine crabs.…”

Growth, tolerance to low ­salinity, and osmoregulation in decapod crustacean larvae

“…Reduced rates of feeding, assimilation and growth have been observed, when decapod larvae are exposed to osmotic stress (Johns 1982. Torres et al (2002) found that the negative effects of reduced salinity on first-stage larval growth were stronger in stenohaline than in euryhaline species (Cancer pagurus, Homarus gammarus vs. Carcinus maenas, Neohelice granulata).…”