Preface.Acknowledgements.Introduction.Form and Function.Origin and Evolution.Nautilus: The Survivor.Biodiversity and Zoogeography.Life Cycle.Growth.Physiological Ecology.Reproductive.From Egg to Recruitment.Coastal and Shelf Species.Oceanic and Deep-Sea Species.Cephalopods as Predators.Cephalopods as Prey.Fishing Methods and Scientific Sampling.Fishery Resources.Fisheries Oceanography.Assessment and Management.Conclusions.Appendix A: Classification of Living Cephalopod Families.Appendix B: Synopsis of Living Cephalopod Families.References.Index.

Cephalopods: Ecology and Fisheries

▪ Abstract Studies investigating the effects of temperature, food availability, or other physical factors on the physiology of marine animals have led to the development of biochemical indicators of growth rate, metabolic condition, and physiological stress. Measurements of metabolic enzyme activity and RNA/DNA have been especially valuable as indicators of condition in studies of marine invertebrates and fishes, groups for which accurate determination of field metabolic rates is difficult. Properly calibrated and applied, biochemical indicators have been successfully used in studies of rocky intertidal ecology, where two decades of experimentation have generated rigorous, testable models for determining the relative influences of biotic and abiotic factors on species distribution, abundance, and interaction. Biochemical indicators of condition and metabolic activity (metabolic enzymes, RNA/DNA) have been used to test nutrient-productivity models by demonstrating tight linkages between nearshore oceanogra...

Biochemical indicators of stress and metabolism: applications for marine ecological studies.

Fluidity and Function of Hepatocyte Plasma Membranes

The regulation of the rate of synthesis of tissue proteins is of the utmost importance to the energetic cost of the maintenance and growth of the whole animal. After water, protein is the largest component of the body mass and minimal theoretical estimates of the cost of synthesising proteins indicate that they represent the most expensive molecules to produce (e.g. Kiorboe et al. 1987; Jorgensen 1988). Studies on mammals have indicated that whole body protein metabolism is closely correlated with basal energy metabolism (Garlick et al. 1976; Waterlow 1980; Meier et al. 1981), and the indications are that similar correlations exist for ectotherms (Hawkins et al. 1989). The aim of this chapter is to review the data which have recently become available on the rates of protein synthesis in ectotherms and attempt to integrate them with the likely energy cost of synthesising these proteins.

Protein Turnover in Ectotherms and Its Relationships to Energetics

Aquaculture potential of the common octopus (Octopus vulgaris Cuvier, 1797): a review

Rates of protein synthesis in the whole body and tissues ofOctopus vulgaris collected in September 1985 and 1986 from the Bay of Naples were measured following a flooding dose injection of3H phenylalanine. There were stable phenylalanine free pool-specific radioactivities and linear incorporation of radiolabel into arm-tip protein from 10 to 30 min after the injection. In starved individuals there were no significant differences between the fractional rates of protein synthesis of the following tissues: ventricle, brain, branchial heart, arm tip, gill, stomach, arm, renal appendage and mantle. The mean value (± SE) for all the tissues was 3.02 ± 0.17% d−1. In individuals fed varying amounts of crab, resulting in differing growth rates, there was a linear increase in fractional rates of whole-body protein synthesis with growth rate. A standard 148 g octopus growing at 3.0% d−1 synthesised 0.54 g of protein, with 0.43 g of this protein retained as growth. The proportion of the total protein synthesis which was retained as growth increased with increasing growth rate; at a maximum growth rate of 6% d−1, over 90% of the protein synthesised was retained as growth. The ventricle, arm tip, gill, arm and mantle also showed similar patterns of a linear increase in fractional rates of protein synthesis with increased growth rates. The RNA concentrations in the whole body and tissues increased with increasing growth rates, but the major change was an increase in the efficiency of translation. It is concluded that rapid growth rates inO. vulgaris are brought about by high rates of protein synthesis and high efficiencies of retention of synthesised protein and, therefore, little protein degradation.

L. Foti

Papers

Protein synthesis and growth in Octopus vulgaris

In vitro cardiac performance in Octopus vulgaris (Lam)

Influence of age on 5'-nucleotidase in plasma membranes isolated from rat liver.

Biosynthesis of cholesterol from long-chain fatty acids in cell-free systems from rat liver

Properties and sidedness of 5'-nucleotidase in rat red cell ghosts.