Herbivore responses to a seasonally fluctuating food supply: Growth potential of two temperate intertidal fishes based on the protein and energy assimilated from their macroalgal diets

摘要: Abstract The protein and energy assimilated from eight main dietary algae by the stichaeid fishes Cebidichthys violaceus (Girard) Xiphister mucosus were calculated using bimonthly data on chemical compositions (carbohydrate, protein, lipid) of these stomach contents assimilation efficiencies two fish species. effects food choice diet quality estimated comparing amounts determined to be actual (selective) diets with those that would hypothetical (nonselective) based algal availability. Both consumed carbohydrate-rich, protein-poor in winter protein-rich, carbohydrate-poor during rest year. Thus, contrary an expectation optimal theory, intake was increased selection only winter, whereas at expense all other times. Growth rates predicted a growth curve relative their or just above maintenance levels higher times additional species small animal material appeared not alter substantially annual pattern. Although seem able grow most year completely diet, consumption, which turn regulate intake, are unknown must examined before more definite conclusions can drawn about fishes.