A Statistical Study of Growth and Maintenance in the Plaice (Pleuronectes platessa L.)

Abstract

The aim of the paper has been to treat the data of the Plaice experiments on Growth and Maintenance, carried out at Cawsand and Lympstone during 1929 and 1930, in a statistical manner. The experiments for each sex, year and place have been resolved into experiments with an average plaice during the “average” 14 days of the third growth season. Growth and food-percentage indices have been provided and a fairly high degree of correlation between food and growth has been indicated, and shown to be uniform for the sexes. Regression coefficients indicating the facility with which food is utilised for purposes of growth have been worked out and have been shown to vary with place and year, but not with sex. Maintenance demands have been evaluated and shown to be slightly greater in males than in females. The diminished demands during winter months have also been evaluated. The outstanding features of the results are the distinct differences shown between the Cawsand and Lympstone plaice, which differences it is suggested arise out of size differences to a large extent.