Variation in the Condition of Northern Pike, <i>Esox lncius</i>

Abstract

The relationship between condition and latitude, temperature, and sex of northern pike (Esox lucius) was examined by regression analysis of 5210 published observations drawn from more than 38 populations. Most populations showed nearly isometric growth, but the overall exponent of the power function relationship between total body length and body weight was slightly less than 3 (p &lt; 0.01). Multiple regression analysis showed that females weighed about 9% more than males of equal length, that body weight for fish of equal length increased about 5% for every 10° increase in north latitude and increased about 4% for every 10 °C decrease in mean annual air temperature, and that fish in European and Asian populations attained about 13% greater weight for a given length than their North American counterparts.