Speed, Acceleration and Manoeuvrability of Two Teleost Fishes

Abstract

Speed, acceleration rate and turning radius were measured for rainbow trout (Salmo gairdneri length 25·7 cm) and smallmouth bass (Micropterus dolomieu; ength 23· 6 cm) attacking live minnows. The observations sampled a range of values for each kinematic variable up to the limits of maximum performance. Minimum turning radius was independent of speed and acceleration rate. Expressed as a ratio of total length, L, minimum radii were 0·18 ± 0·2L for trout and 0·11 ± 0·02L for bass . Differences in minimum turning radius, R, between trout and bass were attributed to differences in the volume of the body and entrained water, V, and projected lateral surface area of the body and median fins, A. For subcarangiform swimmers, the dimensionless minimum specific turning radius R/L = 2V/AL. Since V is numerically equal to the mass of the body, M, and added water mass (approximately 0·2M) for neutrally buoyant fish, R/L can be calculated from two easily measured morphological parameters, M and A.