Swimming Endurance of Juvenile Pallid Sturgeon, Scaphirhynchus albus

Abstract

Hatchery-reared, juvenile pallid sturgeon (Scaphirhynchus albus) were subjected to swimming stamina tests in a 100-L Blazka-type swim tunnel at 17-20 C. Endurance was measured at fixed velocities ranging from 10-70 cm/sec, and sustained, prolonged, and burst swimming speeds were identified for two size groups: 17.0-20.5 and 13.0-16.8 cm FL. Maximum observed sustained swimming speed (no fatigue after 480 min) was 25 and 10 cm/sec, respectively, for the large and small size group. A curvilinear relationship was found between endurance and speed over the prolonged/burst speed range. Burst speeds of 55-70 and 40-70 cm/sec were measured for the large and small fish, respectively. Similar to other lotic, benthic fish, sturgeon could use their pectoral fins and overall body morphology to maintain station against velocity without swimming. Fish typically swam with the ventral body surface in contact with the tunnel bottom during tests, rarely swimming in the water column. Swimming speeds of pallid sturgeon are comparable to speeds reported for similar-sized lake sturgeon (Acipenser fulvescens), but they exhibited lower performance relative to other species. Juvenile pallid sturgeon may inhabit high velocity rivers by taking advantage of low velocity microhabitats.