Evaluation of a gastric lavage method for sturgeons

Because of their threatened status, sturgeon (Acipenseridae) can no longer be sacrificed for stomach content analysis. We tested a non-lethal method of gastric lavage on Siberian sturgeon Acipenser baeri. The efficiency and harmlessness of the method were tested with four different volumes of food (10, 20, 30 and 40 cm3) each composed of sand shrimp Crangon crangon, Chironomidae, earthworm Lumbriscus terrestris and sand goby Pomatoschistus minutus. The Siberian sturgeons were force-fed before the gastric lavage was performed. Some prey were recovered from all the sturgeons and the average food item recovery rate from stomach contents was 67.5%, with a higher recovery of sand shrimp and sand goby (78.2%) than of vermiform items (51.4%). The volume of food used had no significant influence on the prey recovery rate. No mortality resulted from the gastric lavage. However, the method is not totally benign since the fish that had undergone gastric lavage averaged significantly greater weight loss than the control fish during the 60-d follow-up period.