Field endoscopy for identifying gender, reproductive stage and gonadal anomalies in free-ranging sturgeon (Scaphirhynchus) from the lower Mississippi River

• Published in: Journal of applied ichthyology Vol. 25; no. s2; pp. 68 - 74
• Main Authors: Divers, S.J, Boone, S.S, Hoover, J.J, Boysen, K.A, Killgore, K.J, Murphy, C.E, George, S.G, Camus, A.C
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-10-2009; Blackwell Publishing Ltd
• ISSN: 0175-8659; 1439-0426
• DOI: 10.1111/j.1439-0426.2009.01337.x

Thirty-six sturgeon (Scaphirhynchus spp.) were captured from the lower Mississippi River using baited trot-lines, anesthetized using tricaine methanesulfonate, and subjected to endoscopic evaluation of their coelom (coelioscopy) on the river bank. Using a 2.7 mm rod-lens telescope and gravity-fed sterile saline infusion, gender and reproductive stage were determined in the field, and later re-evaluted and confirmed by histology of endoscopic biopsies in the laboratory. Gender and reproductive stage were determined endoscopically in all fish without complication, and proved to correlate 100% with biopsy histology. Modern rod-lens telescopes and sterile saline insufflation can be used under field conditions, provide superior visualization of sturgeon gonads, and offer a high degree of accuracy even with inactive gonads. Rigid endoscopy is recommended as a minimally-invasive means of assessing the reproductive organs of sturgeon and other fish.