The use of fine needle fibre endoscopy in fish for in vivo examination of visceral organs, with special reference to ovarian evaluation

Endoscopic techniques for visceral organ and ovarian examination of rainbow trout (Salmo gairdneri) are described. Internal organs can be readily identified and qualitatively assessed. It is possible to distinguish sex, and in the female, state of maturity can be identified, as well as some morphological characteristics of individual ova. Repeated use of the initial entry hole for the endoscope is recommended. Gross healing of the surgical incision is 70% complete in 7–10 days, without signs of inflammation or other internal damage. The advantages of fine needle fibre endoscopy are discussed.