Induced maturation and spawning in an incidentally caught adult pair of critically endangered European sturgeon, Acipenser sturio L.

Abstract

Described is how a pair of wild spawners of the critically endangered common Atlantic sturgeon, Acipenser sturio L., were induced to provide progeny despite their unsuitable reproductive states. When captured, the female revealed signs of over-maturation. The male, caught in brackish water, yielded no sperm; after 5 days in fresh water and with pituitary injection, motile spermatozoa were produced. A batch of 30% fertilized eggs was produced with a two-injection sequence. As opposed to the Siberian sturgeon, A. baeri, the A. sturio L. hatchlings showed no positive phototaxis.