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

Described is how a pair of wild spawners of the critically endangered commo n Atlantic sturgeon, Acipenser sturio L., were induced to provide progeny d espite their unsuitable reproductive states. When captured, the female reve aled 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, t he A. sturio L. hatchlings showed no positive phototaxis.