Job Baster’s description of nudibranch veliger larvae (1759)

The 18th century physician Job Baster, made extensive studies on marine life along the Dutch coast. Between 1759 and 1765 he published his illustrated books ‘Natuurlijke Uitspanningen’ about his observations. An account that has been poorly understood to date is his description of the release of ‘hand grenade-like young’ from egg masses, which were attached to hydroids. This paper discusses Baster’s observations and concludes that he observed the release of nudibranch larvae. Baster’s illustrated account may well be the first record ever of veliger larvae.