Revision of the Glyceridae Grube 1850 (annelida: polychaeta)

This paper presents the first comprehensive revision of all known Glyceridae species globally. Utilizing light and scanning electron microscopy, the study examines type materials for 172 species and subspecies. Three species, including Glycera baltica and G. glaucopsammensis, are identified as fossil taxa and are not further analyzed. Additionally, three taxa previously classified as glycerids are reclassified into other families: Lumbricus capitatus, Nereis filigera, and Nereis (Nephtys) hirsuta. Glycera viridescens is suggested to belong to the Goniadidae family, while Pseudolacydonia caeca is determined to be synonymous with Glycerella magellanica. Ultimately, only 42 species (36 Glycera, 1 Glycerella, and 5 Hemipodia) are recognized as valid, with the remainder classified as synonyms, nomina dubia, or nomina nuda. The study involved over 4000 specimens worldwide, with detailed descriptions and illustrations of the valid species. An identification key and a comprehensive list of taxa and their synonyms are included, along with biological and ecological data from existing literature. Cladistic analysis indicates a sister group relationship between Goniadidae and Glyceridae, confirming the monophyly of both families and the three genera within Glyceridae.