Fabriciidae

Bick, Andreas & Bastrop, Ralf, 2025, Revision of the genus Manayunkia Leidy, 1859, and establishment of two subfamilies within Fabriciidae (Annelida, Sabellida), Zootaxa 5661 (1), pp. 1-58 : 6

Fabriciidae Rioja, 1923

Type genus: Fabricia Blainville, 1828 .

Diagnosis. Small-bodied, hemisessile polychaetes with eight thoracic and three, exceptionally two or four, abdominal chaetigers.Three pairs of radioles; branchial lobes not fused together mid-dorsally; radioles symmetrically or asymmetrically branched; ventral filamentous appendages present or absent; acellular radiolar skeleton absent or present; radiolar crown with branchial hearts; ventral lips absent. Anterior margin of anterior peristomial ring a low ridge dorsally and laterally; a triangular, rounded or rectangular lobe ventrally. Thoracic uncini acicular, with main fang followed by smaller teeth.Abdominal uncini with elongate manubrium and dentate region; dentate region with multiple rows of equal-sized teeth. Spermiogenesis in thoracic chaetigers; spermatids in large cluster with central cytophore; single, dorsal sperm duct present. Sperm nuclear projection present; sperm nuclear membrane thickening; extra-axonemal sheath present.

Distribution. Marine, brackish and freshwater benthic ecosystems; from intertidal to deep-sea; worldwide.