''Brania pusilla'' is a species of marine

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

in the family

Syllidae Syllidae is a family of small to medium-sized polychaete worms. Syllids are distinguished from other polychaetes by the presence of a muscular region of the anterior digestive tract known as the ''proventricle''. Syllid worms range in size from ...

. The original name for the species was ''Exogone pusilla.'' The species has a

cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...

. The body can be 1 mm to 2.5 mm long with 28 to 35 segments. It is suggested that parthenogenesis is a normal condition in this species. According to the Encyclopedia of Life the species is simultaneous hermaphroditic.

References

Syllidae Animals described in 1851 {{annelid-stub