Syllis Savigny in Lamarck, 1818

Barroso, Rômulo, Paiva, Paulo Cesar De, Nogueira, João Miguel De Matos & Fukuda, Marcelo Veronesi, 2017, Deep sea Syllidae (Annelida, Phyllodocida) from Southwestern Atlantic, Zootaxa 4221 (4), pp. 401-430 : 419

Genus Syllis Savigny in Lamarck, 1818

Type species. Syllis monilaris Savigny in Lamarck, 1818 .

Diagnosis. Body cylindrical of variable size, from relatively medium-sized to large, compared to most syllids. Subpentagonal prostomium, with 1 pair of palps totally free from each other or fused at bases, 3 antennae, 2 pairs of eyes and, sometimes, 1 pair of anterior eyespots. Peristomium usually shorter than segments, with 2 pairs of peristomial cirri; border between prostomium and peristomium usually with conspicuous nuchal organs, as 1 pair of ciliated grooves. Antennae, peristomial cirri, dorsal cirri throughout and anal cirri moniliform; ventral cirri short, digitiform. Parapodia with compound falcigers, some taxa with secondarily simple chaetae, due to fusion between shaft and blade, or loss of blade; spiniger-like chaetae frequently present; dorsal and ventral simple chaetae usually present on posterior chaetigers. Pharynx with large tooth on anterior border or slightly posteriorly to opening, trepan absent ( Nogueira & San Martín 2002; Nogueira & Yunda-Guarin 2008). Reproduction by stolonization, with stolons with different morphologies, according to species. Some species viviparous.

Remarks. The largest genus in the family, Syllis , as currently conceived, seems to be paraphyletic, according to phylogenetic analyses performed on the family ( Aguado et al. 2007, 2012). However, until more detailed studies are made specifically on this genus, we follow herein the opinion of most authors (e.g., San Martín 2003; Álvarez- Campos et al. 2015a, b), considering Typosyllis Langerhans, 1879 as a junior synonym of Syllis .