Paraopisthosyllis Hartmann-Schröder, 1991

Paresque, Karla, Martín, Guillermo San, Álvarez-Campos, Patricia, Nogueira, João Miguel De Matos & Fukuda, Marcelo Veronesi, 2016, Two new species and new records of the genus Paraopisthosyllis Hartmann-Schröder, 1991 (Annelida: Syllidae) from northeastern Brazil and Philippine Islands, Zootaxa 4178 (1), pp. 116-130 : 117-118

Genus Paraopisthosyllis Hartmann-Schröder, 1991

Paraopisthosyllis Hartmann-Schröder, 1991: 27 ; San Martín & Hutchings 2006: 316. Basidiosyllis San Martín, López & Aguado, 2009: 1467 .

Type-species. Opisthosyllis brevicirra Hartmann-Schröder, 1979 , designated by Hartmann-Schröder 1991.

Diagnosis (modified from San Martín & Hutchings, 2006). Body robust, cylindrical in section, broad anteriorly, tapered posteriorly, with numerous segments. Dorsal and ventral surfaces often covered with numerous small papillae. Prostomium with four lensed eyes and three antennae. Palps broad, fused at base, ventrally folded. Peristomium shorter than subsequent segments, sometimes covered dorsally by chaetiger 1; two pairs of peristomial cirri. Nuchal organs as two ciliated grooves between prostomium and peristomium. Dorsal and ventral cirri on all chaetigers; dorsal cirri with papillae in some species. Antennae, peristomial, dorsal and anal cirri nonarticulated, enlarged, club-shaped to foliaceous. Dorsal cirri usually with distinct cirrophores, alternating large and small cirri in anterior segments, larger ones arising more dorsally. Parapodia with distinct prechaetal lobe. Compound, heterogomph chaetae, with strong serration on shafts of posterior chaetae in some species; blades hooked or elongated, unidentate or bidentate. Dorsal and ventral simple chaetae on posterior parapodia, dorsal simple chaetae slender. Pygidium small, with two anal cirri. Pharynx wide, with pharyngeal tooth inserted away from anterior rim. Proventricle wide, massive. Reproduction by schizogamy.

Remarks. Hartmann-Schröder (1991) erected Paraopisthosyllis to accommodate two species, P. brevicirra ( Hartmann-Schröder, 1979) , originally described as Opisthosyllis brevicirra , and P. phyllocirra Hartmann- Schröder, 1991. San Martín & Hutchings (2006) examined specimens lodged in the Australian Museum from all around Australia, revised the material collected and described by Hartmann-Schröder (1979, 1981) and described two species, P. alternocirra San Martín & Hutchings, 2006 and P. ornaticirra San Martín & Hutchings, 2006 . More recently, Aguado & Glasby (2015) described P. pardus Aguado & Glasby, 2015 from Australia and suggested that the genus may be part of a clade within the Syllinae restricted to the Indo-Pacific, together with Alcyonosyllis Glasby & Watson, 2001 and Megasyllis San Martín, Hutchings & Aguado, 2008 .

The emended diagnosis includes the species of Basidiosyllis , B. fusigera ( Augener, 1913) and B. kalimna ( San Martín & Hutchings 2006) , originally belonging to Pionosyllis Malmgren, 1867 , and B. victoriae San Martín, López & Aguado, 2009 . Basidiosyllis was erected by San Martín et al. (2009), based on a morphological phylogenetic analysis. The only autapomorphy found for Basidiosyllis , the dorsal cirri inflated in some segments, is also present in Paraopisthosyllis , which was not included as outgroup. The body papillae, present in all species of Paraopisthosyllis , are also found in B. kalimna . Therefore, we did not find any morphological characters to differentiate these two genera, and so we herein consider Basidiosyllis as a junior synonym of Paraopisthosyllis . The genus now includes 10 valid species ( Table 1 ) and its distribution is extended from Indo-Pacific restricted to include the Atlantic Ocean, being, thus, circuntropical, occurring at low depths ( Fig. 1 ). With the herein proposed synonymy, the family Syllidae presently counts on 74 genera (cf. Fukuda et al. 2016).

Figures

FIGURE 1. Geographic distribution of species of Paraopisthosyllis and ocean surface temperature gradient around the world. World temperature data was obtained from BioOracle (Tyberghein et al. 2012).