Ophryotrocha permanae Paxton & Åkesson, 2010, sp. nov.

Ophryotrocha permanae, sp. nov.

Figure 3 G; Table 1

Ophryotrocha permanni nom. nud. Pleijel & Eide, 1996; Dahlgren et al. 2001; Heggøy et al. 2007; Wiklund et al. 2009.

Material examined. Type material: Holotype (AM W36875), complete female specimen, 1.8 mm long, 0.20 mm wide without parapodia (preserved) for 15 chaetigers; allotype (AM W36876) complete male specimen, 1.6 mm long, 0.20 mm wide without parapodia (preserved) for 14 chaetigers; 9 paratypes (AM W36877); 10 paratypes (SMNH T- 8031); cultured from specimens collected at Link Port, Indian River, Florida, USA, in 1994. Other material: Live cultures from same collection.

Description. Length of most live adults 2–3 mm (13–16 chaetigers), maximum length 4 mm (18 chaetigers). Live animals translucent, preserved opaque white. Pigmentation consisting only of very small lateral red spots on some chaetigers. Prostomium anteriorly rounded, with pair of short ovate antennae; palps absent; two eyes medially connected. Two peristomial achaetous segment-like rings.

Parapodia uniramous, lacking dorsal and ventral cirri, with dorsal protrusion, with retractile ventral lobe; 2–3 supra-acicular simple chaetae, 3–4 subacicular heterogomph falcigers and inferiormost simple chaeta; distal part of simple chaetae and blades of falcigers coarsely serrated. Pair of pygidial cirri present, pygidial median stylus absent in adults. Rosette glands, one per segment, present mid-dorsally on posteriormost segments of mature animals, up to five in males, four in females.

Mandibles with elongate shafts with extensive lateral sclerotisation in old animals (Fig. 3 G), and bifid cutting plates with 24–27 tiny pointed teeth at anterior edge. Maxillary apparatus of P- and K-type in both sexes, with falcate P1-forceps, bidentate P2-forceps, K-forceps right bidentate, left falcate.

Reproduction and development. Ophryotrocha permanae is not strictly gonochoristic. Some populations are mixed, including males, gonochoristic females and thelygenic females. Chromosomes 2n = 6; diameter of eggs 125 µm; tubular egg masses; released larvae without parapodia, with long pygidial median stylus.

Etymology. This species is named in honour of Ms. Jenny Perman, who has been in charge of the extensive Ophryotrocha “living gene bank” cultures at our Gothenburg laboratory for many years.

Remarks. The new species was originally identified through crossbreeding experiments and has been confirmed by gene sequence studies (Dahlgren et al., 2001; Heggøy et al. 2007; Wiklund et al. 2009). Ophryotrocha permanae is morphologically very similar to O. labronica, O. costlowi and O. vellae (Table 1).

The only difference that we could observe is that the lateral sclerotisation of mandibles in relatively large specimens of O. permanae can be more extensive than in any of the other species (Fig. 3 G).

Distribution. North Atlantic: Florida, USA; East China Sea: Sanya and Xiamen, China; Okinawa, Japan.