Pulvinomyzostomum inaki, Summers, Mindi M., Al-Hakim, Iin Inayat & Rouse, Greg W., 2014

Summers, Mindi M., Al-Hakim, Iin Inayat & Rouse, Greg W., 2014, Turbo-taxonomy: 21 new species of Myzostomida (Annelida), Zootaxa 3873 (4), pp. 301-344 : 324-325

Pulvinomyzostomum inaki n. sp. Summers & Rouse

Fig. 8 A–C

Holotype: SIO-BIC A1408 paragenophore (1 male: in 70% ethanol after formalin fixation). Jaco Scarp, Costa Rica (9.1172° N, 84.8417° W), 1866 m. Collected via the R/V Atlantis using the HOV Alvin (Dive 4509) on 3 March 2009.

Host. Antedon sp. ( Antedonidae , Comatulida , Crinoidea) SIO-BIC E4399. Genbank (COI—KM014345). Paratypes: SIO-BIC A1579 paragenophores (2 males: 95% ethanol). Same host and locality. Genbank (COI—KM014173).

Etymology. Named for Jose Ignacio Carvajal.

Diagnosis and description. Large female in host’s mouth, smaller males on female’s ventral surface ( Fig. 8 B). Female thick, circular, body margin slightly scalloped from 20 small cirri ( Fig. 8 A–B). Dorsal surface of female ridged and with papillae. Holotype (male) circular, slightly wider than long, body margin strongly scalloped from 20 triangular cirri ( Fig. 8 C). Mouth and cloaca terminal. Extended proboscis smooth. Five pairs of parapodia, positioned equal distance from the midline to the body margin.

Remarks. Pulvinomyzostomum inaki n. sp. possesses the same lifestyle as Pulvinomyzostomum pulvinar Graff, 1884 b—a large female located in the mouth with small males. The female specimen was found with the small males on the ventral surface, the in situ arrangement in the mouth is not known. Pulvinomyzostomum pulvinar was described from Leptometra phalangium (Müller, 1841) collected in Scottish waters. Pulvinomyzostomum pulvinar possesses a dorsal proboscis and has a smooth dorsal surface (re-examined in Jägersten, 1940b and Eeckhaut & Lanterbecq, 2005), distinguishing it from P. inaki n. sp.

The free-living Myzostoma graffi Nansen, 1885 and M. giganteum Nansen, 1885 from Norwegian waters are described as having a scalloped margin similar to the males of Pulvinomyzostomum inaki n. sp. As the host is similar, Leptometra celtica (M’Andrew & Barrett) , these records could be males of Pulvinomyzostomum pulvinar and warrant further collection now that molecular data are available. Pulvinomyzostomum inaki n. sp. is the first record of this lifestyle (large female in mouth, smaller free-living males) from Pacific waters, and is also distinguished from P. pulvinar based on molecular data (provided in Lanterbecq et al. (2006)).

Figures

FIGURE 8. (A – C) Live photographs of Pulvinomyzostomum inaki n. sp. — (A, B) female, (A) dorsal view showing raised ridges, (B) ventral view showing five pairs of parapodia, cirri on body margin, and small dwarf males, abbreviations: males (m); pharynx (p); (C) males, ventral and dorsal views showing extended smooth proboscis and scalloped margin. (D – G) Pulvinomyzostomum messingi n. sp. — (A) live photograph of host, Gephyrocrinus messingi with ophiuroid associate and possible myzostomids on arms, indicated with arrows; (E – G) photographs of fixed samples, (E – F) on host’s arms, dorsal view showing ridged surface (E), abbreviation: host pinnule (pi), (G) ventral view, showing acirrate body margin. Scalebars 30 cm (D); 1 mm (E – G); 0.5 mm (C); 0.2 mm (A, B).