Myzostoma indocuniculus, 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 : 313

Myzostoma indocuniculus n. sp. Summers, Al-Hakim & Rouse

Fig. 4 J–K

Holotype: MZB Pol. 0 0 129 (1 spm: in 70% ethanol after formalin fixation). Mios Kon, Raja Ampat, Indonesia (0°29'55.54"S, 130°43'38.14"E), less than 20 m. Collected using scuba on 24 October 2013 by MMS and GWR.

Host. Clarkcomanthus alternans (Carpenter) ( Comatulidae , Comatulida , Crinoidea). SIO-BIC E6161. Genbank (COI—KM491779).

Paratypes: SIO-BIC A3763 paragenophores (2 spms: 1—in 70% ethanol after formalin fixation, 1—95% ethanol). Genbank (COI—KM014209). Same host and locality.

Etymology. Named for the type locality in Indonesia and the ‘bunny-ear’ caudal processes—a feature shared with its closest relatives Myzostoma cuniculus Eeckhaut et al., 1998 and M. pseudocuniculus Lanterbecq & Eeckhaut 2003 .

Diagnosis and description. Holotype body oval, separated posteriorly into two broad ‘ear-shaped’ caudal processes, slightly longer than length of main body ( Fig. 4 J). Length ~ 2.2 mm, width ~ 1.5 mm following fixation. Caudal processes twice as long as wide. Two long posterior cirri on each caudal process of holotype [2–4 observed on paratypes]. Main body has scalloped margin with 18 cirri, first and last pair very long, second pair long, pairs 3–8 short ( Fig. 4 K). Mouth and cloaca terminal, cloaca between caudal appendages. Five pairs of parapodia. Color dark red-brown in life, color faded in preservative.

Remarks. Two other species have ‘ear-shaped’ caudal processes. Myzostoma cuniculus Eeckhaut et al., 1998 has been recorded from Hansa Bay, Papua New Guinea and McCluer Islands, Australia, associated with Clarkcomanthus albinotus Rowe et al. , Clarkcomanthus littoralis Rowe et al. (likely = C. albinotus , see Summers et al. (in prep )), and Comanthus wahlbergii (Müller) (Eeckhaut et al. 1998) . Myzostoma pseudocuniculus Lanterbecq & Eeckhaut, 2003 was described from Toliara, Madagascar on Comanthus sp. aff. wahlbergii (later reported as Comanthus parvicirrus by the original authors in Lanterbecq et al. (2006)). These two species and Myzostoma indocuniculus n. sp. formed a well-supported clade in the molecular phylogeny of Summers & Rouse (2014).

Myzostoma indocuniculus n. sp. is distinguished from both M. cuniculus and M. pseudocuniculus by molecular data and occupied host. In addition, Myzostoma indocuniculus n. sp. differs from M. cuniculus by the presence of cirri on the caudal processes (caudal processes acirrate in M. cuniculus ) and three pairs of long cirri on the trunk ( M. cuniculus has 20 trunk cirri, all approximately equal in size). It can be distinguished from M. pseudocuniculus by its elongate form, longer and more developed caudal processes, and uniform color. Eeckhaut et al. (1998) also reported specimens of four undescribed species close to M. cuniculus from Okinawa, Enewatak Atoll, and southern Papua New Guinea. The description of those specimens does not match Myzostoma indocuniculus n. sp.

Figures

FIGURE 4. (A – B) Live photographs of Myzostoma debiae n. sp. paratype (SIO-BIC A 3794) — (A) dorsal, showing characteristic color and patterning; (B) ventral, extended penises adjacent to third pair of parapodia and extended proboscis with seven papillae. (C) Live photograph of Myzostoma miki n. sp. holotype (SIO-BIC A 3662), dorsal, unique honeycomb pattern shown. (D – G) Myzostoma eeckhauti n. sp. paratypes (SIO-BIC A 3668) — (D) dorsal; (E – G) SEM, (E) ventral, specimen with only three pairs of parapodia—all other types had five pairs; (F) smooth extended proboscis, (G) parapodia with hook. (H – I) Live photograph of Myzostoma hollandi n. sp. holotype SIO-BIC A 3791 — (H) dorsal; (I) ventral, showing six acirrate caudal processes and eight distinctive anterior triangular cirri. (J – K) Live photographs of Myzostoma indocuniculus n. sp. paratypes (SIO-BIC A 3763) — (J) dorsal showing two wide bunny ear-shaped caudal processes; (K) from the side, showing the cirri on the body margin and their relative lengths. Scalebars 2 mm (A-B); 1 mm (C – E, H – K); 100 Μm (F, G).