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

Fig. 4 A–B

Holotype: MZB.Pol. 0 0 127 paragenophore (1 spm: in 70% ethanol after formalin fixation). Kri Eco Jetty, Raja Ampat, Indonesia (0°33'27.42"S, 130°40'36.23"E), less than 20 m. Collected at night using scuba on 26 October 2013 by MMS and GWR.

Host. Comactinia titan Messing ( Comatulidae, Comatulida, Crinoidea). SIO-BIC E6159 (DNA subsample only). Genbank (COI—KM491778).

Paratypes: SIO-BIC A3794 paragenophores (3 spms: 2—in 70% ethanol after formalin fixation; 1—in 9% ethanol following fixation in DMSO). Same host and locality. Genbank (COI—KM014210).

Etymology. Named for Deborah Summers, mother of MMS.

Diagnosis and description. Holotype body circular, diameter ~ 4 mm following fixation. Body margin with 20 medium-long cirri (Fig. 4 A–B). Mouth and cloaca on ventral surface. Mouth, cloaca, and 8 lateral organs positioned midway between margin and parapodia, alternating with the latter. Extended proboscis with 9 long, triangular papillae (Fig. 4 B). Five pairs of parapodia. Paired penes in line with third pair of parapodia. Dorsal color pattern with margin resembling ten white hearts (Fig. 4 A).

Remarks. Myzostoma debiae n. sp. is distinct in its dorsal color pattern, the margin resembling ten white hearts. It can be further distinguished from other disc-shaped myzostomids by its cirri, which are equal in length, as well as its association with Comactinia titan . Other disc-shaped myzostomids with long cirri show noticeable differences in cirral length, the most anterior and posterior pairs longer than the rest. Paratype SIO-BIC A3794 (fixed in formalin—Figure 4 A–B) has 7 papillae on the proboscis.