Protomyzostomum lingua Summers, Al-Hakim & Rouse, 2014, n. sp.

Protomyzostomum lingua n. sp. Summers & Rouse

Fig. 7 A–F

Holotype: SIO-BIC A4088 (S1976) paragenophore (1 spm: in 70% ethanol after formalin fixation). Discovery Bank, Antarctica (Stn. DB1-67)(60° 7' 38.733"S, 34° 54' 11.1954"W), 379 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 15 October 2011 by Nerida Wilson, GWR, MMS, and science team.

Host. Gorgonocephalus chilensis (Philippi) (Gorgonocephalidae, Euryalida, Ophiuroidea). SIO-BIC E6110 (S4088) (DNA subsample only). Genbank (COI—KM491789).

Paratypes: SIO-BIC A3226 (S1977) paragenophore (2 spms: 1—in 70% ethanol after formalin fixation; 1—95% ethanol), SIO-BIC A3238 (S1976) paragenophores (2 spms: 1—in 70% ethanol after formalin fixation; 1—95% ethanol). Genbank (COI—KM014171). Same host and locality as holotype. SIO-BIC A3227 (S4381) syngenophores (2 spms: 1—form and 1—95% ethanol). Discovery Bank, Antarctica (Stn. DB1-58)(60° 6' 39.726"S, 34° 49' 35.7594"W), 439 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 13 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6109 (S4561) (DNA subsample only). SIO-BIC A3244 syngenophore (S1034) (1 spm: in 70% ethanol after formalin fixation). Discovery Bank, Antarctica (Stn. DB1-74)(60°8'15.3594"S, 34° 51' 38.6274"W), 407– 409 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 16 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6111 (S1033) (DNA subsample only). SIO- BIC A3853 (S5732) syngenophores (2 spms: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1- 106)(54°39'54.039"S, 61°14' 8.682"W), 307 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6136 (S5660). SIO-BIC A3854 (S5733) syngenophore (1 spm: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1-106)(54°39'54.039"S, 61°14' 8.682"W), 307 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6137 (S5661); Genbank (COI—KM491788). SIO-BIC A3855 (S5734) syngenophore (1 spm: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1-106)(54°39'54.039"S, 61°14' 8.682"W), 307 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6134 (S5658). SIO-BIC A3856 syngenophore (S5735) (1 spm: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1-106)(54°39'54.039"S, 61°14' 8.682"W), 307 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6135 (S5659). SIO-BIC A3857 (S5737) syngenophores (2 spms: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1-106)(54°39'54.039"S, 61°14' 8.682"W), 307 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6141 (S5665). SIO-BIC A3858 (S5737) syngenophores (5 spms: 95% ethanol). Same host and locality as SIO-BIC A3857. SIO-BIC A4005 (S5541) syngenophore (1 spm: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1- 104)(54°39'2.8794"S, 60°1'36.4614"W), 195 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6130 (S5600). SIO-BIC A4006 (S5543) syngenophore (1 spm: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1-104)(54°39'2.8794"S, 60°1'36.4614"W), 195 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis. SIO-BIC A4003 (S5739) syngenophore (3 spms: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1- 107)(54°40'17.328"S, 61°14'1.428"W), 305 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6147 (S5730). SIO-BIC A4004 (S5738) syngenophores (5 spms: 95% ethanol). Burdwood Banks, Antarctica (Stn. BB1-107)(54°40'17.328"S, 61°14'1.428"W), 305 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 31 October 2011 by Nerida Wilson, GWR, MMS, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6145 (S5669). SIO-BIC A4022 (S21383) syngenophores (2 spms: 1—in 70% ethanol after formalin fixation; 1—95% ethanol). Burdwood Banks, Antarctica (Stn. BBW-78)(53°58'9.4794"S, 61°28'2.28"W), 158 m. Collected via the R/V Nathaniel B. Palmer using a Blake trawl on 5 May 2013 by Nerida Wilson, GWR, and science team. Host: Gorgonocephalus chilensis, SIO-BIC E6150 (S21308).

Etymology. Latin for tongue, named for its resemblance to a mammalian tongue.

Diagnosis and description. Holotype recovered from host’s bursa (Fig. 7 A–B). Body elongate, rounded posteriorly and anteriorly (Fig. 7 C–F). Length ~ 1.3 cm, width ~ 6 mm following fixation. Mouth and cloaca terminal. Five pairs of low parapodia with chaetae small and barely emergent. Orange in life, color faded in preservative.

Remarks. Four species of Protomyzostomum have been previously described— Protomyzostomum glanduliferum Bartsch & Faubel, 1995, P. polynephris Fedotov, 1912, P. astrocladi Fedotov, 1925, and P. sagamiense Okada, 1922. Protomyzostomum polynephris and P. sagamiense were recorded from basketstar hosts (Gorgonocephalus), from Arctic and Japanese waters respectively. Protomyzostomum glanduliferum is known from Antarctic waters, but inhabits the brittlestar Ophiacantha antarctica. Sequences of Lanterbecq et al. (2006) for P. glanduliferum and P. polynephris were found to be incorrect in Summers & Rouse (2014). An undescribed myzostomid has also been recorded from another Antarctic brittlestar, Ophionotus victoriae Bell, 1902 by Bartsch & Faubel, 1995.