Turbo-taxonomy: 21 new species of Myzostomida (Annelida) Author Summers, Mindi M. Author Al-Hakim, Iin Inayat Author Rouse, Greg W. text Zootaxa 2014 3873 4 301 344 journal article 42367 10.11646/zootaxa.3873.4.1 fb49ba3b-9228-4653-bad8-a22bf4828785 1175-5326 252208 84F8465A-595F-4C16-841E-1A345DF67AC8 Myzostoma eeckhauti n. sp. Summers & Rouse Fig. 4 D–G Holotype : SIO-BIC A4013 paragenophore (1 spm: 95% ethanol). Madang Harbor, Papua New Guinea ( 5° 13.200'S , 145° 48.879'E ), 5– 20 m . Collected at night using scuba on 7 December 2012 by MMS and GWR. Host. Dichrometra / Lamprometra / Liparometra sp. 1 (Müller) (Crinoidea, Comatulida , Mariametridae ). SIO- BIC E5913 (tissue subsample in 95% ethanol). Paratypes : SIO-BIC A3668 paragenophores (15 spms: 1—in 70% ethanol after formalin fixation; 13—95% ethanol; 1—mounted for SEM). Same host and locality as holotype . Genbank (COI—KM014192). SIO-BIC A3667 syngenophores (6 spms: 95% ethanol). Same locality as holotype . Host. Dichrometra / Lamprometra / Liparometra sp. 1. MNHN-IE-2013-8128 (dried voucher) & SIO-BIC E5912 (tissue subsample in 95% ethanol). Genbank (COI—KM014351). Etymology. Named after Igor Eeckhaut, for his extensive contributions to our understanding of myzostomid biology and systematics. Diagnosis and description. Holotype body elongate, terminating in 6 cylindrical caudal processes ( Fig. 4 D–E). Length ~ 2.5 mm (including caudal processes), width ~ 1 mm following fixation. Medialmost pair of caudal processes longest; outermost pair shortest. Body margin with 20 cirri, most anterior pair more than three times as long as rest, which are short, triangular. Short cirri on some caudal processes, others acirrate. Mouth and cloaca terminal, cloaca located between caudal processes. Extended proboscis smooth ( Fig. 4 F). Five pairs of parapodia, midway between midpoint and body-margin with hooks ( Fig. 4 G). Live color pink, white in preservative. Remarks. Four other species are known with 6 caudal processes ( Table 1 ). Two have caudal processes with cirri as in Myzostoma eeckhauti n. sp. Myzostoma intermedium Graff, 1884 was described from a badly damaged specimen collected on Zygometra microdiscus (Bell) in the Torres Strait. A specimen very similar to the description and drawing in Graff (1884) was collected from the same host species in Lizard Island , Australia (Accession: SIO- BIC A4017). This specimen has a circular body with 20 long marginal cirri and six caudal processes with very long cirri—all features which distinguish it from Myzostoma eeckhauti n. sp. DNA sequences were not amplified from this specimen. Myzostoma jaegersteni Eeckhaut et al. 1994 also possesses caudal processes with cirri. It was described from Heterometra savignii (Müller) from Johore Shoal, Singapore , and specimens assigned to this species by the authors were also found on Neometra multicolor (AH Clark) and Tropiometra carinata (Lamarck) . All identified specimens were dredged, presumably from deeper waters. We collected specimens of a similar size and color (thin and translucent), but from a different host— Dichrometra flagellata —from Lizard Island , Australia . Although we expect these to be a different species from those described in Singapore , we refer to these specimens as Myzostoma cf. jaegersteni . Myzostoma eeckhauti n. sp. can be distinguished from Myzostoma cf. jaegersteni by molecular data, host use, and general appearance ( M. eeckhauti n. sp. is thick and pink).