Myzostoma laurenae, 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 : 316-317

Myzostoma laurenae n. sp. Summers & Rouse

Fig. 5 J–L

Holotype: SIO-BIC A3657 hologenophore (1 spm—95% ethanol). Madang Harbor, Papua New Guinea (5°12'27.63"S, 145°48'32.45"E), 3– 17 m. Collected using scuba at night on 4 December 2012 by MMS and GWR. Genbank (COI—KM014203).

Host. Capillaster multiradiatus s.l. AH Clark, MNHN-IE-2013-8029 (dried voucher) & SIO-BIC E5863 (tissue subsample in 95% ethanol), Genbank (COI—KJ874984).

Paratypes: SIO-BIC A4089 paragenophore (1 spm: in 70% ethanol after formalin fixation). Same host and locality as holotype. SIO-BIC A3809 syngenophore (1 spm: ½—in 70% ethanol after formalin fixation; ½—95% ethanol). South Island, Lizard Island Reef, Australia (14°42’23.5” S, 145°27’10.4” E, less than 20 m. Collected using scuba on 22 November 2001 by GWR. Genbank (COI—KM014198). Host: Capillaster multiradiatus (Linnaeus) ( Comatulidae , Comatulida , Crinoidea). Specimen not collected. SIO-BIC A3674 syngenophores (3 spms: 1 spm—in 70% ethanol after formalin fixation; 2 spms—95% ethanol). Inside of Tabat Island, Madang Harbor, Papua New Guinea (5° 8.187'S, 145° 48.700'E), 5– 20 m. Collected using scuba on 9 December 2012 by GWR and MMS. Genbank (COI—KM491750). Host: Capillaster multiradiatus s.l., MNHN-IE-2013-8127 (dried voucher) & SIO-BIC E5933 (tissue subsample in 95% ethanol); Genbank (COI—KM491781). SIO-BIC A3660 syngenophores (3 spms: 1 spm—in 70% ethanol after formalin fixation; 2 spms—95% ethanol). Madang Harbor, Papua New Guinea (5°12'27.63"S, 145°48'32.45"E), 3– 17 m. Collected using scuba at night on 4 December 2012. Host: Capillaster multiradiatus s.l., SIO-BIC E5905 (tissue subsample in 95% ethanol).

Etymology. Named for Lauren Rouse, niece of GWR, in honor of her birthday.

Diagnosis and description. Holotype body circular, ~ 1 mm diameter following fixation. Body margin with 20 medium-long cirri ( Fig. 5 K). Dorsal surface smooth, with irregular white pigment in lace-like pattern. Mouth and cloaca on ventral surface, in line with lateral organs. Extended proboscis with 7 triangular papillae ( Fig. 5 L). Paired penes. Five pairs of parapodia. Lateral organs closer to parapodia than body margin.

Remarks. Myzostoma laurenae n. sp. is most similar to M. stochoeides Atkins, 1927 and M. longicirrum Graff, 1887 —both with records on (but not originally described from) Capillaster multiradiatus and Capillaster sentosus respectively. Myzostoma stochoeides was originally described from the Great Barrier Reef associated with Comanthus annulatus (i.e. Comanthus parvicirrus ). We collected specimens from near the type locality of Badu Island, Australia associated with Comanthus parvicirrus (SIO-BIC A3661, A3678-79, A3723-24, A3795, A3810—molecular data published in Summers & Rouse (2014)), which we consider most similar to those described by Atkins (1927) (some showing the ringed-pattern of the drawings). These specimens can be distinguished from Myzostoma laurenae n. sp. based on molecular data, host use, size, length of cirri (longer in M. laurenae n. sp.), and color pattern ( M. stochoeides translucent to dark brown). It is possible that those specimens associated with Capillaster previously referred to M. stochoeides in Eeckhaut et al. (1994) may instead be M. laurenae n. sp.

Myzostoma longicirrum Graff, 1887 was described originally from Zamboanga, Philippines on Comanthus parvicirrus . The specimen was badly damaged and the drawing included was a ‘restoration’ and is a ventral view only. Eeckhaut et al. (1994) redescribed this species from material found loose in jars with Capillaster sentosus , Capillaster sp., Comatula pectinata , and Pontiometra andersoni from Singapore, the Philippines, and the Sulu Archipelago. These specimens were described as of the same general size and shape of M. laurenae n. sp, but were dark brown, possessed ‘membranous marginal lobes between the marginal cirri,’ and the three most anterior and posterior pairs of cirri were much longer than the rest. In the one paratype with intact cirri (SIO-BIC A3674), the first three and last four pairs of cirri were approximately two times longer than cirri pairs 4–6. Preserved material was white and translucent, and although slight scalloping might be interpreted, the distinct marginal lobes were not observed in M. laurenae n. sp. In the original description of M. longicirrum , the mouth was in line with the parapodia and the lateral organs were midway between the parapodia and body margin; this placement differs from that observed in M. laurenae n. sp., but these features were suggested by Eeckhaut et al. (1994) to have been a misinterpretation based on the poor quality of the specimens. We consider Myzostoma laurenae n. sp. distinct from M. longicirrum based on color, relative lengths of cirri, host, and locality.

Figures

FIGURE 5. (A – D) Live photographs of Myzostoma josefinae n. sp. — (A, B) paratype (SIO-BIC A 3829) on host, Psathyrometra fragilis; (C) dorsal view of paratype (SIO-BIC A 3829), showing long cirri on body margin and elongate, cylindrical caudal appendages full of oocytes; (D) ventral view of paratype (SIO-BIC A 3798). (E – I) Myzostoma kymae n. sp. — (E – G) SEM of paratype (SIO-BIC A 3682), ventral surface, showing five pairs of parapodia (E), penises aligned with third pair (F), and alternating lateral organs (G); (H – I) Live photographs of holotype (SIO-BIC A 3681) and paratypes (SIO-BIC A 3682), (H) on host, Alloeocomatella pectinifera, showing faint dorsal longitudinal ridge, (I) side and ventral views, showing small cirri along body margin and extended proboscis with papillae. (J – L) Live photographs of Myzostoma laurenae n. sp. holotype (SIO-BIC A 3809), (J) on host, Capillaster multiradiatus, (K) dorsal view showing color pattern and medium-long cirri along body margin, (L) ventral view showing extended proboscis with papillae, five pairs of parapodia and alternating lateral organs. Scalebars 1 mm (H-I); 0.5 mm (A – E, J – L); 100 Μm (F, G).