Heteropolypus roseus, Dautova, 2022

Dautova, Tatiana N., 2022, New species of deep-sea Heteropolypus soft corals (Anthozoa: Octocorallia) from the Kurile Islands, Sea of Okhotsk (Northwest Pacific), with summary data on distinctive characters of the known species of the genus, European Journal of Taxonomy 806 (1), pp. 128-147 : 137-145

Heteropolypus roseus sp. nov.

urn:lsid:zoobank.org:act:3747DFBE-FDD1-467A-ABDC-1138E9BEDD75

Figs 6–8 , Table 1

Diagnosis

Mushroom-shaped Heteropolypus colony with dome-shaped capitulum and distinct wrinkled stalk. The anthocodiae of autozooids in alcohol-preserved material are up to 12 mm high and up to 6 mm wide, completely retractile, evenly distributed on the surface of the capitulum.Anthocodia wall is cylindrical in shape and with a smooth surface with some transverse folds; anthocodial armature evenly distributed in it. Siphonozooids are small, slightly razed above the surface of the capitulum. Mesozooids are crowded near the margin of the capitulum. Sclerites of autozooid tentacles are vesiculate plates with dentate edges and a median constriction or a diagonal keel, elongated plates with asymmetrically developed ends, clublike spindles and clubs, vesiculate spindles, and capstans. Anthocodia walls contain 6-radiate or 8-radiate capstans. Pharynx has tuberculate plates with rounded edges and rods, all these with a narrow median waist or constriction. Surface of the capitulum and the stalk contains 6-, 7- and 8-radiate capstans; colony interior contains long, slender needles with a smooth median part and spiny trihedral ends. Alcoholpreserved specimen is pale rose, sclerites red or rose.

Etymology

The specific epithet refers to the colour of the holotype anthocodia which is similar to a wild rose.

Type material

Holotype SEA OF OKHOTSK – Kurile Islands • colony 42 × 45 mm; Kunashir Is.; expedition of PIBOC FEB RAS and NSCMB FEB RAS on RV Akademik Oparin, station 51; 44°49′ N, 146°23.1′ E; depth 550 m; 24 Jul. 2005; A. Chernyshov leg.; dredged; MIMB 42495 .

Description

Holotype

The specimen is about 45 mm tall ( Fig. 6A ). The capitulum is rounded, dome-shaped and elliptical in the cross section, 20 × 27 mm across and 27 mm high. The stalk is 14 mm in diameter, chaotically wrinkled. Anthocodiae of autozooids are partially retractile into calyces which have sinked rims; only the tentacles are seen above the surface of the capitulum. In contraction, the upper part of the anthocodiae project from the bottom of cylindrical pits in the capitulum. Between the autozooids, numerous tiny siphonozooids occur; these are seen as small verrucae, very slightly raised above the capitulum surface and densely crowded giving to the surface of capitulum granulated appearance ( Fig. 6A–B ). About 100 siphonozooids occur in an area of 5 mm 2.

Mesozooids are crowded along the margin of the capitulum and fully retracted; only small craters 1–1.5 mm in diameter are visible at the capitulum surface ( Fig. 6B–C , arrows 1).

Autozooid tentacles contain vesiculate plates with dentate edges and a median constriction or a diagonal keel, elongated plates with asymmetrically developed ends, club-like spindles and clubs, vesiculate blunt spindles, and capstans. Densely vesiculated plates, up to 0.10 mm long, have dentate edges and a narrow median waist ( Fig. 7A ); some plates are elongated, less denticulate, with a narrow median part, up to 0.15 mm long ( Fig. 7B ). Some dentate plates, up to 0.15 mm long, have a narrow median part and a diagonal keel ( Fig. 7C ). Some elongated plates, up to 0.15 mm long, are slightly bent and have asymmetrically developed ends ( Fig 7D ). Club-like spindles are up to 0.15 mm long ( Fig. 7E ). Clubs have plump heads and thick handles, and are up to 0.11 mm long ( Fig. 5F ). Warty spindles, up to 0.12 mm long, have blunt ends ( Fig. 7G ). Some capstans (6-rayed), usually up to 0.06 mm long, have round outlines; another ones, up to 0.1 mm long, are elongated, 8-rayed or bear unordered warts ( Fig. 7H ).

Pharynx contains vesiculated biscuit-like plates with a narrow median constriction and rounded edges, up to 0.07 mm long ( Fig. 8A ), and rods with blunt ends and a narrow median part, up to 0.09 mm long ( Fig. 8B ). Anthocodial walls contain 6-radiate or 8-radiate capstans, up to 0.09 mm long ( Fig. 8C ).

Surface of capitulum and stalk contains 6-, 7- and 8-radiate capstans ( Fig. 8D–E ); colony interior contains long, slender needles with a smooth median part and spiny trihedral ends. The interior needles, up to 0.6 mm long ( Fig. 8F ), have a smooth cylindrical median part, but trihedral ends. Each ridge at the needle end bears spines or dents ( Fig. 8G ).

Colour

In alcohol-preserved material the capitulum of the colony is pale rose, the autozooids are bright rose, the stalk is brown-rose and the sclerites are red or rose.

Remarks

Heteropolypus roseus sp. nov. differs from all known species of the genus in the presence of the plates with a diagonal keel which are found in its autozooid tentacles ( Table 1 ). Moreover, H. roseus sp. nov. also differs from H. insolitus , H. japonicus , H. ritteri , H. rylovi and H. steenstrupi in having the plates in the tentacles and pharynx. Heteropolypus ritteri also has sclerites with a diagonal ridge, but these are rods ( Table 1 ). Only H. sol contains short plates in the tentacles and platelets in the pharynx, but H. roseus sp. nov. differs from it by having no flanged rods and girdled spindles in the tentacles ( Table 1 ).

Distribution

This species is known for certain from the Kurile Islands, Sea of Okhotsk, Northwestern Pacific, from 550 m depth.

Figures

Fig. 6. Heteropolypus roseus sp. nov., holotype (MIMB 42495), Kurile Islands, Sea of Okhotsk. A. Whole specimen. B. Surface of the capitulum. C. Section of the capitulum; 1 = mesozooid. Scale bars: A = 10 mm; C = 1 mm.

Fig. 7. Heteropolypus roseus sp. nov., holotype (MIMB 42495); sclerites from the autozooid tentacles. A. Waisted plates. B. Plates. C. Plates with diagonal keel. D. Asymmetrical plates. E. Club-like spindle. F. Clubs. G. Warty spindles. H. Capstans. Scale bar = 0.1 mm.

Fig. 8. Heteropolypus roseus sp. nov., holotype (MIMB 42495); sclerites from the autozooid pharynx, anthocodiae, and the colony body. A. Waisted plates. B. Rods. C. Anthocodiae capstans. D. Capitulum surface capstans. E. Stalk surface capstans. F. Needles. G. Ends of the same needle. Scale bars: A–F = 0.1 mm; G = 0.02 mm.

Fig. 5. Heteropolypus annae sp. nov., paratype (MIMB 42494); sclerites from the autozooid pharynx, anthocodiae, and the colony body. A. Waisted plates. B. Waisted rods. C. Anthocodiae capstans. D. Capitulum surface capstans. E. Stalk surface capstans. F. Needles. G. Ends of the same needle. Scale bars: A–F = 0.1 mm; G = 0.02 mm.