Heteropolypus annae, 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 : 130-137

Heteropolypus annae sp. nov.

urn:lsid:zoobank.org:act:788BD2D1-27C8-4164-8F54-778D3E288674

Figs 1–3 , Table 1

Diagnosis

Mushroom-shaped Heteropolypus colonies 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 10 mm wide, completely retractile, evenly distributed on the surface of the capitulum.Anthocodia wall is cylindrical in shape and with smooth surface with some transverse folds; anthocodial armature is evenly distributed in it. Siphonozooids are small, slightly raised above the surface of the capitulum. Mesozooids are arranged chaotically between the autozooids. Sclerites of autozooid tentacles are vesiculate plates, warty and flanged spindles, clubs, rounded 6-radiate capstans and oval capstans.Anthocodia walls contain 6-radiate or 7-radiate round capstans. Pharynx has plates with rounded edges and narrow tapered rods, all these are tuberculate and with a narrow median waist. Surface of the capitulum and the stalk contains 6-radiate capstans; colony interior contains long, slender needles with a smooth median part and spiny trihedral ends. Specimens preserved in alcohol are white, sclerites colourless.

Etymology

The specific epithet is given in honor of Dr Anna Skriptsova, Head of the Laboratory of Autotrophic Organisms (National Scientific Centre of Marine Biology FEB RAS, Vladivostok), enthusiastic researcher of marine biodiversity, who saved the holotype specimen during the field expedition of the PIBOC and NSCMB (RV Akademik Oparin, cruise No 56, 2019).

Type material

Holotype SEA OF OKHOTSK – Kurile Islands • colony 74 × 88.5 mm wide, 42 mm high; Simushir Is.; expedition of PIBOC FEB RAS and NSCMB FEB RAS on RV Akademik Oparin, station 20; 46°56.9′ N, 152°16.7′ E; depth 455– 447 m; 2 Jul. 2019; Anna Skriptsova leg.; dredged; MIMB 42493 .

Paratype SEA OF OKHOTSK – Kurile Islands • colony 107.7 mm wide and 107.7 mm high; Simushir Is.; expedition of PIBOC FEB RAS and NSCMB FEB RAS on RV Akademik Oparin, station 22; 47°15.4′ N, 152°10′ E; depth 205–222 m; 2 Jul. 2019; Daria Demidkoiva leg.; dredged; MIMB 42494 .

Additional material

SEA OF OKHOTSK – Kurile Islands • 2 specimens; same collection data as for paratype; MIMB 42496 .

Description

Holotype

The specimen is about 42 mm tall ( Fig. 1A–B ). The capitulum is rounded, flattened from the top and elliptical in the cross section, 73 × 83 mm across and 28 mm high. The capitulum is slightly concaved in the central area ( Fig. 1A ). The stalk is 33 mm in diameter; its lower part was torn away during the dredging. Anthocodiae of the autozooids are partially retractile into calyces which have slightly sinked rims. In contraction, the upper part of the anthocodiae project from the bottom of crater-like pits in the capitulum. Between the autozooids, numerous siphonozooids occur; these are seen as small verrucae, slightly raised above the capitulum surface and densely crowded giving to the surface of capitulum granulated appearance ( Fig. 1A ). About 60 siphonozooids occur in an area of 5 mm 2.

Mesozooids ( Fig. 1F , arrow 1) are distributed chaotically between the autozooids ( Fig. 1F , arrow 2) and fully retracted; only small pits 1–1.5 mm in diameter are visible at the capitulum surface ( Fig. 1G , arrows 1).

Autozooid tentacles contain vesiculated plates, warty and flanged spindles, clubs, rounded 6-radiate capstans and elongated capstans. Vesiculated plates, up to 0.12 mm long, have a narrow median waist ( Fig. 2A ); some pates are without the waist ( Fig. 2B ). Flanged spindles, up to 0.16 mm long, have one narrow spiny end ( Fig. 2C ); warty spindles, up to 0.14 mm long, have blunt ends ( Fig. 2D ). Club-like spindles, up to 0.12 mm long, not numerous, have one end densely covered by vesicles ( Fig. 2E ). Clubs, up to 0.15 mm long, have warty or denticulate heads and thick or slender blunt-ended handles ( Fig. 2F ). Capstans (6-rayed) are usually up to 0.08 mm long and have round outlines ( Fig. 2G ). Some well calcified capstans, up to 0.08 mm long, are elongated and have oval outlines ( Fig. 2F ). These elongated capstans bear densely crowded warts or dents on the ends.

Pharynx contains vesiculated sclerites with a narrow median constriction; some of these are plates with rounded edges, up to 0.07 mm long ( Fig. 3A ), the others are like rods with conical ends, up to 0.10 mm long ( Fig. 3B ). Anthocodial walls contain 6-radiate or 7-radiate rounded capstans, up to 0.08 mm across ( Fig. 3C ).

Surface of capitulum and stalk contains 6-radiate and 7-radiate capstans, up to 0.08 mm long ( Fig. 3D–E ); colony interior contains long, slender needles with a smooth median part and spiny trihedral ends. The interior needles, up to 0.65 mm long ( Fig. 3F ), have a smooth cylindrical median part, but trihedral ends ( Fig. 3G ). Each ridge at the needle end bears spines or dents.

Paratype and variation

The paratype colony (MIMB 42494) has a shape similar to that of the holotype; it is 1100 mm high and 1070 mm wide ( Fig. 1E ). Anthocodiae wall is smooth and cylindrical when visible; tentacles are folded over the polyp. Anthocodiae are mostly retracted to the inside. Sclerites composition ( Figs 4–5 ) coincides with that in the holotype ( Figs 2–3 ). Clubs in the autozooid tentacles of the paratype are slightly shorter up to 0.13 mm ( Fig. 4F ) vs 0.15 mm in the holotype ( Fig. 2F ). Some capstans of the paratype surface may be less calcified and smaller ( Fig. 5C ) in comparison with those of the holotype ( Fig. 3C ).

The smallest of the additional specimens (MIMB 42496) is about 15 mm across ( Fig 1C ). It has 6 autozooids. The siphonozooids are of the same size as in the holotype and paratype, but the mesozooids are not visible.

The other additional specimen (MIMB 42496) is about 65 mm across the capitulum and 37 mm tall ( Fig. 1D ). The mesozooids are scattered chaotically between the autozooids and crowded near the margin of the capitulum.

Colour

Colonies preserved in alcohol are white, sclerites are colourless.

Remarks

The most remarkable characters of Heteropolypus annae sp. nov. are its white colouration (due to its colourless sclerites) and the remarkably diverse sclerites, including clubs, in its autozooid tentacles. At present the genus Heteropolypus includes six known species ( Table 1 ). Among them, only two species, Heteropolypus rylovi from Kurile Islands and Heteropolypus sol Molodtsova, 2013 from Atlantic, have clubs in their tentacles. However, H. rylovi differs from H. annae sp. nov. in having needles up to 0.5 mm long in its autozooid tentacles and anthocodia wall and the absence of the waisted plates in its pharynx. Heteropolypus sol differs from H. annae sp. nov. by the occurrence of the girdled spindles and longer flanged rods (0.31–0.38 mm long) in the autozooid tentacles. Heteropolypus annae sp. nov. can further be distinguished from H. sol by the absence of the rods with median waist in the pharynx. Furthermore, H. sol has different geographical distributional area. Heteropolypus annae sp. nov. can further be distinguished from H. insolitus by the absence of the needles (up to 0.6 mm long) in the anthocodial walls and the clubs in the stalk surface. Heteropolypus annae sp. nov. differs from H. japonicus by the presence of the clubs in the autozooid tentacles and capstans in the colony surface ( Table 1 ). Heteropolypus annae sp. nov. differs from H. ritteri by the presence of the clubs and the absence of the smooth rods up to 0.24 mm long in the autozooid tentacles ( Table 1 ). Heteropolypus annae sp. nov. differs from H. steenstrupi ( Wright & Studer, 1889) by having shorter clubs and by the absence of the 4-rayed forms 0.24 × 0.06 mm ( Table 1 ).

Distribution

This species is known for certain from the Kurile Islands, Sea of Okhotsk, Northwestern Pacific, between 205 and 455 m depth.

Figures

Fig. 1. Heteropolypus annae sp. nov. A. Holotype (MIMB 42493), Kurile Islands, Sea of Okhotsk. View from above. B. Holotype (MIMB 42493), Kurile Islands, Sea of Okhotsk. View from below. C. One specimen, Kurile Islands, Sea of Okhotsk (MIMB 42496). D. One specimen, Kurile Islands, Sea of Okhotsk (MIMB 42496). E. Paratype (MIMB 42494), Kurile Islands, Sea of Okhotsk. F. Holotype (MIMB 42493); section of the capitulum; 1 = autozooid, 2 = mesozooid. G. Holotype (MIMB 42493); surface of the capitulum; 1 = mesozooids. Scale bars: A–E = 10 mm; F–G = not to scale.

Fig. 2. Heteropolypus annae sp. nov., holotype (MIMB 42493); sclerites from the autozooid tentacles. A. Waisted plates. B. Plates. C. Flanged spindles. D. Warty spindles. E. Club-like spindle. F. Clubs. G. Capstans. H. Slender capstans. Scale bar = 0.1 mm.

Fig. 3. Heteropolypus annae sp. nov., holotype (MIMB 42493); sclerites from the autozooid pharynx, anthocodiae, and 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.

Fig. 4. Heteropolypus annae sp. nov., paratype (MIMB 42494); sclerites from the autozooid tentacles. A. Waisted plates. B. Plates. C. Flanged spindles. D. Warty spindles. E. Club-like spindle. F. Clubs. G. Capstans. H. Slender capstans. Scale bar = 0.1 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.