Calcigorgia japonica Dautova, 2007

Dautova, Tatiana N., 2018, Two new species of deep-water Calcigorgia gorgonians (Anthozoa: Octocorallia) from the Kurile Islands, Sea of Okhotsk, with a review of distinctive characters of the known species of the genus, European Journal of Taxonomy 408, pp. 1-22 : 11-20

Calcigorgia japonica Dautova, 2007

SEA OF JAPAN: 1 specimen, 39°35′ N, 135°01′ E, 832–736 m, 8 Aug. 1933, K.M. Deryugin leg. ( ZIN RAS 1/10706 ).

Description

Colonies irregularly branched. Holotype alcohol preserved colony, 121 mm high and 55 mm wide (Fig. 6A). Paratype 105 mm high and 63 mm wide (Fig. 6B). Polyps up to 10 mm high and 4 mm wide, disposed irregularly at distances of 2–10 mm from each other. Tentacles folded over polyp and partly retracted to inside; polyp body smooth and cylindrical in shape. No polyps entirely retracted into coenenchyme.

Coenenchyme 0.8 mm thick and consists of two layers, a 0.6 mm thick outer layer, with smooth surface and a very thin inner layer. Axis made of concentric layers. Sclerites unordered in tentacles, polyp body wall and coenenchyme.

Tentacles contain clubs and spindles. Clubs mainly 0.2–0.3 mm long, with plump or elongated head consisting of warty processes; larger clubs up to 0.35 mm (Fig. 7A). Their handles straight or slightly curved, pointed or blunt, bearing small tubercles or conical processes inclined toward handle end. Clublike spindles, up to 0.26 mm, with only slight accumulation of the processes on one end (Fig. 7B) and bearing conical hillocks, inclined toward the tips of spindle. Spindles straight or slightly curved, usually up to 0.2–0.38 mm long, some of these up to 0.4 mm (Fig. 7C–D). Some narrow spindles with tapered ends ornamented with tubercles (Fig. 7C), others with well developed conical hillocks, inclined toward tips of spindle ( Fig. 7D ).

In upper part of polyp body wall (about half of height of polyp’s body) numerous clubs, mainly 0.15– 0.28 mm long, with plump head consisting of warty processes (Fig. 8A–B). Handles of short clubs mostly straight and covered with small tubercles ( Fig. 8A ). Longer clubs usually with slightly curved handles bearing tubercles or conical hillocks inclined to handle’s end ( Fig. 8B ). These longer clubs transitional to club-like spindles, up to 0.4 mm long, bearing well-developed conical hillocks usually inclined to ends of spindle (Fig. 8F). Short clubs also coincide with ovals, mostly 0.12–0.13 mm long, densely covered by unordered warts (Fig. 8D), and capstans, mostly 0.12–0.15 mm, ornamented with girdled warts or unordered processes (Fig. 8E). Longer clubs (Fig. 8B) and spindles (Fig. 8C) common here. Capstans and ovals not numerous.

In lower part of polyp body wall (about half of height), clubs mainly up to 0.15–0.28 mm long, not numerous (Fig. 9A–B). Handles of short clubs mostly straight and densely covered with small tubercles ( Fig. 9A ). Longer clubs usually with slightly curved handles bearing processes that tend to be inclined to handle’s end (Fig. 9B). These longer clubs are transitional to a few club-like spindles, up to 0.3 mm long, ornamented with small warts (Fig. 9C), and numerous spindles, mostly up to 0.25–0.3 mm long ( Fig. 9D ). Spindles bear conical hillocks, inclined toward tips of spindle. Short clubs coincide with ovals, mostly 0.11–0.12 mm long (Fig. 9E), and capstans, mostly 0.12–0.15 mm (Fig. 9F). Capstans can be assumed to be 8-radiate sclerites with well-developed plump terminal tufts. Capstans resemble thick spindles, mostly up to 0.17–0.2 mm long, covered by warts, which processes tend to be girdled (Fig. 9G).

External layer of coenenchyme comprises numerous ovals, mostly 0.08–0.11 mm long, with densely arranged warts (Fig. 10A) and capstans, mostly 0.1–0.13 mm, with well-developed girdled warts (Fig. 10B–C). Capstans 8-radiate sclerites with two girdles of warts and plump terminal processes; some have unequally developed ends (Fig. 10B). Capstans with less calcified processes, mostly 0.13–0.15 mm long, also numerous (Fig. 10D). Warty spindles, mostly 0.15 mm long, also present here but scarce (Fig. 10E).

Internal layer of coenenchyme contains weakly calcified capstans, up to 0.13 mm long, of same shape as that in outer layer (Fig. 10E).

Paratype and variations

Paratype MIMB 20703 has same branched colony shape (Fig. 6B). Sclerite composition in paratype (Figs 11–13) coincides with that in holotype. Sclerites in paratype are slightly larger. Clubs of tentacles (Fig. 12A) and upper part of polyp body (Fig. 13A) up to 0.35 mm long vs up to 0.28 mm in holotype (Figs 7A, 8B). Ovals in polyp body wall up to 0.15 mm long (Fig. 12D) vs up to 0.12 mm in holotype (Fig. 9E). Capstans in coenenchyme of paratype up to 0.18 mm long (Fig. 13B–C) vs up to 0.15 mm in holotype (Fig. 10C–D).

Colour

In alcohol preserved material: polyps and coenenchyme creamy, colony axis black or deeply brown, sclerites colourless.

Distribution

This species is known for certain from the Kurile Islands, Sea of Okhotsk, Northwestern Pacific. Depth range is from 140 m to 400 m.

Remarks

This species should be identified as a member of the family Acanthogorgiidae , as it conforms well enough with the distinctive characters of the family: the polyp is not divided into an anthocodia and anthostele; tentacles, when retracted, are folded above the oral disk ( Bayer 1981; Fabricius & Alderslade 2001). Within the family Acanthogorgiidae , the examined specimen should be assigned to the genus Calcigorgia , as its distinctive characters agree with those of that genus: sclerites are small spindles, capstans and clubs that are irregularly distributed in the polyp ( Bayer 1981).

The most obvious distinctive characters of C. simushiri sp. nov., that distinguish it from the known species of the genus, are the shape of polyp (tall body without the folded peduncle in fixed specimens) and the absence of clubs in the coenenchyme (see Table 1 ). Calcigorgia simushiri sp. nov. may be confused, at first glance, with C. spiculifera in terms of composition of sclerites from the polyp wall ( Table 1 ). The size of these sclerites, however, differs significantly. Clubs in the polyp body of C. simushiri sp. nov. are up to 0.28 mm long vs up to 0.22 mm in C. spiculifera ; spindles and club-like spindles are up to 0.4 mm long vs 0.25 mm in C. spiculifera ( Table 1 ). Calcigorgia japonica differs from C. simushiri sp. nov. by having in the polyp body shorter sclerites and no capstans and having clubs in the coenenchyme ( Table 1 ). Finally, C. simushiri sp. nov differs from C. matua sp. nov., in the absence of leafy clubs, which are characteristic for C. matua sp. nov. ( Table 1 ).

Figures

Fig. 7. Calcigorgia simushiri sp. nov., holotype (MIMB 20721), sclerites from the tentacles of polyp.  A. Clubs. B. Club-like spindles. C. Spindles ornamented with tubercles. D. Spindles ornamented with conical hillocks inclined toward the spindle ends. Scale bar: 0.1 mm.

Fig. 8. Calcigorgia simushiri sp. nov., holotype (MIMB 20721), sclerites from the upper part of the  body wall of polyp. A. Short warty clubs. B. Longer clubs with curved handles. C. Spindles. D. Ovals. E. Capstans ornamented with girdled warts. F. Club-like spindles. Scale bar: 0.1 mm.

Fig.9.Calcigorgiasimushirisp. nov., holotype (MIMB 20721), sclerites from the lower part of the polyp  body wall. A. Densely ornamented short clubs. B. Longer clubs with slightly curved handles. C. Clublike spindle. D. Spindles densely ornamented with inclined conical hillocks. E. Ovals. F. Capstans  ornamented with girdled warts. G. Thick spindles covered by warts tending to be girdled. Scale bar: 0.1 mm.