Melithaea japonica (Verrill, 1865)

Matsumoto, Asako K. & van Ofwegen, Leen P., 2015, Melithaeidae of Japan (Octocorallia, Alcyonacea) re-examined with descriptions of 11 new species, ZooKeys 522, pp. 1-127 : 19-22

Taxon classification Animalia Alcyonacea Melithaeidae

Melithaea japonica (Verrill, 1865) Figures 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55

Mopsella japonica : Verrill 1865: 190; Verrill 1870: 80 (Simoda (=Shimoda), Japan).

Melitella japonica : Gray 1870: 7.

? Acabaria japonica : Ridley 1884: 361 (Darwin, Australia).

Acabaria japonica (in part): Kükenthal 1919: 188; 1924: 82.

Acabaria japonica : Hickson 1937: 178 (re-examination of type).

Pleurocorallium confusum : Moroff 1902a: 582; Moroff 1902b: 404, pl. 17 fig. 8, pl. 18 fig. 19.

Pleurocoralloides confusum : Kükenthal 1924: 53.

Pleurocoralloides formosum : Moroff 1902a: 583; Moroff 1902b: 406, pl. 17 fig. 10, pl. 18 fig. 20; Kükenthal 1924: 52, fig. 42.

Melitodes flabellifera : Kükenthal 1908: 190; Kükenthal 1909: 54, figs 50-54, pl. 4 fig. 22 (Japan); Kükenthal 1919: 143; 1924: 58; Aurivillius 1931: 23 (Sagami Bay); Hickson 1937: 122.

Melithaea flabellifera var. reticulata : Kükenthal 1908: 191; Kükenthal 1909: 55, pl. 4 fig. 23; Kükenthal 1924: 59.

Melithaea flabellifera var. cylindrata : Kükenthal 1908: 192; Kükenthal 1909: 57, pl. 4 fig. 24; Kükenthal 1924: 59.

Melitodes densa Kükenthal 1908: 192; 1909: 58, figs 59-60, pl. 5 fig. 25 (Japan); 1919: 143; 1924: 58; Hickson 1937: 122.

? Melithaea flabellifera : Rho et al. 1980: 48 (Korea Strait); Song 2000: 111 (Korea Strait, Sea of Japan).

? Melithaea densa : Rho et al. 1980: 50 (Korea Strait); Song 2000: 114 (Korea Strait).

Material examined.

Holotype of Mopsella japonica BMNH 1946.1.14.207 dried sclerites of the type MCZ 4265, now MCZ Invertebrate Zoology ALCY-412 (microscopic slide only), Simoda (= Shimoda), Japan, coll. Prof. Hickson; NHMW 8046 (A.N. 1156), Nagasaki, Japan, I. Erber in Wien (Dr. A. v. Roretz) (possibly collected between ca.1875-1879); NHMW 8047, Enoshima, Japan, coll. Dr. Richard. v. Drasche; NHMW 12690 (A.N. 4837), Enoshima, Japan, Baron Eug. V. Ransonnet, Ostasiatisches Ex. (1873); Pleurocoralloides formosum , ZSM 20051735, type, Japan, Sagami Bay, leg. Haberer, 1901; Melitodes flabellifera : ZMB 5822, syntype, Japan, up to 20 m depth, coll. Doflein, 1904/05; NHMW 2426, Enoshima, Nagoya, coll. Drasche, Koerbl, 18-19 December 1877; MZS-Cni52, Sagami Bay, coll. Doederlein, 1882; BMNH 1936.7.6.7, Sagami Channel, Sagami Bay, purchased of Shibayama Nat. Sci. Laboratory Cat. No. 7c-7A, 7 August 1931; Melitodes densa : ZMB 5801, syntype, Sagami Bay, 60-250 m?, coll. Doflein 1904/05; ZMB 5809, syntype, Sagami Bay, littoral, coll. Doflein1904/05; previously unidentified museum material: BMNH 1883.8.29.10, Enoshima, Japan, coll. Res. by D?.F.J. Burge; MZS-Cni 235, Jogashima, Sagami Bay, Japan, coll. Doederlein; ZMUC ANT-000591, Misaki, Sagami Bay, Japan, 1-2 fms (2-4 m), coll. Dr. Th. Mortensen, 24 June 1914; UMUTZ-CnidG- 257 (G-23b), gorgonia cave at Koajiro, Misaki, Sagami Bay, 16 July 1897; UMUTZ-CnidG-258 (G-23c), same data as UMUTZ-CnidG-257 (G-23b); UMUTZ-CnidG-259 (G-23d), same data as UMUTZ-CnidG-257 (G-23b); UMUTZ-CnidG-35, Misaki, Sagami Bay, Japan sp. no. 19; UMUTZ-CnidG-260 (G-35b), same data as UMUTZ-CnidG-35; UMUTZ-CnidG-261 (G-35c), same data as UMUTZ-CnidG-35; UMUTZ-CnidG-262 (G-35d), same data as UMUTZ-CnidG-35; UMUTZ-CnidG-36, Misaki, Sagami Bay, Japan; UMUTZ-CnidG-263 (G-36b), same data as UMUTZ-CnidG-36; UMUTZ-CnidG- 264 (G-36c), same data as UMUTZ-CnidG-36; UMUTZ-CnidG-265 (G-36d), same data as UMUTZ-CnidG-36; UMUTZ-CnidG-37, Misaki, Sagami Bay, Japan, coll. K. Kinoshita, summer 1906; UMUTZ-CnidG-266 (G-37b), same data as UMUTZ-CnidG-37; UMUTZ-CnidG-267 (G-37c), same data as UMUTZ-CnidG-37; UMUTZ-CnidG-269 (G-37e), same data as UMUTZ-CnidG-37; UMUTZ-CnidG-38, Cape Makurazaki, Kagoshima Prefecture, coll. M. Miyajima by diving, 7 August 1899; UMUTZ-CnidG-42, Misaki, Sagami Bay, Japan, 1-5 April 1917; UMUTZ-CnidG-272 (G-42b), same data as UMUTZ-CnidG-42; UMUTZ-CnidG-43, Misaki, Sagami Bay, Japasp. n. no. 77; UMUTZ-CnidG-273 (G-43b), same data as UMUTZ-CnidG-43; UMUTZ-CnidG-274 (G-43c), same data as UMUTZ-CnidG-43; UMUTZ-CnidG-275 (G-43d), same data as UMUTZ-CnidG-43; UMUTZ-CnidG-276 (G-43e), same data as UMUTZ-CnidG-43; UMUTZ-CnidG-44, Shimoda Harbour, Izu Peninsula, Japan, vessel Ohnoura-maru cruise, coll. S. Hirota, 28 August 1893; UMUTZ-CnidG-277 (G-44b), same data as UMUTZ-CnidG-44; UMUTZ-CnidG-278 (G-44c), same data as UMUTZ-CnidG-44; UMUTZ-CnidG-116, near Misaki Marine biological Station, Sagami Bay, Japan, coll. I. Ijima by diving, 1913; UMUTZ-CnidG-192, Moroiso, Misaki, Sagami Bay, Japan, collected by diving, 12 August 1904; UMUTZ-CnidG-196, Shimo-Chikura, Kagoshima Prefecture, Japan, coll. M. Miyajima by coral net, 12 July 1899; AKM 1633, Kominato, Japan, April 1944, deposited in Aikappu Museum of Natural History, Akkeshi Marine Station, Field Science Center for Northern Biosphere Hokkaido University; BIK-G224, Saba-shima Is. Koga Bay, Oga Peninsula, Sea of Japan, 7 m, coll. Y. Sato. 14 July 1988; BIK-G226, same data as BIK-G224; RMNH Coel. 41914 (AKM 594), Entrance of Otsuchi Bay, Otsuchi, Iwate Prefecture, 39°21.858'N, 141°59.972'E, 65.6 m, R/V Yayoi, coll. A.K. Matsumoto, 12 September 2005; RMNH Coel. 41915 (AKM 614), same data as RMNH Coel.41914; RMNH Coel. 41916 (AKM 615), Entrance of Otsuchi Bay, Iwate Prefecture, 39°21.917'N, 142°00.031'E, 77.6 m, R/V Yayoi, St.1(=St.2) 1 m biological dredge, coll. A.K. Matsumoto, 12 September 2005; RMNH Coel. 41917 (AKM 618), same data as RMNH Coel.41916; RMNH Coel. 41918 (AKM 619), off Ohako-zaki Cape, Otsuchi Bay, Iwate Prefecture, 39°21.428'N, 142°00.520'E, 69.2 m, R/V Yayoi, St.2(=St.5), 1 m biological dredge, coll. A.K. Matsumoto, 12 September 2005; RMNH Coel. 41919 (AKM 622), same data as RMNH Coel.41918; RMNH Coel. 41920 (AKM 1200), off Ohako-zaki Cape, Otsuchi Bay, Iwate Prefecture, ca. 39°21'N, 142°00'E, ca. 90 m, local fishery boat Taku-maru, gill-net, coll. K. Morita, ca. 21 March 2008; RMNH Coel. 41921 (AKM 1201), same data as RMNH Coel.41920; RMNH Coel. 41922 (AKM 1204), off Ohako-zaki Cape, Otsuchi Bay, Iwate Prefecture, ca. 39°21'N, 142°00'E, ca. 90 m, local fishery boat Taku-maru, gill-net, coll. K. Morita, 2 May. 2008; RMNH Coel. 41923 (AKM 1252), off Ohako-zaki Cape, Otsuchi Bay, Iwate Prefecture, ca. 39°21'N, 142°00'E, ca.75 m, local fishery boat Taku-maru, gill-net, coll. K. Morita, 9 May 2008; RMNH Coel. 41924 (AKM 1526), off Oshima Is. Entrance of Otsuchi Bay and Funakoshi Bay, Iwate Prefecture, 39°22.085'N, 142°01.152'E, 97 m, R/V Yayoi, 1 m biological dredge, coll. A.K. Matsumoto, 26 April 2010.

Re-description.

Colony bushy with few anastomoses. Branches flattened in the plane of branching and polyps arranged bilaterally. Points with slightly bent spindles up to 0.20 mm long, distal end with more developed tubercles (Fig. 38a). Collaret with bent spindles up to 0.25 mm long, middle part with more developed tubercles. Tentacles with platelets, the larger ones crescent-shaped with irregular projections (Fig. 38b). These platelets are up to 0.10 mm long. Pharynx with straight spiny rods, up to 0.05 mm long. Coenenchyme with capstans (Fig. 38c), 0.07-0.08 mm long and small clubs of similar length (Fig. 38d). Furthermore spindles (Fig. 38e), unilaterally spinose spindles (Fig. 38f) and unilaterally spinose spheroids (Fig. 38g) are present, 0.10-0.30 mm long. All with simple and complex tubercles. The calyces with additional clubs, up to 0.20 mm long (Fig. 38h). The axis has smooth and sparsely tuberculate rods (Fig. 38i).

Color.

Red with yellow polyps. Variation: red (most colonies), pink, with yellow or white polyps, tentacle and pharynx sclerites colorless, all others orange; or colonies yellow with all sclerites yellow; or white with yellow polyps with polyp sclerites yellow and all others colorless. RMNH Coel. 41923 is rather unique in having a pale light brown colony, tentacle sclerites colorless, others colorless, partly white and partly yellow, or entirely yellow.

Distribution.

Melithaea japonica is found at the eastern Pacific side of Japan; Sagami Bay, Izu Peninsula, Boso Peninsula, Nagasaki (Kyushu Is.), Shimo-Chikura (Kagoshima Prefecture, Kyushu Is.), Cape Makurazaki (Kagoshima Prefecture, Kyushu Is.), Otsuchi Bay (Sanriku, Iwate Prefecture); and at the western Sea of Japan side; Oga peninsula(Akita Prefecture) (Fig. 55).

Remarks.

The examined type material of Mopsella japonica was fragmented. In Harvard we only found one microscope slide (MCZ 4265, ALCY-412), in London only dried sclerites of the Harvard material (BMNH 1946.1.14.207). The type colony seems to be lost. Only in Vienna we found complete specimens identified as Melithaea japonica ; NHMW 8046, NHMW 8047 (Fig. 37b) and NHMW12690 identified as Melithaea japonica , the sclerites resemble those of the type material (Figs 39, 40). The collector of NHMW 8046, Dr. Albrecht von Roretz visited Japan as a medical attaché of Aus tria (= Hungarian legation) between 1875-1879 and possibly collected this material. NHMW 2426 ( Melithaea flabellifera ) and NHMW 8047 were collected by Dr. Richard. v. Drasche. He visited Japan during the Far East expedition 1875-1876. The Ostasiatisches Expedition by Baron Eug. V. Ransonnet, during which NHMW 12690 was collected, happened in 1873 ( Matsumoto 2013, submitted).

Despite the small remainder of the type we could link it with other species described from Sagami Bay. Apparently this is the most common shallow-water species of the region, Kükenthal (1908) mentioned 40 specimens for his Melitodes flabellifera . We examined ZMB 5822 (Figs 36b, 41, 42) and NHMW 2426 (Figs 36e, 43, 44). They both are similar to Melithaea japonica .

Melithaea densa is also reported to occur in shallow water. According to Kükenthal (1909) it resembles Melithaea flabellifera very much but differs in having more spinose collaret and point sclerites, more densely, stronger ornamented coenenchymal sclerites, and the color always being red with yellow polyps. Later, he separated the two species with Melithaea densa having no clubs ( Kükenthal 1924). The ZMB 5801 colony examined by us (Fig. 36c) showed many disintegrated sclerites (Figs 45, 46). As this mostly concerned the smaller sclerites we were unable to show the capstans and small clubs. But we found a few larger calyx clubs, apparently overlooked by Kükenthal (1909). Also most point sclerites were badly damaged. We also examined ZMB 5809 (Fig. 36d), which had its sclerites less disintegrated (Figs 47, 48).

Kükenthal (1924: 53) referred Pleurocorallium confusum to Pleurocoralloides . Bayer and Cairns (2003: 222) suggested that the species belongs to Acabaria . Moroff (1902a, b), in his descriptions of the species, mentioned flattened branches; polyps on one side of the colony; sclerites straight or bent 0.25 mm long spindles; also plate-like sclerites and crosses present; colony red with yellow polyps. The type seems to be lost. Because of its flattened branches we consider Pleurocoralloides confusum synonymous with Melithaea japonica .

Bayer and Cairns (2003: 222) suggested Pleurocoralloides formosum to belong to Acabaria . It was described as having polyps with 7 spindles per point and 6 rows in the collaret; sclerites orange, tentacles ones yellow, axis orange. We consider it a synonym of Melithaea japonica ; the colonies are shown in Fig. 36a, its sclerites are depicted in Figs 49, 50.

Melithaea flabellifera has been described with two variations: Melithaea flabellifera var. reticulata from Sagami Bay, 80-250 m depth. It differs in having many anastomoses, and no flattened branches, color orange red, sclerites bigger and more spinose. Depository of material is unknown.

Melithaea flabellifera var. cylindrata from an unknown locality in Japan also lacks flattened branches, color red with yellow polyps, sclerites are less spinose. Two syntypes are reported to be in Frankfurt, SMF 1260 and 1262, but we could not find these specimens during a visit.

In northern Japan we found quite a number of specimens: RMNH Coel. 41915-41924. As an example we show the colony of RMNH Coel. 41922 (Fig. 37c) and its sclerites (Figs 51, 52). Here, the smallest colonies are white or yellow, only RMNH Coel. 41922 is red.

We found three specimens with extreme slender sclerites: BIK-G224 (Fig. 37a; sclerites Figs 53, 54), BIK-G226, and RMNH Coel. 41914.