Euplexaura mitsukurii (Kinoshita, 1909)

Matsumoto, Asako K. & van Ofwegen, Leen P., 2016, Species of Elasmogorgia and Euplexaura (Cnidaria, Octocorallia) from Japan with a discussion about the genus Filigella, ZooKeys 589, pp. 1-21 : 7-8

Taxon classification Animalia Alcyonacea Plexauridae

Euplexaura mitsukurii (Kinoshita, 1909) Figures 1, 2d, 8, 9

Filigella mitsukurii Kinoshita, 1909: 1(Sagami Bay); Aurivillius 1931: 129 (Kiu-Shiu = Kyushu); Utinomi 1961: 213; Bayer 1956: F206, fig. 148,3.

Elasmogorgia mitsukurii ; Kükenthal 1924: 149.

Thesea mitsukurii ; Matsumoto et al. 2007: 240 (Table 2, listed); Matsumoto 2014: 158, 159, 160 (Table 1, listed).

Thesea sp. Matsumoto 2014: 161 (Table 1, listed).

Material examined.

Syntypes UMUTZ-CnidG-222, off Jogashima I., Sagami Bay, Japan, depth 70 Japanese fathoms (100-106 m), secured with Hydra dredge, 26 August 1901; UMUTZ-CnidG-223, Japanese 2 nautical miles (5 km in Kinoshita, 1909) of West South off Jogashima I., Sagami Bay, Japan, saba-nawa line, 31 July 1892. Identified museum material UMUTZ-CnidG-122, off Torishima I., Japan, East China Sea, 28°10'N, 126°2'E - 28°20'N, 126°11'E, depth 64 fms (117 m), trawl, coll. N. Yanaghi, 22 June 1913, det. F.M. Bayer, ca.1950, as Filigella mitsukurii ; UMUTZ-CnidG-126 same data as UMUTZ-CnidG-122, as Filigella mitsukurii . Unidentified museum material. ZMUC ANT-000611 (ZMUC120604-09), East China Sea, 33°41'N, 128°50'E, depth 75 fms (137 m), sand, Hyateri maru, trawl, coll. Dr. Th. Mortensen, 17 May 1914; ZMUC ANT-000616 (ZMUC120604-16), East China Sea, 32°15'N, 128°17'E, depth 90 fms (165 m), hard bottom, Hyateri maru, coll. Dr. Th. Mortensen, 15 May 1914; ZMUC ANT-000664 (ZMUC120604-59), 34°20'N, 130°10'E, depth 60 fms (110 m), sand, coll. Dr. Th. Mortensen, 18 May 1914; ZMUC ANT-000655 (ZMUC120604-67), off Misaki Biological Station, Sagami Bay, Japan, depth 200 fms (366 m), sand, coll. Dr. Th. Mortensen, 30 June 1914; AKM1630, Sukumo Bay, Bungo Channel, Japan, ca. 32°38'N, ca.132°29' -30'E, depth 144-150 m, RV Tansei-maru, KT86-16, st.A-8, 1 m ORI biological dredge, coll. S. Ohta, 1 November 1986; AKM1631, off Kashima, Kashima Sea, Japan, 36°07'N, 140°49.0'E, depth 63-71 m, RV Tansei-maru, KT79-13, st. KB2, 2 m Beam trawl, coll. S. Ohta, 7 August 1979; AKM1632, off Toi, Suruga Bay, Japan, depth 192-207 m, 34°55.83'N, 138°44.85'E - 34°56.62'N, 138°45.0'E, RV Tansei-maru, KT75-15, st. 02, 2 m Beam Trawl, coll. S.Ohta, 24 November 1975; AKM1566, South East off Taito-saki Cape, Boso Peninsula, Japan, 35°21.259'N, 140°45.27'E - 35°21.359'N, 140°45.613'E, depth 104-105 m, RV Tansei-maru, KT01-08, st. TZ-7, 1 m ORI biological dredge, coll. S. Ohta, 22 June 2001; AKM 1644, off Hitachi, Kashima sea, Japan, 36°36.4'N, 140°50.1'E - 36°35.2'N, 140°50.5'E, depth 79-82 m, RV Tansei-maru, KT79-13, st. KB14, 2 m Beam trawl, coll. S. Ohta, 9 August 1979.

Diagnosis.

Branches thread-like. The examined syntype has two branches arising from the main stem with a length of 19 cm and 28.5 cm, respectively; the main stem is 9 cm long. Calyces dome-shaped, arranged all around the branches (Figure 2d). The polyps have points with flattened spindles, up to 0.20 mm long (Figure 8b), with simple tubercles. Collaret present, with slightly bent, flattened spindles, up to 0.30 mm long, with sparse, simple tubercles (Figure 8c). Tentacles with small scales, up to 0.10 mm long (Figure 8a).

The surface layer of the coenenchyme has spindles (Figure 8 d–e), up to 0.35 mm long, with complex tubercles. Some of them with one side that is less tuberculate. The interior has small spindles and rods, up to 0.25 mm long (Figure 9), with simple tubercles.

Remarks.

Because the sclerites of this species are spindles with complex tubercles this is actually a species of Euplexaura .

Kinoshita (1909) mentioned 13 specimens of Filigella mitsukurii and three of them were complete. He used two specimens for his original description. Nowadays two specimens are present in UMUT and the data fit Kinoshita's, two specimens in his description.

The locality name "Jogaschima, Pagamibai" of this species in Kükenthal (1924) is a mistyping of "Jogashima, Sagamibai (Sagami Bay)".

Distribution.

Sagami Bay, off Boso Peninsula, Kashima Sea, Suruga Bay, Bungo Channel, East China Sea, Japan.