Euplexaura boninensis (Aurivillius, 1931)

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

Taxon classification Animalia Alcyonacea Plexauridae

Euplexaura boninensis (Aurivillius, 1931) Figures 1, 2c, 6, 7

Filigella boninensis Aurivillius, 1931: 139 (Bonin Islands).

Thesea boninensis ; Matsumoto 2014: 158 (Table 1, listed only).

Material examined.

Holotype UPSZTY2165 (UUZM 68), East of Chichijima I., Ogasawara Is. (= Bonin Is.), Japan, depth 100 m, in formalin, Dr. Sixten Bock's, Japan Expedition, coll. Dr. Sixten Bock, 1 August 1914.

Diagnosis.

Branches thread-like, 6 cm in length. Calyces dome-shaped, arranged all around the branches (Figure 2c). The polyps have points with flattened spindles, up to 0.15 mm long (Figure 6b), with simple tubercles and spiny distal end. Collaret present, with slightly bent, flattened spindles, up to 0.25 mm long, with simple tubercles (Figure 6c). Tentacles with small scales, up to 0.10 mm long (Figure 6a).

The surface layer of the coenenchyme has spindles (Figure 6d) and blunt ellipsoids (Figure 6e), up to 0.65 mm long, with complex tubercles. Several of them with one side less tuberculate. The interior has small spindles and rods, up to 0.25 mm long (Figure 7), with simple tubercles.

Remarks.

Because the sclerites of this species are spindles and ellipsoids with complex tubercles it actually represents an Euplexaura species. It is the only species of Euplexaura with thread-like colony shape which has many sclerites with one side that is less tuberculate.