Elasmogorgia filiformis Wright & Studer, 1889

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 : 4-5

Taxon classification Animalia Alcyonacea Plexauridae

Elasmogorgia filiformis Wright & Studer, 1889 Figures 2a, 3, 4

Elasmogorgia filiformis Wright & Studer, 1889: 133 (Indonesia, Arafura Sea); Kükenthal 1924: 148.

Elasmogorgia filiformis ? Elasmogorgia filiformis ; Nutting 1912: 85 (Tateisha zaki Light, Japan); Thomson and Russell 1910: 159 (Amirantes); Thomson and Simpson 1909: 238 (Birma, India); Tixier-Durivault 1966: 403 (Madagascar); all not re-examined.

Elasmogorgia filiformis NOT Elasmogorgia filiformis ; Nutting 1909: 717 (California = Thesea ); 1910: 45 (Timor = Euplexaura ); Thomson and Dean 1931: 199 (Sulawesi = Astrogorgia ).

Material examined.

Holotype BMNH 1889.5.27.77, Arafura Sea, South of Papua, 28 fms, Challenger st. 188, 10 September 1874; ZMA Coel. 2537, Siboga st. 213, Saleyer anchorage, Sulawesi, Indonesia, 38 m, 26 September 1899 (= Astrogorgia ); ZMA Coel. 2538, Timor, 112 m, Siboga st. 289, 09°00.3'S, 126°24.5'E (= Euplexaura ).

Diagnosis.

Colony thread-like (Figure 2a). Calyces dome-shaped, arranged all around the branches (Figure 2a). Coenenchyme with spindles up to 0.45 mm long, with simple tubercles (Figures 3-4). Colony white with colourless spindles.

Remarks.

One somewhat flattened spindle was found, 0.35 mm long, maybe referable to a collaret (Figure 4b), and one capstan (Figure 3b). As the microscope slide that was made only shows heavily oxidized black sclerites it could not be really ascertained where different types of sclerites came from. The little fragment available was not sufficient for more extensive examination. Wright and Studer (1889) mentioned spindles up to 0.62 mm long. They also mentioned the basal portion of the tentacles has spindle-shaped sclerites of up to 0.18 mm long. Elasmogorgia filiformis mostly resembles a species of Astrogorgia but differs in not having polyp body sclerites and extremely weak ornamentation of spindles. Until new material becomes available for a more thorough examination the genus Elasmogorgia is retained.

ZMA 2537 of Thomson and Dean (1931) is a thread-like colony fragment containing colourless disintegrated sclerites, which were sufficiently recognizable to identify it as a species of Astrogorgia . In a comparison with Astrogorgia bayeri Ofwegen and Hoeksema, 2001, from Sulawesi, the latter species appears to have shorter spindles, up to 0.5 mm long, whereas Thomson and Dean's (1931) specimen has spindles of over 1 mm long. Because of the disintegrated state of its sclerites, no more differences could be ascertained.

ZMA 2538 of Nutting (1910) was also re-examined; it has characters of the genus Euplexaura . Elasmogorgia filiformis of Nutting (1912) is also unlikely an Elasmogorgia .