Xenia delicata Roxas, 1933

Halász, Anna, Mcfadden, Catherine S., Toonen, Robert & Benayahu, Yehuda, 2019, Re-description of type material of Xenia Lamarck, 1816 (Octocorallia: Xeniidae), Zootaxa 4652 (2), pp. 201-239 : 211

Xenia delicata Roxas, 1933

Xenia delicata Roxas, 1933: 89

Material. Holotype and 4 paratypes. ZMB 6908 , Philippines, Puerto Galera Bay , Mindoro , 1912–1914, coll. members of the Zoology Department, University of the Philippines.

Description. The holotype is 21 mm high, its stalk is 8–9 mm wide, split into two branches, 4–5 mm long, and 4 mm wide. The polyp body is 4 mm long, tentacles up to 6 mm long, featuring three irregular rows of pinnules on each side and occasionally a fourth row. The pinnules are relatively short, up to 0.32 mm long and 0.10 mm wide, 18–23 in the outermost row with a space of 1–1.5 pinnule-widths between adjacent pinnules. There are no sclerites in any part of the colony. The ethanol-preserved holotype is light yellowish-beige.

The four paratypes resemble the holotype. The first paratype colony is 15 mm high; its stalk is 10 mm long and 3–4 mm wide, and does not split. The second is 15 mm high; its stalk is 10–12 mm long, divided into five branches, each 6–8 mm long and 3–4 mm wide. The third colony is 20 mm high, its stalk is 7–8 mm wide, splits into two branches, each 4–5 mm long and 3–4 mm wide. The fourth colony is 12–15 mm high; its stalk is 3–4 mm long and splits at the base into five branches, two of which split again into three, and another one into two branches, 2–3 mm above the colony base. They are 8–10 mm long, 4–5 mm wide at their base, and 3–4 mm at their uppermost part. Similar to the holotype, there are no sclerites in any part of the paratypes.

Remarks. Roxas (1933) described X. delicata as having four rows of pinnules and 18–20 pinnules in the outermost row, thus corresponding to the current findings. In contrast to the current findings, the original description indicated: “spicules present especially on external surface of tentacles and pinnules”; it also referred to only one colony although five were found under ZMB 6908. If the sclerites had dissolved due to the acidified preservative, X. delicata would in that case resemble X. membranacea .

Similar species and conclusion. X. sansibariana , X. mucosa Verseveldt & Tursch, 1979 and X. delicata lack sclerites in all parts of the colony, but differ in pinnule arrangement ( X. sansibariana : 4 rows and 26–33, X. mucosa : 4 rows and 30–42, X. delicata : 3 and occasionally 4 rows and 18–23 pinnules) and thus should be considered as separate species.

Distribution. Philippines.