AnimaliaAlcyonaceaClavulariidaeBenayahuYehudaMcFaddenCatherine S.ShohamErezSearch for mesophotic octocorals (Cnidaria, Anthozoa) and their phylogeny: I. A new sclerite-free genus from Eilat, northern Red SeaZookeys1462017201768011110.3897/zookeys.680.12727 Altumia delicata http://zoobank.org/4D9A82B8-F305-43E1-A5A4-3F9DB672781A sp. n.Figures 2, 3Holotype.

ZMTAU CO 37427, Israel, Gulf of Aqaba, Eilat, 29°30'38.31"N, 34°55'59.30"E, 132 m, 30 May 2016, collected by ROV, coll. M. Weis; paratype: ZMTAU CO 37495, Israel, Gulf of Aqaba, Eilat, 29°30'37.29"N, 34°55'59.28"E, 118 m, 8 March 2017, collected by ROV, coll. M. Weis

Diagnosis.

The ethanol-preserved holotype is comprised of thin patches of short stolon-like crusts growing over the dead branch of a black coral (Antipatharia) (Figure 2A), almost invisible to the naked eye. The milky-white, thin (<0.5 mm) crusts are a few mm long (Figure 2B), very soft, almost slime-like. Polyps completely retracted and practically invisible in the preserved colonies. No sclerites observed in any part of the colony.

Altumia delicata gen. n. sp. n. holotype ZMTAU CO 37427. A Colony growing over a branch of a black coral B close up of holotype. Scale 10 mm at A, 1 mm at B.

When alive, the delicate, semi-transparent expanded polyps are distinct and are up to 20 mm long, featuring eight pinnate tentacles (Figure 3A). The ROV photographs indicate that the colonies commonly grow on dead black corals; the latter may reach a large size (~45 cm in length) and can be predominantly fouled by A. delicata (Figure 3B). Interestingly, debris, such as PVC net found at a depth of 100 m, was found to be colonized by this octocoral (Figure 3C).

Altumia delicata gen. n. sp. n. live colonies. A, B colonies growing over branch of black coral with expanded polyps C colonies growing on PVC net (arrow heads).

Intraspecific variability.

There are no differences between the holotype and the paratype except for the size of the colonies.

Etymology.

The species name is formed from the Latin ‘delicata’, delicate, referring to the fine texture of the colonies and their polyps. Gender female.