Aldersladum jengi, Benayahu, Yehuda & McFadden, Catherine S., 2011

Benayahu, Yehuda & McFadden, Catherine S., 2011, A new genus of soft coral of the family Alcyoniidae (Cnidaria, Octocorallia) with re-description of a new combination and description of a new species, ZooKeys 84, pp. 1-11 : 4-5

Aldersladum jengi sp. n. Figs 36b

Holotype:

ZMTAU Co 33607 and 2 microscope slides, Taiwan, Penghu Is. Gupo Reef, 23°42'859"N, 119°33'488"E; 2-8 m, 29 July 2006. Paratypes: ZMTAU Co 31687, Japan, Ryukyu Archipelago, Yoron Is., 27°03'28"N, 128°23'59"E, 9 m, 1 July 2000; RMNH Coel. 39926, Japan, Ryukyu Archipelago, Okinoerabu Is. 27°23'38"N, 128°31'32"E, 11 m, 30 June 2000. Each ZMTAU Co number represents one colony. Material was collected by Y. Benayahu.

Etymology.

The species is named after Prof. M.-S. Jeng, Institute of Zoology, Academia Sinica, Taipei, Taiwan, in appreciation of his continuous support of octocoral studies in Taiwan.

Diagnosis and description.

The holotype is a flabby colony with a maximum cross-section of 6 × 5 cm (Fig. 3a). It has a low base, holdfast-like, 3-5 mm high, attached to a fragment of calcareous substrate. The base gives rise to primary finger-like lobes that occasionally branch once or twice into short lobules. The polyps feature densely on the lobes, with their density markedly decreasing on the basal part. The polyps are expanded and in only a few of them the anthocodial wall is partially contracted. Very rarely, the tentacles are withdrawn into the mouth.

The sclerites are platelets, mostly narrower across their lateral middle-line, 0.023-0.042 mm long (Fig. 4). These sclerites are found in all parts of the colony, including the polyps. The vast majority of sclerites have a longitudinal median slit on their flat surface. The slit is often calcified along most of its length, thus leaving two, or rarely one, aperture-like structures at its ends. The base of the colony has fewer sclerites compared to the lobes; these reach up to 0.060 mm long, mostly with no median slit (Fig. 5). These latter sclerites may have a circumferential waist, rather than being narrow across their lateral middle-line. The architectural features of these sclerites give them the appearance of rods with a median constriction (Fig. 5), which is more pronounced compared to the sclerites of the lobes (Fig. 4). All sclerites feature a “spongy” texture that seems to result from the uneven alignment of the crystal-nodules that construct them. The colony is zooxanthellate. The alcohol- preserved colony is cream-beige.

The preserved paratypes differ in size (Fig. 3b, c) and are more rigid than the holotype. The few sclerites in the base of both paratypes are up to 0.080 mm long, and thus larger compared to those found in the holotype.

When alive the polyps of the holotype were dark brown and the surface of the lobes was brighter (Fig. 6b). The flabby lobes tend to undulate with the water surge and in this sense resemble certain Klyxum colonies (pers. obs.)