Cladiella hicksoni (Tixier-Durivault, 1944)

Lazar, Einav, Mcfadden, Catherine S., Huchon, Dorothée & Benayahu, Yehuda, 2025, Redescription of type material of the genus Cladiella Gray, 1869 (Octocorallia, Malacalcyonacea, Cladiellidae) from the Red Sea, Zootaxa 5674 (1), pp. 1-84 : 41-42

Cladiella hicksoni (Tixier-Durivault, 1944)

( Figs. 15F , 26 & 27 )

Lobularia Hicksoni Tixier-Durivault, 1944a: 186 ; Tixier-Durivault 1948: 206–213, Figs. 201–207.

? Cladiella hicksoni ; Tixier-Durivault 1970a: 202 ( New Caledonia); 1970b: 121–122 ( Vietnam).

Not Alcyonium sphaerophorum and Alcyonium brachyclados ; Stiasny 1937: 392.

Material examined. Syntypes. MNHN-IK-2000-383, Red Sea, coll. H. Michelin; MNHN-IK-2000-491, same details as MNHN-IK-2000-383; MNHN-IK-2000-402 (3 fragments), 1850, coll. A. B. Clot Bey, MNHN-IK-2000- 500 (3 fragments), same details as MNHN-IK-2000-383 .

Description. Syntype MNHN-IK-2000-383 is a fragment of an encrusting colony with a cross section of 66 x 60 mm, attached in part to a calcareous fragment ( Fig. 15F ). The laterally flattened lobes and lobules are arranged in two groups and the location of the retracted polyps is indicated by distinct pits on their surface.

The sclerome of the polyps includes some platelets, 0.05-0.06 mm long, featuring a lateral median constriction and occasionally lateral slits ( Fig. 26A ). Their surface has both a tuberculate and a cristate-like texture. An elevated rim sounding a central depression exists in some of these platelets. Some sclerites are figure eights. The surface of the lobe includes poorly developed dumbbells, 0.05–0.08 mm long, with rounded surface tubercles or blunt-ended conical ones ( Fig. 26B ). The sclerites from the interior of the lobes are dumbbells, 0.07–0.09 mm long, ornamented with pointed conical and blunt-ended conical tubercles, separated by a bare waist, 0.02–0.04 mm wide and 0.01– 0.02 mm long ( Fig. 26C ). The poorly developed dumbbells of the surface layer of the colony base are 0.05–0.08 mm long, featuring some blunt-ended conical tubercles and rounded ones at either end ( Fig. 27A ). The sclerites from the interior of the colony base are dumbbells with blunt-ended conical or pointed conical tubercles ( Figs. 27B ), 0.06–0.10 mm long, and their bare waist is 0.02–0.04 mm wide and 0.01–0.02 mm long.

Color. The dry syntype MNHN-IK-2000-383 is beige.

Remarks. The initial species assignment of L. hicksoni by Tixier-Durivault (1944a: 186) did not depict its morphological characters. These were subsequently presented in the revision of the genus ( Tixier-Durivault 1948: 206–213, Figs. 201–207). There are some differences between the amende description of L. hicksoni and the current findings. Notably, Tixier-Durivault (1948: Fig. 202) depicted platelets from the surface of the colony base, which were not found in the current study. Similarly, Fig. 206 of that study presents rods from the surface and the interior of the lobes and, similarly, they were not found in the examined syntypes. This species is characterized by short tubercles of the dumbbells from the interior of the base, also featuring a waist bordered by two distinct, almost parallel, straight lines, formed by the tubercles of the two sclerite ends.All syntypes, MNHN-IK-2000-491, MNHN- IK-2000-402 and MNHN-IK-2000-500 (both not shown) resemble syntype MNHN-IK-2000-383, except for their size. No details on the precise locality in the Red Sea where the type-material was collected are provided. The records of C. hicksoni from Vietnam and from New Caledonia ( Tixier-Durivault 1970a, b) should be re-examined in order to validate their taxonomic assignment.

Distribution. Red Sea.

Figures

FIGURE 15. Images of Cladiella type colonies.A. Cladiella elongata (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-379. B. Cladiella exigua (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-380. C. Cladiella germaini (Tixier-Durivault, 1943), syntype, MNHN-IK-2000-381. D. Cladiella globulifera Klunzinger, 1877, holotype, ZMB Cni 1873. E. Cladiella gracilis (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-382. F. Cladiella hicksoni (Tixier-Durivault, 1944), syntype, MNHN-IK- 2000-383.

FIGURE 26. Cladiella hicksoni (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-383. Scanning electron micrographs of sclerites of the colony top. A. Polyp sclerites. B. Poorly developed dumbbells of the surface layer of the lobes. C. Dumbbells from the interior of the lobes.

FIGURE 27. Cladiella hicksoni (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-383. Scanning electron micrographs of colony base sclerites. A. Poorly developed dumbbells of the surface of colony the base. B. Dumbbells from the interior of the base.