Cladiella letourneuxi (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 : 51-52

Cladiella letourneuxi (Tixier-Durivault, 1944)

( Figs. 28D , 35 & 36 )

Lobularia Letourneuxi Tixier-Durivault, 1944a: 189 ; Tixier-Durivault 1948: 134–139, Figs. 127–130.

Material examined. Syntypes. MNHN-IK-2000-31, Gulf of Suez, Red Sea, 1878, coll. M. Letourneux; MNHN- IK-2000-32, same details as MNHN-IK-2000-31 .

Description. Syntype MNHN-IK-2000-31 is a fragment of an encrusting colony with a maximum cross-section of 87 x 60 mm wide attached to a calcareous fragment ( Fig. 28D ). Its elongated digitate lobes are divided into lobules. Most of the polyps are partially contracted into the lobes, leaving part of the polyp body and the tentacles on the colony surface.

The sclerome of the polyps includes platelets, some featuring irregular outlines and some with a minor lateral constriction or slits, 0.05–0.07 mm long ( Fig. 35A ). Their surface has a tuberculate texture associated with a cristate-like texture. The surface of the lobes features mostly elongated, poorly developed dumbbells ornamented with rounded tubercles, 0.05–0.07 long ( Fig. 35B ). The dumbbells from the interior of the lobes featuring mostly blunt-ended conical and some distinctly pointed conical tubercles. These sclerites are 0.07–0.09 mm long featuring a bare waist, 0.02–0.03 mm wide and 0.01–0.02 mm long ( Fig. 35C ). No sclerites were found on the surface layer of the colony base. The interior of the colony base features dumbbells with low pointed conical or blunt-ended conical tubercles. These dumbbells are 0.05–0.09 mm long and their bare waist is 0.02–0.04 mm wide and 0.01–0.02 mm long ( Fig. 36 ).

Color. The ethanol preserved syntype MNHN-IK-2000-31 is beige.

Remarks. The initial species assignment of L. letourneuxi by Tixier-Durivault (1944a: 189) did not depict its morphological characters. They were subsequently presented in the revision of the genus ( Tixier-Durivault 1948: 134–139, Figs. 127–130). In general, the current examination of both the colony and the sclerites of syntype MNHN-IK-2000-31 corresponds to the amended description by Tixier-Durivault (1948). An absence of sclerites on the surface layer of the colony base is suggested to be a diagnostic of this species, along with the dumbbells from the interior of the colony featuring low tubercles. In addition, this species is one of the few congeners that features distinct digitiform lobes (see Discussion). Syntype MNHN-IK-2000-32 (not shown) resembles the other syntype except for its size. No details are provided on the precise locality in the Gulf of Suez where the type colonies were collected.

Distribution. Gulf of Suez (Red Sea).

Figures

FIGURE 28. Images of Cladiella type colonies. A. Cladiella irregularis (Tixier-Durivault, 1944), syntype MNHN-IK-2000- 384. B. Cladiella kükenthali (Tixier-Durivault, 1942), holotype, MNHN-IK-2000-385. C. Cladiella laciniosa (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-386. D. Cladiella letourneuxi (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-31. E. Cladiella lineata (Tixier-Durivault, 1944), holotype MNHN-IK-2000-387. F. Cladiella michelini (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-388.

FIGURE 35. Cladiella letourneuxi (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-31. 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 36. Cladiella letourneuxi (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-31. Scanning electron micrographs of dumbbell sclerites from the interior of the colony base.