Cladiella studeri (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 : 66-69

Cladiella studeri (Tixier-Durivault, 1944)

( Figs. 41E , 50 & 51 )

Lobularia Studeri Tixier-Durivault, 1944b: 344 ; Tixier-Durivault 1948: 213–219, Figs. 208–214.

Material examined. Syntypes. MNHN-IK-2000-390, 3 fragments, Red Sea, 1844, coll. A. Portier; MNHN-IK-2015-2016, 2 fragments, same details as MNHN-IK-2000-390 .

Description. Syntype MNHN-IK-2000-390 comprises three fragments of an encrusting colony with a maximum cross-section 83 x 56 mm, 55 x 37 mm, and 32 x 20 mm, respectively ( Fig. 41E ). Their small knob-like lobes are arranged in distinct groups with empty spaces between them. The location of the retracted polyps is visible as surface pits.

The sclerome of the polyps comprises platelets, figure-eights and a few rods, 0.05–0.06 mm long ( Fig. 50A ). The surface of these sclerites has a tuberculate texture commonly combined with a cristate-like one. The peripheral rim of the platelets is irregular and elevated. As such the platelets present a central depression of variable shape and dimensions. The sclerites of the surface of the lobes comprise poorly developed dumbbells, 0.06–0.07 mm long, mostly with rounded or blunt-ended conical tubercles ( Fig. 50B ). The dumbbells from the interior of the lobes are 0.05–0.10 mm long, featuring a bare waist 0.01–0.03 mm wide and 0.01–0.02 mm long ( Fig. 50C ). Their tubercles are mostly blunt-ended conical, with some pointed conical. The surface of the colony base has poorly developed dumbbells 0.05–0.09 mm long ( Fig. 51A ) featuring similar tubercles to those of the lobe surface. The interior of the base features dumbbells, 0.08–0.11 mm long, with blunt-ended conical or pointed conical tubercles ( Fig. 51B ). Their bare waist is 0.02–0.04 mm wide and 0.01–0.03 mm long.

Color. The dry syntype MNHN-IK-2000-390 is beige-brown.

Remarks. The initial species assignment of L. studeri by Tixier-Durivault (1944b: 344) did not depict the morphological characters of the syntype colony. These were subsequently presented in the revision of the genus ( Tixier-Durivault 1948: 213–219, Figs. 208–214). This species is characterized by its polyp sclerites in combination with the long dumbbells in the interior of the colony base (0.11 mm) and features long, rounded conical tubercles. The current examination of both the colony morphology and the sclerites of syntype MNHN-IK-2000-390 corresponds to the amended description by Tixier-Durivault (1948). Syntype MNHN-IK-2015-2016 (not shown) resembles the other syntype except for its size. Details on the exact locality in the Red Sea where the syntypes were collected are not given.

Distribution. Red Sea.

Figures

FIGURE 41. Images of Cladiella type colonies. A. Cladiella minuta (Tixier-Durivault, 1944), holotype, MNHN-IK-2000- 34. B. Cladiella pachyclados (Klunzinger, 1877), holotype, ZMB CNI 1874. C. Cladiella prattae (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-398. D. Cladiella sphaerophora (Ehrenberg, 1834), holotype, ZMB Cni 294. E. Cladiella studeri (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-390. F. Cladiella suezensis (Tixier-Durivault, 1944), syntype, MNHN-IK- 2000-41.

FIGURE 50. Cladiella studeri (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-390. Scanning electron micrographs of sclerites of the colony top. A. Polyp sclerites. B. Poorly developed dumbbells of the surface of the lobes. C. Dumbbells from the interior of the lobes.

FIGURE 51. Cladiella studeri (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-390. Scanning electron micrographs of the colony base sclerites. A. Poorly developed dumbbells of the surface of the base. B. Dumbbells from the interior of the base.