Cladiella elongata (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 : 26-31

Cladiella elongata (Tixier-Durivault, 1944)

( Figures. 15A , 16 & 17 )

Lobularia elongata Tixier-Durivault, 1944a: 183 ; Tixier-Durivault 1948: 161–166, Figs. 155–160.

? Cladiella elongata ; Tixier-Durivault 1970a: 199 ( New Caledonia); Verseveldt & Benayahu 1978: 58 (Red Sea, listed only).

Material examined. Syntypes. MNHN-IK-2000-379, Red Sea, 1841, coll. M. Portier; MNHN-IK-2000-515, same details as MNHN-IK-2000-379 .

Description. The encrusting syntype MNHN-IK-2000-379 is a fragment of a colony with a maximum cross-section of 68 x 64 mm featuring densely placed lobes that are mostly laterally compressed, with some divided into lobules ( Fig. 15A ). The locations of the retractile polyps are noted as small pits on the surface of the lobes.

The platelets of the polyps are 0.05–0.08 mm long and include some figure-eight-like shapes and others that have a lateral median constriction the lateral outline can be irregular and includes slits ( Fig. 16A ). Their surface has a cristate-like texture and some have a tuberculate texture. The former is especially distinct at either end of some platelets thus providing them with a distinct striated appearance. The surface of the lobes comprises poorly developed dumbbells, 0.06–0.08 mm long, predominantly featuring rounded tubercles and a few pointed conical ones ( Fig. 16B ). The dumbbells from the interior of the lobes are 0.09–0.11 mm long ( Fig. 16C ). They feature pointed conical or blunt-ended conical tubercles, also a few rounded ones, and their bare waist is 0.03–0.04 mm wide and 0.02–0.03 mm long. The surface of the colony base has poorly developed dumbbells, 0.06–0.09 mm long, with low rounded tubercles at either end ( Fig. 17A ). The dumbbells from the interior of the colony base are 0.08–0.12 mm long, their bare waist is 0.02–0.03 mm wide and 0.02–0.03 mm long ( Fig. 17B ). The latter dumbbells feature similar tubercles to those from the interior of the lobes.

Figure 13. Cladiella echinata ( Tixier-Durivault, 1941) , syntype, MNHN-IK-2000-28. 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.

Color. The dry syntype MNHN-IK-2000-379 is beige-light brown.

Remarks. The initial species assignment of L. elongata by Tixier-Durivault (1944a: 183) did not depict any of the morphological characters of the syntype colony. Subsequently, they were presented in the revision of the genus ( Tixier-Durivault 1948: 161–166, Figs. 155–160).

In general, the observed morphological features of the syntype MNHN-IK-2000-379 correspond to those of its amended description. However, no mention of the polyp sclerites, which are depicted here in Fig. 16A , was made by Tixier-Durivault (1944a). It should be noted that this species has dumbbells up to 0.12 mm long, the longest recorded for the genus, similar to some other congeneric Red Sea types ( Tables 2). In addition, the dumbbells feature a remarkably bare waist up to 0.03 mm long, and the polyp sclerites have a striated cristate-like microstructure at either end .

The morphological characters of syntype MNHN-IK-2000-515 (not shown), are in agreement with those of syntype MNHN-IK-2000-379, except for its size. It should be noted that the precise locality in the Red Sea where the syntypes were collected is not reported. The other records of this species indicated above need to be validated following re-examination of the the relevant material .

Distribution. Egyptian 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 16. Cladiella elongata (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-379. 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 17. Cladiella elongata (Tixier-Durivault, 1944), syntype, MNHN-IK-2000-379. 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.