Zanclea spec.

Schuchert, Peter & Collins, Richard, 2021, Hydromedusae observed during night dives in the Gulf Stream, Revue suisse de Zoologie 128 (2), pp. 237-356 : 271

Zanclea spec.

Fig. 20 A-B

Examined material: BFLA4278 ; 1 specimen; 06-DEC- 2019; height 2 mm; preserved in alcohol for DNA extraction; 16S sequence MW528696 .

Observations: Zanclea medusa, height 2 mm, bell as wide as high, apical part a flat cone. Four exumbrellar nematocyst bands reaching from tentacle bulbs to level of manubrium base (ca. 4/5 of bell height). Manubrium relatively small, bottle-shaped, in upper part with several polyps, these sessile, partly embedded, cylindrical body, with up to three whorls of capitate tentacles. Gonads apparently not yet developed. Four equally well-developed marginal tentacles with stalked cnidophores, no distinct bulb formation, tentacles evenly tapering from origin to distal. No ocelli present. Upper, broader part of manubriumas well as tentacles intensively green.

16S Data: A maximum likelihood tree using part of the 16S sequence data of Maggioni et al. (2018) did not associate the sample with any other ( Fig. 21 ). The sequence is rather distinct from those of Z. mayeri n. spec. as it shares only 91% identical base pairs.

Remarks: Only one immature animal of this striking Zanclea species was observed. The green colour, the four tentacles, and the hydranths on the stomach make it rather unique. Although it is likely an undescribed species, we nevertheless renounced on naming it as we think that we do not have enough photos showing more details for a complete description. It is also immature and the polyps could be a parasite or some teratological development and not a normal feature of the species.

The animal resembles Zanclea medusopolypata Boero, Bouillon & Gravili, 2000 from Papua New Guinea, but the latter has only two tentacles. Although tentacle numbers can be variable in Zanclea species ( Brinckmann-Voss, 1970; Altuna, 2016) it should not be referred to Z. medusopolypata for biogeographic reasons and because its polyp stage remains unknown.

Figures

Fig. 20. Zanclea spec. (A-B) BFLA4278, bell height 2 mm.

Fig. 21. 16S maximum likelihood phylogenetic tree of Zancleidae and related taxa obtained with PhyML (GTR+G model) and based on about 600 bp positions of the mitochondrial 16S gene. Node-support values are bootstrap values of 100 pseudoreplicates (shown only if> 70%). All sequence labels start with the GenBank numbers permitting the retrieval of more information. Red labels are new sequences from this study.