Carybdea xaymacana , Conant 1897
Creators: name: Acevedo, Melissa J.
name: Straehler-Pohl, Ilka
name: Morandini, André C.
name: Stampar, Sergio N.
name: Bentlage, Bastian
name: Matsumoto, George I.
name: Yanagihara, Angel
name: Toshino, Sho
name: Bordehore, César
name: Fuentes, Verónica L.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Cubozoa
Carybdeida
Carybdeidae
Carybdea
Carybdea xaymacana

description: Carybdea xaymacana Conant, 1897
Figs. 1 E–I; 7B, D, F
Material examined: Five (5) specimens from Smithsonian Institution (USNM 54457, 54458, 54461); polyps and newly released medusae from the cultures of R. Petie, member of the working group of Assistant Prof. A. Garm, University of Copenhagen, Denmark, originally sampled by B. Werner, C. E. Cutress, and J. P. Studebaker (1971) in Puerto Rico.
Diagnosis: Gastric phacellae epaulette shaped, single rooted; Velarial canals 2 per octant; biforked; Pedalia knee bend volcano-shaped to triangular.
Description: Adult medusa: Bell (Fig. 1E), highly transparent, colourless, bell-shaped, scattered with very small colourless nematocyst warts; mammilation scatters bell from apex to bell margin (bigger nematocyst warts at interradial furrows, smaller nematocyst warts on bell sides): apex plane convex (Fig. 1E), slight horizontal constriction near the top present. Bell height up to 24 mm, bell width up to 27 mm.
Pedalia (Fig. 1H), 4, simple, unbranched flattened, scalpel-shaped, measures approx. 1/3 – 1/2 bell height in length, situated in each interradial corner, with irregular, white nematocyst bands on outer keel of pedalia, very small warts scatter outer half of pedalia, carrying single, flesh coloured tentacles in the interradial corners of the bell rim, pedalial canal strongly depressed at base (diamond-shaped in diameter), going straight through pedalium, showing a volcano-shaped to triangular knee bend with small peak appendage on outer knee bend.
Rhopalia, 4, located inside heart-shaped rhopalial niche ostium, with triangular covering scale ("angle" rounded), scale scattered with very small nematocysts, approx. 1/7 to 1/8 of bell height up from margin; rhopalium with 6 eyes (2 median lens eyes + 2 lateral slit eyes + 2 lateral pit eyes).
Velarium (Fig. 1I), with very small nematocyst warts, containing 2 velarial canals per octant, broad in width, forked at tips, sharp tips, seldom dendritic, at times with more than 2 branches; canals flanking frenulum simpler, sometimes unforked, canals flanking pedalia more complex with 2 to 3 main branches and sometimes with single side branches.
Manubrium (1/3 – 1/2 bell height in length), 4 lobes, cruciform without nematocyst warts, and connected to flat and shallow stomach; stomach communicates perradially with 4 gastric pockets leading into velarial canals. Gastric phacellae (Figs. 3F, G), 4, epaulette-shaped, mounted on 4 stomach corners, consisting of 30–35 filaments per quadrant originating from a single root.
Gonads, 4 pairs, narrow leaf-like, separated by unperforated interradial septum, extending from stomach rim to bell margin, tapering toward stomach rim and bell margin; differences in the gonads between both sexes can be observed under the microscope, as for other carybdeid species; ripe gonads milky whitish.
Early development of newly released medusae from polyps (Figs. 7B, D, F): Bell (Fig. 7B), yellowish, tetraradial, slightly pyramidal shaped with large, ovoid (0.14 mm x 0.06 mm) nematocyst warts, both sides of the interradial furrow; bell height up to 1.4 mm, bell width up to 1.2 mm.
Tentacles, 2 (primary) (Fig. 7B), located on opposite corners, lacking pedalia, resembling pearl-string with spherical, orange coloured, and lens-shaped, white nematocyst batteries (Fig. 7D); during further growth medusa develops a second pair of tentacles between primary tentacles.
Rhopalial niche ostia not yet developed, rhopalium with 6 eyes (Fig. 7F) (2 median lens eyes + 2 lateral slit eyes + 2 lateral pit eyes).
Gastric filaments, 4, one per quadrant.
Remarks: The species C. xaymacana was first reclassified as C. marsupialis var. xaymacana by Mayer (1910) and then as C. marsupialis xaymacana by Bigelow (1938). Later, Kramp (1961) and Studebaker (1972) listed both C. xaymacana and C. murrayana as synonyms of C. marsupialis, but Gershwin (2005) hinted at the separation of these species.
Reported distribution of C. xaymacana: Caribbean Sea
description: Published as part of Acevedo, Melissa J., Straehler-Pohl, Ilka, Morandini, André C., Stampar, Sergio N., Bentlage, Bastian, Matsumoto, George I., Yanagihara, Angel, Toshino, Sho, Bordehore, César & Fuentes, Verónica L., 2019, Revision of the genus Carybdea (Cnidaria: Cubozoa: Carybdeidae): clarifying the identity of its type species Carybdea marsupialis, pp. 515-548 in Zootaxa 4543 (4) on page 524, DOI: 10.11646/zootaxa.4543.4.3, http://zenodo.org/record/2618013