Phymanthus crucifer ( Le Sueur, 1817 )

Gonzalez-Muñoz, Ricardo, Simões, Nuno, Sanchez-Rodriguez, Judith, Rodriguez, Estefania & Segura-Puertas, Lourdes, 2012, First Inventory of Sea Anemones (Cnidaria: Actiniaria) of the Mexican Caribbean, Zootaxa 3556, pp. 1-38 : 22-24

Phymanthus crucifer ( Le Sueur, 1817)

( Figure 7 , Table 2 )

Actinia crucifera Le Sueur, 1817: 174 –175.

Cereus crucifer Duchassaing & Michelotti, 1864: 31 , pl. VI, fig. 13.

Cereus Crucifer [sic] Duchassaing, 1870: 20.

Phymanthus cruciferus Andres, 1883: 501 .

Ragactis cruciata Andres, 1883: 471 .

Phymanthus crucifer McMurrich, 1889a: 51 –55.

Epicystis crucifera Verrill, 1898: 496 .

Epicystis osculifera Verrill, 1900: 556 .

Phymantes crucifer Cutress & Cutress, 1976: 310 .

Phimanthus crucifer Zamponi, 1981: 165 .

Epicystis crucifer Cairns , den Hartog, & Arneson, 1986: 177, 179, pl. 51.

Material examined.— Puerto Morelos (20°51’48.66” N, 86°51’33.32” W; 7 specimens); Punta Cancún (21°9’10.5” N, 86°44’41.2” W; 1 specimen).

Diagnosis.—Fully expanded tentacles and oral disc 40–100 mm in diameter. Oral disc 32–55 mm in diameter, rough, variable in color, often white with dark brown, olive-green with white, or grey with green and brown ( Figure 7 A, B). Marginal and discal tentacles ( Figure 7 A, B). Marginal tentacles short, about 350–360, tapering distally, with annular thickenings ( Figure 7 A) or smooth, olive green or light brown with longitudinal colored stripes ( Figure 7 B). Discal tentacles reduced, small, vesicle-like, arranged in radial rows on oral disc. Column margin with one row of small vesicles without holotrichs ( Figure 7 C). Column cylindrical, smooth, 27–45 mm in diameter and 15–35 mm in height, plate-like, with rough surface, pinkish proximally and fading into whitish distally, with flamelike staining pattern. Column with longitudinal rows of adherent pink verrucae distally, 5–6 verrucae per row ( Figure 7 C, D, F). Pedal disc well developed, 12–35 mm in diameter, bright pink or orange ( Figure 7 D). Mesenteries hexamerously arranged in four cycles (48 pairs in specimens examined): first two cycles and some mesenteries of third cycle perfect and fertile, others imperfect and sterile; gonochoric (?), only oocytes in examined specimens. Two pairs of directives each attached to a well-developed siphonoglyph. Retractor muscles strong, restricted; parietobasilar muscles well developed with long free mesogleal pennon ( Figure 7 E). Basilar muscles well developed. Marginal sphincter muscle absent. Zooxanthellae present. Cnidom: basitrichs, microbasic pmastigophores and spirocysts ( Figure 7 G–M; see Table 2 ).

Natural history.— Phymanthus crucifer lives attached strongly to coral rocks and dead coral rubble, between 1–7 m depth, in the lagoon and fore-reef zones; the column is usually burrowed in sandy patches with only the oral disc visible above substratum.

Distribution.— Phymanthus crucifer is found along the Caribbean Sea, from Bermuda to Barbados (see Table 1); however, our specimens represent the first record for the Mexican Caribbean (Puerto Morelos and Punta Cancún reefs).

Remarks.— Phymanthus crucifer is the only species of the twelve valid species of the genus reported in the Caribbean Sea ( Fautin 2011). Carlgren (1949) used the presence or absence of thickenings in the marginal tentacles to differentiate Phymanthus and Heteranthus Klunzinger, 1877 , the genera within Phymanthidae . However, P. crucifer includes morphs with and without thickenings in their marginal tentacles. According to Duerden (1900), all forms are different stages of development of these organisms. Although a detailed morphological study is still needed to determine the value of thickenings in the marginal tentacles as a generic or species level character, preliminary results indicate that there are no differences in other morphological characters or cnidae within Phymanthus crucifer .

Figures

FIGURE 7. — Phymanthus crucifer. (A) Oral view, morph with marginal tentacles with annular thickenings. (B) Oral view, morph with marginal smooth tentacles. (C) Lateral view. (D) Pedal disc view. (E) Cross section through proximal column. (F) Longitudinal section through oral disc and distal column. (G – M) Cnidae. — tentacle: (G) basitrich, (H) spirocyst; actinopharynx: (I) basitrich, (J) microbasic p - mastigophore; column: (K) basitrich; filament: (L) basitrich, (M) microbasic p - mastigophore. Abbreviations. — c: column, dt: discal tentacles, e: epidermis, g: gastrodermis, mt: marginal tentacles, pb: parietobasilar muscles, pd: pedal disc, rm: retractor muscle, o: oocyte, ve: vesicle, vr: verrucae. Scale bars. — A – D: 10 mm; E – F: 200 µm; G – M: 25 µm.