Bartholomea annulata ( Le Sueur, 1817 )

Grajales, Alejandro & Rodríguez, Estefanía, 2014, Morphological revision of the genus Aiptasia and the family Aiptasiidae (Cnidaria, Actiniaria, Metridioidea), Zootaxa 3826 (1), pp. 55-100 : 80-85

Bartholomea annulata ( Le Sueur, 1817)

( Figs. 14 –16, Table 5)

Actinia annulata Le Sueur, 1817

Actinia solifera Le Sueur, 1817

Non Actinia annulata Gay, 1854

Paractis solifera: Milne Edwards 1857

Dysactis annulata: Milne Edwards 1857 Bartholomea solifera Duchassaing de Fombressin & Michelotti, 1864. Bartholomea [sic] Solifera : Duchassaing 1870 Aiptasia solifera: Andres 1883 ( 1884)

Aiptasia annulata: Andres 1883 ( 1884)

Aiptasia annulata solifera: Verrill 1907 Bartholomea annulata: Stephenson 1920 ? Carlgreniella robusta Watzl, 1922

Aiptasia arrulata Atoda, 1954

Batholomea [sic] annulata: Chen et al. 2008

Material examined. (See Appendix 1).

Description. External anatomy ( Fig. 14 ): Pedal disc to 40 mm diameter in preserved specimens, only slightly wider than column in living specimens. Column elongate, divisible into scapus and capitulum, to 40 mm height and to 20 mm diameter in preserved specimens (to 100 mm height and 40 mm diameter in living specimens). Cinclides in 4–5 rows in mid-column ( Fig. 14 C). Small, rounded oral stoma. Mesenterial insertions visible. Oral disc to 13 mm diameter in preserved specimens. Tentacles to 192, tapering toward tips, rather long, all of same length, 5–11 mm in preserved specimens (50–70 mm length in living specimens). Tentacles not fully retractile, with spiral or incompletely annular raised bands with batteries of microbasic p -amastigophores and basitrichs ( Fig. 15 F); bands from tip to base of each tentacle ( Figs. 14 A, B).

Internal anatomy and microanatomy ( Fig. 15 ): Mesogleal marginal sphincter muscle diffuse, short and weak ( Fig. 15 D). Mesenteries hexamerously arranged in five cycles ( Fig. 15 A). More mesenteries proximally than distally. Only first cycle perfect. All cycles fertile. including directives. Two pairs of directives each associated with a deep siphonoglyph. Retractor muscles diffuse, strong and long ( Fig. 15 A). Parietobasilar muscles differentiated, weak. Longitudinal muscles of tentacles ectodermal ( Fig. 15 E). Relatively weak longitudinal ectodermal muscles in distal end of column ( Fig. 15 C). Basilar muscles well differentiated, distinct, strong, with fibers on long mesogleal pennon ( Fig. 15 B). Acontia numerous, well developed.

TABLE 5. Size ranges of the cnidae of Bartholomea annulata . x, mean; SD, standard deviation; S, ratio of number of specimens in which each cnida was found to number of specimens examined; N, Total number of capsules measured; F, frequency; +++, very common; ++, common; +, rather common; Abbreviations: M, Microbasic.

FIGURE 16. Cnidae of Bartholomea annulata . A, C, F, I, K, L, N, O) Microbasic p -amastigophores. B, D, G, J, M, P) Basitrichs. E) Microbasic b -mastigophore. H) Spirocyst.

Color ( Fig. 14 ): Living specimens with proximal column translucent whitish, brownish with white dots distally; tentacles brown with distinct white annular bands ( Figs. 14 A, B). Preserved specimens with whitish column; tentacles dark brown when preserved; annular bands sometimes visible in preserved specimens ( Fig. 14 C). Cnidom: Spirocysts, basitrichs microbasic b -mastigophores and p -amastigophores (Fig. 16). See Table 5 for size and distribution.

Geographic and bathymetric distribution. Bartholomea annulata is reported along the entire Caribbean Sea, from Bermuda to Barbados ( González-Muñoz et al. 2012). It is a shallow-water species found between 1– 20 m.

Taxonomic remarks. Currently, Bartholomea includes four valid species ( Fautin 2013): B. annulata , B. pseudotagetes Pax, 1924 , B. werneri Watzl, 1922 and B. peruviana . All but B. peruviana (described from the coast of Peru) are distributed in the Caribbean Sea. Watzl (1922) provided a relatively detailed description of B. werneri and differentiated it from B. annulata based on the number of tentacles (to 96 in B. werneri vs. to 192), shape of tentacular bands (wide but flatter in B. werneri ), and the relative prominence of the cinclides (not conspicuous externally in B. werneri ). He also provided an account of cnidae sizes and ranges of both species but it is incomplete; the provided ranges do not differ between both species. The cited differences may be due to less developed examined specimens and intraspecific variation. In addition, Watzl (1922) erroneously described the genus Bartholomea with the first cycle of mesenteries sterile. We agree with Gonzalez-Muñoz et al. (2012) in that species descriptions for this genus (except for B. annulata ) are not complete to modern taxonomic standards and no clear differences distinguish the four putative species. In addition, type material is not available for any of the species ( Fautin 2013). According to Pax (1926), B. peruviana differs from B. annulata in the absence of marginal sphincter muscle, tentacular bands only present distally and lack of zooxanthellae. Based on these differences (although taken with reservations because of the often-challenged taxonomic rigor from Pax) and the different geographical distribution of B. peruviana we consider, until newly material from the type locality is available, the latter as a valid species. Thus, we currently consider two valid species: B. annulata distributed along the entire Caribbean Sea and B. peruviana distributed along the coast of Peru.

Figures

FIGURE 14. External anatomy of Bartholomea annulata. A) Oral view of living specimen. B) Detail of tentacular bands (arrow). C) Lateral view of preserved and contracted specimen; notice up to five rows of cinclides. Scale bars: A – C, 10 mm.

FIGURE 15. Internal anatomy of Bartholomea annulata. A) Cross section of the column at the level of the actinopharynx showing the cycles of mesenteries (indicated by roman numerals between pairs). B) Detail of a longitudinal section of the proximal end showing the distinct basilar muscles (arrows). C) Cross section through distal column showing the weak ectodermal longitudinal musculature. D) Longitudinal section of the distal column showing weak mesogleal marginal sphincter muscle. E) Cross section through a tentacle showing the ectodermal longitudinal musculature. F) Longitudinal section of the tentacle; notice zooxanthellae in gastrodermis and nematocyst batteries in the epidermis (arrows). Abbreviations: ep, epidermis; ga, gastrodermis; me, mesoglea; s, siphonoglyph. Scale bars: A, C – F, 0.1 mm; B, 0.05 mm.