Chondrophellia coronata ( Verrill, 1883 )

Gusmão, Luciana C. & Rodríguez, Estefanía, 2021, Deep-Sea Anemones (Cnidaria: Anthozoa: Actiniaria) From The South Atlantic, Bulletin of the American Museum of Natural History 2021 (444), pp. 1-73 : 36-39

Chondrophellia coronata ( Verrill, 1883)

Figures 15–16 , table 7

MATERIAL: MNRJ 5714 (1 specimen) ; locality: OceanProf II-BC Norte-Cenpes /UFRJ, dredging #16-1, N/ RB Astro Garoupa, southwestern Atlantic , Brazil, off the coast of Rio de Janeiro ( RJ), 23°27.73′ S – 22°15.07′ S 39°59.0′ W – 39°55.72′ W, collected on 22 August 2003 by? (1059–1110 m). MNRJ 5687 (3 specimens) ; locality: Projeto OceanProf II-BC Sul-Cenpes / UFRJ, N/ RB Astro Garou pa, southwestern Atlantic , Brazil, off the coast of Rio de Janeiro ( RJ), 22°28.65′ S 40°04.30′ W / 22°29.7′ S 40°05.1′ W, collected on 25 August 2003 (1290– 1325 m). MNRJ 6918 (1 specimens) ; locality: southwestern Atlantic , Brazil, off the coast of Rio de Janeiro ( RJ), Projeto OceanProf I-BC Norte-Cenpes /UFRJ, dredging #15, N/ RB Astro Garoupa, 22°01.98′ S – 21°52.22′ S 39°49.87′ W – 40°02.28′ W, collected on 14 February 2003 (1620– 1598 m). MNRJ 6664 (2 specimens) ; locality: Projeto Caracterização de corais de água profunda, Mergulho 2, Área 32, Banco 85N, Dop. 8, ROV Toisa Conqueror , southwestern Atlantic , Brazil, off the coast of Rio de Janeiro ( RJ), 22°25.73′ S 39°57.73′ W, collected on 23 July 2005 (1059–1110 m) .

EXTERNAL ANATOMY (fig. 15): Pedal disc flat, circular, highly adherent, equal to or broader than column, insertion of mesenteries visible when exposed, 3–13 mm in diameter in preserved specimens (fig. 15B). Column cylindrical, mostly covered by small tubercles (fig. 15A) in proximal and midcolumn, with a distal crown of 12 larger tubercles above which 12 smaller tubercles are (fig. 15B, C); column divided into long scapus and short scapulus with longitudinal ridges (fig. 15C). Column with thick, deciduous cuticle, highly adherent in some preserved specimens (fig. 15A) or entirely missing in others (fig. 15A–C). Margin of scapulus not tentaculate (fig. 15C). Cinclides absent. Column white in preserved specimens with mesenterial insertions visible as white lines, particularly in proximal column and limbus without cuticle (fig. 15B). Column 9–25 mm in length and 5–18 mm in diameter in preserved specimens. Oral disc circular, small, as wide or slightly narrower than column, mostly retracted in preserved specimens (fig. 15C). Central, small mouth. Oral disc diameter 1–6 mm in preserved specimens (fig. 15B, C). Tentacles up to 96, smooth, short, slender, and pointed, in five cycles (6+6+12+24+n) in preserved specimens. Tentacles with no markings and translucent beige in preserved specimens (fig. 15C). Longest tentacle up to 3 mm in preserved specimens.

INTERNAL ANATOMY AND HISTOLOGY (fig. 15): Body long and narrow in preserved specimens (fig. 15A, B) with wall thickness varying along column: mesoglea thicker in scapulus than in scapus, whereas epidermis is thicker in scapus than in scapulus (fig. 15D, E). Marginal sphincter long, with mesogleal musculature (fig. 15E); fibers in most of mesoglea distally (fig. 15E); alveolar proximally with tendency for reticulation elsewhere (fig. 15F). Longitudinal musculature of tentacles ectodermal (fig. 15G). Actinopharynx up to 8 mm in length, approximately one third of column’s length; longitudinally sulcated throughout (fig. 15H, I); with thick mesoglea (fig. 15J, I). Specimens with two weakly differentiated siphonoglyphs (fig. 15H, I) with thin gastrodermis and mesoglea, but glandular epidermis as in actinopharynx.

Mesenteries hexamerously arranged in four cycles (6+6+12+24 = 48): first cycle perfect, including two pairs of directives, each associated to one siphonoglyph (fig. 15I); second and third cycles imperfect (fig. 15I). All mesenteries of first and second cycles, including directives, fertile and with filaments (fig. 15J–L, N); those of third cycle sterile and without filaments (fig. 15M). A fourth cycle of imperfect, sterile mesenteries only proximally; insertion of mesenteries visible on limbus (fig. 15B). More mesenteries proximally than distally (fig. 15B). All fertile specimens female, collected in July; major axis of oocytes up to 72 μm in diameter (fig. 15N). Species inferred gonochoric. Retractors of first and second cycles well developed, diffuse (fig. 15J–L); those of third cycle diffuse (fig. 15J, M). Parietobasilar musculature small, weak in all mesenteries (fig. 15K–M). Basilar musculature of mesenteries weak (not shown).

CNIDOM (fig. 16): Spirocysts, basitrichs, p -mastigophores A, and p -mastigophores B1. The scyphozoanlike nematocyst (fig. 16L) found in the filament of this species is likely the result of contamination by feeding. See figure 16 and table 7 for size and distribution.

DISTRIBUTION AND NATURAL HISTORY: Specimens of Chondrophellia coronata were collected off the coast of Rio de Janeiro state close to the Campos Basin in Brazil. Some of these specimens were collected attached to pieces of coral skeleton. Chondrophellia coronata is widely distributed in the North Atlantic ( Carlgren, 1942; Molodtsova et al., 2008) and Gulf of Mexico (Ammons and Daly, 2008), but this is the first record of the species in the South Atlantic. The species has also been collected in the eastern Pacific off the coast of Chile (McMurrich, 1893) and off California (Doumenc and Van Präet, 1988). The Pacific records for C. coronata are somewhat questionable ( Carlgren, 1942; Molodtsova et al., 2008; Zelnio et al., 2009). The specimens of C. coronata examined by Doumenc and Van Präet (1988) were collected in hydrothermal vents of the eastern Pacific and are similar to C. orangina collected off hydrothermal vents in the Lau Basin in the southwestern Pacific ( Zelnio et al., 2009). The specimens of C. coronata off Brasil were collected between 1077–1620 m, which falls within the known range for the North Atlantic records (599–2448 m).

REMARKS: The Brazilian specimens of Chondrophellia coronata agree closely with previous morphological descriptions of external and internal anatomy for the species ( Carlgren, 1942). In particular, the distinctive combination of a distal corona of tubercles, the number of cycles of mesenteries (three spanning most of the column and a fourth only proximally), and the fertility of first and second cycles of mesenteries easily places our material within Chondrophellia . Types and size range of nematocysts from our specimens agree with those given by Carlgren (1942) and Zelnio et al. (2009) for C. coronata , except for the small basitrichs in the column and acontia found only in our specimens. These differences could be explained by the scarcity and difficulty of finding these small nematocysts, particularly in the acontia where the larger category is abundant. Our specimens are different from the C. coronata identified by Ammons and Daly (2008) in the Gulf of Mexico, which, given the asymmetrical morphology of the oral disc, resemble species of Phelliactis or Paraphelliactis .

The cnidae of Chondrophellia coronata from Brazil differs from the cnidae of C. africana Carlgren, 1928b , given by Zelnio et al. (2009). Our specimens are clearly different from C. orangina , based on the number of mesenteries (four cycles in C. coronata ; five in C. orangina ) and tentacles (five cycles in C. coronata ; six in C. orangina ), number of distal tubercles (12 rows in C. coronata ; 24 in C. orangina ), sphincter musculature (mostly reticular in C. coronata ; alveolar in C. orangina ), and other cnidae differences. Given the larger size of Chondrophellia specimens collected in the Pacific, it is possible that the Chilean specimens described by McMurrich (1893) and later examined by Carlgren (1942) as well as the C. coronata described by Doumenc and Van Präet (1988) for the eastern Pacific are similar to C. orangina from the Lau Basin in the western Pacific. A detailed revision of the mesentery arrangement of the material from Chile and California could help elucidate the specific identity of eastern Pacific Chondrophellia .

note six pairs of perfect mesenteries of first cycle; I, cross section through scapus at actinopharynx level and cycles of mesenteries (indicated by numbers); J, cross section through column at the actinopharynx level and three cycles of mesenteries (indicated by numbers); K, detail of a pair of directive mesenteries attached to actinopharynx not differentiated into a siphonoglyph; note the weak, diffuse retractor and short, weak parietobasilar musculature; L, detail of a pair of mesentery of second cycle with weak, diffuse retractor musculature and weak parietobasilar; M, detail of a pair of mesenteries of third cycle with weak diffuse retractor and weak parietobasilar musculatures; N, one mesentery of first cycle and one pair of second cycle fertile. Abbreviation: cu, cuticle; di, directive pair of mesenteries; fi, filaments; me, mesoglea; oo, oocytes; pb, parietobasilar musculature; scp, scapulus; sca, scapus; si, siphonoglyph; sp, marginal sphincter musculature. Scale bars: A, 5 mm; B, 8 mm; C, 3 mm; D, E, L–N, 0.4 mm; F, 0.1 mm; G, K, 0.2 mm; H, 2 mm; I, J, 1 mm.

Figures

FIG. 15. External and internal anatomy and histology of Chondrophellia coronata (Verrill, 1883). A, Lateral view of preserved specimen showing column with cuticle; note smaller tubercles on scapus and larger ones forming a crown around distal scapus; B, lateral view of preserved specimen, column without epidermis and cuticle; note insertion of mesenteries on limbus; C, detail of scapus with thick cuticle and short scapulus; note crown of larger tubercles and one ring of smaller tubercles just above it (arrows); D, cross section through midcolumn and thick mesoglea, corrugated thin epidermis, and thick cuticle; E, longitudinal section through distal scapus and long mesogleal sphincter musculature; F, detail of mesogleal sphincter and reticular arrangement of fibers; G, cross section through tentacle with weak ectodermal longitudinal musculature (arrow); H, cross section through scapus at actinopharynx level with 24 pairs of mesenteries in three cycles (numbers);

FIG. 16. Cnidom of Chondrophellia coronata (Verrill, 1883): A, B, E–H, J, M, N, basitrich; C, K, p-mastigophore B1; D, spirocyst; I, p-mastigophore A; L, scyphozoan nematocyst.