Actinoscyphia saginata ( Verrill, 1882 )

Targino, Alessandra K. G., De Melo, Yago A. & Gomes, Paula B., 2025, Deep-sea anemones (Cnidaria, Actiniaria) from off the northeastern coast of Brazil: new records and description of Stephanauge prima sp. nov., Zootaxa 5569 (2), pp. 328-344 : 337-338

Actinoscyphia saginata ( Verrill, 1882)

( Fig. 4 , Table 5)

MATERIAL EXAMINED. MNRJ 9092 (two specimens), South Atlantic Ocean , Potiguar Basin, Rio Grande do Norte, Brazil, station MT83 (04° 28.3642’S, 036° 24.7602’W), May 4, 2011, 1950 m . MOUFPE-CNI 874 (two specimens) South Atlantic Ocean , Potiguar Basin, Rio Grande do Norte, Brazil, station MT83 (04° 28.3642’S, 036° 24.7602’W), May 21, 2011, 1950 m . LC 156 (10 specimens) South Atlantic Ocean , Potiguar Basin, Rio Grande do Norte, Brazil, station MT83-2 (04° 40.1817’S, 036° 23.8647’W), May 21, 2011, 2123 m .

SHORT DESCRIPTION. Column 35.6 to 56.7 mm in height, oral disc diameter 72.4 to 114.5 mm, base diameter 21.6 to 43.5 mm. Oral disc bilobed. Tentacles with mesogleal swellings at their base, total approximately 160, in two cycles. Mesenteries in five cycles, only first one perfect. Acontia absent.

CNIDOM. Spirocysts, basitrichs, holotrichs, and microbasic p -mastigophores B1 ( Fig. 4I : k–o, Table 5).

GEOGRAPHIC DISTRIBUTION. Actinoscyphia saginata was originally known from the Atlantic coast of North America ( Verrill 1882) and later described from France, Morocco and Brazil ( Riemann-Zürneck 1978; Gusmão & Rodríguez 2021), at depths ranging from 978 to 2177 m. Our findings extend its distributional records northwards off the Brazilian coast, suggesting a more continuous Atlantic range for this species.

REMARKS. In Riemann-Zürneck’s (1978) review of Actinoscyphia , the cnidom was interpreted as an important characteristic to distinguish species. Following the identification key proposed by Eash-Loucks & Fautin (2012), Actinoscyphia saginata has approximately 160 long tentacles, which differentiates it from closer species, such as Actinoscyphia aurelia , with around 275 tentacles and more than five mesentery cycles. The attributes of our specimens fit well to the original description of Actinoscyphia saginata by Verrill (1882) to later treatments by Riemann-Zürneck (1978) and Gusmão & Rodríguez (2021).

Figures

FIGURE 4. External view, internal anatomy and cnidae of some sea anemones analyzed in this work. A) External view of Actinoscyphia saginata showing the bilobed oral disc. B) Specimen of Chondrophellia coronata. C) Amphianthus bathybium on Chrysogorgia tuberculata branch (arrow). D) Specimens of Amphianthus michaelsarsi, arrows showing rows of tubercles. E) Cross section of Actinoscyphia saginata column, showing cycles of mesenteries (roman numbers) and gametogenic tissue (arrows). F) Gametogenic tissue on A. saginata as viewed on the stereomicroscope (arrows). G) Mesogleal marginal sphincter band on Amphianthus bathybium (arrow). H) Cross section of mesenterial cycles present in C. coronata (roman numbers). I) Cnidae found in the sea anemones, a–e) Amphianthus bathybium; f–j) Amphianthus michaelsarsi; k–o) Actinoscyphia saginata and; p–s) C. coronata. Cnidae; a, f, k, p: Gracile spirocysts; b, g, l, q: Robust spirocysts; c, h, m, r: basitrichs; d, i, n: holotrichs; e, j, o, s: microbasic p-mastigophores B1. Abbreviations: oc, octocoral; tu, tubercles; gt, gametogenic tissue; ms, marginal sphincter. Scale bars: A: 20 mm; B, C: 5 mm; D: 2 mm; E–G: 400 μm; H: 300 μm; I: 20 μm.