Nausithoe eumedusoides ( Werner, 1974 )

Molinari, Clarissa G., Collins, Allen G. & Morandini, André C., 2023, A morphological review of the jellyfish genus Nausithoe Kölliker, 1853 (Nausithoideae, Coronatae, Scyphozoa, Cnidaria), Zootaxa 5336 (1), pp. 1-32 : 9-11

Nausithoe eumedusoides ( Werner, 1974)

( Fig. 6 : E–H)

Stephanoscyphus eumedusoides Werner, 1974: 439–461 , figs 1–5.

Nausithoe eumedusoides — Jarms, 1990: 11.

Holotype ZMH C9797 .

Material examined: Living polyps kept in laboratory cultures (from submarine caves in Mljet, Croatia, 2002; 26m depth; H. Zibrowius col.).

Diagnosis: medusoid—tetrameric form with no manubrium, can be hermaphroditic; polyp—solitary with single cusp closer to the base.

Description: Based on Werner (1970) and original description. Medusoid 1–1.5 mm in umbrella width and 1–1.2 mm in height; quasi-tetrameric; lack of manubrium; rhopalia with minimally developed sense organ; absence of coronal groove until the final moments of strobilation; no gastric filaments; reduced umbrella musculature with 4 thin longitudinal muscle strands; beating flagella on the epidermis; four gonads in total (eight merged in pairs), bean-shaped or oblong, with yellow to brown pigmentation; can be hermaphroditic (with even the production of both eggs and sperm cells at the same time in the same gonad) or single sexed. Polyp solitary; 22.2 mm in total length; 1–2 single cusp closer to the base (arranged vertically one above the other); produces 4–5 medusoids per strobilation.

Type locality: Submarine caves near Marseille, France.

Distribution: Marine caves probably of all Mediterranean (2–50 m depth).

Remarks: Only N. eumedusoides and N. racemosa have a medusoid described in their life cycle, but the polyps are extremely different from each other. N. eumedusoides is a solitary species while N. racemosa is colonial (and with significant soft body differences, e.g., oral disc, symbiosis with algae).

Figures

FIGURE 6. Nausithoe clausi (A–D) and Nausithoe eumedusoides (E–H). A and B—Drawing from Vanĥffen 1892: aboral view (A) and oral view (B) of adult medusa. C and D—Lateral view (C) and oral view (D) of a possible adult medusa of N. clausi from Anilao, Philippines, shallow waters (photos: © Suzan Meldonian 2019). E—Polyp strobilating and releasing the eumedusoids. F—Closer view of medusoid showing the gonads (g) and planulae (pl). G—Two polyps in culture; the upper polyp is strobilating. H—Polyp with tentacles extended; notice the wide collar.