Campanulina elata, Watson, Jeanette E., 2011

Watson, Jeanette E., 2011, New species, new records and redescriptions of Thecate hydroids (Cnidaria: Hydrozoa: Leptothecata) from Southern Australia, Zootaxa 3122, pp. 1-36 : 4-6

Campanulina elata sp. nov.

Fig. 2 A–E

Material examined. Holotype, NMV F171356, infertile colony of 20 hydrothecae on mussel shell, Clifton Springs boat harbour, depth 1 m, coll: J. Watson, 14/08/2008. Material examined alive, initially preserved in 4% formalin and later transferred to 70% ethanol.

Description from holotype (from live material). Colony stolonal, hydrorhiza reticulate, stolons tubular, weakly rugose; pedicellate hydrothecae borne at intervals along stolon. Hydrotheca small, weakly conical to cylindrical, borne on a short indistinct pedicel with three or four basal twists; body of hydrotheca smooth to faintly rugose, margin circular with slightly thickened rim, operculum of c. 10 triangular flaps meeting apically, a distinct crease-line around margin, opercular remnants drawn deeply inside the margin of some younger hydrothecae. Hydranth tubular, extensile and very long, a single whorl of c. 16 long moniliform tentacles with whorls of nematocysts held out in an amphicoronate pattern below a flat domed hypostome; no true intertentacular web but a ring of small birefringent granules between the bases of tentacles

Cnidome comprising one class of microbasic mastigophore in tentacles, capsule lenticular, 8–10 x 2.5–3.5 µm, shaft moderately long, tubule very long.

Perisarc of hydrorhiza and hydrotheca very thin, pale brown in colour; body of hydranth and tentacles colourless, transparent.

Hydrorhiza, width 32–64

Hydranth

length of extended column 300–600 tentacle length, extended 300–400

Hydrotheca

length 240–360 width at base 32–48 diameter of margin 100–120 Remarks. Difficulty in referral of the species to Campanulina is equally problematical as discussed above for Campanulina cliftonia . Several genera in the Campanulinidae were also considered but rejected because of morphology of the pedicel and the presence of a clear demarcation between the operculum and body of the hydrotheca. The new species represented by the present material is therefore placed in Campanulina until fertile material is found allowing for taxonomic refinement.

The hydranth of Campanulina elata is very active, with long, thin tentacles extending out stiffly in an amphicoronate pattern. When disturbed it withdraws deeply into the hydrotheca. The area of tissue between the bases of the tentacles does not seem to be a true intertentacular web nor are the large yellowish birefringent granules between the tentacles nematocysts; their structure or function could not be determined.

As the hydrotheca is very soft, after initial examination the material was hardened in formalin. The circular margin then became more distinct in older hydrothecae, although it was seldom sharply defined from the operceulum. The operculum is present in some younger hydrothecae and is probably shed at maturity. In some older hydrothecae the internal submarginal wall is lined by a flimsy skirt of tissue, presumably the remains of opercular segments; in other hydrothecae shredded opercular remnants are visible deep within the margin, entrained during withdrawal of the hydranth.

Etymology. The species in named for its tall hydranth.

Figures

FIGURE 2. Campanulina elata sp. nov. A, hydrotheca and extended hydranth, drawn from live material. B, three hydrothecae on hydrorhiza. C, D, hydrothecae with opercular remnants. E, microbasic mastigophore from tentacles. Scale bar: A, B, 0.3 mm, C, D, 0.2 mm, E, 10 µm.