Catablema vesicarium (A. Agassiz, 1862 )

Schuchert, Peter, 2018, DNA barcoding of some Pandeidae species (Cnidaria, Hydrozoa, Anthoathecata), Revue suisse de Zoologie 125 (1), pp. 101-127 : 117

Catablema vesicarium (A. Agassiz, 1862)

? Medusa campanula Fabricius, 1780: 366 .

Catablema campanula . ‒ Haeckel, 1879: 63, pl. 4 figs 4-5. ‒ Kramp, 1955: 153, re-examined material of Haeckel.

Turris vesicaria A. Agassiz, 1862: 97 . ‒ Agassiz, 1865: 164, figs 261-268.

in part Turris vesicaria . – Mayer, 1910: 126, pl. 12 figs 2-3 (not pl. 13. fig. 7 = L. octona ).

Catablema vesicarium . ‒ Bigelow, 1909b: 304, pl. 30 figs 3-4, pl. 31 fig. 6. – in part Hartlaub, 1914: 315, figs 263-267. ‒ Kramp, 1926: 87, pl. 2 figs 10-11. – Kramp 1959: 122, 208-212, fig. 125. – Kramp, 1961: 96. – Kramp, 1968: 50, fig. 132. – Schuchert, 2007: 345, fig. 64, redescription. ‒ Prudkovsky & Neretina, 2016: 533, figs 1-8, life cycle.

Catablema eurystoma Haeckel, 1879: 64 , pl. 4 figs 6-7. ‒ Kramp, 1955: 153, synonym.

Tiara conifera Haeckel, 1879: 59 . ‒ Kramp, 1955: 152, reexamination of type specimen, synonymy.

in part Perigonimus vesicarius . – Naumov, 1969: 202,? not fig. 69.

Type locality: Nahant , Massachusetts Bay, USA .

Material examined: See Schuchert (2007). The molecular comparisons of this study included also 16S sequences of the material described in Prudkovsky & Neretina (2016), as well as of a medusa from the Nuuk-Fjord in Greenland (GenBank KT809324 ) collected 22 June 2010 and identified by Russell Hopcroft. It had about 28-30 tentacles, about as many rudimentary bulbs, and a large apical projection (after data and photos kindly provided by R. Hopcroft).

Diagnosis: Catablema medusa with bell up to 25 mm wide and 30 mm high, including the large, globular apical projection; gonads in long, irregular folds, oblique in lateral parts, almost perpendicular in middle part of each quadrant, with or without pits on gonad folds; 24-32 tentacles, rarely up to 48, often with small, rudimentary bulbs between two tentacle pairs; usually with small abaxial ocelli on at least some tentacles or bulbs, sometimes missing; mesenteries short.

Hydroid arising from reticulate stolons on bivalves, hydranths stolonal or with very short pedicel only, base of hydranth surrounded by a membranous pseudohydrotheca; hydranth fusiform, up to 0.75 mm long, conical hypostome, 3-8 filiform amphicoronate tentacles in a single whorl. Medusa buds arise from stolons, diameter reaches sizes similar as hydranths, young medusa released with two opposite tentacles only.

Description and illustrations: See Schuchert (2007) and Prudkovsky & Neretina (2015).

Distribution: An Arctic species, rarely penetrating into boreal regions.

Remarks: The medusae identified by Prudkovsky & Neretina (2016) had up to 28 tentacles, matched thus exactly the concept of C. vesicarium given in Kramp (1959) and also in the original description of Agassiz (1862, 1865). Likewise, the 16S and COI sequences of the sample from Greenland (GenBank KT809324 ) are derived from a typical specimen and can also be used as a reliably identified reference specimen and sequence.

Although C. nodulosum is likely conspecific with C. vesicarium , it is discussed separately below to allow a better separation and clearer presentation of this morphotype.