Fig. 11
Catablema vesicarium var. nodulosa Bigelow, 1913: 17, pl. 1 figs 8-9.
Catablema nodulosa. – Arai & Brinckmann-Voss, 1980: 45, fig. 21.
Material examined: 2 specimens, not in permanent collection; USA, San Juan Islands, Friday Harbor, 48.5451° -123.01206°; collection date 16.05.2011 and 20.05.2011; collected at water surface with a dipping jar; DNA isolates 932 and 957; GenBank numbers see Table 1.
Diagnosis: North Pacific Catablema medusa, up to 25 mm in size, including the apical projection of variable size and shape; gonads in long, irregular folds, oblique in lateral parts, almost perpendicular in middle part of each quadrant, gonadal folds usually without pits, rarely a few present; With 8 to 16 tentacles, rarely up to 25, with 2-6 small, rudimentary bulbs between adjoining tentacles, usually with small, inconspicuous abaxial ocelli on the rudimentary bulbs, fully formed tentacles lack ocelli; mesenteries about 1/3 of manubrium height. Manubrium gold-brown or peach colour in living specimens.
Hydroid unknown.
Remarks: In the examined material, only the smaller tentacles and the rudiments had small ocelli, the fully developed tentacles lacked them.
Bigelow (1913) found that some Catablema medusae from the North Pacific differed in tentacle numbers and gonad structure from C. vesicarium he had seen in the NorthAtlantic.Although he states that they were probably still within the extremes of the nominal species and no morphological discontinuity existed, he treated them as species. The COI sequence data did not show significant differences between the nodulosa form from the NE Pacific and typical C. vesicarium from the Greenland Sea (Fig. 9; the 16S data show very little divergences within this genus). Catablema nodulosum should therefore be regarded as conspecific with C. vesicarium, or at most be treated as a subspecies of the latter. According to the ICZN (§45.6.4), a name introduced as variety before 1961 gets the rank of subspecies.