Catablema Nodulosa

Scientific name: Catablema nodulosa

Size:  up to 20mm wide.

Identifying features: This species has a very distinct bell in the shape of a ball.

Catablema nodulosa is a relatively newly discovered jelly fish in the class Hydrozoa.  It is easily identified by its large round gelatinous bell on top. They have 8, 16, or 32 tentacles. C. nodulosa do not have any ocelli. Their stomachs are attached to the bottom of the bell and also have radial canals with frilly lips. The stomach colour can vary from golden-brown to salmon pink similar to the gonads.

C. nodulosa is usually found in Puget Sound and B.C. and north to the Aleutian Islands and the Bering Sea.  Though they reside in the upper 100 meters large numbers are quite common near the surface of the water in bays in the late spring.   This species is known to be a voracious predator for ctenophores (comb jellies) and hydromedusae. Hydroids of this species have never been identified.

References:

Mills, C. (1998). Pacific Coast Pelagic Invertebrates. A guide to the Common Gelatinous Animals. Monterey, California: Monterey Bay Aquarium.