Hybocodon cryptus is a species of tubularian hydrozoan in the family Tubulariidae. It is known around southern Port Phillip Bay and Bass Strait, growing and reproducing at temperatures of at least 10 °C on sponges, often on sandy surfaces of rocks between late autumn and winter.Watson, J.E., 1984. Two new species of tubularian hydroids from southern Australia. Mems natn. Mus. Victoria 45 1-2: 7-12.
Description Hydrocauli up to 3 cm, total height of up to 8 cm. Solitary and unbranched greenish-yellow stems. 12-18 transparent aboral tentacles, 2.5 mm long, white oral tentacles. As a medusa, it has a diameter of 0.5 mm, with a single tentacle from a yellowish marginal bulb. Margin of the bell is slightly oblique, and a scattering of nematocysts on the exumbrella.
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