Note:  Do not rely on this information. It is very old.


Hydra tuba, the name of the first stage after the egg in the development of some of the Hydrozoa (q.v.) of the subclass Acraspeda (q.v.). It is a small fixed hydra-like body, but with solid tentacles. By a series of transverse constrictions it is divided into a series of segments, each of which ultimeetely develops a series of lobes and breaks away from the parent; they then swim about as independent jelly-fish. This method of development occurs in the commonest English jelly-fish, Aurelia aurita.

It is found in the Rhizostontecs and many of the Pelaijidw.