Sporosac \Spo"ro*sac\ (sp[=o]"r[-o]*s[a^]k), n. [Spore + sac.]
(Zool.)
(a) A hydrozoan reproductive zooid or gonophore which does
not become medusoid in form or structure. See Illust.
under {Athecata}.
(b) An early or simple larval stage of trematode worms and
some other invertebrates, which is capable of reproducing
other germs by asexual generation; a nurse; a redia.
[1913 Webster]