M. Tsurumi et Hm. Reiswig, SEXUAL VERSUS ASEXUAL REPRODUCTION IN AN OVIPAROUS ROPE-FORM SPONGE, APLYSINA-CAULIFORMIS (PORIFERA, VERONGIDA), INVERTEBRATE REPRODUCTION & DEVELOPMENT, 32(1), 1997, pp. 1-9
The order Verongida, considered to be exclusively oviparous and dioeci
ous, exhibits great range in body form, including thin-bodied, rope- a
nd stick-form members which have been postulated to be morphologically
adapted to exploit fragmentation as an important asexual reproductive
process. Here we report results of a one-year survey of sexual reprod
uctive stages in a rope-form verongid, Aplysina cauliformis, which tes
t the hypotheses of verongiid sexual pattern and reduced resource allo
cation to sexual reproduction in rope-form sponges. Results confirm th
e verongiid pattern of oviparity, dioeciousness and production of smal
l oocytes. Data also support the hypothesis that rope-form sponges are
characterized by reduced investment in gamete production relative to
sponges of other body forms. The sexual reproductive pattern of the ma
in macrosymbiont (parasite) polychaete, Haplosyllis spongicola, shows
no correlation to that of its sponge host.