Posted 21 July 2004 - 02:27 PM
Hi Alex
it looked like a spionid, so I forwarded your photos to the curator of Polychaeta in the Natural History Musuem of Los Angeles County, Leslie Harris, and here is what she wrote (all credits to her, of course, I just post her reply to me):
Yes, it's a spionid, genus Polydorella, possibly Polydorella smurovi Tzetlin and Britayev 1985. This species was first collected from a red sponge, 25 m, in a coral bank near the Dachlak Archipelago, Red Sea. Living animals of P. smurovi have white palps (the paired appendages at the head) and orange bodies; they build thin mucous tubes on the surface of the sponge; an illustration in the original description shows dark pigment on the prostomium (the median part of the head) and lateral stripes on the first 3 setigers. The animals in the pictures differ by having very obvious lateral stripes on the whole body and the tubes appear to have attached bits of sand or debris. Without specimens to examine I can't tell if the differences are intra- or interspecific. The genus is very interesting as the life cycle includes alternation of sexual and asexual reproduction. Even more interesting, the mode of asexual reproduction is paratomy, in which the growth zone producing the new individual is in the middle of the animal rather than at the posterior end or sides.
Good references are:
Tzetlin, A.B., and Britayev, T.A. 1985. Zoologica Scripta 14: 177-181.
Radashevsky, V.I. 1996. Morphology, ecology and sexual reproduction of a new Polydorella species (Polychaeta: Spionidae) from the South China Sea. Bulletin of Marine Science 58(3): 684-693.
hope this helps !
cheers
Art
