Geoff, Thomas, and all,
The pictures look very similar to the sensory structures we find on the
abfrontal palp surface of the spionid Dipolydora quadrilobata (and on three
other spionid species). Our preliminary experiments using activity-dependent
cell labeling methods suggest these are probably chemoreceptors, but they may
also be mechanoreceptors. TEM shows relatively short ciliary rootlets,
however, whereas mechanoreceptors often have very long ciliary rootlets. The
cells are definitely sensory -- confocal imaging of preparations stained for
acetylated alpha-tubulin reveals axons that project to the palp nerve. See
the recently published article in The Biological Bulletin
(http://www.biolbull.org/current.shtml) . Stay tuned for more details on
serotonin and FMRF-amide immunoreactivity, and with any luck this summer, some
electrophysiology.
Sara M. Lindsay, Timothy J. Riordan, Jr., and D. Forest
Identification and Activity-Dependent Labeling of Peripheral Sensory
Structures on a Spionid Polychaete. Biol Bull 2004 206: 65-77.
Cheers,
Sara
X-Sieve: cmu-sieve 2.0
X-Original-To: annelida-list at hgmp.mrc.ac.uk
To: annelida at net.bio.net
From: "Geoff Read" <g.read at niwa.co.nz>
Organization:NIWA (Nat. Inst. Water & Atmos. Res. NZ)
Subject:Re: External sensory structure in Annelids
Date: Wed, 19 May 2004 21:30:09 +0100 (BST)
Thomas Hesselberg wrote:
> While examining some errant polychaetes in the SEM, I found some (what I
> believe must be!) external sensory structures on all surfaces of the worm. My
> question now exactly what kind of sensory receptor this is? See photos on
><http://www.bath.ac.uk/~enpth/SensoryStruct.html>. I would also be interested
> to know if similar structures are found in other annelid groups. And if
> anyone knows of studies done on the ultra-structure and function of these or
> similar sensory structures in the annelids (or indeed other invertebrates), I
> would like to have some references.
The structures found in Platynereis dumerilii (your worm) are figured in Fig.
1 of:
Hardege, J. D. 1999: Nereidid polychaetes as model organisms for marine
chemical ecology. Hydrobiologia 402: 145-161.
There they are on the modified parapodial cirri. The implication in the text
is that they are 'olfactory' chemosensory and there are references to papers
by Boilly-Marer & Lasalle 1978, 1980 which I have not read. I too would be
interested if anyone has 'proved' what the function is. Please post to the
list.
Boilly-Marer, Y. ; Lassalle, B. 1978: Electrophysiological responses of
Heteronereis stimulated with sex pheromones (Annelida Polychaeta). Journal of
Experimental Zoology. 205: 119-124
Boilly-Marer, Y. ; Lassalle, B. 1980: Electrophysiological responses of the
central nervous system in the presence of homospecific and heterospecific sex
pheromones in nereids (Annelida Polychaeta). Journal of Experimental Zoology.
213: 33-39
--
Geoff Read <g.read at niwa.co.nz>
http://www.annelida.net/
=======================
Sara M. Lindsay
Asst. Research Professor
School of Marine Sciences
5751 Murray Hall
University of Maine
Orono, ME 04469
tel. 207-581-2739
FAX: 207-581-2537
-- ANNELIDA LIST
Discuss = <annelida at net.bio.net> = talk to all members
Server = <biosci-server at net.bio.net> = un/subscribes
Archives = http://www.bio.net/hypermail/annelida/
Resources = http://www.annelida.net/
--
