[Annelida] SV: Oligochaete with anal cirri?
(by christer.erseus from zool.gu.se)
Thu Feb 2 02:01:23 EST 2012
No, the worm that you show is most probably not a clitellate, I still would suggest an interstitial cirratulid or so. Hair chaetae on the dorsal as well as the ventral side (as we see here) are seldom present in oligochaetes; in the sea the only exception being the Southern hemisphere family Capilloventridae (yes, the name says it!), but the very few marine capilloventrids known to date have no pygidial appendages.
In freshwater, the naidid genus Dero, by some authors divided into Dero and Aulophorus, has a few pairs of ciliated anal gills. One pair of them are particularly long in Dero (Aulophorus) furcatus.
Från: annelida-bounces from oat.bio.indiana.edu [annelida-bounces from oat.bio.indiana.edu] för Geoff Read [Geoffrey.Read from niwa.co.nz]
Skickat: den 2 februari 2012 06:34
Till: Polychaete mailing list
Ämne: [Annelida] RE: Oligochaete with anal cirri?
And here is a couple of small images, one of either end. Magnification x200 or so.
> -----Original Message-----
> From: annelida-bounces from oat.bio.indiana.edu [mailto:annelida-
> bounces from oat.bio.indiana.edu] On Behalf Of Geoff Read
> Sent: Thursday, 2 February 2012 2:58 p.m.
> To: Polychaete mailing list
> Subject: [Annelida] Oligochaete with anal cirri?
> Dear all,
> Quick question? Do oligochaetes ever have a pair of anal cirri? I have been
> looking at offshore samples from mobile coarse sands with some interesting
> small worms in them, and there is this apparent oligochaete (or not) which has a
> lovely pair of delicate anal cirri. It has a long prostomium, or perhaps it's the
> pygidium if I've oriented it wrong way round (it's hard to say), is exceedingly thin
> (0.15 mm w, & TL 10 mm) like a marine oligochaete, has mixed capillaries and
> slightly thicker shorter unifid S-shaped single chaetae. What do you reckon it
> could be if not an oligochaete? There are no tentacles along the body (as in
> cirratulids and affiliates). There is a polygordiid genus which has chaetae, but
> apparently not along the whole body as this worm has.
> Thanks in advance for your ideas to enlighten me.
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