Author Topic: Orthocladiinae females with reduced eyes  (Read 4300 times)

Baranov_Viktor

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Orthocladiinae females with reduced eyes
« on: September 07, 2014, 02:28:15 AM »
Dear collegaues!
Due to my cooperation with Zagreb university i was able to put my hands on very first samples of dipteran adults from the deepest cave of the Dinaric alps - Lucina jama  which is about 1240 something meters dept. Apparently, all (all 10) specimens of diptera from this cave where chironomids.They where collected in the relartivley large chamber (most of the cave is a vertical shaft, our  collegaue from Zagreb - brave subterrain arachnologist, Martina Pavlek spent 10 terrible days geting down  to this chamber) All this  beast are Orthocladiinae females, all  was very  pale, with thin cuticle. Living animal (see  the photo) was brownish, in  alcohol -pale greenish. Eyes very reduced -they have bean-like "eye field" of normal chironomid size but only couple of ommatidia are sitting at it! Trond Andersen and me are going to describe COI and 18S sequences dont really fits anywhere showing the same distance to the  some Chaetochladius, Cricotopus and Bryophaenocladius (88% of similarity my best match at GenBank for COI). So most probaly it is not just partenogenetic cave form of something described, like some spp have partenogenetic and sexual forms.
 In relation to that i have a question - could any one recall any chironomids which show ommatidia reduction in number and size? I could recall only Oreadomyia albertae - in the original description it seems to have a small eyes with relativly small number of facets, but their eyes are divided into dorsal and ventral part and facets are quite big...
I would like to hear you suggestions about morphological similarities, maybe some similar adaptations of other chironomids/ diptera.
Best wishes from Berlin
Viktor

Martin Spies

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Re: Orthocladiinae females with reduced eyes
« Reply #1 on: September 08, 2014, 02:10:02 AM »
Thank you, Viktor, for this interesting contribution!

Concerning your question about other species with reduced numbers of ommatidia, I am unaware of any, but assume that this might not indicate systematic relations anyway, as the primary cause of reduction in your case probably is autapomorphic adaptation to the cave habitat.
« Last Edit: September 08, 2014, 02:14:50 AM by Martin Spies »

Baranov_Viktor

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Re: Orthocladiinae females with reduced eyes
« Reply #2 on: September 08, 2014, 03:01:39 AM »
Thanks for reply Martin!
I am actually not suppose to find relatives of this beast based on specialized characters like eyes structure or long legs - i am rather looking for ecological analogous , with convergent traits  to find out is such adaptations unique within the diptera or not. Forgot to mention that in Saether (1974) this females keys to Paracricotopus.

peter cranston

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Re: Orthocladiinae females with reduced eyes
« Reply #3 on: October 08, 2014, 01:51:48 PM »
Just a note that in BLAST searches of CO1 88% seems to be a kind of default, essentially equivalent to 'no matches'. So never informative of relationships. Matt Krosch and I have sequences (but for CO1 not Fulmer) for many austral orthoclads plus some from n hemisphere but with poor coverage. May be worth contacting him  at kroschie@gmail.com

Baranov_Viktor

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Re: Orthocladiinae females with reduced eyes
« Reply #4 on: October 08, 2014, 02:44:26 PM »
Thanks for suggestion, Dr. Cranston!