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Crimson loach species, one or the same?

Posted: Fri Mar 13, 2009 8:51 pm
by Emma Turner
This might be one that The.Dark.One will want to look at. Two very similar looking loaches, which may even be the same species, imported on the same week, under two separate names. One was imported as Crimson loach - Schistura sp. 'crimson', the other as Scarlet loach - Nemacheilus nilgiriensis. They look identical to me, but their vastly different behaviur makes me question this. The ones imported under Schistura sp. 'crimson' have created nothing short of a blood bath in their tank, yet in the same conditions, a few tanks away, the ones imported as Nemacheilus nilgiriensis have been completely peaceful. In both cases, there have been good sized groups, and they have had the same amount of space, decor, foods etc. When I went to catch out some specimens of each to put into my photo tank, I had great difficulty in finding any S. sp. 'crimson' that was not damaged in some way. Most have big chunks or rips in the dorsal fins (this is males and females). Yet there is honestly not a single bite mark on the ones imported as N. nilgiriensis.

Here are some pics, the colours have faded a little upon being put in the photo tank.....

Schistura sp. 'crimson' - male
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Schistura sp. 'crimson' - male
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Schistura sp. 'crimson' - male (this one had the best dorsal, but is clearly damaged)
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Schistura sp. 'crimson' - male
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Schistura sp. 'crimson' - female
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Schistura sp. 'crimson' - female
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Schistura sp. 'crimson' - female
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Schistura sp. 'crimson' - female
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Schistura sp. 'crimson' - female
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Schistura sp. 'crimson' - female
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Nemacheilus nilgiriensis - male
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Nemacheilus nilgiriensis - male
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Nemacheilus nilgiriensis - male
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Nemacheilus nilgiriensis - male
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Nemacheilus nilgiriensis - male
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Nemacheilus nilgiriensis - male
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Nemacheilus nilgiriensis - male
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Nemacheilus nilgiriensis - female
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Nemacheilus nilgiriensis - female
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Nemacheilus nilgiriensis - female
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Nemacheilus nilgiriensis - female
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Just to clarify, this behaviour difference is not imaginary. Both batches of fish have been in at the shop for over 2 months, and I often observe them after hours. Can they really be the same? Could they be different populations of the same species, but evolved with a different aggression level?

Emma

Posted: Sat Mar 14, 2009 6:34 am
by mickthefish
Em, i remember a thread that Beta had on petfrd, where he was up in the hills in india, he shown a loach that i would have sworn was a crimson, and was told that there are quite a few look-alikes to them.

mick
ps, the posterior bars on t'other one are far broader than the crimson's.

Posted: Sat Mar 14, 2009 9:48 am
by afroturf
wow love the nilgiriensis.

Posted: Sat Mar 14, 2009 7:41 pm
by bslindgren
Really interesting, and really beautiful fish. It sure sounds like you have a case. The first ray in the dorsal seem to differ slightly in shape (in addition to the bar width pointed out by Mick), but I guess some DNA comparisons are needed for this one.

Posted: Sat Mar 14, 2009 8:01 pm
by helen nightingale
Em, do you know much about the range/location of these two "species"?

i have been reading about ring species.

imagine a horseshoe shape. species 1 lives at one end, and species 2 live at the other end. they dont interbreed, and behave or look like separate species. but in the middle of the horseshoe, they do interbreed and would appear to be one species. (herring gulls are like this, and some salamanders).

i am too tired to look for the subtle differences the others have noticed

Posted: Sun Mar 15, 2009 2:11 am
by random2
AFAIK, Shistura sp. Crimson are from Kerala and also Nemacheilus nilgiriensis (maybe also Tamil Nadu). Yesterday when searching around on the net found that Nemacheilus nilgiriensis are also found in mid-northern part of Karnataka in river Sharavati. According to the content at least 250-300kms north of previous known location.

http://ces.iisc.ernet.in/envis/sdev/sus ... /index.htm

As per my knowledge, these two places are quite far with no linkage of water bodies. Dont know about rivers of Kerala, but Sharavati flows west and is one of the few rivers that join the arabian sea (most major rivers flow east).

PS:
offtopic: One of the well known places about this river-
http://en.wikipedia.org/wiki/Jog_Falls
http://commons.wikimedia.org/wiki/Category:Jog_Falls

Posted: Sun Mar 15, 2009 5:40 am
by Graeme Robson
Very nice Loach with Superb pictures! 8)

I would love to know what these Loaches eat from within the region where they have this colouration....

Posted: Mon Mar 16, 2009 3:43 pm
by The.Dark.One
Emma

These to me appear to be the same species as each other. Although they may show different behaviour I don't think this alone is enough for differentiating them, when in all other useable morphological factors they appear to be the same fish. However, I do think that both of these are closer to S. nilgiriensis. I do not think they are the same Crimson as first came in: http://forums.loaches.com/viewtopic.php ... ht=crimson

These new ones appear to have more complete bands, different head shape, and appear to have a shorter lateral line, which would tie them in with S. nilgiriensis.

Posted: Mon Mar 16, 2009 4:17 pm
by mickthefish
Steve, this is a pic of the crimsons Neil got in at the date on the pic mate, use this to compare.
Image

mick

Posted: Mon Mar 16, 2009 6:51 pm
by plaalye
My god that's an incredible fish!!

Posted: Mon Mar 16, 2009 7:24 pm
by The.Dark.One
Nice pic n fish Mick.

They are very similar but I think they are different. Mick's fish and the ones in Emma's old thread look different to me to the ones in this thread. The colours and slight differences in pattern could be down to regional variation or diet but the lateral line does look different (although it is hard to tell).