Indian Glyptothorax

Post by **Silurus** » 22 Dec 2003, 23:50

Bought this Glyptothorax telchitta at an LFS here in Singapore.

Mixed in with them was this other unidentified Indian Glyptothorax.

Opinions anyone?

Antti · Post by **Antti** » 28 Dec 2003, 01:38

Their coloration looks pretty much the same, the telchitta being paler. The telchitta looks more slender, are they different species for sure? If they are and come from the same river it would be mimicry..? That would be pretty cool, starting new G-number system for all short and long snouts and so on.

Antti

Ps. My fewer has gotten down to 38,5C

Post by **Silurus** » 28 Dec 2003, 05:25

The second fish is indeed more deeper-bodied than the telchitta. The color pattern you see here is pretty standard for many Glyptothorax from India, Myanmar, and some from Thailand and Laos. This leads me to suspect not so much mimicry as common ancestry...

YouTube · Post by **Jools** » 28 Dec 2003, 11:08

How do you sex <I>Glyptothorax</i>? I mean these fish are so close and if from the same river then my first thought would be to check we aren't looking at different sexes. I realise this would mean that the batch of fish you looked at should be rouhgly half and half these two types - but often you find prettier fish as sold first from a LFS is we don't know they are boys and girls.

Jools

Post by **Silurus** » 28 Dec 2003, 11:22

Sisorids are sexed like many other catfishes: the males have different external genitalia (usually a genital papilla which can be somewhat elaborate in some species).
Having looked at large series of Glyptothorax before, I do not think the differences are sexual, since they do not appear to show sexual dichromatism.
Having collected Glyptothorax in India, I would not be surprised that two or more species would be found in the same habitat (since I caught two species at one river).

Antti · Post by **Antti** » 29 Dec 2003, 11:07

What kind of differences these Glyptothorax species inhabiting same river show in food and habitat preference? (if any) Shouldn't they be moving towards different preferences or otherwise one replacing other in the long run, if they are almost same all the way to coloration?

Antti

Post by **Silurus** » 29 Dec 2003, 16:33

I'm not sure if there is any diet/habitat segregation in cases where two or more species of Glyptothorax are found syntopically. In Java, one usually finds G. platypogon in virtually the same areas of the stream with G. robustus. In fact, one can get a mixture of the two species in the same haul.

Post by **Shane** » 30 Dec 2003, 01:22

HH (and others),
I have noted the same thing with Chaetostoma. In some small streams (even in small restricted watersheds like the Rio Tuy in Venezuela) you can encounter three spp. living together. I have always wondered why three spp. of the same genus would be found in one small habitat. I do not mean to hijack this topic, but it is something that has always made me very curious. HH, have you ever wondered/looked into this topic?
-Shane

YouTube · Post by **Jools** » 07 Jan 2004, 12:57

One reason might be that one species is nocturnal and the other not?

Jools