Rama/Chandramara/Batasio chandramara

Post by **Silurus** » 23 Aug 2003, 15:16

I have a question for those who are keeping/have kept the fish. Have you ever noticed a very distinct and very dark line running along the posterior two-thirds of the body?
I am curious because in the late 1980s and early 1990s, Indian exporters have exported an apparently undescribed species that has a very distinct dark line and a seemingly more slender body.
Just wondering if the dark line is something that would be highly variable. All of the true R. chandramara I have seen, both live and preserved, don't seem to have a very distinct line, but I want to know if the experiences of others.

Post by **Shane** » 28 Aug 2003, 04:02

HH,
Believe that I have some photos of these. I'll scan them in and post one.
-Shane

Post by **Dinyar** » 15 Feb 2004, 22:25

When stressed, the black line disappears and the fish looks almost transparent; once the fish feel at home, it is very visible. Will post some pix shortly.

Dinyar

Post by **Silurus** » 15 Feb 2004, 22:30

Actually, I have looked at enough preserved material to conclude that there are two species involved: the original Chandramara from Bengal, and an undescribed species from Assam. All of the fishes collected for the aquarium trade are the undescribed species from Assam.
FWIW, this Assamese species can reach a fairly large size (ca. 50 mm SL), and in the large specimens, the black line is very broad and distinct.

Post by **Dinyar** » 17 Feb 2004, 01:03

Our good friend Hambuck described Pimelodus chandramara and Pimelodus rama, the former from the Atreyi river in Bengal and the latter (now declared a junior synonym of the former) from the Brahmaputra in Assam. Could this be the "undescribed species" you are referring to?

BTW, could not find much info on the Atreyi river, except that it's in North Bengal, but the Brahmaputra in Assam is no longer a fast flowing mountain stream. So perhaps this Assamese fish IS from slower moving water.

Dinyar

Post by **Silurus** » 17 Feb 2004, 01:21

The "Atreyi River" of Hamilton is the Atrai River (which drains into the Jamuna River, itself part of the Brahmaputra drainage) in northern Bangladesh. I believe Pimelodus chandramara and P. rama are one and the same thing, having compared both original drawings of Hamilton. I do not think that that they type locality of P. rama is in Assam (Hamilton merely mentions it as the Brahmaputra River), since he seems to have obtained all of his material from the lower Ganges/Brahmaputra.
This leaves the Assamese fish still without a name.

Post by **Dinyar** » 17 Feb 2004, 15:30

Silurus wrote:Actually, I have looked at enough preserved material to conclude that there are two species involved: the original Chandramara from Bengal, and an undescribed species from Assam. All of the fishes collected for the aquarium trade are the undescribed species from Assam.
FWIW, this Assamese species can reach a fairly large size (ca. 50 mm SL), and in the large specimens, the black line is very broad and distinct.

I have news today from a reliable second-hand source (who has photographic evidence) that Chandramara is collected for the aquarium trade from still water in West Bengal.

Dinyar