Silurus wrote:That they are mostly deepwater species found at the bottom of the lakes. They are so specialized in living in the deep, dark depths that they have essentially lost the accessory breathing organ (and the ability to breathe air along with it). Many of these species are a dark gray or black in color, and like many deepwater fish, they do not survive for very long when captured.
They are rare, and so no one really knows much about their biology.
Heok Hee
You may be right about this Heok Hee, but I have some questions. Malawi is not a very deep lake. Mean depth is close to 300 m. But in all Rift lakes, AFAIK, anoxia occurs at >200 m. Moreover, unlike L. Tang., the shores shelve gently, so you don't get into deep water until really far from the shore.
I also read that nowadays fish exprters in the Rift lakes dive to great depths, well over 50 m, and bring fish up in a multi-stage, multi-day acclimitization process. Once acclimatized, most of these fish (ciklids, mostly -- did I beat the thought police?) do just fine in aquaria.
It may well be that many of the deepwater clarriids would not adapt well to life in shallow water (e.g., aquaria), but I suspect there must be a number that are from habitats at a depth of <80 m and could adapt to aquarium life. Could there be other reasons we don't see these fish in the hobby? Of course, all Clarriids are banned from import into the US. But I suspect that there is just no demand for Rift lake Clariids because they're (1) tough to catch in relatively deep water, (2) for the most part, grow pretty large, (3) highly predatory, and (4) unattactive and reclusive.
Whadya think?
Dinyar