Corydoras njisseni

3. February 2016

we were able to import again the smallest and cutest of all the
different “orange blotch” Corydoras from the Rio Negro: Corydoras
nijsseni. This fish is a close relative of C. elegans. The coloration,
which is the same in Corydoras adolfoi, C. duplicareus, C. imitator, C.
sp. C39, C. serratus, and serveral other species, does not reflect the
phylogenetic relationship at all. Research has shown that it is simply a
case of mimicry that is used as a protection against predators. A bird
or another fish-eating animal will learn from the first Corydoras it
preys on that they are nasty scratchy in the throat. In future it will
avoid to feed on such fish. So all fish with the same coloration are
protected, this is the sense of this mimicry.

in most members of the Corydoras-elegans-relationship – the generic
name Gastrodermus is available for them – the males and the females show
a quite different coloration. Males are much darker during the mating
season. Very old males can even develop a black-dark network all over
the body. However, our fish are still young adults and the difference is
hence not that clearly visible yet.

our customers: the fish have code 237603 on our stocklist. Please note
that we exclusively supply the wholesale trade. Available in limited
numbers only!

Text & photos: Frank Schäfer