longsnouted and saddle-nosed Corydoras appear in the wild either
solitary or in small schools. This is the reason why they are much more
difficult to collect than the round-nosed Corydoras which most often
live in very large swarms. This fact makes the longsnouted and
saddle-nosed Corydoras much more expensive and also more desired by
Corydoras specialists. Longsnouted, saddle-nosed and round-nosed
Corydoras are not close relatives to each other and even belong to
different genera, despite that fact that they are traditionally still
grouped under Corydoras.
advantage for the longsnouted and saddle-nosed Corydoras in imitating
the coloration of the round-snouted Corydoras is the fact that predators
that feed on fish will avoid the spiny Corydoras after the first trial.
So longsnouted and saddle-nosed Corydoras profit from the bad
experiences fish-eaters make with the common round-nosed species. This
phenomenon – eg imitatiting the coloration of another species – is
called mimicry in biology.
A quite rare saddle-nosed species is known to imitate Corydoras reynoldsi from Colombia (see http://www.aquariumglaser.de/en/fish-archive/corydoras-en/_en-5/). The saddle-nosed species as known as the “reynoldsi longnose” or “CW12” in the hobby (see also http://www.aquariumglaser.de/en/fish-archive/corydoras-en/Corydoras_sp_aff_reynoldsi_CW12_en/).
Now we were able for the first time ever to import a larger group of
that pretty fish. This enables us to study the variation in the species.
And indeed, there is a lot of variation! Besides animals that look like
regular CW12 also very light, almost patternless specimens appear. Were
there not the intermediate morphs also present, no one would hesitate
to proclaim these fish to belong to different species!
most probably all the CW12 and the light fish belong to the very same
species, namely Corydoras septentrionalis and are only ecological sports
of that species.
For our customers: the fish have code 243655 on our stocklist. Please note that we exclusively supply the wholesale trade.
Text & photos: Frank Schäfer