The as yet unexplained phenomena in the catch-all genus Corydoras include the existence of a host ofmimetic species, that is species whose markings are almost exactly the same as those of another species.Initially it was discovered that for (almost) every round-nosed species there is also a long-nosed double. Thenit was established that in addition there is also often a “saddle-nosed” species. And only recently it hasbecome known that in some cases species of the Corydoras elegans assemblage likewise resemble otherspecies as regards their coloration.

Aqualognews N U M B E R 7 5 6

R E P O R T

New Corydoras species-pairsby Frank Schäfer

he phenomenon of several species

that are not closely related having

similar coloration is very widespread in

nature. This is known as mimicry or

mimesis. The term mimicry is used where

a harmless species imitates the coloration

of one capable of defending itself. In such

cases it is assumed that potential

predators have an innate perception that

strikingly-coloured animals are either

poisonous or may be dangerous in some

other way. A notable example of this is

the wasps, which are truly only to be

handled with care as they can deliver a

powerful sting. But numerous completely

defenceless insects imitate the wasps, and

this apparently conveys no disadvantage,

even if not beneficial, in an evolutionary

sense.

The term mimesis is used where instead of

potential predators being scared off by

warning coloration, the special colour

adaptation serves as camouflage. If an

animal mimics an inanimate object then

this is termed allomimesis; if a plant is

imitated the term is phytomimesis; and if

an animal is imitated this is zoomimesis.

Mimicry can, if you like, be regarded as a

specialised form of zoomimesis.

So how does this relate to the various,

reciprocally mimetic Corydoras species? As

ever, there is still no really satisfactory

answer to this question. Mailed catfishes

have virtually no enemies on account of

the stout bony scutes that encase their

bodies and the powerful, stabbing dorsal-

TCorydoras aeneus from Colombia

Juvenile Corydoras melanotaenia from Colombia,which live together with C. aeneus, barely differfrom the latter in their coloration.

S u p e r b g l o s s y p o s t e r s f r o m A Q U A LO G

Aqualog VerlagLiebigstraße 1D-63110 RodgauGermanyFax: + 49 (0) 6106 644692Tel: + 49 (0) 6106 644691

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Loricariidae L-Numbers I

ISBN (10)3-931702-02-2ISBN (13)978-3-931702-02-1Article-No .: P01-A

LoricariidaeL-Numbers II

ISBN (10)3-931702-03-0ISBN (13)978-3-931702-03-8Article-No .: P01-B

Corydoras

ISBN (10)3-931702-14-6ISBN (13)978-3-931702-14-4Article-No.: P04-A

news75engl.qxd 07.01.2008 9:13 Uhr Seite 6

Aqualognews N U M B E R 7 5 7

Adult Corydoras melanotaenia of the Colombian population that lives togetherwith C. aeneus.

Corydoras sp. C89/C93 has only relatively recently become known in the hobby.This is an adult male of the Colombian population which occurs together withthe C. aeneus and C. melanotaenia pictured here.

Juvenile Corydoras sp. C89/C93. Adult female of Corydoras sp. C89/C93.

and anal-fin spines that can be erected

and locked in place in the event of any

threat. In cases where a harmless characin

species imitates the coloration of a mailed

catfish this is apparently mimicry.

Something of this sort is seen, for

example, in that wherever Corydoras

hastatus is found, an open-swimming

species like the characins .

But what does a mailed catfish achieve by

imitating another mailed catfish?

Unfortunately we lack the field

observations necessary in order to answer

this question. We know from aquarium

observations that the various mailed

catfish species exhibit very different

behaviour. Thus, for example, many

saddle-noses (eg C. serratus) are very

territorial and despatch conspecifics in

the aquarium without further ado. And

yet in their coloration they closely

resemble peaceful shoaling species (eg C.

adolfoi and C. nijsseni).

Why? But unfortunately this question

must also remain unanswered for the

newly-discovered mimics from Colombia.

ISBN (10-stellig) 3-931702-13-8ISBN (13-stellig) 978-3-931702-13-7AQUALOG All Corydoras;U. Glaser, sen.

ISBN (10-stellig) 3-936027-41-2ISBN (13-stellig) 978-3-936027-41-9AQUALOGExtra Alle C-Nummern/All C-Numbers; H.-G. Evers, F. Schäfer

ISBN (10-stellig) 3-936027-80-3ISBN (13-stellig) 978-3-936027-80-8Identifying Corydoradinae Catfish;I. Fuller, H.-G. Evers

The most comprehensive and completeidentification work on mailed catfishes in the world!

Aqualog VerlagLiebigstraße 1D-63110 RodgauGermanyFax: + 49 (0) 6106 644692Tel: + 49 (0) 6106 644691e-mail: info@aqualog.deweb: www.aqualog.de

144 pages, Format DIN A4, morethan 650 colour photos.

48 pages, Format DIN A4, 271colour photos.

384 pages, Format DIN A5, morethan 400 colour photos.

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