his
member of the Callichthyidae family is a well known
favourite amongst Corydoras lovers. The 'Skunk'
or 'Arched Cory' is sometimes difficult to pick up
in the shops and seems to come and go in periods so
you have to snap them up when seen and of course the
recently unfolding story of the true C. arcuatus
is told below.
Corydoras
arcuatus
Water conditions
are of paramount importance on this species as the
barbels are very susceptible and can very quickly
wear away if the water changes are not adhered to
and the bacteria builds up in the substrate, why this
species of Corydoras is effected more than
any other is a mystery to me.
In the following
picture you can see the worn down barbels on this
species. Sand would probably be a good bet for the
bottom of their tank, just a light scattering should
suffice.
Corydoras
arcuatus
This species is
sometimes confused with its longer nosed cousin Corydoras
narcissus, but the length of the snout is the
main difference, and also the stripe in narcissus
tends to be longer, running into the lower lobe of
the caudal fin.
This species
was given the CW-number (Corydoras World) of 36 as
it had not previously been given a C-number. It is
now thought (Grant, S. 2014) that this species, CW036,
is the true Corydoras arcuatus instead of
the shorter nosed C020.
Above
is a young speciman, (C020) and as it grows the black
spots will join up to show the adult black line.
Placed in Lineage
8 sub clade 4 which comprises the "intermediate
long-snouts" with deeper bodies. It also includes
Brochis in sub-clade 1 which was synonymised
with Corydoras by Britto in 2003 but in time
there will be a revision which will resurrect Brochis
(Cope, 1871) to full genera again.
UPDATE:
It is now been proven (Grant,
S. 2014) that CW036
is the true Corydoras arcuatus instead of
C020.
Common
Name:
Skunk
Cory, Arched Cory.
Synonyms:
None
Family:
Callichthyidae
Subfamily:
Corydoradinae
Distribution:
South America:
Brazil,
Rio Madeira, Humaita-region.
Size:
Male: 7.5 cm (3ins) Female:
8.0cm (3¼ins)
Temp:
22-26°C (71-79°F)
p.H.
6.5-7.2.
Characteristics
Dorsal
1/7; Anal 1/6; 22-24 bony scutes in the upper lateral
series, 20-22 in the lower.
Colouration
Grey-yellowish to delicate
grey-green; underside pure white. A broad, dark
longitudinal band commences at the corner of the
mouth and passes across the eye into an arched course
following the profile of the back to the root of
the tail where it turns abruptly downwards and,
becoming narrower, continues along the lower edge
of the caudal fin. No other markings. Fins colourless;
caudal with fine dark spots and a blackish upper
edge.
Aquarium
Care & Compatibility
Will do well in a community
setup with smaller tankmates such as Rasboras and
Tetra's. Do not house with aggressive species or large
Cichlids.
Reproduction
Not one of the
easiest cory's to breed, but in one reported spawning
a cold water change down to 60f (17c) induces spawning,
with the eggs being laid in Java Moss. Eggs will hatch
in 3 to 4 days. U.K. Corydoras breeder Ian
Fuller of the Corydoras
World web site has
bred this species in 1980 and reported the usual Cory
T-mating clinch fashion. 110 eggs were laid with about
65 of them in the Java moss the remainder were stuck
on the sides of the tank mainly in the corners. Temperature
was 68f (20c) and the eggs hatched in 3 to 4 days.
There was a 95% hatch rate.
30 years later in 2010 In Scotland, aquarist Graham
Ramsay has also bred this species. See
breeding article on breeding the afore mentioned species
C020 here
Diet
After the fry are 3 days old,
feed microworm, fry flake then progress on to brineshrimp,
keeping up the water changes. Adults can be fed on
the usual good quality aquarium flake with tablet
food and frozen bloodworm being a good diet.
Etymology
Corydoras:
Cory = helmeted;doras = leathery skin,(helmeted
Doras) cuirass. arcuatus: Arched, like a
bow, (referring to the stripe).
References
Lambourne,
Derek,
Corydoras Catfish, An Aquarists Handbook 1995. Sterba, Günther; Freshwater
fishes of the World Vol.1 1973 Fuller, A.M. Ian, Breeding
Corydoradine Catfishes. Grant S.,
2014, Catfish Study Group Journal V15 - I4.
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