This is the second in a series of
articles on the collections carried out by the authors
in their native environment around the Paraná River
in northern Argentina near to the city of the same name,
(Paraná City), and also into the Misiones province
near Posadas city in the south west zone of the province
near the Paraguayan border. In this current article they
also collected 400km to the north in the Corrientes province.
I will now hand you over to Carlos and Noemi to take you
through their collecting experiences.
n one of our collecting trips three years ago ( 2001)
in the port of Diamante on the Paraná River, which
is just south of our home, (you can see this on the Paraná
River image on the sidebar) we stumbled across a Rineloricaria
species which was in a bunch of rooted plants which have
their leaves floating on the surface and is very common
here. The size of this Rineloricaria was about
50mm total length. A few weeks later we caught two fishes
of the same species, but from a two different locations,
in a lagoon near Santa Fe city, about 120 Km, crossing
the Paraná river. The size was the same. In the
three capture sites the substrate was a sandy bottom,
in two cases with rooted plants. From that summer we caught
several fishes of the same species, in some cases tiny
fishes, almost threadlike. We always captured them among
dense vegetation and almost always under floating plants.
Allan has replied on the identification of this species
and below are his comments.
<I have been in touch with Hans Georg-Evers who wrote
the Catfish Atlas for the Mergus publishing house with
Ingo Seidel in Germany, and he tells me that there are
a lot of Rineloricaria species in the Rio Uruguay
and Parana drainage to be described. There was supposed
to have been about 10 new species being described but
the paper never did come about so I was advised at the
moment to call these species Rineloricaria sp. "Parana"
which I was doing originally. Each species will have to
be numbered "Parana" 1- Parana 2 etc.>
As you can see in the photos this fish has a double whiptail,
not only the upper radius of the tail are elongated in
a filament, but also the lower radius.
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Rineloricaria
sp. "Paraná 1"
Along with the Rineloricaria we captured two Otocinclus
species, we believe O.huaorani and O. affinis,
a Hypoptopoma species, Callichthys callichthys,
juvenile Herichthys facetum and Cichlasoma
portalegrensis, and several characins. The most interesting
fish was a Farlowella sp, but unfortunately it
did not eat and only survived a week.
We put all of our fishes in a 130l community tank. In the
beginning the Rineloricaria sp. was almost all
the time sitting on a rock that seemed to be a favourite
place. After several weeks the fishes hid behind the rocks
or plants. It passed all the autumn and winter hidden, only
to come out in the open waters in the night, if one put
the the lights on they would go quickly back to their hiding
places. In the spring they reappeared more and more, and
in the summer they spend the most of the time in open waters.
As the time passes we can confirm that this fish is a seasonal
fish. They pass the autumn and winter hidden and come out
to to the open in the spring. In the autumn and winter they
only come out in the night. These fishes are totally vegetarians,
they never pick over the meat foods and wait for the vegetable
food that we offer in the night. Today our fishes have about
110 mm TL, and have not grown for the last year. We believe
that they are adult specimens now. We kept four for them
and sold or gave away several to people that liked them.
We ask, and all the people say that the fishes are hardy
and easy to keep.
We later found out from Allan that the Otocinclus
species is actually O. vittatus which you can see
in the photographs below.
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Otocinclus
vittatus
We hope that the next species will be more easy to identify,
we believe that this is a Hypoptopoma species,
we caught the first fish for this species a year and half
ago (June 2003) in a trek to Misiones province, and to its
capital, Posadas city, which is over the same Paraná
river but on the border with Paraguay. We caught a few fishes.
A Corydoras species, two Otocinclus species
and a unknown species, only a bit more larger that an Otocinclus.
We call this Hypoptopoma species "Flat nose"
and put it in a 50 l. tank with Xiphophorus variatus
(Platy), Xiphophorus helleri (Swordtail)
and some Corydoras aeneus.
The Hypoptopoma species that are described from this
area are Hypoptopoma inexspectatum. There
are no description notes but we would think that this is
indeed this species.
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Hypoptopoma
inexspectatum
The next summer we caught some fish of this species [Hypoptopoma
inexspectatum] in the same
Paraná river, but much more near to our home, about
25 miles near to Valle María town. There we caught
a dozen or so, that are living among floating plants with
various Otocinclus species, Hemiloricaria parva?,
Callichthys callichthys, juvenile Herichthys
facetum and Cichlasoma portalegrensis, and
several characins. This was the same site where we caught
some of our Rineloricaria sp. "Paraná
1", a quiet site with a lot of floating plants, to
a distance of 100 m, with no floating plants and no quiet
water, where there are not the same fishes to be found.
These fish are totally sedate, they are always over a submerged
branch, they really love the wood. When we want to take
photos we can
not, as the fishes are always behind or below a branch.
So we prepared a little tank with a small branch, some sand,
and a flowerpot with vallisneria, and put the fishes in
there. The flowerpot with the vallisneria plant was outside
of our home, with plenty solar light for the vallisneria
to grow. As you can see in the above photos the fish enjoy
the algae over the flowerpot.
The next species is not a Loracariidae species, but a Corydoras.
We fish for them along with our first Hypoptopoma
specimen in Posadas city. When we caught them we looked
and .... it is a Corydoras but .... what species?.
It was pale with fear and his colour was gone, we took it
to our home and into a 60 l tank. In a week or so it was
settled and its colour came through, then we waited for
it to grow, but it grows very slowly. We would think that
it could be Corydoras polystictus, but the photos
that we have show a totally spoted fish, and this is spoted
only in the head, also, the size is very small. All the
Corydoras are a bit shy, but they are extremely
shy, and spends all its time behind a branch or a rock.
We would think that it is unhappy because it is alone ....
In the same tank there are four Corydoras undulatus,
but it will not join them in a group. This may be its final
size .... may be, may be not.
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Corydoras
polystictus (caught in Posadas City)
At this time of the year our Corydoras aeneus are
specially beautiful and we get some good photos, They are
all wild captured specimens. We caught them in a little
creek in Corrientes province, about 400 km to the north.
The creek has a rocky and sandy bottom, clear water and
portions of plenty plants along the bottom, the Corydoras
are almost always in the planted portions, but some
times they come out among the rocks and we can see them
swimming over the substrate. A lot of people say that there
are Corydoras aeneus to the South, in the Buenos
Aires province, but I have had no luck over there, some
times the sports fishermen say that there are Corydoras
aeneus in the Paraná islands and they use them
as bait. In all cases C. aeneus are reported in
quite clear waters, but we have no data about the pH and
dH, when we caught them the water temp was about 15 ºC,
yes, I put my feet in the water and it was quite cold!.
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Corydoras
aeneus (caught in the Corrientes Province))
Next in the series we will be showing you pictures of the
habitats around our area in the Paraná River basin.
We hope that you enjoyed the latest in this "Collecting
Argentina" series.
