he
first month of 2016 and we make a return to the Callichthyidae
family but this time not to your ubiquitous Corydoras
but to an old friend in the eyes of the aquarist of
the more advancing years and a reminder that Megalechis
picta known then as Hoplosternum thoracatum (now Megalechis
thoracata)
was once, 20 or 30 years ago, held in the same esteem
as the fancy L-numbers of today's 21st century.
Megalechis
picta- male
In
the 1960's and 70's the catfish that the average U.K.
aquarist could only get a hold of were the Corydoras
with aeneus and paleatus being the
norm with maybe a few other varieties thrown in. Only
a few specialist shops were bringing in the more unusual
pets such as a few Synodontis when imports
from Africa were obtainable and the more common plecs
such as the different varieties of whiptails from
South America. That is why the "Port Hoplo"
alongside Callichthys callichthys were much
sought after all these years ago.
You can distinguish
between our factsheet of the month and Callichthys
callichthysby
the shape of the caudal fin with the latter being
more rounded and also possessing smaller eyes. The
Megalechis genera has had a checkered history
as this genus was revised in 1996 by the Brazilian
Ichthyologist, Roberto E. Reis, and only Hoplosternum
littorale was kept with him creating a new genus
for thoracata with a second species added,
Megalechis personata. There was a second
paper on the genus Megalechis (1997) and
what we used to know as M. thoracata is now
M. picta. The difference between these two
species rests on the pattern in the caudal fin with
M. picta possessing a band and M. thoracata
having a spotted caudal fin. M. picta also
has bands on the body whereas M. thoracata
is spotted. There is quite a marked difference between
juveniles and adults and some juveniles (as seen in
image) are quite attractive. M. personata
is now a synonym of M. thoracata.
Megalechis
thoracata can be further distinguished from M.
picta by the smaller dorsal-fin spine, generally
higher number of anal-fin rays (six, rarely five vs.
five, rarely four) and mainly by the colour pattern
of caudal fin (see Reis et al. 2005). In M. thoracata
the base of caudal fin displays a whitish band and
the remaining part is dusky or black spotted, while
M. picta presents caudal-fin base blackened,
with a conspicuous dark bar in the middle and the
distal border also blackened, the regions between
the blackened bands are clearly whitish yellow.
Megalechis
picta - male
pectoral spine
Megalechis
picta - juvenile
To finalise these
two species, the paper by P-Y Le Bail and JHA Mol
(2005), discovered after re-examination the holotypes
of Callichthys thoracatus and Callichthys
longifilis, which were used to describe the species
now placed in Megalechis. The fish were found
to be those currently known as Megalechis personata,
the so-called Tail-bar hoplo. However, since C.
thoracatus was described first, it had priority
and is a senior synonym. This meant that the scientists
needed a new name for the current Megalechis thoracata,
and the next available name was Callichthys pictus,
making the new name for the fish Megalechis picta.
Megalechis
thoracata- female
The
above image of Megalechis thoracata showing
you the difference between the two species.
Megalechis
picta is native from Amazon and Orinoco river
basins, as well as coastal rivers of the Guianas and
northern Brazil, it has also been found in the upper
Rio Paraná basin.
Common
Name
Port
Hoplo,
Tail Bar Armoured Catfish
Synonyms
Callichthys
longifilis, C. pictus, C. sulcatus, C. thoracatus,
Hoplosternum orinocoi, H. thoracatum
Family
Callichthyidae
Subfamily
Callichthyinae
Distribution
South America:
Amazon,
Orinoco and upper Essequibo River basins, and coastal
rivers of northern Brazil.
Size
15.5cm (6¼ins)
Temp.
18-28°C
(64-82°F)
p.H.
6.0-8.0.
Characteristics
Dorsal: 1/8: Anal: 1/5: 25-26
bony scutes in the upper lateral series, 23-24 in
the lower.
Colouration
Caudal-fin base blackened,
with a conspicuous dark bar in the middle and the
distal border also blackened, the regions between
the blackened bands are clearly whitish yellow.
Aquarium
Care & Compatibility
Keeping this species is not
too difficult a task. They can become quite boisterous
in a community setup with their digging and unsettling
other fish at night but as long as your other inhabitants
are of a decent size and are not "Neon Tetra
size", as remember this fish can get to nearly
7inchs in size and a small 1 inch tetra at night may
be too much of a temptation to even the most docile
of animals. The only time they can get aggressive
is if you have a pair and they are in the throes of
spawning as the males can get quite tetchy and it
is not unknown for a male to kill the female in the
quest to produce a family. This does not happen all
the time but best to keep a look-out for any aggressive
behavior.
Reproduction
This species is
a bubblenester with the male building it at the water
surface. The female lays her eggs in the nest and
the male looks after them. This is the point that
you may have to take the female out of the tank as
the male may kill it, as they can get aggressive when
guarding the nest.
Sexual
Differences
To differentiate
between the sexes is not too hard. The males posses
thicker pectoral spines with minute hairs adorning them
and have an orangey colouration when in breeding condition
(see top picture) If you can see underneath your specimens
you will also see that the female has a broader gap
between the thorax plates than the male so as to give
room to the swelling which is involved when carrying
eggs.
Diet
A good quality flake and tablet
food. They also relish garden worms and frozen bloodworm.
Glossary
of Terms
Anal fin:
The median, unpaired, ventrally
located fin that lies behind the anus, usually on
the posterior half of the fish. Caudal fin:
The tail. Dorsal fin: The primary rayed fin(s)
on top of the body. Scutes:
Bony covering.
Reis,
1997; New Arrangement in the Synonymy of Megalechis
(Siluriformes: Callichthyidae). Copeia 2005: 678-682. Reis, RE, P-Y Le Bail & JHA Mol,
2005. (New Arrangement in the Synonymy of Megalechis
Reis, 1997 (Siluriformes: Callichthyidae). Copeia
2005: 678–682.). Sterba, Gunther;Sterba's
Freshwater Fishes of the World vol 1. Tencatt, Luiz Fernando
Caserta; da Graça, Weferson Júnio and
Pavanelli, Carla Simone. 2013. First record
of Megalechis picta (Müller and Troschel, 1849)
(Siluriformes: Callichthyidae) in the upper Rio Paraná
basin, Brazil.
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