his
months factsheet (Sept. 2014) brings us to the South
American family Auchenipteridae and a little known
member from the Auchenipterus genera, the
Paraguay Shark-cat, Auchenipterus nigripinnis.
Your first thoughts
when you see this species is the resemblance to the
shark cats of the Pangasidae catfish family of Asia,
hence its common name.
But the likeness to this family
stops there as the Auchenipterus do not grow
to the huge sizes of the Pangaidae shark cats and
A. nigripinnis will reach a manageable size
of 8ins ( 20.5cm.)
Auchenipterus
nigripinnis
The genus Auchenipterus
is closely related to and is similar to, Epapterus
and Pseudepapterus.Distinguished
from all species except A.
brachyurus by
the following combination of characters: anal fin
origin posterior to the middle of the body; and caudal
fin without terminal band, but with a chevron-shaped
dark mask near base of each lobe. The caudal markings
are the very best way to identify this species and
from the aforementioned A.
brachyurus which
has two horizontal bands running through the caudal
fin lobes.
Auchenipterus
nigripinnis
As mentioned earlier
this species is not seen very often in the hobby and
only arrived via Aquarium Glaser in Germany in 2009,
but a group of them in a large tank will very often
be seen during the day especially at feeding time.
They do not eat plants so a planted setup with added
floating plants would be advantages to this species.
In its natural habitat, it lives in the LaPlata basin
of Argentina, Brazil, Paraguay, and Uruguay so lower
temperatures are the norm for this species.
Common
Name:
Paraguay
Shark-cat
Synonyms:
Euanemus
nigripinnis, Auchenipterus paysanduanus
Family:
Auchenipteridae
Subfamily:
-
Distribution:
South America:
La
Plata River basin. Known only from the Rio de La Plata
drainage. In the Rio Paraná, the species has
been recorded above the junction of the Rio Paraguay.
Type locality:Paraguay.
Size:
20.5cm. (8ins)
Temp:
18-24°c (63-75°f.)
p.H.
6.5-7.2.
Characteristics
Body comparatively deep, elongate;
body depth an anal fin origin 20-25% SL; body compressed,
width at anal fin origin approximately 42% (38-45%)
of body depth at that point. Barbels slender, maxillary
pair extending at least to tip of adpressed pectoral
fin spine. Mandibular barbels originate in transverse
row at margin of lower jaw, just lateral to jaw symphysis;
barbels extend posteriorly at least to pectoral fin
base, basal portion of each barbel rests in shallow
groove that extends posteriorly approximately to vertical
through posterior margin of orbit. Nasal barbels absent.
Caudal fin forked, lobes pointed. Lobes somewhat asymmetrical,
longest branched ray of upper lobe longer than than
that of lower lobe.
Colouration
Body silvery white, grey
dorsally. Abdomen and underside of head white. Complete
midlateral, posteriorly tapering, dark stripe present
in some specimens, but often stripe extends from
humeral region posteriorly only to region above
pelvic fin base. Dorsal fin with scattered dark
pigmentation basally, especially anteriorly, but
pigmentation does not extend far into fin membranes.
Dorsal fin with thin dark margin in some specimens,
width of marginal pigmentation varies, but always
decreases posteriorly. Caudal
fin with lightly scattered pigmentation along margin
not usually forming dark marginal bar. Middle of
upper caudal fin lobe with broad oblique, and somewhat
curved dark bar. Lower caudal fin lobe with thin
dark bar, more basally situated.
Aquarium
Care & Compatibility
Good community catfish with
normal sized patrons. Not to be trusted with small
Tetras for instance, which will be picked of at night
on its twilight patrols.
Reproduction
Not reported but
would be along the lines of other members of this
family. Internal fertilisation with the eggs deposited
24-48 hours later. The eggs being encased in a gelatine
mass and placing their adhesive eggs on the underside
of wood with no broodcare after the event.
Diet
Can be fed most aquarium fare
such as good quality flake, white worm, tablet and
pellet foods and frozen foods such as bloodworm. Better
to feed at lights out until they get accustomed to
the daytime feeding regime when they may very well
join in.
Glossary
of Terms
Anal
fin: The
median, unpaired, ventrally located fin that lies behind
the anus, usually on the posterior half of the fish. Maxillary barbels:
Pertaining to the upper jaw. (maxillary barbels) Mandibular barbels:
Pertaining to the lower jaw. (mandibular barbels). Caudal:
The tail. Pectoral fins:
The paired fins
just behind the head. Pelvic fins:
The paired fins, between
the pectorals and the anal fins. (also referred to as
ventrals). S.L.:
Standard length as measured from the snout to the caudal
peduncle. Dorsal fin:
The primary rayed fin(s)
on top of the body.
Aquarium
Glaser.
Ferraris, C.J. Jr.,
2007. Checklist of catfishes, recent and fossil (Osteichthyes:
Siluriformes), and catalogue of siluriform primary
types. Zootaxa 1418:1-628. Ferraris, C.J. Jr., 1999. The South
American catfish genus Auchenipterus Valenciennes,
1840 (Ostariophysi: Siluriformes: Auchenipteridae)
: monopoly and relationships, with a revisionary study.
Zoological Journal. Vol. 126, Part 4, 1999.
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