the river Pilcomayo upstream from puente Diabalo
Surubí, predatory fish in the river Pilcomayo that feeds mainly on Sábalo
nightview near Villa Montes on the Pilcomayo river at the foot of the Andes
tradicional Weenayek fishermen
fieldwork in theTampinta river (a tribute to the Pilcomayo)
Los Amigos del Pilcomayo
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Species
Apareiodon affinis  (Steindacher, 1879)
In co-operation with department of Aquatic Ecology & Environmental Biology.
Fishes of the Pilcomayo
Common name: Virolito
link to fishbase on Apareiodon affinis
Class:                 Actinopterygii (ray-finned fishes)   
Order:                Characiformes  (characins)
Family:                Parodontidae
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Source: translated from 100 Peces argentinos;
Hernán Laita y Gustavo Aparicio; Editorial Albatros;
2005; ISBN 950-24-1012-2

In nature there are numerous of examples of
species that, without being related,  present a
similar anatomical structure. This phenomenon is
known as "convergent” evolution, similar forms
derived from an adaptive pressure in the same
sense.
In this sense the Virolito, resembles certain
anatomical characteristics with Siluriforms like the
Bagre.
Its body rests on the pectoral and ventral fins, the
small mouth is directed downward and is lined with
thick lips. These features denote its detritivorous
and limnofagous character.
The Virolito is rarely encountered in the big rivers.
More usually it is found in streams and channels
with a muddy bottom and with abundant branches,
Source: translated from: Peces de los Ríos Bermejo, Juramento y Cuencas Endorreicas de
la Provincia Salta; Gladys Monasterio de Gonzo; Museo de Ciencias Naturales y Consejo de
Investigación Universidad Nacional de Salta; Octubre 2003.

Identification: Body sub-cylindrical, lengthened, with little curved dorsal and ventral profiles.
The maximum width of the body at the level of the dorsal fin is more than half of the corporal
maximum height. Caudal Peduncle wide, approximately a third of the maximum height of the
body. Small and conical head. Mouth in ventral position forming a direct line, in shovel form.
Only presents superior, lightly curved and sawed teeth. Origin of the dorsal fin in the
previous third of the body, halfway between the end of the pectoral fins and the base of the
pelvic fins. The distal end of the pectoral fins it arrives some seven arrays of flakes before
the beginning of the pelvic fins. They begin before the vertical line that goes by the base of
the last radio of the dorsal and recumbent fin they are to eight flakes of the anal fin. Anal
short, recumbent fin doesn't reach the fin flow. This last fin is cut, scaled in the base.

Color: Yellowish, grizzly in the back and silver in the ventral region. Behind the operculum a
dark narrow fringe that reaches the radios means of the fin flow is born. In juveniles eight to
ten dark vertical bands are visible among that lower from the dorsal border without reaching
the fringe longitudinal.

Ecology: Inhabits slime-sandy bottoms where it looks for food, iliófagous.
Source: Peces de los Ríos Bermejo, Juramento y Cuencas Endorreicas de la Provincia
Salta;Gladys Monasterio de Gonzo; Museo de Ciencias Naturales y Consejo de
Investigación Universidad Nacional de Salta; Octubre 2003.
Nombre común: Virolito.
Identificación: Cuerpo subcilíndrico,
alargado, con los perfiles dorsal y ventral poco
de la aleta dorsal es más de la mitad de la
máxima altura corporal. Pedúnculo caudal
ancho, aproximadamente un tercio de la altura
máxima del cuerpo.
Cabeza pequeña y cónica. Boca en posición
ventral formando una línea recta, en forma de
pala. Únicamente presenta dientes superiores,
ligeramente curvos y aserrados. Origen de la aleta dorsal en el tercio anterior del cuerpo,
equidistante entre el extremo de las aletas pectorales y la base de las aletas pélvicas. El
extremo distal* de las aletas pectorales llega unas siete hileras de escamas antes del inicio
de las aletas pélvicas. Estas se inician por delante de la línea vertical que pasa por la base
del último radio de la aleta dorsal y reclinadas quedan a ocho escamas de la aleta anal.
Aleta anal corta, reclinada no alcanza a la aleta caudal. Esta última aleta es escotada,
escamada en la base.
Color: Amarillento, grisáceo en el dorso y plateado en la región ventral. Detrás del opérculo
nace una franja oscura angosta que alcanza a los radios medios de la aleta caudal. En
ejemplares juveniles son visibles
entre ocho a diez bandas oscuras verticales, que bajan desde el borde dorsal sin alcanzar
a la franja longitudinal.
Dimensiones: Hasta 135 mm.
Distribución geográfica: Cuenca del río Bermejo, cuerpos de agua temporarios en
Hickmann (departamento San Martín).
Tipo ecológico: Frecuentador de los fondos limo-arenosos donde busca su alimento. Son
peces iliófagos.
Source: translated from 100 Peces argentinos; Hernán Laita y Gustavo Aparicio; Editorial
Albatros; 2005; ISBN 950-24-1012-2

In nature there are numerous of examples of species that, without being related,  present a
similar anatomical structure. This phenomenon is known as "convergent” evolution, similar
forms derived from an adaptive pressure in the same sense.
In this sense the Virolito, resembles certain anatomical characteristics with Siluriforms like
the Bagre.
Its slender body is lengthwise marked by a dark band that marks the and furthermore by eight
or nine vertical diffuse bands, in the superior half of the body. Due to its lengthy form the
Virolito has been given its Guarani-Castilian name (piró=stick).
It can be found from the southeast of Brazil to the La Plata river. Although it is not a very
well-known species, it is sometimes used as bait. Their beautiful coloration, together with its
peaceful temperament, makes it an ideal fish to maintain in aquarium.