The Fishes: Pimelodidae

SILURIFORMES - catfish - Page 2

Family: Pimelodidae
This is a large family of catfish whose members generally have an elongate body plan and a naked skin. They possess 3 pairs of barbels, a dorsal fin with a well developed spine and 5 to 7 rays, an adipose fin and usually a forked tail. They tend to inhabit flowing waters and some species undertake extensive upstream spawning migrations. This family varies greatly in size from small fish that inhabit leaf litter banks in forest streams, to giant fish of the main Amazon river channel.

Brachyplatystoma	Leiarius	Phractocephalus	Pimelodus
Pseudoplatystoma	Phreatobius	Calophysus	Paulicea
Pimelodella	Pinirampus	Sorubim	Heptapterus

Brachyplatystoma
This genus holds 6 large catfish species. The head is broad and flat and the maxillary barbels are long, extending to at least the beginning of the tail. Brachyplatystoma filamentosum is the largest catfish in the Amazon, reaching a length in excess of 3 m and a weight of 150 kg. It lives in large river channels.

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A recently caught Brachyplatystoma filamentosum	A recently caught Brachyplatystoma filamentosum

Leiarius
This genus only holds two species. The eyes are placed on the top of the head and the adipose fin is unusually long.

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A recently caught Leiarius marmoratus

Phractocephalus
This genus comprises only the single species Phractocephalus hemioliopterus, which is a stout catfish that can exceed 1 m in length and 80 kg in weight. It is a general predator.

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A recently caught specimen of Phractocephalus hemioliopterus

Pimelodus
This genus holds about 25 species. They are abundant within floodplain lakes where they feed at night.

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A preserved specimen of Pimelodus blochi	A preserved specimen of a Pimelodus species

Pseudoplatystoma
This genus holds three large catfish that have flattened heads and beautiful camouflage patterning. They are general predators. Pseudoplatystoma tigrinum is known as the tiger shovelnose catfish.

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Lateral view of a preserved specimen of Pseudoplatystoma tigrinum	An Amazonian beauty, Pseudoplatystoma tigrinum, held up to my camera by the boat's cook	Recently caught specimen of Pseudoplatystoma tigrinum viewed from above	A recently caught specimen of Pseudoplatystoma sp.

Phreatobius sp.
Identification: This catfish is immediately identified by its blood-red colour and worm-like appearance . The eyes are rudimentary, and the body is covered with skin. After preservation the colour becomes dull brown. There is no other species within the Taruma-Mirim with which it can be confused. This is only the second species allocated to this genus. The first P. cisternarum (Goeldi 1905) has the type locality Ilha de Marajo. The Taruma-Mirim form is clearly different. Buckup(1988) synonomized this genus with Heptapterus. This is clearly inappropiate as the general form is so different
Habitat: Deep within leaf-litter. It probably lives at the inter-face of the ground water and the air. It is possible that it lives under ground within the igapo away from streams. It avoids open water and when placed in an aquaria moves to the water surface.
Abundance: Phreatobius sp is localised in distribution and never abundant. However, we have no idea how large the populations are.
Food: Probably a predator upon small infaunal invertebrates.
References: Buckup (1988). Copeia 3

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Phreatobius catfish found in leaf litter	Phreatobius catfish found in leaf litter	Phreatobius catfish found in leaf litter

Calophysus
This genus holds a single species, Calophysus macropterus. This species can reach 50 cm in length and is a piscivore and general scavenger. It lives in river channels.

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A preserved specimen of Calophysus macropterus

Paulicea
This genus only holds two species. Unlike many other pimelodids the barbels are short. Paulicea lutkeni is a large catfish reaching a length of 1.5 m and 150 kg. Only the young show a spotty colour pattern. It lives in main river channels and is a piscivore.

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Dorsal view of a preserved juvenile specimen of Paulicea lutkeni

Pimelodella
This is a large genus with over 60 species, most of which are small to medium sized fish. They are slender, actively swimming catfish with a long adipose fin. The tail fin is deeply forked. They are abundant within Amazon floodplain lakes.

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Lateral view of a preserved specimen of Pimelodella	Lateral view of a preserved specimen of Pimelodella	Lateral view of a preserved specimen of Pimelodella
Head of Pimelodella viewed from above	Recently caught specimen of Pimelodella viewed from above	A pimelodid, probably Pimelodella sp at the surface of a white water lake during a period of low oxygen

Pinirampus
This genus only holds Pinirampus pirinampu. This is a large catfish up to 60 cm in length which has barbels with a flattened cross-section. It lives in river channels and is a general scavenger.

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A recently caught specimen of Pinirampus pirinampu

Sorubim
This genus holds three species which have a long body and an exceptionally flattened head. Sorubim lima, the duckbeak shovelnose, is abundant in both white water river channels and floodplain lakes. It can reach a length of 50 cm.

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View from above of a preserved specimen of Sorubim lima

Heptapterus sp. (Chasmocranus)
Identification: The only catfish with this general form within the litter-banks, so unmistakable. A revision has placed this genus Chasmocranus within Heptapterus.
Habitat: Within leaf-litter.
Abundance: Common, average density of 4 individuals per square meter with a maximum of 60 recorded.
Food: Predatory on small invertebrates.

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A Chasmocranus species commonly caught in submerged leaf litter	A Chasmocranus species commonly caught in submerged leaf litter	A Chasmocranus species commonly caught in submerged leaf litter