Family Trichomycteridae Pygidiidae 129pencil catfishes or parasitic catfishes

Freshwater; Costa Rica, Panama, and throughout South America.

Body naked and elongate; chin (mental) barbels usually absent, nasal barbel usually present, usually two pairs of maxillary barbels; usually no adipose fin;

opercle usually with spines. Pelvic fins have been lost in at least three lineages— Eremophilus, Glanapteryginae, and Miuroglanis.

The common name "parasitic catfishes" is derived from the habits found in species of two subfamilies. Members of the Vandelliinae are hematophagous and pierce the skin of living fishes or other animals and gorge themselves on blood; some live on blood obtained within the gill cavities of other fishes. In addition, individuals of Vandellia (a candiru) of Brazil are known to enter the urethra of humans with serious consequences for both the fish and the person (see review by de Carvalho, 2003, of a book on the candiru). Members of the Stegophilinae feed on the mucus and scales of other fishes. This family and the Nematogenyidae are probably sister groups (de Pinna, 1998).

Eight subfamilies provisionally recognized, with about 41 genera and 201 species, are recognized as follows (de Pinna, 1998; de Pinna and Wosiacki, 2003; Teugals, 2003).

Subfamily Copionodontinae. Adipose fin well developed; origin of dorsal fin in anterior half of body; maxilla articulating with lower jaw. Two genera, Copionodon (3) and Glaphyropoma (1), with four species from northeastern Brazil (de Pinna and Wosiacki, 2003). This group and the Trichogeninae may be part of a trichotomy with the remaining trichomycterids (de Pinna, 1998).

Subfamily Trichogeninae. Anal fin long, with more than 30 rays. One species, Trichogenes longipinnis, from southeastern Brazil (de Pinna and Wosiacki, 2003).

Subfamily Trichomycterinae. Eight genera, Bullockia (1), Eremophilus (1), Hatcheria (1), Ituglanis (11), Rhizosomichthys (1), Scleronema (3), Silvinichthys (1), and Trichomycterus (about 120), with about 139 species (de Pinna and Wosiacki, 2003; Wosiacki and Garavello, 2004). They occur from near sea level to 4,500 m elevation. Some of the species in the unusually widespread genus Trichomycterus can inhabit torrential streams. one species, T. catamarcensis from the Andes of Argentina, lacks the pelvic fins and girdle. This subfamily is a non-monophyletic assemblage, in need of revision (de Pinna, 1998).

Subfamily Vandelliinae. About four genera, Paracanthopoma (1), Paravandellia (2, synonyms Branchioicaand Pleurophysus), Plectrochilus (3), and Vandellia (3), with about nine species (de Pinna and Wosiacki, 2003; Teugals, 2003).

Subfamily Stegophilinae. About 12 genera (e.g., Acanthopoma, Henonemus, Homodiaetus, Ochmacanthus, Parastegophilus, Pareiodon, Schultzichthys, and Stegophilus) with about 26 species (de Pinna and Wosiacki, 2003; Teugals, 2003).

Subfamily Tridentinae. Anal fin relatively long, more than 15 fin rays. About four genera, Miuroglanis (1), Tridens (1), Tridensimilis (2), and Tridentopsis (3), with about seven species (de Pinna and Wosiacki, 2003; Teugals, 2003).

Subfamily Glanapteryginae. Pectoral fin with three or four rays; principal caudal-fin rays 11 or fewer; pelvic skeleton and fin present or absent within

Glanapteryx anguilla, both absent in the other species; dorsal fin present in only the two species of Listrura; anal fin absent in G. anguilla; hypurals completely fused. They have a transparent body and are sand-dwelling. Four genera, Glanapteryx (2), Listrura (4), Pygidianops (1), and Typhlobelus (2), with about nine species (de Pinna and Wosiacki, 2003; Teugals, 2003).

Subfamily Sarcoglanidinae. Six genera, Ammoglanis, Malacoglanis, Microcambeva, Sarcoglanis, Stauroglanis, and Stenolicmus, all monotypic to date but undescribed species are known (de Pinna and Wosiacki, 2003; Teugals, 2003). Poorly known and specialized minute catfishes known only from a few specimens from the Amazon Basin.

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