Pseudobunocephalus, Friel, 2008

Friel, John P., 2008, Pseudobunocephalus, a new genus of banjo catfish with the description of a new species from the Orinoco River system of Colombia and Venezuela (Siluriformes: Aspredinidae), Neotropical Ichthyology 6 (3), pp. 293-300 : 294-295

Pseudobunocephalus , new genus

Type species. Pseudobunocephalus lundbergi new species by original designation. Gender: masculine.

Additional included species. Further nomenclatural details including junior synonyms for recognized species can be found in Friel (2003).

Pseudobunocephalus amazonicus ( Mees, 1989)

Pseudobunocephalus bifidus ( Eigenmann, 1942)

Pseudobunocephalus iheringii ( Boulenger, 1891)

Pseudobunocephalus quadriradiatus ( Mees, 1989)

Pseudobunocephalus rugosus (Eigenmann & Kennedy, 1903) Diagnosis. A genus of relatively small banjo catfishes (less than 80 mm SL) distinguished from other aspredinids by having the following unique characters: the dentary teeth are restricted to broad tooth patch near symphysis of lower jaw ( Fig. 1 ) (vs. more broadly distributed along the length of the dentary); the metapterygoid lacks a bony connection with the quadrate ( Fig. 1 ); the posterior end of autopalatine is distinctly forked and bears two separate terminal cartilages ( Fig. 2 ); the absence of the fourth pharyngobranchial; the absence of gill rakers on all branchial arches; and the lack of bifid hemal spines on vertebrae that articulate with anal-fin pterygiophores.

Other characters not unique to this genus, but still useful for distinguishing it from other aspredinid genera include: the anterior limits of upper and lower jaws are approximately equal (also in Acanthobunocephalus ); the lateral line is truncated at approximately the level of the dorsal-fin origin (also in Acanthobunocephalus ); the dorsal- and ventral-most principal caudal rays much shorter in length than other principal caudal rays (also in Acanthobunocephalus ); the dorsal- and anal-fin membranes are not adnate with body (also in Acanthobunocephalus ); the interhyal is absent (also in Hoplomyzon ); and the abdominal and precaudal centra lack bony horizontal lamina (also in Dupouyichthys , Ernstichthys , Hoplomyzon and Micromyzon ).

Etymology. The generic name is a combination of the Greek word pseudes, meaning false or deceptive, plus the aspredinid genus Bunocephalus . It alludes to the fact that members of this new genus have previously been mistaken for juveniles of various species of Bunocephalus .

Key to species of Pseudobunocephalus .

1a. Dorsal surface of skull ornamented with numerous bony knobs of equal size; epiphyseal bar present between frontals; infraorbital canal exits from sphenotic ( Fig. 3 ), bears up to four pores, and extends anteriorly beyond eye (Orinoco basin) .................................................. P. lundbergi

1b. Dorsal surface of skull relatively smooth or ornamented with longitudinal bony ridges bearing a few bony knobs; epiphyseal bar between frontals absent, and area between eyes concave; infraorbital canal exits from frontal, bears 1 or 2 pores, and does not extend anteriorly beyond eye .... 2

2a. Posterolateral mental barbels simple, without any accessory lobes ............................................................................... 3

2b. Posterolateral mental barbels with one or more fleshy lobes proximally along the posterior margin ................................ 5

3a. Overall pigmentation relatively uniform, without strong contrast between dark and light areas (Paraguay-Paraná basin) ..................................................................... P. rugosus

3b. Body pigmentation with strong contrast between dark and light areas....................................................................... 4

4a. Pectoral fin with 5 soft rays (Amazon basin) .... P.amazonicus

4b. Pectoral fin with 4 soft rays (Amazon basin) ...................... ..................................................................... P. quadriradiatus

5a. Dorsal fin with flexible spine and 4 soft rays; pectoral fin with 5 soft rays (Amazon basin) ............................ P. bifidus

5b. Dorsal fin with flexible spine and 3 soft rays; pectoral fin with 4 soft rays (Paraguay-Paraná, Uruguay and laguna dos Patos basins) .................................................... P. iheringii

Figures

Fig. 1. Lateral view (anterior to the right) of the suspensorium, hyoid arch and lower jaw of Pseudobunocephalus lundbergi, ANSP 172505, paratype. Scale bar equals 1 mm.

Fig. 2. Medial view (anterior to the left) of the autopalatine of Pseudobunocephalus lundbergi, ANSP 172505, paratype. Note forked posterior margin with two separate terminal cartilages (stippled with open circles). Scale bar equals 1 mm.

Fig. 3. Dorsal view of the neurocranium and Weberian complex of Pseudobunocephalus lundbergi, ANSP 172505. Arrow indicates the exit of the infraorbital canal from the sphenotic. Scale bar equals 1 mm.