THE CATFISHES OF VENEZUELA — ^^SCHULTZ 181 



KEY TO THE FAMILIES OF CATFISHES, OR BAGRE, REPORTED FROM VENEZUELA 



la. "Mouth terminal or inferior in position, but lower lip not reverted or folded 

 back to form a disklike mouth. 

 2a. Anterior and posterior nasal openings close together, posterior openings 

 covered with a valve; skin naked, no plates; a pair of maxillary and 2 pairs 

 of mental barbels present; teeth villiform, conical or granular on jaws, pres- 

 ent or absent on vomer and palatines; gill membranes broadly attached 

 to each other and to isthmus with or without a free fold across it; eyes 

 superior in position; pelvics inserted behind base of dorsal fin; adipose 

 fin present, base restricted; branched caudal fin rays usually 13 to 15 



(marine catfishes) Bagreidae (p. 182) 



2b. Nostrils distinctly separated by skin covering head, anterior and posterior 

 nasal openings usually far apart. 

 3a. Skin smooth and naked, without bony plates completely covering sides 

 and no series of plates along the lateral line with backward-projecting 

 spines ; 

 4a. Adipose fin present, long or short; opercle well developed; maxillary 

 barbels sometimes obscured in a groove; pelvics inserted under or a 

 little behind base of dorsal; 14 to 16 branched caudal fin rays. 

 5a. Mental barbels 4, usually arranged in 2 pairs; air bladder well 

 developed. 

 6a. Gill membranes not joined to each other but extending far forward 

 before their attachment to isthmus; eyes superior in position. 

 7a. Teeth villiform, in a band on lower jaw and usually a similar 

 band on premaxillaries; pelvics usually inserted under rear of 

 base of dorsal fin; adipose fin base long or short. 



Pimelodidae (p. 185) 

 76. Numerous teeth in a single row in each jaw, these teeth evenly 

 spaced and incisorlike, rounded distally; pelvics inserted a 

 little behind dorsal base; adipose fin base very long. 



Callophysidae (p. 235) 

 66. Gill opening not extending far forward, gill membranes joined to 

 isthmus or in front of or above pectoral fin; eyes lateral in posi- 

 tion, margins of eyes not free; dorsal rays I, 4 to I, 6; no teeth on 

 palatines; pelvics inserted behind base of dorsal fin; adipose 



fin short Auchenipteridae (p. 236) 



56. Mental barbels absent; teeth villiform on jaws only; gill membranes 

 joined to isthmus, gill opening not extending forward ; eyes lateral, 

 margin not free; air bladder much reduced, enclosed in bony 



processes of cervical vertebrae Ageneiosidae (p. 240) 



46. Adipose fin absent. 



8a. Dorsal fin in middle or anterior part of body; a pair of maxillary 



barbels and 2 pairs of mental barbels; opercle and interopercle 



without spines; gill membranes joined to isthmus, gill opening 



restricted, not extending forward along isthmus; pelvics inserted 



under dorsal or behind it. 



9a. Caudal fin rays usually 1 + 6 to 8+ i, or about 6 to 10 if they are all 



simple rays; anal rays always fewer than 11; teeth villiform; gill 



openings usually a small slit in front of pectorals; head and skin 



with knobs, sometimes with platelets along anal or dorsal fins; 



pectoral spines strongly serrated; opercle vestigial; air bladder well 



developed; body depressed forward, expanded to form head; 



anus near middle of length Bunocephalidae (p. 243) 



