Siluriformes

Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., López-Delgado, Edwin O., García-Melo, Jorge E. & Villa-Navarro, Francisco A., 2020, Fishes from the Río Alvarado drainage, Upper Río Magdalena Basin, Colombia, Check List 16 (5), pp. 1181-1198 : 1194

Siluriformes

1 Body naked................................................................2

1′ Body covered with plates.................... Loricariidae : 6

2 Mouth ventral; oral disk present .... Astroblepidae : 10

2′ Mouth terminal or subterminal; oral disk absent ..... 3

3 Adipose fin present....................................................4

3′ Adipose fin absent.................... Trichomycteridae : 12

4 Dendritic pattern of lateral line tubes in skin of snout, cheek and nape; posterior supraoccipital process con- tacting nuchal plate .................................................. 5

4′ Simple pattern of lateral line tubes in skin of snout, cheek and nape; posterior supraoccipital process not contacting nuchal plate ........................ Heptapteridae (except Pimelodella floridablancaensis ): 14

5 Dark lateral stripe along body; dorsal surface of head smooth ................................................. Heptapteridae : Pimelodella floridablancaensis ( Fig. 3B)

5′ Dark lateral stripe along body absent; dorsal surface of head rough..... Pimelodidae : Pimelodus yuma ( Fig. 3E)

6 Caudal fin with 12 or more rays; adipose fin present ................................................................................... 7

6′ Caudal fin with 12 rays; adipose fin absent ................ ......................... Sturisomatichthys leigthoni ( Fig. 4A)

7 Abdomen naked; teeth villiform...............................8 7′ Abdomen with plates; teeth spoon-shaped .................

.............. Hypostomus (Cochliodon) hondae ( Fig. 3K)

8 Anterior region of snout naked; whisker-like odon- todes on cheek absent................................................ 9

8′ Anterior region of snout covered with plates; whiskerlike odontodes on cheek .............................................. ............................... Lasiancistrus caucanus ( Fig. 3L)

9 Head and body gray, usually with small dark spots; caudal fin with undulated dark stripe at distal mar- gin.................................. Chaetostoma milesi ( Fig. 3I)

9′ Head and body dark brown, sometimes with light spots; caudal fin without undulated dark stripe at dis- tal margin ................ Chaetostoma thomsoni ( Fig. 3J)

10 Adipose fin long and deep, with short spine embedded

in posterior region; first pectoral-fin ray and first dor- sal-fin ray prolonged as filaments .............................. ................................... Astroblepus grixalvii ( Fig. 4B)

10′ Adipose fin short and low, with visible spine covered with odontodes; first pectoral-fin ray and first dorsalfin ray not prolonged as long filaments ................... 11

11 Premaxillary teeth bicuspid; body light brown with black scattered spots and blotches, sometimes with small yellow blotch on adipose-spine base................. .................................. Astroblepus homodon ( Fig. 4C)

11′ Premaxillary teeth incisiform; body usually dark, with variable light blotch on middle of caudal peduncle, sometimes with light blotch on posterior region of dorsal-fin base .................... Astroblepus sp. ( Fig. 4D)

12 Head squared in dorsal view, dark lateral band well defined on body........................................................... .................... Trichomycterus transandianus ( Fig. 3G)

12′ Head triangular in dorsal view, dark lateral band absent....................................................................... 13

13 Body with a series of dark lateral spots, usually larger than eye; premaxilla with 27 teeth; dentary with 30 teeth ................... Trichomycterus banneaui ( Fig. 3F)

13′ Body with dark spots, usually smaller than eye; pre- maxilla with 37 teeth; dentary with 37 teeth .............. ......................... Trichomycterus mogotensis ( Fig. 3H)

14 Maxillary barbel not reaching pelvic-fin insertion; adipose fin short (<30% SL), adipose-fin origin equi- distant between dorsal fin and caudal fin; body with conspicuous transverse pale bands ......................... 15

14′ Maxillary barbel reaching pelvic-fin insertion; adi- pose fin long (>39% SL), adipose-fin origin closer to dorsal fin than the caudal fin; body variably pig- mented, sometimes dark or light brown, often with a dark lateral stripe along lateral line ............................ .............................. Rhamdia guatemalensis ( Fig. 3C)

15 Adipose fin triangular; caudal-fin lobes pointed; body with conspicuous pale transverse bands ..................... ............................ Cetopsorhamdia molinae ( Fig. 3A)

15′ Adipose fin rounded; caudal-fin lobes rounded; body with conspicuous pale band behind head and in front of dorsal fin ...... Heptapteridae undescribed ( Fig. 3D)