Morphology Data of Brachyhypopomus gauderio
Identification keys
Abnormalities
Main Ref. Giora, J. and L.R. Malabarba, 2009
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks The caudal filament of dominant mature males is laterally compressed, especially on its distal portion, differing from that of females, juveniles and non-dominant males, which is usually cylindrical (J. Giora & C. Fialho, not yet published).. However, there is no sexual dimorphism in the caudal filament length of B. gauderio during any of its maturation stages.

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral elongated
Cross section compressed
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth
Type of scales
Diagnosis

Head conical, nearly triangular in lateral view,

snout short and blunt, eyes small, mouth terminal with upper jaw length equal to lower jaw, no teeth in both jaws. Body laterally compressed. Dorsal profile convex from snout to caudal filament, most notably at anterior half of body. Ventral profile convex from lower jaw to anterior anal-fin base; nearly straight from that point to caudal filament. Highest body depth located at anal-fin origin. Body depth increasing from head to anal-fin origin, remaining nearly same depth to close to 40th anal-fin ray, sharply decreasing from that point to caudal filament. Caudal filament moderately short in all specimens; caudal filament slender and nearly cylindrical in females, juveniles and males in non-reproductive period; caudal filament vertically broadened and laterally compressed in sexually mature males. Cycloid scales covering body, except head and fins. Scales smaller on anterior portion of body; five to seven series of large scales along mid-lateral portion of body, reducing to two or three series posteriorly. Mid-lateral scales nearly twice larger than dorso-lateral and dorsal scales and four times larger in diameter than anterior ones; smallest scales covering region of anal-fin pterygiophores. First anterior perforated scale of lateral line above pectoral-fin origin; lateral line irregular, not extending to caudal filament. Branchial aperture small and slightly anterior to pectoral-fin origin. Pectoral fins rounded and with perpendicular insertion; pectoral-fin rays i–ii + 13–15 (15–17 total pectoral-fin rays, n=38, mode=16). Anal-fin relatively long with vi–x + 173–206 rays (180–216 total anal-fin rays, n=38, mode=198). Anal-fin origin located at same line of posterior edge of pectoral fin. Precaudal vertebrae 20–21 (18–19 anterior, 1–2 transitional; n=5). General body color varying from light brown to yellow. Head darker than rest of body. Dorsal surface with chocolate-brown stains that are connected forming reticulated drawing contrasting with yellow background. Variable number of brown stripes running from dorsal stains to base of anal fin, roughly defined in middle of body and occurring from head to tip of caudal filament. Anal and pectoral fins speckled with dark brown pigment, with hyaline inter-radial membranes. (Ref. 80844).

Ease of Identification

Meristic characteristics of Brachyhypopomus gauderio

Lateral Lines Interrupted: No
Scales on lateral line
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Barbels
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb
total
Vertebrae
preanal
total

Fins

Dorsal fin(s)

Attributes
Fins number
Finlets No. Dorsal   
Ventral  
Spines total 1 - 2
Soft-rays total 13 - 15
Adipose fin

Caudal fin

Attributes

Anal fin(s)

Fins number
Spines total 6 - 10
Soft-rays total 173 - 206

Paired fins

Pectoral Attributes  
Spines     
Soft-rays   
Pelvics Attributes  
Position    
Spines     
Soft-rays   
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