Morphology Data of Fontitrygon ukpam
Identification keys
Abnormalities
Main Ref. Compagno, L.J.V. and T.R. Roberts, 1984
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs claspers (m)
Different appearance
Different colors
Remarks

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral other
Cross section flattened
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth sub-terminal/inferior
Type of scales placoid scales
Diagnosis

Diagnosis: Dasyatis ukpam is a very large and thick-bodied freshwater dasyatid (Ref. 26277). Entire dorsal surface of disc covered with stout-spined denticles, smooth in newborn (Ref. 26277). Sting greatly reduced in size or absent (Ref. 26277).

Description: A very large stingray with a thick and almost circular disc, with broadly rounded corners and about as wide as long, and a scarcely distinct snout (Ref. 81259, 81625). Disc oval, very thick; medial lobe narrow-based and short, its anterior margin broadly convex; disc depth 13.3-15.7% of disc width; dorsal surface of disc very rough, entirely covered with rounded or heart-shaped stout-spined dermal denticles, which are particularly concentrated on the centre of the disc (Ref. 26277, 81259). One or two pearly tubercles sometimes present, but especially an irregular mid-dorsal row of large, conical pointed thorny tubercles and a few similar ones scattered over the pectoralfins (Ref. 81259). Mouth slightly arched, with 38-46/38-48 rows of teeth set in a pavement pattern, and 4 or 5 elongated finger-like mouth papillae (Ref. 7397, 81259, 81625). Nasal curtain fringed along its posterior margin, eyes relatively small and slightly elevated, spiracles large (Ref. 81625). Pelvic fins almost entirely covered by disc dorsally (Ref. 81625). Total pectoral radials 142-149 (Ref. 26277). Tail long and very spiny, rather stout and circular in cross-section at base; sting reduced or absent, dorsal ridge absent and ventral fold reduced (Ref. 81259, 81625).

Colouration: Disc and pelvic fins dark brown or gray-brown above, without spots or prominent markings; belly white except for broad dark margins; tail blackish except for underside of its base (Ref. 26277, 81259, 81625).

Ease of Identification

Meristic characteristics of Fontitrygon ukpam

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) 5present
Gill rakers
on lower limb
on upper limb
total
Vertebrae
preanal
total 108 - 122

Fins

Dorsal fin(s)

Attributes
Fins number
Finlets No. Dorsal   
Ventral  
Spines total
Soft-rays total
Adipose fin

Caudal fin

Attributes

Anal fin(s)

Fins number
Spines total
Soft-rays total

Paired fins

Pectoral Attributes  transformed to 'aerofoils'
Spines     
Soft-rays   
Pelvics Attributes  more or less normal
Position    abdominal
Spines     
Soft-rays   
Back to Search
Comments & Corrections
cfm script by eagbayani, 17.10.00, php script by rolavides, 13/03/08 ,  last modified by sortiz, 06.27.17