Morphology Data of Fontitrygon garouaensis
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 Teeth of males with triangular, concave, cuspidate crowns; females with low, rhomboidal, truncated, cuspless crowns (Ref. 26277).

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 more or less normal
Position of mouth sub-terminal/inferior
Type of scales placoid scales
Diagnosis

Diagnosis: A moderately large and thin-bodied freshwater dasyatid; disc flatter than in any other West African dasyatid, its depth only 8.7-11.0% of disc width vs. 11.0% or more in other species; denticles on dorsal surface of disc highly variable, sometimes absent, always restricted to central portion; pearl spine absent or represented by 2-3 low denticles (Ref. 26277). It is most similar to the small marine species Dasyatis margaritella and the larger marine species Dasyatis margarita, both of which have well-developed pearl spines and shorter snouts (Ref. 26277).

Description: Disc oval, strongly flattened and broadly rounded at corners; tip of snout projecting as a small triangular process beyond anterior disc margin (Ref. 31256, 81259, 81625). Mouth slightly arched; upper jaw with 5-7 and lower jaw with 7-9 functional tooth series; a total of 32-40/37-45 rows of jaw teeth; teeth in males with a central cusp, blunt in females; a transverse row of five elongated fleshy mouth papillae (Ref. 26277, 81259, 81625). Nasal curtain posteriorly fringed, eyes and spiracles adjacent (Ref. 81625). Pelvic fins mostly concealed by disc in dorsal view (Ref. 81625). Tail long and thin, whip-like, with a denticulate sting at base, a short dorsal ridge behind the sting, and a ventral fold; tail base oval in cross-section with greatest width at base not as great as interorbital distance; caudal sting markedly lender (Ref. 81259, 81625). Skin armour variable: disc smooth in juveniles, the dermal denticles appearing with growth; the granulation remains restricted to the central disc area, sometimes including a nacreous tubercle, and usually a longitudinal row of 2-4 rounded or heart-shaped tubercles (Ref. 81259).

Colouration: Back of disc and pelvic fins uniformly brownish- to greyish-beige or gray-brown above, without spots or prominent markings, although some specimens have diffuse dark marblings; white below and without dark margins; tail brownish, darker or blackish behind the sting, lighter below (Ref. 26277, 81259, 81625).

Ease of Identification

Meristic characteristics of Fontitrygon garouaensis

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 120 - 131

Fins

Dorsal fin(s)

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

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    
Spines     
Soft-rays   
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Boden, Gert
Modified by Bailly, Nicolas
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cfm script by eagbayani, 17.10.00, php script by rolavides, 13/03/08 ,  last modified by sortiz, 06.27.17