Morphology Data of Hemitrygon longicauda
Identification keys
Abnormalities
Main Ref. Last, P.R., W.T. White, M.R. de Carvalho, B. Séret, M.F.W. Stehmann and G.J.P. Naylor, 2016
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral other (see remarks)
Cross section flattened
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth
Type of scales placoid scales
Diagnosis

This small species is distinguished by the following combination of characters: plain-coloured with disc subcircular to weakly rhombic, denticle patch developing on central disc with age, continuous row of closely spaced thorns extending along mid-line of disc and tail, small mid-shoulder thorns sometimes present and long tail with dorsal fold reduced to low ridge or none at all, width of disc 1.0-1.1 times its length, trunk depressed; pectoral-fin apex broadly rounded; snout broadly triangular, tip extended slightly anterior margins almost straight; very small eyes, length of orbit and spiracle 2-2.3 in snout length; broad interorbital space, more than 3 times orbit length; narrow mouth with 5 oral papillae; weak labial furrows and folds; lower jaw strongly convex; nasal curtain skirt-shaped, short and broad, the margin weakly fringed, nostrils rather oblique; thorns are spear-shaped or lanceleote, in continuous median row, variable in size and becoming larger posteriorly, 3 nearest caudal sting often greatly enlarged; widely-spaced denticles confined to patched between orbits and on central disc of largest individuals; elongated tail is slender and constricted slightly at sting then becoming whip-like, it length 2.3-2.9 times WD, probably 1 sting; ventral fold elongate, low, (base length about equal to distance from snout to 5th gill slit); dorsal fold often a low ridge or absent; triangular pelvic fin (Ref. 114953).

Ease of Identification

Meristic characteristics of Hemitrygon longicauda

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
Soft-rays total
Adipose fin

Caudal fin

Attributes

Anal fin(s)

Fins number
Spines total
Soft-rays total

Paired fins

Pectoral Attributes  
Spines     
Soft-rays   
Pelvics Attributes  
Position    
Spines     
Soft-rays   
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
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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