Morphology Data of Mastacembelus sexdecimspinus
Identification keys
Abnormalities
Main Ref. Vreven, E.J., 2003
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 eel-like
Cross section
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth
Type of scales
Diagnosis

Diagnosis: 14+1 to 18+1 (median 16+1) dorsal spines; distance from anterior border of snout to last externally visible dorsal spine relatively short, 37.1-44.2% SL (m=40.9), decreasing with size; as a result origin of soft dorsal fin far anterior to origin of soft anal fin (Ref. 57415, 81678).

Description: 2 pre-opercular spines; 1 pre-orbital spine; origin of 1st dorsal spine always situated before posterior edge of pectoral fin, between (-8.6) and (-1.7)% HL [m = -5.4]; origin of soft dorsal fin far before origin of soft anal fin (Ref. 57415, 81678). Distance from anterior border of snout to last externally visible dorsal spine 37.1-44.2% SL (mean 40.9%), decreasing with size (Ref. 81678). Distance from anterior border of snout to last externally visible anal spine 51.2-56.8% SL (m=54.2), decreasing with size; post-anal length 47.9-51.8% SL (m=50.1), increasing with size, comparable to pre-anal length, 46.4-51.6% SL (m=48.9), decreasing with size; difference between number of soft dorsal fin rays and number of soft anal fin rays (+25)-(+34) (mean +31); 9-12 caudal fin rays; 6-7 predorsal vertebrae; 30-33 abdominal vertebrae; (+9)-(+12) in-between vertebrae; 54-61 caudal vertebrae (Ref. 57415, 81678).

Coloration: preserved specimens: uniformly light brown overall background colour; dorsal midline with a series of large, dark brown, rectangular spots, extending along dorsal, caudal and anal fin bases; dark brown lateral band originating at base of rostral appendage, passing through eye, above pectoral fin and continuing on lateral side of body and tail as a series of large rectangular or more X-like dark brown spots; spots sometimes contacting spots on dorsal midline and/or spots on basal part of unpaired fins; however, a few specimens have more uniformly coloured dark brown sides; lips, ventral surface of head, belly, abdomen and tail light brown, yellowish-white, with some darker parts; belly with large white spots surrounded by a darker brown network; overall background colour of dorsal, caudal and anal fins whitish (Ref. 57415, 81678). Dorsal and anal fin base with a series of large, dark brown, spots partially situated on tail; dorsal fin base light brown diminishing contrast between dark brown spots and background colour of fin; caudal fin with a vertical, dark brown band (Ref. 57415). Dorsal and anal fins with additional dark brown spots of irregular shape occasionally forming a band towards outer margin of fins; nevertheless, outermost part of unpaired fins remains white; pectoral fins whitish of overall background colour with several irregular shaped, dark brown spots forming a kind of network in some specimens; size-related colour pattern changes, especially a general darkening of unpaired fins; in addition, sometimes dark brown spots at base of anal fin contact dark brown band situated towards outer margin of fin resulting in a series of light brown, white spots at base of anal fin (Ref. 57415, 81678). Live specimens: colour pattern considerably variable (Teugels et al., 1992); Roberts&Travers (1986) reported a grey life colour for background or darker coloration on body and fins of some specimens; further, lighter areas on dorsal and anal fins were yellow or sometimes merely pale or colourless and round spots on abdomen were always yellow (Ref. 57415).

Ease of Identification

Meristic characteristics of Mastacembelus sexdecimspinus

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 0
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb
total
Vertebrae
preanal
total 85 - 92

Fins

Dorsal fin(s)

Attributes continuous with caudal fin
Fins number 1
Finlets No. Dorsal   0
Ventral  0
Spines total 15 - 19
Soft-rays total 112 - 132
Adipose fin absent

Caudal fin

Attributes confluent

Anal fin(s)

Fins number 1
Spines total
Soft-rays total 81 - 98

Paired fins

Pectoral Attributes  more or less normal
Spines     
Soft-rays   
Pelvics Attributes  suppressed/absent
Position    absent
Spines     
Soft-rays   
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
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