Morphology Data of Microsynodontis nasutus
Identification keys
Main Ref. Ng, H.H., 2004
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus; females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla (Ref. 52369).

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral fusiform / normal
Cross section
Dorsal head profile
Type of eyes more or less normal
Type of mouth/snout
Position of mouth sub-terminal/inferior

Body compressed (Ref. 52369). Predorsal profile gently convex; postdorsal body sloping gently ventrally (Ref. 52369). Head depressed and broad, broadly rounded when viewed laterally and with rounded snout margin when viewed from above (Ref. 52369). Eye ovoid, horizontal axis longest (Ref. 52369). Distinguished from other Microsynodontis species by having a longer snout, 50.0-53.3% of head length (Ref. 52369). %Mouth inferior and crescent-shaped; lips plicate (Ref. 52369). Barbels in three pairs; maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray; inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3-5 long, thin branches on posterior half; outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3-5 long, thin branches (Ref. 52369). Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine (Ref. 52369). Dorsal fin located at anterior third of body, with convex margin; dorsal-fin spine long, stout and slightly curved, smooth on both anterior and posterior margins (Ref. 52369). Adipose fin moderately long; margin slightly convex for entire length and posterior end deeply incised (Ref. 52369). Caudal fin rounded, with i,5-6,5-6,i principal rays (Ref. 52369). Anal-fin base located ventral to posterior half of adipose fin, with iv-v,6 rays and convex margin (Ref. 52369). Pelvic-fin origin at vertical ventral to posterior end of dorsal-fin base, with slightly convex margin (Ref. 52369). Pectoral-fin spine slightly curved and stout; anterior spine margin with 16-22 small serrations along entire length of spine, serrations antrorse on distal two thirds and anteriorly directed on proximal third; posterior spine margin with 7-9 strong serrations along entire length (Ref. 52369). Lateral line complete and midlateral (Ref. 52369). Dorsal and lateral surfaces of head and body medium brown, fading to cream or light grayish brown on ventral third of body, belly, and ventral surface of head in preserved specimens (Ref. 52369). Snout with a series of cream spots delineating anterior and posterior nares; cheek region with one or two cream spots immediately ventral to orbit; cream band encircling nape at supraoccipital (Ref. 52369). Dorsal third of body with series of four cream vertical bar-shaped marks extending beyond lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin (Ref. 52369). Ventral third of flanks with a longitudinal series of five to seven cream spots or vertical bar-shaped marks (Ref. 52369). Dorsal, pectoral, pelvic and anal fins hyaline and sometimes with one or two rows of faint spots forming longitudinal brown rows; caudal fin with similar series of elongate marks forming two to three irregular columns (Ref. 52369).

Ease of Identification

Meristic characteristics of Microsynodontis nasutus

Lateral Lines 1 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
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb
total 36 - 36


Dorsal fin(s)

Fins number 1
Finlets No. Dorsal   
Spines total 2 - 2
Soft-rays total 7 - 7
Adipose fin present

Caudal fin

Attributes more or less truncate; more or less normal

Anal fin(s)

Fins number 1
Spines total 0 - 0
Soft-rays total 10 - 11

Paired fins

Pectoral Attributes  1st ray hardened with locking structure
Spines     1
Soft-rays   6 - 6
Pelvics Attributes  more or less normal
Position    abdominal  behind origin of D1
Spines     0
Soft-rays   7 - 7
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Boden, Gert
Modified by Boden, Gert
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