Morphology Data of Mastacembelus marchei
Identification keys
Abnormalities
Main Ref. Vreven, E.J., 2008
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: 22+1 - 27+1 (median 24+1) dorsal spines; postorbital length relatively short, 53.3-62.6% HL (mean 58.2%); pectoral fin relatively long, 24.7-38.1% HL (mean 30.5%); distance from anterior border of snout to last externally visible dorsal spine 53.9-62.2% SL (mean 57.1%), decreasing with size; origin of soft dorsal fin at about same level as origin of soft anal fin; lower jaw length relatively short, 14.4-23.1% HL (mean 18.3%), increasing with size; origin of first dorsal spine situated before, below, or just posterior to posterior edge of pectoral fin, (-27.9)-2.0% HL [mean (-12.7%)]; distance from gill opening to dorsal pectoral fin base 4.3-9.6% HL (mean 6.9%) (Ref. 81678).

Description: generally 2, exceptionally 3, preopercular spines; 1 strong preorbital spine; postanal length 43.9-50.8% SL (mean 47.0%), increasing with size, shorter than preanal length, 48.2-55.3% SL (mean 51.7%), decreasing with size, in small- and medium-sized specimens and gradually becoming of equal length with increasing size; distance from anterior border of snout to last externally visible anal spine 54.9-63.3% SL (mean 58.1%); distance from anterior border of snout to last externally visible dorsal spine generally slightly shorter than distance from anterior border of snout to last externally visible anal spine; 76 mean soft rays in dorsal fin, 72 in anal fin; difference between number of soft dorsal fin rays and number of soft anal fin rays (-5)-(+12) (mean +4); 8-14 caudal fin rays (mean 11); 4-6 predorsal vertebrae (mean 5); 26-33 abdominal vertebrae (mean 30); (0)-(+1) in-between vertebrae (mean 0); 42-53 caudal vertebrae (mean 48), 78 mean total vertebrae (Ref. 81678).

Coloration: In preservation: overall colour uniformly light brown; dorsal mid-line with a series of squared, dark brown spots extending along dorsal, caudal and anal fin bases; spots on dorsal fin base not so well contrasted owing to dark brown colour of fin base; dark brown lateral band originating at base of rostral appendage and continuing posteriorly on lateral sides of body and tail as a series of squared or more X-shaped, dark brown blotches; small specimens typically with a leopard patterning, gradually disappearing with increasing size; large specimens with a more uniform colour pattern; ventral side of head, belly and abdomen yellowish white; general colour of dorsal, caudal and anal fins whitish; dorsal, caudal and anal fins with a series of small dark brown spots, sometimes forming a continuous band, situated close to outer margin of fins; nevertheless, margin of unpaired fins whitish; eventually, dark brown spots at anal fin base and dark brown band contacting each other resulting in a series of large, round, whitish spots at anal fin base; pectoral fins whitish with several, small, dark brown spots; unpaired fins darker in large specimens (Ref. 81678). Life colouration of Ntem River basin specimens (Cameroon): characterized by a vivid orange overall colour of unpaired fins (whitish preserved parts)(Ref. 81678). Life colouration of Ogowe River basin specimens (Gabon): characterized by vivid more yellowish overall colour of unpaired fins (Ref. 81678).

Ease of Identification

Meristic characteristics of Mastacembelus marchei

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 71 - 85

Fins

Dorsal fin(s)

Attributes continuous with caudal fin
Fins number 1
Finlets No. Dorsal   0
Ventral  0
Spines total 23 - 28
Soft-rays total 60 - 75
Adipose fin absent

Caudal fin

Attributes confluent

Anal fin(s)

Fins number 1
Spines total 2 - 3
Soft-rays total 61 - 83

Paired fins

Pectoral Attributes  
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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