Mastacembelus marchei Sauvage, 1879
Mastacembelus marchei
photo by RMCA

Family:  Mastacembelidae (Spiny eels)
Max. size:  32.6 cm SL (male/unsexed)
Environment:  benthopelagic; freshwater
Distribution:  Africa: Kribi River basin (Cameroon) to the Kouilou-Niari (Republic of Congo); also known from the lower Congo River and Pool Malebo (Democratic Republic of the Congo), forming the south-eastern distribution limit, and from the Dja River (middle Congo River basin), forming its north-eastern distribution border (Ref. 81678).
Diagnosis:  Dorsal spines (total): 23-28; Dorsal soft rays (total): 60-75; Anal spines: 2-3; Anal soft rays: 61-83; Vertebrae: 71-85. 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).
Biology:  Maximum reported total length 388 mm (Ref. 81678).
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless


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