Marcusenius sanagaensis Boden, Teugels & Hopkins, 1997

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Diagnostic Description:

From Boden et al. (1997). Diagnosis. Dorsal-fin origin behind or in line with the anal-fin origin. The posterior base of the dorsal fin ends before the posterior base of the anal fin. Dorsalfin margin is pointed and concave, its height shorter than its length. Lateral-line scales number 49-56; four, rarely three, scale rows on dark coloured transverse band. Scales between dorsal- and anal-fin origins number 22-28. Dorsal-fin rays are 24-28 while anal-fin rays are 29-33. Description. Mouth terminal. Teeth bicuspid, five in upper jaw, six in lower jaw. Sub-mental swelling very rounded and projecting slightly forwards, its posterior margin located under anterior border of the eye. Snout rounded and blunt. Anterior nostril midway between tip of snout and eye; posterior nostril at about 0·25 the distance from eye to anterior end of the snout. Eye diameter 4 7-7 5% of snout length. Preanal distance shorter or about the same length as predorsal distance. Dorsal fin shorter than anal fin. Height of both fins smaller than their lengths. Pectoral fin twice as long as pelvic fin, reaching halfway to the pelvic fin. Distance between pectoral- and pelvic-fin bases a little >0·33 of the distance between pectoral-fin base and anal-fin origin. Posterior end of pelvic fin at about 0·4 of the distance between pelvic-fin base and anal-fin origin. Number of dorsal-fin rays (24-28) less than anal-fin rays (29-33). Lateral-line scales numbers 49-56. Dark transverse band between dorsal- and anal-fin origin covered by 4, rarely 3, lateral-line scale rows. Scales between the dorsal- and anal-fin origins numbers 22-28. There are 43-45 vertebrae. The electric organ electrocytes with non-penetrating stalks which are innervated on the posterior side (type NPp). Coloration in life. Colour of the body grey, with head a little darker. Two dark vertical bands between the dorsal fin and the anal fin, the first situated between the anterior ends of the two fins, the second between the posterior ends. The latter is not always clearly visible.

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorSullivan, John P., Hopkins, C.D., Boden, G., Teugels, G., Africhthy
Sourcehttp://mormyrids.lifedesks.org/pages/2132

Habitat and Ecology:

Habitat and Ecology

Marcusenius sanagaensis is a demersal species. It is found in raceways with sandy bottoms of larger rivers (50-200 m), in the tree savannah and the more or less degraded semi-tropical forest.

Systems

  • Freshwater
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/182215

Environment:

demersal; freshwater

Licensehttp://creativecommons.org/licenses/by-nc/3.0/
Rights holder/AuthorArmi G. Torres, FishBase
Sourcehttp://www.fishbase.org/summary/SpeciesSummary.php?id=50320

Electric Organ Discharge:

Unknown.

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorSullivan, John P., Sullivan, John P., Africhthy
Sourcehttp://mormyrids.lifedesks.org/pages/2132

IUCN Red List Assessment:
Red List Category

VU
Vulnerable

Red List Criteria

B1ab(iii)+2ab(iii)

Version

3.1

Year Assessed

2010

Assessor/s

Moelants, T.

Reviewer/s

Brummett, R., Mbe Tawe, A.N., Dening Touokong, C., Reid, G.M., Snoeks, J. Staissny, M., Moelants, T., Mamonekene, V., Ndodet, B., Ifuta, S.N.B., Chilala, A., Monsembula, R., Ibala Zamba, A., Opoye Itoua, O., Pouomogne, V., Darwall, W. & Smith, K.

Contributor/s

Justification

The most western part of the species distribution is declining in quality due to urbanisation and to the very intensive agricultural farming, leading to pollution from pesticides and sedimentation. It also is threatened by sedimentation from slash and burn agriculture and commercial logging in the Mbam River. Both the EOO and AOO qualify for the Vulnerable status and the species is known from fewer than 10 localities.
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/182215

Population:

Population

No information available.

Population Trend

Unknown
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/182215

Biology:

Found in raceways with sandy bottoms of larger rivers (50-200 m), in the tree savannah and the more or less degraded semi-tropical forest.

Licensehttp://creativecommons.org/licenses/by-nc/3.0/
Rights holder/AuthorArmi G. Torres, FishBase
Sourcehttp://www.fishbase.org/summary/SpeciesSummary.php?id=50320

Threats:

Major Threats

The most western part of the species distribution is declining in quality due to urbanisation and to the very intensive agricultural farming, leading to pollution from pesticides and sedimentation. It also is threatened by sedimentation from slash and burn agriculture and commercial logging in the Mbam River.
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/182215

General Description:

Marcusenius sanagaensis has eight circumpeduncular scales, 49-56 lateral line scales (median 52), 24-28 dorsal rays (median 25), 29-33 anal fin rays (median 31), and a dark vertical band between dorsal and anal fins covered by 3-4 scales. Depth of body 26.2-28.9% SL; length of head 22-24% SL, head 1.11 times as long as deep. Snout blunt, 28% HL. Mouth terminal. Teeth bicuspid, five in upper jaw, six in lower. Fleshy submental appendage, round and forward-projecting. Eye small, 18% HL. Dorsal fin length, 22-24.5% SL with 24-28 rays; anal fin length 26-29.2% SL, with 29-33 rays. Dorsal originates slightly posterior to origin of anal, vertically aligned with 3rd-5th anal ray. Pre-anal distance is 93.7% of pre-dorsal distance. Caudal peduncle length 17.6% SL; 2.9 times as long as high. Caudal fin small with obtusely pointed lobes; 49-56 scales in the lateral line, eight circumpeduncular scales.

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorSullivan, John P., Hopkins, Carl D., Africhthy
Sourcehttp://mormyrids.lifedesks.org/pages/2132

Vulnerable (VU) (B1ab(iii)+2ab(iii))

Licensehttp://creativecommons.org/licenses/by-nc/3.0/
Rights holder/AuthorArmi G. Torres, FishBase
Sourcehttp://www.fishbase.org/summary/SpeciesSummary.php?id=50320
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith