Synodontis njassae

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

Bibliography

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	ACTINOPTERYGII	SILURIFORMES	MOCHOKIDAE

Scientific Name:

Synodontis njassae

Species Authority:

Keilhack, 1908

Common Name/s:

English

–

Malawi Squeaker

Assessment Information [top]

Red List Category & Criteria:	Least Concern ver 3.1
Year Published:	2006
Assessor/s:	Kazembe, J., Magombo, Z. & Kaunda, E.
Reviewer/s:	Snoeks, J. (Freshwater Fish Red List Authority) & Darwall, W. (Freshwater Biodiversity Assessment Programme)
Justification: Endemic to Lake Malawi and its larger rivers where it is widespread and abundant throughout a great depth and geographic range and has no known threats.

Geographic Range [top]

Range Description:	Endemic to Malawi. Widely spread and abundant throughout the lake. Also occurs in the larger rivers flowing into the lake, such as the Bua.
Countries:	Native: Malawi; Mozambique; Tanzania, United Republic of
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	No quantitative information but it is very abundant in demersal trawl catches and bottom set gillnets.
Population Trend:	Unknown

Habitat and Ecology [top]

Habitat and Ecology:	Mostly found among rocks and it hides in crevices during the daytime. It can also be found off sandy shores down to the limits of dissolved oxygen (as deep as 220 m). It is reported to be more abundant in the northern part of the lake but is common throughout. It migrates up the larger ephemeral rivers to spawn when they are in spate. It is thought to breed in during October to December. During this time most individuals are caught over sandy and muddy bottoms in shallow water. It is not known whether this species breeds in the main lake. It is an omnivorous scavenger, mainly feeds on insects, crustaceans, molluscs, and other invertebrates. Few individuals less than 10 cm are caught from the offshore water. Average size at first maturity is estimated at 11 cm TL and by 14 cm TL. This species shows a distinct upwards, vertical movement that may be dependent upon the phase of the moon. It has been observed that on nights without moonlight this species is distributed equally between the surface and deep-water layers whereas on moonlit nights almost all individuals were caught in the surface waters.
Systems:	Freshwater

Habitat and Ecology:

Mostly found among rocks and it hides in crevices during the daytime. It can also be found off sandy shores down to the limits of dissolved oxygen (as deep as 220 m). It is reported to be more abundant in the northern part of the lake but is common throughout. It migrates up the larger ephemeral rivers to spawn when they are in spate. It is thought to breed in during October to December. During this time most individuals are caught over sandy and muddy bottoms in shallow water. It is not known whether this species breeds in the main lake. It is an omnivorous scavenger, mainly feeds on insects, crustaceans, molluscs, and other invertebrates. Few individuals less than 10 cm are caught from the offshore water. Average size at first maturity is estimated at 11 cm TL and by 14 cm TL. This species shows a distinct upwards, vertical movement that may be dependent upon the phase of the moon. It has been observed that on nights without moonlight this species is distributed equally between the surface and deep-water layers whereas on moonlit nights almost all individuals were caught in the surface waters.

Systems:

Freshwater

Threats [top]

Major Threat(s):	None known.

Major Threat(s):

None known.

Conservation Actions [top]

Conservation Actions:	No information available.

Conservation Actions:

No information available.

Bibliography [top]

	IUCN. 2006. 2006 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 04 May 2006. Jackson, P.B.N. 1961. Check-list of fishes of Nyasaland. Occasional Papers of the National Museums of Southern Rhodesia 3(25B): 535–621 Konings, A. 1990. Konings's Book of Cichlids and All the Other Fishes of Lake Malawi. T.F.H. Publications, Inc., Neptune City New Jersey. Thompson, A.B., Allison, E.H. and Ngatunga, B.P. 1996. Distribution and breeding biology of offshore pelagic cyprinids and catfish in Lake Malawi/Nyasa. Environmental Biology of Fishes 47(1): 27–42 Tweddle, D 1993. River fishes of Lake Malawi catchment area. Part 1: Fishes of intermittent drainages. Nyala 16(2): 55–72. Tweddle, D. 1996. Fish survey of Nkhotakota wildlife reserve. A report to the Japanese International Cooperation Agency on behalf of the Wildlife Society of Malawi. In: JLB Smith Institute of Ichthyology. Investigational report. No. 53. Tweddle, D and Willoughby, N.G. 1977. Further notes on the fishes of Malawi’s game reserves. Nyala 3(2): 4–13.

IUCN. 2006. 2006 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 04 May 2006.

Jackson, P.B.N. 1961. Check-list of fishes of Nyasaland. Occasional Papers of the National Museums of Southern Rhodesia 3(25B): 535–621

Konings, A. 1990. Konings's Book of Cichlids and All the Other Fishes of Lake Malawi. T.F.H. Publications, Inc., Neptune City New Jersey.

Thompson, A.B., Allison, E.H. and Ngatunga, B.P. 1996. Distribution and breeding biology of offshore pelagic cyprinids and catfish in Lake Malawi/Nyasa. Environmental Biology of Fishes 47(1): 27–42

Tweddle, D 1993. River fishes of Lake Malawi catchment area. Part 1: Fishes of intermittent drainages. Nyala 16(2): 55–72.

Tweddle, D. 1996. Fish survey of Nkhotakota wildlife reserve. A report to the Japanese International Cooperation Agency on behalf of the Wildlife Society of Malawi. In: JLB Smith Institute of Ichthyology. Investigational report. No. 53.

Tweddle, D and Willoughby, N.G. 1977. Further notes on the fishes of Malawi’s game reserves. Nyala 3(2): 4–13.

Citation:	Kazembe, J., Magombo, Z. & Kaunda, E. 2006. Synodontis njassae. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 23 May 2012.
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