Spotted Sand Catlet

This taxon is one of a number of demersal species in the Kunene River system. Demersal river fish are found at the river bottom, feeding on benthos and zooplankton The Kunene River rises in the central highlands of Angola, and thence flows southward to form a major element of the border between Namibia and Angola before the final discharge is to the Atlantic Ocean in the vicinity of the Angola-Benguela Front. The geometry of the Kunene riparian zone is distinctly narrow, with rugged arid landscapes persisting on both sides of the river over long distances, and a virtual lack of any extensive floodplains. There is a relatively high rate of endemism of aquatic biota in the Kunene. Proposed expansion of dams on the Kunene poses a threat to biodiversity in the river, especially regarding proposals at Epupa Falls. However, a greater threat to the Kunene is a plan by Angola to greatly expand withdrawal of water from the river to expand irrigated agriculture by 600,000 hectares; not only will this action significantly diminish downriver flow rates, but also add considerable nitrate, herbicide and pesticide substances to the river. The catchment area of the Kunene Basin is approximately 106,560 square kilometres (41,143 square miles) in area, of which 14 100 km² (13%) lies within Namibian territory. Its mean annual discharge is 174 cubic meters per second (6145 cubic feet per second) at its mouth on the Atlantic. Water quality of the Kunene River is relatively high, since the human population density and agricultural intensity is relatively low, including a conspicuous absence of overgrazing. However, bacteria and other microbial pathogens pose a material threat to Kunene water quality, due to the fact that only a small fraction of the domestic wastewater in Angola is treated; Regarding freshwater bivalves, the central reaches of the Kunene manifest particularly high endemism, similar to parts of the Okavango, Chobe, Upper Zambezi and Etosha Pan basins. The bivalve Etheria elliptica, which also occurs in the Upper Zambezi, is a freshwater mussel in the family Etheriidae, known from a limited extent of the central Kunene River in Angola. It is threatened by proposed dam construction on the Kunene. There are two endemic denmersal fish in the Kunene: the 26 centimeter (cm) long demersal Kunene happy (Sargochromis coulteri) and the demersal fish Hippopotamyrus longilateralis.

Diagnosis: This species differs from Zaireichthys lacustris and Z. maravensis in possessing a premaxillary tooth patch that is less than 40% of the mouth width; it has shorter barbels than Z. wamiensis, maxillary barbel 0.9-1.3 in head length vs. 0.7-0.9; and it is distinguished from Z. compactus by higher number of branched pectoral-fin rays, 7 vs. 6 (Ref. 86935).Description: Lateral line moderate, ending over middle or anterior part of anal fin base (Ref. 86935). Head broad and depressed; snout blunt; eye moderate; mouth narrow; barbels relatively short (Ref. 86935). Dorsal fin II,5-6; caudal fin slightly emarginate, with the lower lobe a little longer than the upper, the upper and lower lobes each with 7 or 8 branched rays; anal fin with 11-13 rays, the first 3-4 simple; pectoral fins with 7 branched rays (Ref. 86935). Premaxillary tooth patch narrow, less than 40% of mouth width, sub-rectangular; humeral process of cleithrum extending to between level of end of supraoccipital process and base of dorsal fin; branchiostegal rays 6-7 (Ref. 86935).Colouration: Preserved: generally yellowish brown with a series of about nine faint dark blotches along centre of flank and traces of additional series above and below (Ref. 86935).

Dorsal spines (total): 2; Dorsal soft rays (total): 5 - 6; Analspines: 0; Analsoft rays: 11 - 13; Vertebrae: 35 - 38

Frequency of occurrence in Caprivi: occasionally on rocky streams (Ref. 037065). Inhabits fairly shallow water (Ref. 13337). Occurs over sand, usually buried with just the eyes protruding. Feeds on minute organisms.

Inhabits fairly shallow water (Ref. 13337). Occurs over sand, usually buried with just the eyes protruding. Feeds on minute organisms. Eggs few (12-16) and large (3-5 mm diameter) suggesting possible parental care (Ref. 7248).

fisheries: of potential interest; aquarium: potential

Zaireichthys rotundiceps, the Spotted sand catlet, is a species of loach catfish that occurs in the countries of Botswana, Kenya, Malawi, Mozambique, Namibia, Tanzania, Zambia and Zimbabwe with uncertain records from Burundi and the Democratic Republic of the Congo. This species may actually consist of several species. It reaches a length of 3.8 cm. The colouration of Z. rotundiceps is highly variable, from abundant dark spots in several rows to a light pale spotting pattern; marks are often present on the head and fins as well as the body. The humeral process of the pectoral girdle is moderately long with poorly developed or fine denticulations. The caudal fin shape is variable, from slightly forked through, emarginate, truncate, or even slightly rounded, but not deeply forked. The dorsal and pectoral fins have strong and stout spines. It inhabits fairly shallow water where it occur over sand, usually buried with just the eyes protruding. Its eggs are few (12–16) and large (3–5 millimetres diameter), which suggests that the parents may care for the eggs and young.