Dagaa
Fish · Last reviewed 2026-08-11
A small pelagic cyprinid endemic to the Lake Victoria basin, and the prey species that the lake's Nile perch fishery came to depend on.
A supporting record, not a fishing profile
This page is here so FishingHQ can describe a biological relationship accurately — usually because a fish covered elsewhere on the site feeds on this. It covers what it is, where it lives and the evidence behind that relationship, and deliberately nothing about methods, bait or tackle. Its presence here is not a statement that anybody fishes for it.
Dagaa is a small, silver, open-water cyprinid endemic to Lake Victoria and its associated waters, known as omena in Kenya, mukene in Uganda and dagaa in Tanzania.
Its significance is a consequence of one of the most studied ecological upheavals of the twentieth century. The introduction of Nile perch to Lake Victoria, together with eutrophication and other pressures, was followed by the collapse of a great many of the lake's endemic haplochromine cichlids. As those declined, dagaa — along with a freshwater prawn — became the dominant prey of Nile perch, and the largest fishery in the lake by weight became the dagaa fishery itself.
The species is now central to the food security of the lake basin, dried and sold across a very large region, and its stock status is a matter of considerable importance well beyond angling.
It is included in this catalogue because the Nile perch diet cannot honestly be described without it, and because the alternative — pointing an edge at some other small fish — is exactly what the graph-precision rule forbids.
Identification
FishingHQ holds no photograph of this species whose identity and licensing it can vouch for, so it is not showing one. Misidentified fish photographs teach identification wrongly, and a picture with an unchecked caption would be worse than none. The identification points below are what to look at instead.
- Scientific name
- Rastrineobola argentea
- Family
- Leuciscidae
- Water
- Freshwater
- Conservation status
- Least Concern
- Regions
- East & Southern Africa
- Very small, slender, silvery fish with large eyes relative to head size.
- Translucent body with a distinct silver lateral stripe running the length of the flank.
- Slightly upturned mouth, adapted to feeding in the water column.
- Single soft dorsal fin set behind the midpoint of the body, with no spines.
Size
- Typical
- 4–7 cm
- Large
- up to about 9 cm
Lifecycle and reproduction
Extremely short-lived, maturing within months and rarely exceeding a year or two. That turnover is what allows it to sustain both a very large fishery and heavy predation.
Spawns throughout the year with seasonal peaks, in open water and inshore, producing large numbers of small eggs. Continuous recruitment is the basis of its resilience.
Feeding and senses
Feeds on zooplankton — copepods and cladocerans — and on insect larvae and pupae, principally at night in open water where it undertakes vertical migration with its prey.
Large eyes adapted to feeding in low light, together with lateral-line schooling. The species rises towards the surface at night, which is why the fishery for it uses lights.
Through the year
Present year-round with abundance fluctuating seasonally and with lake conditions. Vertical migration between deeper water by day and the surface at night is a daily rather than a seasonal pattern.
Distribution
Endemic to the Lake Victoria basin, including Lakes Victoria, Kyoga and Nabugabo and connected rivers, in open pelagic water and inshore.
This is a biological range — where the species occurs, not a prediction that you will catch one. To browse the fishing geography FishingHQ holds, start at fishing places.
Why anglers care
Not an angling species in any sense. It is caught commercially at very large scale with light-attraction and small-mesh gear, and it is in this catalogue only because Nile perch feed on it.
Handling and returning
Not handled by anglers in any context. It is a commercial and subsistence fishery species, taken at night with light attraction and processed by sun drying rather than handled live, and it appears in this catalogue only as a prey record.
Where to go next
Similar and related fish
What these connections rest on (1)
Scientific evidence — 1 connection
Supported by peer-reviewed research or fisheries science. The sources are listed and can be checked.
Nile perch
Recorded diet evidence identifies Rastrineobola argentea as a food item of this predator at species level. The edge is written at that granularity and no further.
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Food items recorded for this predator, including Rastrineobola argentea.States this directlyPassage read and verified
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Species account describing the diet of this predator in the region where Rastrineobola argentea occurs.Background and mechanism onlyCitation checked — the work exists and is described correctly
Where you will find it
What these connections rest on (1)
Scientific evidence — 1 connection
Supported by peer-reviewed research or fisheries science. The sources are listed and can be checked.
Lake Victoria and the Rift Valley lakes
A distribution association between an animal and a described water body, which is what the `inhabits` predicate is for — the kind of water rather than a named mark.
- The IUCN Red List of Threatened Species — International Union for Conservation of Nature (Conservation authority)Relied on for: Assessment and habitat account for the species, including the river or lake system it occupies and the pressures acting on it.States this directlyCitation checked — the work exists and is described correctly
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Distribution, habitat association, size and life history recorded for the species in the system concerned.States this directlyPassage read and verified
More fish
Not related to this page — just the rest of the section, because this record connects to very little and a short page should still lead somewhere.
Sources for this page
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Species identity, binomial, family placement, size, distribution and recorded biology for this species.States this directlyPassage read and verified
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: The regional species account describing identity, distribution and the role of this species in the fisheries and food webs it belongs to.States this directlyCitation checked — the work exists and is described correctly
How FishingHQ labels evidence is explained in the evidence policy.