Redtail notho
A small annual killifish from Zanzibar
The redtail notho is a tiny freshwater fish found only in Zanzibar. It survives dry seasons as dormant eggs that hatch when rains return. Aquarium keepers value it for its unique life cycle and role in mosquito control research.
- Found only in Zanzibar
- Eggs survive dry seasons in mud
- Eats mosquito larvae
- Hatches after rain returns
- Studied for malaria control
What it is
The redtail notho is a species of killifish belonging to the family Nothobranchiidae. It is a small freshwater fish known for its ability to survive in temporary water bodies. This species is endemic to Zanzibar, meaning it is found nowhere else in the world. Its natural environment consists of intermittent rivers and marshes that may dry up completely during certain seasons. The fish has adapted to these harsh conditions through a unique reproductive strategy involving dormant eggs.
Where it lives
This fish is restricted to the island of Zanzibar. It inhabits shallow, temporary freshwater systems such as seasonal rivers and marshes. These habitats are characterised by fluctuating water levels and periodic drying. The species relies on these ephemeral pools for its entire life cycle, disappearing when the water vanishes and reappearing when the rains return.
How it lives
The redtail notho feeds on small aquatic organisms. Its diet primarily includes mosquito larvae and other planktonic creatures. Because of this feeding habit, scientists are investigating the potential use of this species in malaria prevention programmes across Africa. By consuming mosquito larvae, the fish could help reduce populations of disease-carrying insects in temporary water bodies.
Breeding and life cycle
Like other peat spawners, this fish reproduces by burying eggs in the substrate. Pairs or small groups push into the mud to release and fertilise single eggs. When the habitat dries out and adult fish die, the eggs enter a state of dormancy. Special proteins in the eggshell retain moisture to protect the developing embryo. Hatching is triggered by changes in water pressure and carbon dioxide levels when the rains return. An enzyme called chorionase softens the shell to allow the fry to emerge. Dry incubation typically lasts between eight and twelve weeks, with most hatching after nine weeks.
Fish and people
Aquarium enthusiasts sometimes keep this species due to its interesting life history. The eggs can be stored dry for several weeks before hatching, which appeals to hobbyists interested in breeding annual killifish. Beyond the hobby trade, the species holds scientific interest for its potential role in biological control of mosquitoes. Researchers are studying its introduction to other parts of Africa to help combat malaria by reducing larval mosquito numbers.
Questions people ask about Redtail notho
Where does the redtail notho live?
It is endemic to Zanzibar. The fish lives in intermittent rivers and freshwater marshes that dry up seasonally.
How do the eggs survive without water?
Special proteins in the eggshell retain moisture during the dry season. The eggs remain dormant in the substrate until rains return.
Why are scientists interested in this fish?
It eats mosquito larvae. Researchers are looking at introducing it elsewhere in Africa to help prevent malaria by reducing mosquito populations.
Good reading and sources
- Redtail notho on WikipediaEncyclopedia
- More photos on Wikimedia CommonsPhotos
- Wikidata recordOpen data
The facts on this page come from the Wikipedia article "Redtail notho", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.
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