Mastacembelus plagiostomus
Formerly Caecomastacembelus plagiostomus
Last revised 2026Edit this page
On this page11 sections
Quick factsEdit
Difficulty4 of 8 measures
- Space
- large tank
- Water
- needs alkaline water
- Temp
- needs a steady temperature
- Diet
- unknown
- Temperament
- eats smaller fish
- Social
- unknown
- Compatibility
- unknown
Other demands
Each of these can raise the rating on its own, whatever the measures above say.
- Hardiness
- unknown
Mastacembelus plagiostomus is a spiny eel endemic to Lake Tanganyika, found in shallow water over rocky areas around the shoreline. Very rarely seen in the hobby, it suits a Tanganyikan community of species too large to be considered food and is somewhat territorial with conspecifics. It grows to 300 mm SL, and its stiffened dorsal rays call for care when handling it.
Distribution
EditHabitat
Write a noteEditIt inhabits rocky areas around the shoreline of the lake, usually in shallow water.
Aquarium size
Write a noteEdit48" x 18" x 18" (120cm x 45cm x 45cm), although the width of the tank is far more important than the height.
Maintenance
Write a noteEditUse piles of rocks to form sheltered areas. It is essential that the tank bottom is covered in sand as the fish spends much of its time burrowed into the substrate. Gravel is not recommended as its sharp edges can damage the eel's skin. There should be no strong currents in the aquarium.
Water conditions
EditTemperature: 23 – 27 °C73 – 81 °F
pH: 8.0-9.5
Hardness: 8-25°H
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Diet
Write a noteEditIn nature, it preys on small fish but aquarium specimens readily accept dead alternatives. Prawn, cockle, mussel, earthworms and bloodworm can all be offered.
Behaviour and compatibility
Write a noteEditIt is peaceful with species it cannot fit into its mouth but is not suitable for most freshwater tanks due to its hard, alkaline water requirements. It is best kept in a Tanganyikan community, where it can be combined with any species too large to be considered food. It tends to be somewhat territorial with conspecifics and a large tank is required if more than one is to be kept.
Sexual dimorphism
Write a noteEditUnknown.
Reproduction
Write a noteEditHas been achieved in the aquarium but very few details are available. The eels should be bred in a species tank. Apparently, the eggs are laid in the substrate or on the underside of rocks and are adhesive. The fry are very small and require infusoria as first food. They look like normal fish fry initially, developing the elongated body as they grow. No parental care is exhibited in this species so if you do get a successful brood it is probably a good idea to remove the parents post-spawning.
Notes
EditVery rarely seen in the hobby, this species makes an interesting oddball addition to the Tanganyikan community tank. The species in the family Mastacembelidae are known as "spiny" eels because the dorsal rays are stiffened. Care must therefore be exercised when handling them to avoid injuries. Spiny eels also have no swim bladder, an adaptation to their benthic lifestyle..
Species images · 1
These photographs are used with each photographer's permission.
Send a photographHow the name has changed
Moved from Caecomastacembelus plagiostomus to Mastacembelus plagiostomus.
Distribution
Profile completeness19 of 24
79% complete
Also missing: a common name, etymology.
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