The Mastacembelidae are a family of

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

es, known as the spiny eels. The Mastacembelids are part of the Order

Synbranchiformes Synbranchiformes, often called swamp eels, is an order of ray-finned fishes that are eel-like but have spiny rays, indicating that they belong to the superorder Acanthopterygii. Taxonomy No synbrachiform fossil is known. The Mastacembeloidei were ...

, the swamp eels, which are part of the

Actinopterygii Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

(ray-finned fishes). In an evaluation of the family in 2004, the subfamilies of Mastacembelidae were found to not be well supported and were rejected. Also, the genera ''Caecomastacembelus'' and ''Aethiomastacembelus'' were placed in

synonymy A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

with ''Mastacembelus''. These fish originate from Africa, and southern and eastern Asia. Spiny eels generally inhabit soft-bottomed habitats in fresh and occasionally

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

water. Some species burrow in the substrate during the day or for certain months and have been found buried in soil in drying periods. These fish have an

eel Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...

-like body. The largest species can reach a maximum length of . Very characteristic of this group is the long nose appendage with two tubulated nostrils. Mastacembelids have a series of well-separated dorsal spines on their back, hence the name of their family, spiny eels. In some areas these fish are regarded as

food fish Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingest ...

. Several species of Mastacembelidae are

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

fish, such as the

fire eel The fire eel (''Mastacembelus erythrotaenia'') is a relatively large species of spiny eel. This omnivorous freshwater fish is native to in Southeast Asia but is also found in the aquarium trade. Although it has declined locally (especially in Thai ...

References

Fish of Africa Fish of Asia {{Symbranchiformes-stub