黄鳝 · Swamp Eel

Overview

Despite its eel-like shape, Monopterus albus is not a true eel. It uses accessory respiration, is mainly active at night, and preys on fishes and other animals. Large adult size favors solitary housing, with a heavy, secure, closely fitting cover as an essential precaution.

Distribution & habitat

Records extend through India, Myanmar, China including Hong Kong and Taiwan, Thailand, Cambodia, Laos, Vietnam, Japan, Malaysia, Indonesia, the Philippines, and Australia. Introduced populations in the United States, including Hawaii, must be distinguished from the natural range.

Rivers, ponds, rice fields, canals, ditches, and swamps are occupied. It tolerates stagnant, oxygen-poor conditions and retreats into moist soil during drought until rain returns. Such resilience is not a reason to allow aquarium water quality to deteriorate.

Aquarium setup

Supply multiple refuges using plants, wood, rocks, and appropriately sized tubes. Examine edges and equipment openings carefully, since small gaps can become escape routes even in a large aquarium.

The cover must resist displacement as well as fit tightly. A moist fish can move some distance over land, so an escaped individual may not remain immediately beside the aquarium.

Diet & feeding

Wild prey includes fishes, amphibians, and invertebrates. Shrimp, suitable white fish, and earthworms are accepted in captivity. Arrange deliberate feeding with appropriately sized animal foods; it is not an ordinary scavenger to be sustained on leftovers.

Behaviour & compatibility

Adult size and piscivory make housing one fish alone preferable. Smaller fishes that can be swallowed are particularly unsuitable companions. Most activity takes place after dark, with greater concealment during daylight.

Sexual dimorphism

External appearance offers no dependable sexing method. Individuals begin life as females, with some changing to males at maturity. Males are said to grow larger after transition, but size alone cannot provide accurate identification.

Breeding

Natural spawning occurs in shallow water. A loose foam nest may contain up to approximately 1,000 eggs, guarded by the male. Reproduction can occur throughout the year rather than being restricted to one season.

Notes

A single opening under the throat serves the gills, with accessory respiratory structures behind the gill chamber allowing brief breathing out of water. Burrowing into damp ground during drought has been reported to reach about 1.5 m. The tiny eyes are covered by a thin tissue layer, consistent with a concealed, nocturnal way of life.

Scales are absent and the dorsal, anal, and tail fins are highly reduced. Hardiness does not remove the demands of adult space, escape prevention, and dedicated feeding.