黑鳍多齿脂鲤 · Black Phantom Tetra

Overview

Male Megalamphodus megalopterus display enlarged black fins, contrasting with the reddish fins of females. This peaceful social tetra is most engaging in a substantial group, where displays and temporary rank competition bring out color and natural behavior.

Distribution & habitat

It occurs in upper Madeira drainages in Bolivia and Brazil, including the Beni and Mamoré, and in the upper Paraguay in Brazil. Many records come from the Guaporé, also called the Iténez.

Still or sluggish tributaries, backwaters, ponds, and small lakes provide gatherings around marginal vegetation and submerged roots. Some Pantanal habitats are exceptionally clear and rich in underwater plants.

Aquarium setup

A footprint of at least approximately 80 × 30 cm is appropriate. Sand, roots, and branches create a natural arrangement, while dense planting is another option. Leaves provide cover and microbial growth that can supplement both adult and fry nutrition.

Diet & feeding

The wild diet is probably mixed, including small invertebrates, crustaceans, filamentous algae, and fallen fruit. Dry foods are accepted, with live or frozen bloodworms, mosquito larvae, and small water fleas providing a varied menu.

Behaviour & compatibility

Its mild nature suits appropriately chosen companions, including comparable characins, small peaceful bottom dwellers, and non-piscivorous small or medium cichlids. Maintain at least eight to ten of mixed sex. Temporary hierarchies and male competition for females add interest and strengthen display colors.

Sexual dimorphism

Adult males have black fins, with the pelvic, dorsal, and anal enlarged. Females are deeper-bodied and usually show reddish pelvic, anal, and adipose fins.

Breeding

Eggs are scattered without subsequent parental care. Well-conditioned fish may spawn often, and some fry can survive in a mature aquarium. For better yields, use a separate dim tank with mature water and fine plants, spawning mops, marbles, or mesh protecting eggs from the adults.

Introduce a conditioned pair or one or two males with several females, checking for eggs the following morning. Slightly acidic to neutral water, temperatures toward the upper suitable range, and gentle sponge filtration or aeration are appropriate. Separate the breeders and clutch after spawning.

Start fry on Paramecium or very fine prepared starter food, then move to Artemia nauplii and microworms when their mouths are large enough.

Notes

Commercial breeding supplies much of the trade, with a long-finned ornamental form sometimes available. Historical shifts between genera explain the variety of older scientific names. A large shoulder mark, enlarged dark male fins, and sexual differences aid identification.