大斑筛耳鲶 · Oto

Overview

A conspicuous round mark at the tail base helps identify Otocinclus macrospilus. Newly imported fish can be fragile after food deprivation in transit. Establishing dependable grazing in a mature planted aquarium is more useful than introducing it simply as an algae-control measure.

Distribution & habitat

The core reported range is Peru’s upper Amazon, with conflicting claims from additional basins and neighboring countries. It uses dense marginal vegetation and can occur in large numbers on floating plant mats.

Aquarium setup

Provide at least a 45 by 30 cm base with broad-leaved plants, branches, and useful vertical surfaces. It spends much of its time away from the floor, though sand is appreciated during bottom grazing. Stock only an established system with stable water and ample algae and microorganisms.

Diet & feeding

Natural grazing targets algae and associated microorganisms. Supply vegetables and plant-based prepared foods as the main supplements. Small animal foods can be occasional additions, but high protein is unnecessary. Ensure food remains available rather than assuming visible algae always provides enough.

Behaviour & compatibility

Keep at least six. Its shy, retiring behavior makes vigorous feeders poor companions; select small peaceful fishes that will not repeatedly interrupt access to food.

Sexual dimorphism

Mature females appear broader when viewed from above.

Breeding

Spawning has been achieved, involving T-shaped pairing and eggs scattered around plants or glass. Substantial cooler-water changes may help trigger it, while stimulation by another breeding species remains speculative. The tiny fry need abundant algae and other suitable plant foods.

Notes

Trade labels are frequently inaccurate. The large tail-base blotch and less consistently defined pale border above the lateral stripe help comparison with look-alikes. Occasional rapid air gulps are observed; associated anatomy may support air use and buoyancy.