扁鼻奇非鲫 · Big-Eyed Xenotilapia

Overview

Xenotilapia sima is a gentle, easily startled cichlid that searches sand for tiny animal prey. Its social nature favors a group, while its nervousness calls for quiet surroundings and restrained companions. Feeding success needs direct observation in a mixed aquarium.

Distribution & habitat

Endemic to Lake Tanganyika, it occurs in large aggregations over sandy ground.

Aquarium setup

Use fine sand across a broad, open floor, with a few scattered rocks offering shelter. Coarse gravel can lodge in the throat during sifting or damage the gills. Provide efficient filtration and avoid excessive decoration that removes feeding space. Sudden movement outside the glass and abrupt lighting changes can frighten the fish.

Diet & feeding

Natural feeding involves separating small invertebrates from mouthfuls of sand. Although aquarium fish accept many foods, live and frozen items should supply most of the diet. Food must reach the floor: this species takes nearly all its meals from the substrate, so faster tankmates may intercept its ration before it becomes accessible.

Behaviour & compatibility

A group of six to ten reflects its nonbreeding social behavior. Peaceful Tanganyikan companions may work, but vigorous or dominant fishes, including mbuna, are poor choices. Males establish territories for breeding. Multiple males may require separation if the aquarium cannot accommodate their defended areas; breeding groups should include several females per male.

Sexual dimorphism

Males are generally larger and darker, with more pointed tips to the dorsal and anal fins.

Breeding

Aquarium reproduction is uncommon. Young fish can be raised together before the developing social structure guides adjustments to the group. Maintain stable, hard, alkaline water and offer a varied conditioning diet.

The male excavates a shallow depression within a territory and displays to attract a female. She lays there, waits for fertilization, and collects the eggs into her mouth. Only the female incubates the brood, carrying it for about three weeks without eating. Her expanded mouth helps reveal that she is brooding. Disturbance can cause premature release or consumption of the eggs, so moving her requires particular care. The young emerge ready to swim and accept brine shrimp nauplii or microworms.

Notes

Nervous behavior and food interception can occur together. Check that each fish actually feeds on the floor, and approach the aquarium calmly rather than assuming a visible feeding response guarantees an adequate meal.