大吻鰕虎鱼

Overview

Rhinogobius gigas is an eastern Taiwanese goby with distinct dark body bands, spotted cheeks, and rows of spots in the second dorsal and anal fins. It is uncommon in aquariums, and similar fishes are sometimes sold under its name.

Distribution & habitat

It inhabits middle and lower river sections in Yilan, Hualien, and Taitung. Small rivers, tributaries, and streams have bottoms of gravel, rocks, boulders, and bedrock. Depth, flow, and turbidity vary seasonally, especially during heavy rains and tropical storms.

Aquarium setup

Provide a small group a footprint around 80 × 30 cm or larger. Use sand, gravel, stones, wood, ceramic tubes, and pots to create shaded retreats and interrupted sight lines. Hardy attached plants can be included. Maintain high oxygen levels and some circulation without a constant torrent. Weekly changes of roughly 30–50 percent help prevent organic waste buildup.

Diet & feeding

The genus generally feeds opportunistically on small animal prey. Offer suitably sized live or frozen foods such as bloodworms, mosquito larvae, brine shrimp, water fleas, and mysids. Dry food may be accepted after acclimation but should not be a regular staple.

Behaviour & compatibility

These robust fish can be aggressive. Peaceful upper-water companions with similar requirements are better candidates. In small tanks, leave the bottom to the gobies; compatible loaches are more feasible in larger quarters. Small freshwater shrimp may be eaten. Avoid territorial bottom fishes and other species of the genus, whose hybridization potential is unresolved.

Keep at least two males with an equal or greater number of females. Sufficient cover usually limits serious male conflict, while inadequate company may lead to inactivity.

Sexual dimorphism

Males are larger and more colorful with longer dorsal and anal fins. Females may show a vertical curved dark mark at the tail base, and ripe females have a bluish egg mass visible through the abdomen.

Breeding

Eggs attach to the roof of a cave or crevice and receive male care. Offer several sites. Pairs may hide for two or three days; avoid disturbance and inspect gently underwater only after the female emerges.

Early attempts may involve egg eating, incomplete fertilization, or poor attachment. Remove other fish or move the male and clutch to safety. Broods can be large, but a fixed egg count is not established. The relatively large eggs usually hatch after nine to twelve days. Young occupy the water column initially before settling and can take brine shrimp nauplii, microworms, and comparable live foods immediately.

Notes

Use cheek spots, rows of fin markings, and clear body bands together. Large size or a single stripe is not sufficient identification.