台湾名古屋吻鰕虎鱼

Overview

Rhinogobius formosanus is a robust stream goby with irregular reddish-brown, worm-like lines on the cheek and gill cover. Territorial males need caves and visual barriers. Larval requirements may differ between populations, so neither a compulsory marine phase nor universal freshwater development should be assumed.

Distribution & habitat

It is endemic to river systems of northern and northeastern Taiwan. The historical type-locality name refers to an administrative region in northern Taiwan and should not be used to extend the range elsewhere.

Aquarium setup

Allow a small group at least about 80 × 30 cm of floor space. Sand, gravel, rocks, wood, ceramic tubes, and pots can form a network of shaded crevices and interrupted sight lines. Hardy attached plants are suitable.

Prevent organic pollution with routine maintenance, including weekly changes of roughly 30–50 percent. Maintain high oxygen levels and useful circulation without a constant torrent.

Diet & feeding

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

Behaviour & compatibility

Some aggression is possible. Peaceful upper-water companions with matching requirements are better choices. Leave the bottom to these gobies in small aquariums; suitable loaches are more feasible in larger quarters. Avoid strongly territorial bottom fishes, and expect possible predation on small freshwater shrimp.

Keep at least two males with an equal or greater number of females. Adequate cover usually limits serious injury between males. Avoid other species of the genus because hybridization potential remains unresolved.

Sexual dimorphism

Males become larger and more colorful, with longer dorsal and anal fins. A bluish egg mass may be visible through a ripe female's abdomen.

Breeding

Some wild populations spawn in fresh or brackish streams, with larvae drifting into estuarine or marine nursery areas before migrating upstream. Aquarium-traded fish appear capable of freshwater reproduction, or may adapt to it, but this should not be generalized to every population.

Males defend sites beneath flat stones. Females leave after spawning, and males guard clutches that can approach three thousand small eggs. Hatching usually takes three to four days. Newly hatched larvae drift for about a day before movement becomes more directed.

Initial food must be tiny, such as freshwater rotifers. Brine shrimp nauplii become suitable only later; feeding methods for large-egged gobies should not be assumed appropriate.

Notes

Three pairs of red snout stripes and the cheek pattern aid identification. Older names reflect its former subspecies status, making provenance and the complete marking pattern useful when purchasing fish.