Hemimyzon Formosanus

Datasheet

General Description

Hemimyzon Formosanus, commonly known as the Hemimyzon, is a rare species in the aquarium trade primarily found among shipments of other wild-caught fishes from its native Taiwan. With a maximum size of 10.0cm, this species is part of the Balitoridae family within the Cypriniformes classification order. It is distinguishable by various anatomical features, including dorsal-fin rays, pectoral-fin rays, and the presence of inner posterior barbels.

Aquarium Setup

For setting up an ideal aquarium for Hemimyzon, a minimum tank size of 120 liters is recommended. It can thrive in warmer conditions as long as dissolved oxygen levels are maintained. The tank should have clean, well-oxygenated water with a turnover rate of 10-15 times per hour. Utilizing an over-sized filter, additional powerheads, and airstones is crucial. A substrate of gravel or sand, along with water-worn rocks and pebbles, should be provided. Aged driftwood and aquatic plants can also be included to mimic its natural habitat.

Behaviour

The Hemimyzon species is known to be largely peaceful but requires specific environmental conditions for optimal well-being. It is loosely territorial towards conspecifics, emphasizing the need for a group of at least four specimens for proper social interactions. While it can coexist with other fish species, careful consideration of tankmates is necessary due to its specific environmental requirements.

Feeding and Diet

In the wild, Hemimyzon primarily feeds on benthic algae and associated micro-organisms. In captivity, they readily accept high-quality dried foods, live or frozen bloodworms, and home-made foods rich in fresh vegetables and Spirulina. A mature aquarium with algae-covered rocks is beneficial for their long-term health. Additionally, maintaining a separate tank to grow algae can be necessary if algae consumption is high in the main tank.

Reproduction & Dimorphism

Limited information is available on the reproductive behavior of Hemimyzon in both natural and aquarium settings. Sexual dimorphism is unconfirmed, but based on related genera, adult females are likely to be heavier-bodied and slightly larger than males.

Habitat and Distribution

Endemic to Taiwan, Hemimyzon is predominantly found in river systems on the western slopes of the island's Central Mountain Range and some northern drainages. It inhabits shallow, fast-flowing, highly-oxygenated waters characterized by riffles, runs, pools, and cascades. The presence of biofilm on submerged surfaces is crucial for their habitat, and other species such as Candidia barbata and various Rhinogobius species share similar environments in Taiwan.