Tasseled‑mouth River Loach (Crossostoma lacustre)

Crossostoma lacustre is a Taiwanese hillstream loach species found in fast‑flowing, oxygen‑rich mountain streams. It is a specialized rheophilic fish adapted to high‑flow environments, with a flattened body and enlarged fins for clinging to rocks. 

This species reaches 10–12 cm in length.

Distribution & Habitat

• Endemic to Taiwan, with populations across Taipei, Ilan/Yilan, Hsinchu, Miaoli, Taichung, and other regions
• Lives exclusively in swift, rocky hillstreams, riffles, and shallow runs with clear, highly oxygenated water 
• Substrate consists of gravel, stones, and boulders covered in biofilm

Aquarium Care Requirements

Tank Setup

• Strong water flow and high oxygen levels are essential 
• Use powerheads, oversized filtration, or river‑tank manifolds 
• Provide flat stones and river rocks for grazing and resting 
• Lighting can be bright to encourage algae growth for grazing 

Water Parameters

• Temperature: 18–25 °C
  
• pH: 6.4–7.5 
• Hardness: Medium hardness, 10–15

Minimum Tank Size

• At least 120 × 30 cm footprint (river‑tank style preferred) 

Diet

Crossostoma lacustre accepts a wide range of foods:

• Bloodworms
• Brine shrimp
• Pelleted foods
• Blanched vegetables (spinach, kale)
• Natural algae/biofilm (important component) 

Behaviour

• Occupies high‑flow zones and adheres to rocks
• Peaceful with other hillstream species
• Sensitive to poor water quality; requires mature, stable tanks