BLOODY MARY HILLSTREAM LOACH (Gastromyzon sp. “Bloody Mary”)

Bloody Mary Hillstream Loach

Gastromyzon sp. “Bloody Mary”

The Bloody Mary Hillstream Loach is a rare and visually striking freshwater species, known for its deep red to burgundy coloration accented by subtle patterning across its body. Native to the fast-moving, crystal-clear streams of Borneo, this unique loach is specially adapted to life in strong currents, using its flattened body and suction-like fins to cling to rocks and aquarium glass.

Both beautiful and functional, the Bloody Mary Hillstream Loach is an excellent natural grazer, constantly feeding on biofilm and algae. Its peaceful temperament and fascinating behavior make it a standout addition to any river-style or high-flow aquarium.

Key Features

• Rich red to “bloody” coloration with subtle markings
• Unique flattened body with suction-cup fins
• Active algae and biofilm grazer
• Peaceful and suitable for specialty community tanks
• Rare and highly desirable among collectors

Care Guide

Tank Size

Minimum 20 gallons (larger preferred, especially for groups)

Temperature

20–24°C (68–75°F)

pH

6.5–7.5

Hardness

Soft to moderately hard

Tank Setup

To keep this species thriving, replicate a fast-flowing stream environment:

• Strong current (powerheads or wavemakers recommended)
• High oxygen levels (air stones or strong surface agitation)
• Smooth rocks and driftwood for grazing
• Sand or fine gravel substrate
• Mature aquarium with established biofilm

A river-style or manifold system setup is ideal.

Diet

Primarily herbivorous:

• Natural algae and biofilm (very important)
• Sinking algae wafers
• Spirulina-based foods
• Blanched vegetables (zucchini, spinach)
• Occasional protein treats (brine shrimp, daphnia)

Temperament

• Peaceful and non-aggressive
• Best kept in small groups (3–6+)
• Minor territorial displays may occur, but rarely harmful

Tank Mates

Best suited with:

• Small, peaceful, current-loving species
• Danios, white cloud minnows, and similar fish

Avoid:

• Aggressive or territorial fish
• Species that prefer warm, slow-moving water

Special Notes

• Requires clean, well-oxygenated water
• Sensitive to high temperatures and poor water quality
• Not recommended for newly set up tanks
• Thrives in established systems with natural grazing surfaces

Why You’ll Love It

The Bloody Mary Hillstream Loach combines rare coloration with fascinating behavior, making it a true centerpiece for river-style aquariums. Its constant grazing activity and peaceful nature make it both a functional and visually stunning addition to any advanced freshwater setup.