Spiney-headed hillstream loach - Gastromyzon ocellatus

Scientific name: Gastromyzon ocellatus

Common name: Spiney-headed hillstream loach

Family: Gastromyzontidae

Usual size in fish tanks: 4 - 6 cm (1.57 - 2.36 inch)

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Recommended pH range for the species: 7 - 8

Recommended water hardness (dGH): 0 - 14°N (0 - 250ppm)

0°C 32°F30°C 86°F

Recommended temperature: 20 - 24 °C (68 - 75.2°F)

The way how these fish reproduce: Spawning

Where the species comes from: South Asia

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Bottom levels

Food and Feeding

The Spiney-headed Hillstream Loach (Gastromyzon ocellatus) is an omnivorous species that thrives on a varied diet. While quality flake food and sinking catfish pellets can serve as their staple diet, they also consume natural algae growing in the tank. Algae wafers make an excellent substitute when algae levels are low. To maintain their health, offer protein-rich treats such as bloodworms and frozen Mysis shrimp. Additionally, incorporate blanched spinach and peas into their diet to ensure they receive essential nutrients and vegetable matter.

Origin

The Spiney-headed Hillstream Loach (Gastromyzon ocellatus) is native to Southeast Asia, specifically the fast-flowing rivers and streams of Sarawak and Borneo. These regions are known for their clear, oxygen-rich waters, which must be replicated in captivity to keep the fish healthy and stress-free.

Sexing

Sexing Gastromyzon ocellatus can be done by observing the body shape. Females generally have a plumper appearance, especially when ready to spawn, while males tend to be more streamlined.

Breeding

Currently, there are no documented cases of Spiney-headed Hillstream Loaches breeding in home aquariums. In the wild, these fish likely spawn in fast-moving water where the eggs are scattered over rocky surfaces. Replicating these conditions in captivity has proven to be difficult.

Lifespan

With proper care, Gastromyzon ocellatus can live up to 6 years in a well-maintained aquarium. High water quality, proper diet, and appropriate tank conditions are key to maximizing their lifespan.

Tank Requirements

To mimic the natural habitat of Spiney-headed Hillstream Loaches, it's essential to provide strong water flow and highly oxygenated water. A tank with a lower temperature, ranging from 20-24°C (68-75.2°F), is ideal, along with a pH of 7-8 and soft to moderately hard water. Use a sand or fine gravel substrate, and include smooth rocks and driftwood to create hiding spots and grazing surfaces for algae. Maintaining high water flow is critical, as it helps replicate the fast-moving streams of their natural environment.

Adding hardy, low-maintenance plants such as Java Fern, Anubias, and Cryptocoryne will help create a natural environment. These plants can tolerate the strong water flow and offer additional hiding spaces for the loaches.

Tankmates

Due to their peaceful nature and specific water requirements, Spiney-headed Hillstream Loaches do best with similarly sized, peaceful species that thrive in cooler, well-oxygenated water. Ideal tankmates include White Cloud Mountain Minnows, Harlequin Rasboras, other hillstream loaches, and shrimp species such as Amano or Cherry Shrimp. Avoid larger, aggressive fish or species that prefer warmer, slower-moving water.

Short Description

Gastromyzon ocellatus, commonly known as the Spiney-headed Hillstream Loach, is a peaceful, bottom-dwelling species native to the fast-flowing rivers of Sarawak and Borneo. Known for their ability to cling to rocks in strong currents, these loaches require well-oxygenated water and cooler temperatures than many tropical species. They are ideal for a biotope-style aquarium with a focus on replicating river environments. Although they are peaceful toward other fish, they should be kept in tanks with similarly sized species that can tolerate high water flow.