Arrow loach

Nemacheilus masyae

Also known as Masya's stone loach

FreshwaterFish

Arrow loach (Nemacheilus masyae) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 72–81°F (22–27°C)
pH: 6.5–7.5
Adult size: 6.3 in (16 cm)
Minimum tank: 42 gal (160 L)
Temperament: Mostly peaceful
Social behavior: Social
Swim level: Bottom
Difficulty: Medium
Breeding: No record
Rarity: Rare
Origin: Peninsular Thailand and western Malaysia
Family: Nemacheilidae

Overview

A large, active bottom loach that stays peaceful for its size but bolts when startled, so it needs open sand to cruise and clear escape routes rather than a cramped floor. Keep a few together over fine sand; they are sociable, but each fish wants room to nose and dig, so give the tank length. Suitable tankmates are medium, calm midwater fish that will not nip or crowd it. Feed sinking pellets, wafers, and frozen foods such as bloodworm and tubifex, making sure enough reaches the bottom. Because it grows sizeable and swims hard, plan on a long tank of around 160 liters or more, and fit a tight lid, since a spooked fish can shoot clean out of the water.

In the wild

The arrow loach lives in clear, flowing streams of peninsular Thailand and western Malaysia, often over sand where it can half-bury itself and face into the current. Recreate that with a deep, soft sand bed, some rounded stones and roots for structure, and steady water movement from the filter or a powerhead. Keep it warm at 22 to 27 degrees Celsius with clean, well-oxygenated water and a pH of 6.5 to 7.5. Regular water changes matter, since stream fish are used to fresh, moving water.

Good to know

Nemacheilus masyae belongs to the stone loach family, Nemacheilidae, and is one of the larger members of its genus, reaching around 16 centimeters with a pointed snout and a slim, torpedo-shaped body that suits its darting habits. The genus name comes from the Greek for thread and lip, a nod to the fringed lips these loaches share. It was described by Hugh Smith in 1933 from a river in southern Thailand. Its breeding in aquaria is not documented, so any spawning would be new ground for a keeper.

Did you know

The species honors Luang Masya Chitrakarn, a Thai ichthyologist and fish illustrator for the old Siamese fisheries department, so the arrow loach quietly carries the name of one of the people who first drew Thailand's fishes.