TankBud

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
Family
Nemacheilidae
Origin
Peninsular Thailand and western Malaysia

Overview

The arrow loach is a large, active bottom loach that stays peaceful for its size. It is a fish for a keeper past the beginner stage.

Did you know

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

Caring for the arrow loach

Plan on a long tank of at least 42 gal (160 L), since the arrow loach grows sizeable and swims hard. It bolts when startled, so give it open sand to cruise and clear escape routes rather than a cramped floor. Lay a deep, soft sand bed with some rounded stones and roots for structure. Fit a tight lid, because a spooked fish can shoot clean out of the water.

Run steady water movement from the filter or a powerhead, and keep the water clean and well oxygenated. Hold it at 72 to 81°F (22 to 27°C) with a pH of 6.5 to 7.5. Regular water changes matter, since stream fish are used to fresh, moving water.

Feed sinking pellets, wafers and frozen foods such as bloodworm and tubifex, and make sure enough reaches the bottom. Keep a few together, since they are sociable, but each fish wants room to nose and dig. Suitable tank mates are medium, calm midwater fish that will not nip or crowd it.

Its breeding in aquariums is not documented. Any spawning would be new ground for a keeper.

Good to know

Nemacheilus masyae belongs to the stone loach family, Nemacheilidae, and is one of the larger members of its genus. It has 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. Hugh Smith described it in 1933 from a river in southern Thailand, and it is also called Masya's stone loach.

In the wild

The arrow loach lives in clear, flowing streams of peninsular Thailand and western Malaysia. It is often found over sand, where it can half-bury itself and face into the current.

Weekly picks

Tank mates

The arrow loach is a mostly peaceful, social species that keeps to the bottom. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does an arrow loach need?

An arrow loach needs at least 42 gal (160 L). It spends most of its time in the bottom.

What temperature and pH does an arrow loach need?

An arrow loach is comfortable at 72–81°F (22–27°C) with a pH of 6.5–7.5.

What does an arrow loach eat?

An arrow loach eats sinking pellets, wafers and frozen foods such as bloodworm and tubifex. Make sure enough of it reaches the bottom.

How big does an arrow loach get?

An adult arrow loach reaches about 6.3 in (16 cm).

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