Cow River Loach

Neogastromyzon crassiobex

Cow River Loach (Neogastromyzon crassiobex) is a peaceful bottom-dwelling fish that suits calm freshwater aquariums. It stays small, but it should be kept in a group and needs enough open substrate area for feeding and movement.

Peaceful Bottom dweller Groups of 5 or more recommended Intermediate
Save this fish or add it directly to one of your aquariums.

Quick facts

Adult size
up to 5 cm
Aquarium size
45 L or larger
Care level
Intermediate
Temperament
Peaceful
Swimming zone
Bottom dweller
Temperature
21–26 °C
pH
7–8
GH
2–12 dGH
Diet
Omnivore
Lifespan
up to 8 years
Group behavior
Groups of 5 or more recommended

Overview

Cow River Loach (Neogastromyzon crassiobex) is a bottom-dwelling fish for aquariums where the layout leaves enough open substrate area and the water stays stable.

Use these values as planning checks, then make sure the aquarium still has room for behavior, group needs, and calm community fish.

Care requirements

With a Intermediate care level, Cow River Loach is best for aquarists who can keep water quality steady and plan compatibility before adding the fish.

Because it uses the bottom area, leave enough open substrate area instead of crowding that part of the aquarium.

Plan the aquarium around the group, not just one individual.

With a lifespan of up to 8 years, this is a fish to plan for long term rather than an impulse addition.

Aquarium size and space needs

An aquarium of 45 L or larger can be a reasonable starting point, but it should not be read as permission to overstock.

At up to 5 cm, Cow River Loach stays small, but a group still needs room to move, feed, and avoid constant competition.

Uses the bottom area, so leave enough open substrate area for movement and feeding.

A group of 5 or more should have enough open substrate area for movement and feeding.

Water parameters

The temperature range for this fish is 21 to 26 °C, which fits many tropical freshwater aquariums. Choose other fish with overlapping temperature needs.

The pH range for this fish is 7 to 8. That points to neutral to slightly alkaline water, but stability is more important than sudden corrections.

The GH range for this fish is 2 to 12 dGH. That gives some flexibility, but sudden changes are usually more stressful than a stable value that is slightly imperfect.

Temperament and compatibility

As a peaceful bottom-dwelling fish, Cow River Loach is best kept with calm species that will not harass it or dominate the feeding area.

If kept in a group of 5 or more, the aquarium should have enough open substrate area for the group rather than being planned around a single fish.

Because this fish uses the bottom area, compatibility is easier when other fish are not all competing for the same swimming space.

Swimming zone and behavior

This fish uses the bottom area, so leave enough open substrate area for movement and feeding.

Because this species is best planned as a group of 5 or more, bottom space matters more than body size alone.

Feeding

As an omnivore, Cow River Loach should receive a varied diet rather than one repeated food type.

Because it feeds near the bottom, make sure food reaches the substrate and is not completely taken by faster fish in the open water.

Natural habitat and origin

This profile currently lists the origin as Indonesia. Treat this as a broad regional note rather than a complete habitat description.

Before adding this fish

Use this checklist before treating the profile as a match for an existing aquarium.

  • Plan for an aquarium of 45 L or larger.
  • Make sure the bottom area has enough open substrate for a group.
  • Choose other fish with overlapping temperature needs.
  • Keep pH stable within the listed range instead of making sudden corrections.
  • Avoid aggressive or highly competitive fish.
  • Plan for a group of 5 or more.
  • Offer a varied diet suitable for an omnivorous bottom-dwelling fish.

Similar fish profiles

Use these profiles to compare fish with similar care level, size, temperature range, or swimming behavior.

FAQ

How large does Cow River Loach get?

Cow River Loach reaches up to 5 cm according to this profile. It stays relatively small, but aquarium planning should still account for group size and bottom space.

What aquarium size does Cow River Loach need?

Plan for an aquarium of 45 L or larger. Treat this as a baseline, because a grouped bottom-dwelling fish also needs open substrate area and compatible fish.

Is Cow River Loach peaceful?

Yes. Cow River Loach is recorded as peaceful and is best planned with calm community fish that do not harass it or dominate the feeding area.

What temperature is suitable for Cow River Loach?

The temperature range for this fish is 21 to 26 °C. Choose other fish with overlapping temperature needs and avoid sudden temperature swings.

Should Cow River Loach be kept alone or in a group?

This profile recommends groups of 5 or more. Plan the aquarium around the group rather than a single fish.

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