Glassfish: Species Overview

Category: Glassfish

Common Names: Glassfish

Scientific Name: Parambassis sp

Family: Ambassidae

Minimum Tank Size: 20 Gallons

Care Level: Moderate

Temperament: Peaceful

Max Size: 3 Inches

Temperature: 70-84 F

pH: 6.5-7.5

Tank Level: All

Colors: Clear

Diet: Omnivore

Breeding: Difficult

Left Side of Glassfish on White Background

Glassfish: Species Overview

Glassfish get their name because they have see-through bodies, making their bones and organs visible.

These fish are well-liked for that reason, along with the fluorescent dyes that some pet stores put on them. But as you’ll soon learn, these dyes can harm the fish.

Because of their fragile nature and shy demeanor, glassfish are better suited for intermediate or advanced fish keepers. We’ll equip you with must-know information about buying and caring for this unique species.

Distinguishing Features

By nature, glassfish have transparent bodies. They’re a narrow fish girth-wise but showcase their spine that runs down the middle of their body with a significant amount of flesh above and below it.

Glassfish have mostly long, round fins. The exception is their pointed dorsal fins, which separate in the middle.

They have a forked caudal fin, large black eyes, and a mildly indented forehead.

Glassfish have a naturally green, silver, or amber iridescence hue depending on the lighting.

Sadly, some glassfish breeders take advantage of the glassfish’s see-through bodies and inject them with dye. So, you may see these fish boasting the following fluorescent colors:

  • Pink
  • Green
  • Yellow

We discourage you from buying these fish. Dye injections, which also go by the name juicing, cause glassfish to undergo an immense amount of pain and stress.

Dye injections also open the opportunity for the fish to develop several diseases.

Glassfish on Black Background


Glassfish hail from South Asia and commonly go by “Indian glassfish.”

They’re freshwater fish that enjoys still or slowly moving water, such as that in dammed rivers. That said, they can survive in some brackish water.

Clear water is their preferred condition, but they can handle murky water during monsoon season.

Glassfish are shoaling fish, so they enjoy having open space to move freely in large groups. But if these fish get separated from the group, they gravitate toward thick vegetation to hide.


Glassfish grow up to three inches long.

There’s little difference between males and females in terms of their size. However, when a female is getting ready to spawn, she’ll have a notably larger stomach.


The glassfish has a lifespan of three to four years in captivity.

Ensuring your fish have ideal tank parameters is vital to helping them live as long as possible.


Telling male and female glassfish apart is simple, thanks to differences in their coloring, especially when they’re getting ready to breed.

Males have a blackish-blue color on the tip of their dorsal and anal fins. They also have a slightly yellower hue to their body.

In contrast, female glassfish have a clear to silver body hue.

Group of Glassfish on Black Background


Glassfish are notoriously peaceful and social.

As shoaling fish, this species requires to be in groups, preferably in a minimum of five, to remain emotionally healthy.

Since they’re shy, you shouldn’t place glassfish in a tank with aggressive fish. There’s little difference in the temperament between males and females, and these fish would rather hide than pick a fight.

Tank Parameters

Since glassfish are relatively fragile for being tropical fish, following the tank parameters below is crucial.

Minimum Tank Size

You should keep five glassfish in a minimum tank size of 30 gallons. The tank dimensions should be no smaller than 32 x 12 x 12 inches.

The more space your glassfish have in their tank to swim in a school, the happier they’ll be.

Water Parameters

Maintaining the following water conditions is vital to your glassfish’s health.


The glassfish is unique for tropical fish since it can handle cooler than average temperatures. As long as you keep its tank between 68°F-86°F, it’ll be happy.


You should keep your glassfish’s pH between 6.5 to 7.5. So, these fish prefer slightly acidic to slightly alkaline water.


Many misconceptions exist about a glassfish’s need for salt. Although these fish can live in brackish conditions in the wild, freshwater is their preferred habitat.

Therefore, it isn’t necessary to add salt to your glassfish tank.

Tank Setup

Read on for details about equipping your glassfish tank.


Sand or small gravel substrate is ideal for glassfish.

We recommend choosing a dark or black substrate, as it’ll help showcase their translucent bodies better than a tan or white substrate.


Adding decorations that your glassfish would encounter in the wild is best for their tank. Rocks and driftwood with holes they can hide in are excellent examples.

Just be sure you don’t overload their tank with decor; these fish require lots of room to swim.


Live plants are an excellent addition to your glassfish aquarium, especially if you have other fish species in the tank so that they have a place to hide.

It’s best to carve out a section of your tank where you can place a dense group of plants. That way, they won’t hinder your glassfish’s ability to swim.

Some excellent plants for glassfish include:

  • Java ferns
  • Java moss
  • Anubias


Glassfish don’t need lots of light since they tend to live in areas in the wild where plant vegetation at the top of the water blocks out a lot of sunlight.

Nevertheless, all fish have a circadian rhythm, and purchasing a timed aquarium lamp ensures they can follow a waking and resting cycle according to the presence or lack of light.

Group of Glassfish on White Background


A quality filter is one of the most important aspects of having an aquarium with any kind of fish. The three primary types of tank filters for glassfish include:

  • Mechanical
  • Biological
  • Chemical

All three filters complement each other. But at a minimum, you should install the mechanical and biological varieties.


Although glassfish tolerate a wide range of temperatures, it’s still wise to use a heater.

That way, you ensure their tank remains at a consistent temperature. The result is less stress on your fish’s body.


Glassfish are primarily carnivores. They enjoy eating foods such as:

  • Bloodworms
  • Tubifex worms
  • Mosquito larvae

Feeding your glassfish the fresh or frozen version of these foods is an excellent option. We recommend avoiding dried food and flakes, though, for glassfish will turn up their noses to it.

That said, glassfish will usually eat high-protein fish pellets.

You should feed your glassfish twice daily and allow them to dine on their food for two to three minutes. Then, remove the food that remains.

Doing so prevents them from overeating and decomposing food from turning into toxins in their tank.

Glassfish on Dark Background


Should you wish to breed your glassfish, move them to a tank with lots of plants and direct morning sunlight. You should also ensure the temperature remains between 70°F to 75°F.

Place six to eight glassfish in the breeding tank and begin feeding them a high protein diet, preferably from fresh food sources.

You’ll know your fish are ready to spawn when the males take on an intenser yellowish hue, and the females grow rounder bellies. At that point, increase the water temperature to the low 80s.

The females will then release up to 200 eggs, and the males will fertilize them. Remove the fish soon after that happens.

Otherwise, they might start eating the eggs.

The fry (baby glassfish) will hatch in 24 hours. But caring for them is challenging, so you’ll need to keep the tank well-stocked with small brine shrimp.

Common Diseases

Sadly, glassfish treated with injectable dyes have a significantly higher chance of disease than those with their natural color.

Some of the most common diseases these dye-injected glassfish suffer from include:

  • Ich
  • Fin rot
  • Lymphocystis

To be fair, even non-injected glassfish can suffer from the conditions above. But since they’ll have a higher immune system, their chances of contracting these diseases are less.

Ich is a parasitic infection with a long life cycle that makes it challenging—but not impossible—to kill the perpetrator.

In contrast, fin rot is either a fungal or bacterial infection that eats away at the fins, leaving them stringy and with a white appearance.

Finally, lymphocystis is a virus without a cure. It causes glassfish to develop white cysts until the fish eventually dies.

The good news is that fin rot is rarely deadly, and ich is curable if you catch it early and remain vigilant. In these cases, adding salt to the water is often beneficial for helping to strengthen the glassfish’s immune system.

Several ich and fin rot mediations also exist on the market. Applying these medications to their tank and doing frequent partial water changes will help get your glassfish back to optimal health.

Frank M. Greco [CC-BY-SA-3.0]

Potential Tank Mates

Glassfish get along with many other fish species. But you should never use other species as a replacement for glassfish.

So, once you have a minimum of five glassfish in the tank, you’re welcome to add other fish such as:

  • Guppies
  • Small tetras
  • White cloud mountain minnows

Should you add other fish species to your glassfish’s tank, buying a larger tank size per how much space the other fish need is crucial.