Do Plecos Have Scales? [Do They Shed Their Scales?]

A pleco without scales

Most fish have scales that protect them and assist them in moving around. So, like other fish, do plecos have scales?

Plecos don’t have scales. Instead, they have bony plates that are often referred to as scales. The body of a pleco is covered by tough, bony plates called armor-clad scales. These bony plates protect the plecos from any harm. However, these plates are missing on the head and belly of the pleco fish.

Let’s now understand more about these pleco scales.

Do Plecos Shed Their Scales?

Plecos don’t shed their scales. Instead, they shed a coat of their protective slime or mucusor in some cases, a thin brown layer of guck called mulm. So it’s not the scales or skin that sheds, but the slime coat present on the top of the skin comes off as plecos grow.

When plecos shed their slime coats, most people mistakenly think they’re shedding their skin.

However, you can stop worrying about shedding because plecos don’t shed.

As plecos continue to grow, the protective slime on their skin must be shed.

It’s something that happens to many kinds of catfish and armored fish.

5 Reasons Why Plecos Shed Their Slime Coat

The slime coat comes off a pleco’s body as it keeps growing.

However, it also comes off in excess when plecos produce extra slime under stress.

Given below are some of the main reasons why plecos shed their slime coat.

1. Growth

Slime coat will build up and release when a pleco grows. It may appear as if the pleco is shedding its skin.

However, it’s what’s on the skin that is coming off.

If the water movement is fast in the tank, similar to their natural habitat, the plecos will sit near the flow so that the slime coat comes off.

The slime coat that comes off the pleco’s skin will accumulate at the bottom of the tank.

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2. Aggressive Tankmates

Plecos are peaceful fish and don’t like to be stressed.

So avoid keeping other bottom feeders that are faster than plecos in the same tank.

The other fish will directly compete with plecos for food and stress them.

If you keep large, aggressive fish with peaceful plecos, they can bully and injure the slower-moving plecos.

Increased stress can result in more slime generation, which eventually will come off the plecos’ skin.

Some tankmates that you can keep with plecos are:

  • Cichlids (docile ones),
  • Corydoras,
  • Guppies,
  • Mollies,
  • Gouramis,
  • Shrimp,
  • Hatchet fish,
  • Platy fish,
  • Swordtail, and
  • Freshwater crabs.

The peaceful pleco doesn’t like aggressive behavior.

If your pet pleco has trouble with aggressive fish, consider moving them to another tank or try a bigger tank.

3. Inadequate Tank Size

Most pleco species tend to grow large.

So the tank size needs to be at least 100 gallons to accommodate the large-sized adult plecos.

The plecos can get stressed in the absence of sufficient space to swim and move around the tank.

As a result, they can shed their slime coating.

4. Less Hiding Places

Pleco resting at the bottom of the tank

To keep your plecos calm and relaxed, provide them with enough hiding spots to avoid stress.

It can also reduce the build-up and shedding of excess slime.

Aquatic plants, caves, castles, overhangs, and shipwrecks are great hiding spots for plecos.

Most plecos also love eating and resting on driftwood. So include some of these decorations in the tank.

Plecos like to occupy the dark corners of the tank.

The shade helps to boost their immune system and reduce slime build-up and shedding.

5. Food Scarcity

Plecos are opportunistic scavengers that eat detritus and decaying fish.

However, plecos are extremely slow and will lose out on food if there is competition.

They will feel stressed due to the scarcity of food. This can trigger a faster build-up and release of slime in the aquarium.

So ensure that the plecos get a well-balanced diet that can fulfill their nutrient requirements and keep them healthy and stress-free.

When Should You Worry About Pleco Shedding?

Plecos shed their slime coat from time to time as they grow.

So there is no reason to worry if their increasing size results in the shedding of their slime coat.

On the other hand, if you see your pleco’s scales are peeling off or pointing out, it could be suffering from severe illness, infection, or bloating.

The scales of the pleco fish will not come off under normal circumstances. The damaged scales will also repair themselves.

However, if the scales start to peel off or they’re loose or damaged, you should seek a veterinarian’s advice as soon as possible.

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Does Water Quality Cause Plecos To Shed Their Slime Coat?

Water parameters, like water temperature and pH levels, should be suitable and stable for the plecos to stay happy and healthy.

Unsuitable water conditions will stress the plecos. As a result, they will start producing and shedding excess slime.

So it’s recommended to run a water test to check and maintain suitable parameters.

The ideal water parameters for plecos are:

Water Temperature: 73°F to 82°F (23°C to 28°C)

Water pH: 7.0 to 8.0

Water Hardness (dGH): 20 to 35

Plecos can also survive in tank conditions with varying water parameters.

However, it’s essential to provide them with stable water conditions for optimum health.