What Do Pleco Fish Eggs Look Like? A Detailed Picture Guide

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Pleco fish are really interesting, I agree. Besides looking nice, it’s pretty exciting to see them lay eggs.

But what do their eggs actually look like? How can you tell the differences between eggs that are fertilized, unfertilized, and infected? And what should you do in each situation?

In this article, you’ll learn everything about this topic, so you leave with all the information you need. Let’s jump right in.

Also Read: Pleco Fish Eggs

What Do Pleco Fish Eggs Look Like?

When it comes to the appearance of Pleco fish eggs, there are three primary states to take into account: fertilized, unfertilized, and fungus-infected eggs.

Here’s the essential information you need:

FeatureFertilized EggsUnfertilized EggsEggs Affected by Fungus
ColorationLight amber or opaqueClearer, lacking amber tintCottony or fluffy white appearance
SizeConsistent, 2-4mmIrregularNot specified
OpacityNon-transparentMore transparentLikely opaque due to fungal growth
GuardingVigilant parental guardingLesser guardingEggs may be abandoned
PositioningSecure, hidden locationsMay be in more exposed areasTypically found isolated
Additional InfoIndicate high chance of successful hatching, robust and vitalIndicate non-viable state, permit more light passageRisk of total contamination, immediate action essential for treatment

1. Fertilized Pleco Fish Eggs

Fertilized Pleco fish eggs exhibit a healthy, vibrant appearance, generally embodying a light amber or opaque color. Plecos guard these eggs vigilantly, underscoring their vitality.

  • Coloration: Fertilized eggs possess a light amber or opaque hue. Plecos’ healthy eggs usually reflect this coloration, indicating a high chance of successful hatching.
  • Size: Fertilized eggs are consistently sized. Plecos typically lay eggs measuring around 2 to 4mm, showcasing a uniform appearance.
  • Opacity: Fertilized eggs appear non-transparent. Plecos’ fertile eggs, robust and vital, do not allow light to pass through easily, signaling healthy development.
  • Parental Guarding: Vigilant parental guarding is observed. Plecos often guard their fertilized eggs zealously, a natural instinct ensuring offspring’s survival.
  • Positioning: Eggs are generally found in secure locations. Plecos choose hidden, safe spots for egg-laying, minimizing external threats to the embryos.

2. Unfertilized Pleco Fish Eggs

Unfertilized Pleco eggs generally lack the robust characteristics of fertilized eggs, appearing more transparent and lacking the healthy amber tint.

Plecos may not guard these eggs as attentively, revealing their non-viable status.

  • Coloration: Unfertilized eggs showcase a clearer appearance. Plecos’ unfertilized eggs lack the amber tint, signifying their non-viable state.
  • Size: These eggs may appear irregular in size. Plecos’ unfertilized eggs often deviate in dimensions, lacking the uniformity of fertilized counterparts.
  • Opacity: Unfertilized eggs are more transparent. Plecos’ non-viable eggs permit more light passage, underscoring their lack of development.
  • Parental Guarding: Lesser guarding is observed with unfertilized eggs. Plecos may intuitively recognize the eggs’ state, exhibiting diminished protective behaviors.
  • Positioning: Eggs may be located in more exposed areas. Plecos, sensing the eggs’ non-viable nature, might not prioritize securing their placement.

Also Read: Fertilized vs. Unfertilized Pleco Eggs

3. Pleco Fish Eggs Affected by Fungus

When Pleco fish eggs are affected by fungus, they exhibit a cottony or fluffy white appearance.

Plecos may abandon these eggs, as the fungal invasion denotes a loss of viability.

  • Appearance: Fungus-infected eggs exhibit a cottony look. Plecos’ eggs, when plagued by fungus, bear a distinctive fluffy white surface, signaling a loss of vitality.
  • Abandonment: Infected eggs may be deserted by the parents. Plecos often leave these compromised eggs, acknowledging the unlikely survival of the embryos.
  • Spread: Fungus can quickly overrun an entire clutch. Plecos’ egg clusters risk total contamination if any egg succumbs to fungal invasion, jeopardizing the entire brood.
  • Treatment: Immediate action is essential to prevent spread. Plecos’ healthy eggs require swift isolation from affected ones to curtail extensive damage.
  • Positioning: Infected eggs are typically found isolated. Plecos may instinctively distance the diseased eggs, minimizing fungal transmission to healthy ones.

Do Different Plecos Share the Same Egg Appearances?

No, different Pleco species do not share the exact same egg appearances. There are subtle differences, particularly in size and color, among the eggs of various Pleco species.

  • Common Pleco (Hypostomus plecostomus): Eggs are relatively large, creamy, and robust. Plecos of this species produce eggs with a sturdy, opaque appearance.
  • Bristlenose Pleco (Ancistrus spp.): Eggs are smaller and orange-hued. Plecos in this category present a distinctive, vibrant egg coloration.
  • Zebra Pleco (Hypancistrus zebra): Zebra Pleco eggs exhibit a light yellow tint. Plecos of this type lay eggs with a unique pale coloration.
  • Clown Pleco (Panaqolus maccus): Eggs of Clown Pleco are tiny and light-colored. Plecos in this class offer minute, delicate egg forms.
  • Royal Pleco (Panaque nigrolineatus): Royal Pleco eggs are notable for their size and opacity. Plecos of this species maintain substantial, non-transparent eggs.

When Can You Determine Unfertilized Eggs?

You can determine unfertilized Pleco eggs usually within 3 to 7 days post-laying, as they fail to develop and exhibit characteristic transparency.

Plecos’ unfertilized eggs also might not be guarded by the parents, signaling their non-viable status.

  • Within 24 Hours: Unfertilized eggs might not adhere to surfaces. Plecos’ fertilized eggs typically stick to surfaces, while non-viable ones may detach within a day.
  • 2-3 Days Post-Laying: Lack of noticeable developmental changes hints at non-viability. Plecos’ fertilized eggs generally begin showing embryonic signs in this period.
  • By Day 4-5: Unfertilized eggs may start decaying, exhibiting a noticeable off-putting smell. Plecos’ non-viable eggs lack the growth progress, leading to early decay.
  • Within a Week (3-7 days): Clear, unchanged appearance highlights unfertilized status. Plecos’ non-viable eggs maintain transparency, devoid of any growing embryo within this period.

How to Handle Pleco Fish Eggs

As mentioned previously, by examining your Pleco fish’s eggs, you can determine whether they are fertilized, unfertilized, or affected by fungus. Here’s how to handle each situation:

1. Tips for Fertilized Eggs

Handling fertilized Pleco eggs demands delicate care to ensure their viability and successful development.

Creating a conducive environment mirrors their natural habitat, aiding in healthy growth.

  • Temperature Control: Keep the aquarium at 78-82°F (25-28°C). Plecos’ eggs need consistent warmth, use a reliable heater and thermometer. I personally went with the Fluval E300 Advanced Heater (link to Amazon).
  • Gentle Water Current: Employ a low-flow water pump. Plecos’ eggs flourish in mild currents, simulating their natural river environments.
  • Proper Aeration: Use an aquarium air stone for adequate oxygen. Plecos’ eggs demand sufficient oxygen, ensuring proper growth and development. My recommendation: Hygger Aquarium Air Stone (link to Amazon).
  • Security: Create secluded spots using caves or PVC pipes. Plecos lay eggs in hidden areas, replicating this provides a feeling of safety.
  • Lighting: Maintain low, indirect lighting in the tank. Plecos’ eggs require dim light, resembling the subdued lighting of their natural habitat.

2. Managing Unfertilized Eggs

Unfertilized Pleco eggs should be removed promptly to prevent contamination and ensure the health of the remaining eggs. Proper identification and timely action are critical.

  • Timely Removal: Extract unfertilized eggs within 3-7 days. Plecos’ non-viable eggs, left unchecked, could decay and pollute the water.
  • Use a Turkey Baster: Gently remove the eggs using a turkey baster. Plecos’ delicate ecosystem remains undisturbed with this careful extraction method.
  • Observe Remaining Eggs: Closely monitor the other eggs for changes. Plecos’ healthy eggs should continue to show growth and development.
  • Water Quality: Regularly check and maintain water parameters. Plecos’ environment must stay clean to avoid further egg issues.
  • Consult Expert: When in doubt, seek professional advice. Plecos’ well-being and successful breeding rely on informed decisions.

3. Addressing Fungus-Infected Eggs

Fungus-infected Pleco eggs require immediate action to curtail further spread. Efficient isolation and treatment are paramount for safeguarding the rest of the clutch.

  • Immediate Isolation: Separate infected eggs instantly to prevent spread. Plecos’ healthy eggs remain protected through swift action and segregation.
  • Anti-Fungal Treatment: Apply a mild anti-fungal agent as advised. Plecos’ egg clusters benefit from timely, appropriate medication, ensuring their survival. The well-known Seachem PolyGuard (link to Amazon) will do the trick.
  • Thorough Cleaning: Clean the affected area meticulously. Plecos’ breeding environment should be pristine to avoid recurrent fungal issues.
  • Monitor the Clutch: Keep a close eye on the remaining eggs. Plecos’ uninfected eggs need vigilance to confirm no further fungal invasion.
  • Healthy Environment: Reinstate and ensure optimal tank conditions. Plecos’ thriving depends on clean, balanced water and suitable temperatures.

Steps to Follow If Fertilized Pleco Fish Eggs Fail to Hatch

If fertilized Pleco fish eggs fail to hatch, it’s crucial to promptly identify and address the potential causes to enhance future breeding success.

Proper assessment and corrective actions can help improve the hatching rate for Plecos and ensure the well-being of your fish.

  • Evaluate Water Parameters: Ensure water temperature is 78-82°F (25-28°C) and pH 6.5-7.5. Plecos’ eggs need these precise conditions for healthy development and successful hatching.
  • Inspect Egg Health: Observe for unusual colors or spots on the eggs. Plecos’ infected eggs require immediate removal and possibly treatment of the entire clutch.
  • Review Parental Care: Monitor the adult Plecos for attentive egg care. Plecos, if stressed or uncomfortable, might inadvertently harm or abandon the eggs.
  • Analyze Diet: Feed Plecos high-quality pellets, vegetables, and occasional proteins. Plecos’ robust health, ensured by a balanced diet, contributes to successful breeding.
  • Check Equipment: Ensure heaters, pumps, and filters function correctly. Plecos’ eggs need consistent temperature and clean, well-oxygenated water for optimal development.
  • Consult an Expert: Reach out to experienced breeders or veterinarians. Plecos’ breeding success increases with expert insights and personalized advice for your setup.


For those of you who are just skimming through, here’s a short recap:

  • Fertilized Pleco fish eggs are identifiable by their healthy amber or opaque color, uniform size, non-transparency, and vigilant parental guarding, indicating a high chance of successful hatching.
  • Unfertilized Pleco fish eggs lack the robust characteristics of fertilized eggs, appearing more transparent, irregular in size, and less guarded, signaling their non-viable status.
  • Pleco fish eggs affected by fungus exhibit a cottony white appearance and are often abandoned by the parents, requiring immediate treatment to prevent the spread of the infection.
  • Different Pleco species have distinct egg appearances in terms of size and color, allowing for species differentiation.
  • Unfertilized Pleco eggs can be identified within 3 to 7 days post-laying based on transparency, lack of adherence, developmental changes, and odor, prompting their removal.