Can Parallel Cory and Peacock Eel Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Possible with Caution

Keeping Parallel Cory and Peacock Eel together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 150 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Parallel Cory

Corydoras parallelus

Peacock Eel

Macrognathus siamensis

🐠Family Group
Parallel Cory
Catfish
Peacock Eel
Oddballs
Temperament
Parallel Cory
Peaceful (1/10)
Peacock Eel
Peaceful (2/10)
Temperature
✓ Compatible
Parallel Cory
24–28°C
Peacock Eel
23–28°C
pH Range
✓ Compatible
Parallel Cory
5.5–7
Peacock Eel
6.5–8
Hardness (dGH)
✓ Compatible
Parallel Cory
1–10
Peacock Eel
5–15
Water Type
✓ Compatible
Parallel Cory
Freshwater Only
Peacock Eel
Freshwater Only
Flow Preference
✓ Compatible
Parallel Cory
Moderate
Peacock Eel
Low
Min Tank Volume
Combined: 150 L
Parallel Cory
60 L
Peacock Eel
150 L
Swimming Level
Shared: 1 zone
Parallel Cory
Bottom
Peacock Eel
Bottom
🏷️Behavior Tags
Parallel Cory
Shy / Slow Moving (Easily Stressed)
Peacock Eel
Digger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)Shrimp EaterFry PredatorAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Parallel Cory and Peacock Eel?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Parallel Cory
Peacock Eel
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Behaviour & Temperament

Parallel Cory is a peaceful species (1/10), while Peacock Eel is peaceful (2/10). This modest difference means Peacock Eel may occasionally assert dominance over Parallel Cory.

Parallel Cory and Peacock Eel both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Peacock Eel is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Peacock Eel is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–10 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Parallel Cory and Peacock Eel together, plan for an aquarium of at least 150 litres with a minimum length of 90 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Plants - Densely covered. Meeting these requirements will help both species thrive.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Parallel Cory and Peacock Eel need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Parallel Cory and Peacock Eel.

Show 9 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Peacock Eel is an aggressive eater that may prevent Parallel Cory from getting enough food.

Because Peacock Eel is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Parallel Cory receives an adequate share.

Frequently Asked Questions

Can Parallel Cory and Peacock Eel live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 150 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Parallel Cory and Peacock Eel need?

A minimum of 150 litres (tank length at least 90 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Parallel Cory and Peacock Eel together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Parallel Cory or Peacock Eel aggressive?

Parallel Cory is peaceful (1/10) and Peacock Eel is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Parallel Cory and Peacock Eel need?

Both species overlap in the 6.5–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Peacock Eel being nocturnal affect compatibility?

Peacock Eel is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Peacock Eel during evening hours.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 11, 2026
Last updated
May 11, 2026
Issues or corrections?
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