---
type: species
title: "Delhezi Bichir Care Guide: Keeping the Stunning Barred Polypterus"
slug: "delhezi-bichir"
category: "freshwater"
scientificName: "Polypterus delhezi"
subcategory: "Bichir"
lastUpdated: "2026-04-26"
readingTime: 10
url: https://www.fishstores.org/species/delhezi-bichir
---

# Delhezi Bichir Care Guide: Keeping the Stunning Barred Polypterus

*Polypterus delhezi*

Master Delhezi Bichir care. Learn about Polypterus delhezi tank size (50+ gal), diet, compatibility, and how to keep this prehistoric Barred Bichir thriving.

## Species Overview

The Delhezi Bichir (*Polypterus delhezi*) is a living fossil. While most aquarium species trace their lineage back tens of millions of years, bichirs as a group split off from the main fish line roughly 400 million years ago — long before dinosaurs walked the earth. Run a finger along a Delhezi's flank and you can feel that history: the body is sheathed in interlocking ganoid scales that function more like armor plating than the cycloid scales of a tetra or barb.

Among the bichir family, the Delhezi (also called the Barred Bichir or Armored Bichir) is one of the most striking and one of the most manageable. It tops out around 12 to 14 inches, which is a fraction of the size of monster bichirs like the *P. endlicheri* or *P. bichir bichir*, yet it carries the same prehistoric profile and the same nocturnal predator behavior. For an intermediate hobbyist who wants a centerpiece oddball without committing to a 180-gallon build, this species is the sweet spot.

| Field       | Value               |
| ----------- | ------------------- |
| Adult size  | 12-14 in (30-36 cm) |
| Lifespan    | 15-20 years         |
| Min tank    | 55 gallons          |
| Temperament | Peaceful predator   |
| Difficulty  | Intermediate        |
| Diet        | Carnivore           |

### The "Barred" Aesthetic: Identifying *Polypterus delhezi*

The defining visual trait of the Delhezi is the series of 8 to 12 vertical dark bars that run down the dorsal half of the body. These bars sit over a base color that ranges from olive-green to slate-grey, with a creamy or pale-yellow belly. The dorsal fin is not a single sail like most fish — instead, the species carries a row of 9 to 14 individual finlets along the spine, each one independently raised or lowered.

Delhezi are upper-jaw bichirs, meaning the upper jaw protrudes slightly past the lower jaw. This is a useful identification cue when distinguishing them from lower-jaw species like the [Endlicheri Bichir](/species/endlicheri-bichir), which carry a heavier, undershot lower jaw. Bar quality varies enormously between individual specimens — and this is exactly the variation that makes LFS pattern selection so important (more on this below).

### Natural Habitat: The Congo River Basin

*Polypterus delhezi* is native to the central Congo River basin and its slow-moving tributaries in the Democratic Republic of the Congo. The water there is warm, soft, and tannin-stained from leaf litter and overhanging vegetation. Visibility is poor, current is moderate, and the substrate is fine sand or silt overlaid with submerged wood and root mats.

Bichirs in the wild spend most of the day wedged into root tangles or buried partially in soft substrate, then emerge at dusk to hunt small fish, crustaceans, and invertebrates. Their primitive lung-like organ — a modified swim bladder that acts as a labyrinth-style breathing apparatus — lets them survive in low-oxygen backwaters that would kill most other fish, which is why they can be found in stagnant flood pools during the dry season.

### Lifespan and Maximum Size (12–14 inches)

In a properly sized tank with good water quality, a Delhezi Bichir will live 15 to 20 years. They grow slowly — expect a 4-inch juvenile to take roughly two years to reach 10 inches, and another year or two to hit full adult size. This slow growth is one of the reasons people dramatically undersize their tanks: a 6-inch Delhezi looks perfectly comfortable in a 40-gallon, but the same fish at 13 inches needs at least double that footprint to turn around without scraping itself.

## Water Parameters & Tank Requirements

Bichirs are tougher than they look when it comes to water chemistry, but tougher doesn't mean indestructible. The two parameters that genuinely matter for long-term Delhezi health are stability and dissolved oxygen at the surface — not exact pH or hardness numbers.

### Ideal Parameters: Temp (77-82°F), pH (6.0-7.5), Soft to Medium Hardness

Aim for 77 to 82°F (25 to 28°C), pH between 6.0 and 7.5, and soft to medium hardness (4 to 15 dGH). Most municipal tap water in North America falls within this range without any adjustment. Ammonia and nitrite must read zero at all times; nitrate should stay under 30 ppm with weekly 30 percent water changes.

| Parameter         | Target                    | Notes                                                 |
| ----------------- | ------------------------- | ----------------------------------------------------- |
| Temperature       | 77-82°F (25-28°C)         | Stable temperature matters more than the exact number |
| pH                | 6.0-7.5                   | Slightly acidic to neutral preferred                  |
| Hardness (dGH)    | 4-15                      | Soft to moderately hard                               |
| Ammonia / Nitrite | 0 ppm                     | Non-negotiable                                        |
| Nitrate           | Under 30 ppm              | Weekly 30% water changes                              |
| Min tank size     | 55 gallons (75 preferred) | Floor footprint matters more than volume              |

### The Importance of Floor Space: Why a "Breeder" Footprint Matters

A Delhezi spends 95 percent of its life within an inch of the substrate. That makes the tank's floor footprint — length times width — far more important than total water volume. A 75-gallon "breeder" with an 18-inch front-to-back depth gives an adult Delhezi room to actually turn its body without contortion. A standard 75 with a 21-inch depth is even better. A 55-gallon tank works as a long-term home only because it offers a 48-inch length, but the 13-inch depth is genuinely tight for a fully-grown specimen.

Pair the right footprint with a fine sand substrate. Smooth pool filter sand or aragonite-free aquarium sand is ideal — the species was built to scoot and bury, and rough gravel will scrape the underside of the body and lead to chronic skin irritation. For a deeper look at substrate selection across the hobby, see our [freshwater fish guide](/guides/freshwater-fish).

> **Skip the gravel and sharp decor**
>
> Coarse gravel, lava rock, and sharp slate edges are the most common cause of physical injury in captive bichirs. Their soft bellies drag along the substrate constantly, and a single sharp piece of decor can cause persistent abrasions that invite secondary bacterial infection. When in doubt, run your hand across any decor before adding it — if it feels rough to your palm, it's too rough for the fish.

### Filtration and the "Bichir Jump": Securing Your Lid

Bichirs are notorious escape artists. Their facultative breathing means they can survive on a carpet for hours — which gives them ample time to die slowly if they slip out of an unsecured tank. Every external opening must be covered. That means filter intake gaps, the cutout for HOB filters, the slit for heater cords, and the lid itself.

Use a glass canopy with all openings sealed by foam or mesh, or build a custom acrylic top with weighted edges. Standard plastic hoods leave too many cord gaps. Pair the secured lid with a canister filter rated for at least 4x the tank volume per hour — bichirs are heavy producers of waste, and the slow current of a canister mimics their natural habitat better than a wave-style powerhead.

> **The ten-minute lid that costs a fish**
>
> The most common cause of premature bichir death isn't disease — it's escape. Owners often leave the lid open during a quick water change or feeding, walk away for a phone call, and return to find the fish on the floor. Treat the lid like a submarine hatch. Closed and latched, every single time, before you do anything else.

## Diet & Feeding

Delhezi Bichirs are obligate carnivores with poor eyesight and an exceptional sense of smell. They hunt by tracking chemical cues in the water, then snapping at prey with surprising speed once they've zeroed in. This sensory bias has practical implications: pellets need to smell like food (sinking, meaty, oily) and they need time to settle.

### Carnivorous Instincts: Best Sinking Pellets and Frozen Foods

Build the staple diet around high-quality sinking carnivore pellets — Hikari Massivore, NLS Predator Formula, or Repashy Grub Pie are all excellent. Supplement two to three times per week with frozen foods: bloodworms, frozen krill, mysis shrimp, and chopped tilapia or smelt strips. Variety matters; a Delhezi fed only pellets will eat them but will not thrive long-term the way one fed a rotating diet will.

Feed adults three to four times per week, not daily. These are slow-metabolism predators that gorge then digest for days in the wild. Daily feeding leads to obesity, fatty liver disease, and reduced lifespan. Juveniles can be fed every other day until they reach 8 inches, then taper down to the adult schedule.

### Live Feeding vs. Prepared Foods

Skip live feeders. Goldfish and rosy reds are the worst possible "live food" for a captive bichir — they carry parasites, disease, and an excess of thiaminase that breaks down vitamin B1 over time, leading to neurological problems. If you genuinely want to offer live prey, stick to home-cultured options like blackworms, earthworms, or river shrimp from a clean source.

### Nighttime Feeding Strategies

Bichirs are most active at dusk and through the night. Drop food in 30 minutes after the lights go off, when the fish has emerged from its daytime hide and is actively cruising. If you keep tank mates that compete aggressively for food at the surface, target-feed the bichir directly with long aquarium tongs — it ensures the slow-moving predator actually gets its share before mid-water fish swarm the food.

## Tank Mates & Compatibility

The compatibility rule for any Delhezi is simple: tank mates must be too large to fit in the bichir's mouth, and they must not be aggressive fin-nippers. Get either part wrong and you'll lose fish.

### Suitable Large Tank Mates (Silver Dollars, Datnoids, Large Cichlids)

The classic Delhezi community pairs the species with mid-water schooling fish that are too tall and too fast to be eaten. Silver Dollars are the gold standard — they grow to 6 inches, occupy the upper third of the tank, and ignore the bichir entirely. Datnoids, larger Geophagus cichlids, peaceful Severums, and Bala Sharks all work in the same role. Bottom-dwelling tank mates are trickier because they compete for the same floor space; large [Tiger Shovelnose Catfish](/species/tiger-shovelnose-catfish) or armored plecos like the [Sailfin Pleco](/species/sailfin-pleco) are usually fine, but only in tanks of 125 gallons or more.

### Species to Avoid: Small Fish and Aggressive Bottom Dwellers

Anything under 3 inches is food. That includes neon tetras, guppies, harlequin rasboras, and small corydoras — even if the Delhezi seems to ignore them at first, eventually it will hunt one down at night and the rest will follow. Equally bad are aggressive bottom-dwellers like Red Devil Cichlids, Jack Dempseys, or large Loricariid plecos that suck on the bichir's flanks for the protective slime coat. Sucker damage from a hungry pleco is one of the most common chronic injuries seen in adult bichirs.

### Keeping Delhezi Bichirs in Groups

Delhezi can be kept in groups of two or three of the same species, provided the tank is large enough (125 gallons minimum for a group). They aren't social in the way schooling fish are — they tolerate each other rather than seek each other out — and you'll occasionally see scuffling at feeding time. Multiple males will sometimes fence with their finlets, but serious damage is rare as long as everyone has a hide of their own.

## Common Health Issues

### External Parasites (*Macrogyrodactylus polypteri*)

The most species-specific bichir parasite is *Macrogyrodactylus polypteri*, a monogenean fluke that lives on the skin and gills of *Polypterus* species. Wild-caught and even some captive-bred Delhezi can arrive with a low-grade infestation that flares up under stress. Symptoms include flashing against decor, excess slime production, and labored breathing.

The standard treatment is praziquantel dosed at 2 mg per liter, repeated after 7 days. Diagnose carefully before treating — generic ich and fungal medications won't touch *Macrogyrodactylus*, and aggressive copper-based treatments can be fatal to bichirs.

### Physical Injuries from Sharp Decor or Jumping

The other persistent threat to Delhezi health is mechanical injury. Belly abrasions from rough substrate, snout damage from glass-banging at lights-out, and missing scales from a failed jump attempt all open the door for bacterial infection. Treat any visible wound proactively with daily 25 percent water changes and a methylene blue dip if the wound looks inflamed. Most superficial damage heals on its own — the species' armored scales regenerate, just slowly.

## Where to Buy & What to Look For

Delhezi Bichirs are commonly available at well-stocked LFS and through specialty online retailers, typically priced between $35 and $80 for a 4 to 6 inch juvenile. Captive-bred specimens are increasingly available and are generally hardier than wild imports, though wild Delhezi often display more dramatic bar patterns.

### Assessing Pattern Quality and Fin Health at the LFS

Pattern variation between individual Delhezi is dramatic. Some specimens carry crisp, high-contrast vertical bars that stand out against the body; others have faded, blurry bars that almost disappear into the base color. Pattern is set genetically and will not improve significantly with diet or water quality, so buying a juvenile with weak bars and hoping it'll fill in is a losing bet.

When inspecting a juvenile, ask the LFS to net it into a small bag where you can see the body straight-on rather than through curved tank glass. Look for:

### Buyer Checklist

- [ ] 8 to 12 distinct vertical bars across the dorsal half of the body
- [ ] High contrast between the bars and the base body color
- [ ] All finlets present and standing upright (no missing or shredded finlets)
- [ ] Clear eyes with no cloudiness or pitting
- [ ] Clean, intact pelvic fins underneath the body (these get damaged easily in shipping)
- [ ] Active, alert behavior with the fish exploring the bag rather than lying flat
- [ ] No visible sores, fungus patches, or red streaks along the lateral line
- [ ] Belly is full and rounded, not sunken or pinched

> **Why a local store visit beats online ordering for bichirs**
>
> Pattern variation is the single biggest reason to buy a Delhezi in person. Online retailers send you whatever fish is in the bag, and a high-contrast specimen will be the centerpiece of your tank for the next 15 to 20 years. Walk the LFS, ask to see all the juveniles in the tank, and pick the one with the boldest bars. A reputable local store will let you point at a specific fish.

### Quarantining New Polypterus

Quarantine every new Delhezi for at least 4 weeks in a 20-gallon bare-bottom tank. The combination of long shipping times, parasite risk, and the species' tendency to mask stress until it's too late makes this non-negotiable. Run the QT tank with a sponge filter, a heater, and a single piece of PVC pipe for cover. Treat preemptively with praziquantel (2 mg/L, two doses 7 days apart) to clear *Macrogyrodactylus*, observe for any secondary issues, and only move the fish to the display tank once you've seen consistent feeding for 14 days. For the basics on acclimating a new arrival, see our [acclimation guide](/guides/how-to-acclimate-fish).

## Quick-Reference Cheat Sheet

The Delhezi Bichir rewards an intermediate hobbyist who's willing to commit to a properly sized tank, clean substrate, secured lid, and a varied carnivorous diet. Get those four elements right and the species will reward you with two decades of slow, prehistoric presence — a fish that watches the tank from the substrate the way a crocodile watches the bank.

**Find a local fish store** — [Find stores near me](https://www.fishstores.org/near-me)

## Frequently Asked Questions

### How big do Delhezi Bichirs get?

In captivity, they typically reach 12 to 14 inches. While smaller than the Polypterus endlicheri, they still require a wide tank (at least 18 inches front-to-back) to turn comfortably as they mature.

### Are Delhezi Bichirs aggressive?

They are predatory but generally peaceful toward fish they cannot swallow. They are gape-limited predators; if a tank mate fits in their mouth, it will eventually be eaten, but they rarely harass larger fish.

### Do Delhezi Bichirs need an air pump?

They are facultative air-breathers and will swim to the surface to gulp air. While they don't need an air stone for oxygenation like other fish, you must leave a gap of air between the water line and the lid.

### What is the best substrate for a Delhezi?

Smooth aquarium sand is best. Bichirs are bottom-dwellers that scoot along the floor; rough gravel can scrape their bellies, and large pebbles can trap waste or be accidentally swallowed during feeding.

### Can I keep a Delhezi Bichir in a 40-gallon tank?

A 40-gallon Long or Breeder works for juveniles, but adults need at least a 55-gallon or 75-gallon tank due to their length and the need for significant floor surface area.

---
*Source: [FishStores.org](https://www.fishstores.org/species/delhezi-bichir)*
*Last updated: April 26, 2026*