Adult guppies—including the mother—may eat newborn fry, and some tankmates can prey on them too. Aquarium Co-Op and the Ornamental Aquatic Trade Association (OATA) recommend hiding places such as dense plants; separating fry in a suitable breeding net or rearing tank can offer more protection. Neither approach guarantees that every fry will survive.
Which fish eat guppy fry?
Adult guppies, including the mother
Guppies may eat their own young, particularly when newborns have nowhere to hide. Do not assume the mother is safe to leave with the fry. Aquarium Co-Op discusses this risk in its guppy care guide.
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Other fish that can catch and swallow fry
In a response to an aquarium question, sera names characins around 6 cm (2.4 in), including Hyphessobrycon, and dwarf cichlids, mainly Apistogramma, as fry predators. These are examples, not a universal list of suitable tankmates or a guarantee that a particular fish will target only fry. Sera also cautions that dwarf cichlids may reproduce, creating another population-management issue. See the sera FAQ response, signed by Dr. Bodo Schnell.
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Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →Predation depends on the fish and circumstances. A tankmate able to catch and swallow a fry may be a risk, but a predator should not be treated as a safe, reliable way to control guppy numbers. PetMD recommends peaceful, compatible tankmates and notes that goldfish prefer cooler water and can grow large enough to eat guppies; that is a compatibility warning, not a recommendation to use goldfish to manage fry. Its guppy care guide also emphasizes hiding places.
#1 Best Overall
- Medium Hatching Box: With inner size of 5.3" L x 3.5" W x 3.9" H, it protects newborn fry from being eaten or attacked, improving the survival rate of newborn fish.
- Versatile Uses: 2 removable separators constitute 3 rooms. The bottom is the hatchery for baby fish, and another 2 rooms can be used to isolate aggressive or sick fish.
- Floating Design: The balancing panel and 2 handles help keep the box floating in water, it can also be secured inside the tank with 2 suction cups. Space-saving during use.
- Acrylic Material: The highly transparent acrylic box allows you to watch the breeding process or fish fighting without any barriers, bringing you with endless enjoyment.
- Easy to Use: The incubator can be easily installed or disassembled for cleaning without any tool. And its side vents ensure optimum water flow, requiring no heater or air pump.
How can you protect guppy fry?
Add dense plant cover in the community tank
Thick plant growth gives fry places to hide from adults and other fish. Aquarium Co-Op specifically identifies java moss as cover young guppies can use to escape larger fish. OATA warns that breeding in a community aquarium may be unsuccessful without substantial plant growth. Cover can improve their chances, but it does not ensure survival.
Separate fry for more control
If you want to protect more of a batch, move the fry to a suitable rearing space or use a breeding net large enough for them. OATA also advises separating the female from newborns to reduce the risk that she will eat them. Separation means providing appropriate water quality and care in the new space; it is not a survival guarantee. See OATA’s guppy and molly care sheet.
Rank #2
- Mesh on 3 Sides Plus Base: Ultra-fine 316 stainless mesh with 0.012 in (0.3 mm) openings keeps newborn fry inside while water moves through the left, right, back and base; the solid clear front gives you a full view without opening anything.
- Mother & Fry Separation: The raised transparent separator sits mid-box; its V-slots let newborn fry slip through to the lower area while the mother stays above—made for pregnant livebearers such as guppies, mollies, platies and swordtails.
- 2 removable perforated dividers slide down the U-channels to separate adult fish—house 2 females before birth or keep a bully apart. Note: divider holes let fry swim through, so rely on the separator for fry, not the dividers.
- Mount It or Float It: 4 suction cups (2 spare) fix the box to the glass at any height, with the clear front facing you; pop the cups off and it floats near the surface. Overall 5.1" x 5.1" x 5.5"; it hangs in upper tank space, so check clearance before ordering.
- Short-Term Fry Care Kit: Includes 2 feeding droppers, a fine fry net and a folded quick-start sheet covering the first 21 days; built for birthing and early fry care in freshwater or saltwater (rinse in fresh water after salt use), not for long-term housing or medication baths.
Use gentle filtration and suitable food
For a fry rearing setup, Aquarium Co-Op recommends a sponge filter to reduce the chance that tiny fry will be sucked into filtration. It recommends feeding fry three to five smaller meals a day. Treat that frequency as Aquarium Co-Op’s care guidance, not a universal veterinary rule. OATA recommends specialist foods for fry.
Should you leave fry in the tank or separate them?
| Option | Best suited to | Trade-offs |
|---|---|---|
| Dense plants in the existing tank | Keepers who can provide substantial cover and are comfortable with some fry being lost. | Fry remain exposed to adult guppies and other tankmates; plants do not guarantee survival. |
| Breeding net or separate rearing space | Keepers seeking to protect more fry and able to maintain a suitable grow-out environment. | Requires adequate space, appropriate water quality, gentle filtration and feeding. OATA advises a breeding net large enough for the fry. |
The better fit depends on how much of the batch you want to protect, available tank and rearing space, your ability to maintain the grow-out setup, and whether the adult fish are compatible. The cited care guidance does not establish comparative survival rates for plants versus nets.
Rank #3
- Large Hatching Box: With inner size of 6.8" L x 4" W x 3.9" H, it protects newborn fry from being eaten or attacked, improving the survival rate of newborn fish.
- Versatile Uses: 2 removable separators constitute 3 rooms. The bottom is the hatchery for baby fish, and another 2 rooms can be used to isolate aggressive or sick fish.
- Floating Design: The balancing panel and 2 handles help keep the box floating in water, it can also be secured inside the tank with 2 suction cups. Space-saving during use.
- Acrylic Material: The highly transparent acrylic box allows you to watch the breeding process or fish fighting without any barriers, bringing you with endless enjoyment.
- Easy to Use: The incubator can be easily installed or disassembled for cleaning without any tool. And its side vents ensure optimum water flow, requiring no heater or air pump.
How many fry might there be?
OATA’s care sheet gives a range of 20–80 fry after a pregnancy and a pregnancy duration of 24–30 days; the page does not state a publication year. These figures help explain why a keeper may need to plan for a batch, but they do not predict how many fry a particular guppy will have or how many will survive.
Quick Recap
Best Value
- Breed, Isolate, Raise - All-in-1 Box: Serves as a hatchery for livebearers like guppies and mollies, an isolation/quarantine cage for sick or aggressive fish (e.g., bettas), a dedicated acclimation space for introducing new fish, and a protected zone where shrimp can molt or feed with confidence.
- Dual-Chamber & Dual-Layer Design: Dual chambers (with a removable divider panel) let you keep fish or fry apart as needed. The upper compartment lets a pregnant fish give birth, and newborn fry drop into the lower nursery section—shielding them from adult fish and improving survival outcomes.
- Dual Mounting Methods: The breeder box easily attaches with the included hanging hook or suction cups for flexible placement inside the tank. The adjustable spacer ring sets the box at the right distance from the tank wall so fish won’t get trapped. (For stability, keep the breeder box fully submerged during use.)
- Gentle on Delicate Fry: A secure lid with a feeding opening helps keep fish from jumping out. Fine 0.04" slit vents deliver ample water flow through the breeder while keeping even the tiniest fry contained. Crystal-clear walls turn the unit into a fish tank viewing box for observing behavior and health at a glance without disturbance.
- Easy Assembly & Complete Kit: Assembles in minutes with no tools required, and the removable bottom tray makes it simple to clean or release fish. Includes a fine-mesh net for safely catching or transferring fry, and cleaning pipettes for feeding babies or removing waste. Comes with all the accessories you need for convenient fish breeding and isolation.
Rank #4
- Large Breeder Box: Size: 3.95" L x 2.77" W x 5.1" H. The fish breeding box is an ideal haven for vulnerable fry, shrimp, and small fish. Effectively protect newborns from being eaten or attacked by other tank mates. Perfect for 10-40 gallon aquariums
- 2 Versatile Chambers: The removable funnel-like divider creates up to 2 separate rooms. The upper half can isolate aggressive or sick fish, and the lower space makes an ideal fry hatchery. Enjoy a peaceful tank with a higher fish survival rate
- Self-Floating Design: The hatching box always stays afloat in the tank. It can also be secured to the tank wall using the 2 attached suction cups. You can fully disassemble it for thorough cleaning and maintenance when needed
- Safe & Reliable: Include a cover with two 0.55-inch holes. It practically prevents fish from jumping out while allowing for easy feeding. And the side vents on the isolation box ensure smooth water flow all the time
- Robust & Clear: Made of strong plastic, the fish breeder won’t warp or crack easily. The high transparency enables you to monitor fish behavior and breeding activities without any barriers, bringing you endless enjoyment
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