Reticulate round ray
Urotrygon reticulata
The Reticulate round ray features a distinctive pattern of intricate, dark brown reticulations on a pale background, with a rounded body and broad pectoral fins.
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About the Reticulate round ray
A small, demersal round ray endemic to the Gulf of Panama that inhabits shallow sandy bottoms. Like other stingrays it has a venomous tail spine, and it is assessed as Critically Endangered (IUCN, assessed 24 Jan 2020), so it should not be targeted for aquarium trade.
Also known as
Quick Facts
Size
24.1 cm TL
Temperament
Peaceful
Difficulty
Expert
Min Tank Size
180 gallons
Lifespan
10-15 years
Origin
Eastern Central Pacific (Panama area)
Diet
Carnivore - small benthic invertebrates (worms, crustaceans); in captivity would take meaty seafoods
Water Parameters
24-28°C
8.1-8.4
8-12 dGH
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This species needs 24-28°C in a 180 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeCare Notes
- Go big and go wide - think 240+ gallons with a big footprint (8x3 ft is a sweet spot) because they cruise and turn, not hover. Cover the bottom with fine sand and skip sharp crushed coral or you'll end up with belly and fin edge scrapes.
- Species-specific aquarium parameters for Urotrygon reticulata are not well-documented in authoritative references; if kept at all (e.g., public aquaria), maintain stable, clean, well-oxygenated marine conditions and avoid rapid parameter swings. Note: this species is Critically Endangered and should not be sourced for the aquarium trade.
- Feed meaty foods on the sand: chopped shrimp, squid, scallop, clam, and quality marine carnivore pellets once they recognize them. Target feed with tongs and make sure the food actually hits the bottom, or faster fish will steal it and the ray will slowly starve.
- New rays often come in skinny and picky - offer small meals daily at first, then move to 3-5 feedings a week once the disc thickens and they're hunting. Soak foods in a vitamin supplement weekly and consider adding iodine occasionally if your diet is mostly frozen seafood.
- Tankmates: choose calm, non-nippy fish that won't pester the ray or compete like maniacs at feeding time. Avoid triggers, large wrasses, puffers, and anything that bites fins or tries to sample the ray's eyes and spiracles.
- Skip most 'cleanup crew' crabs and big hermits - they can harass a resting ray and steal food right off its face. Snails are usually fine, and small sand-sifting stars are hit-or-miss depending on how food-driven they are.
- Watch for the usual ray problems: refusal to eat, rapid breathing, and red patches on the belly from rough substrate or ammonia spikes. Also cover every pump and overflow intake with guards - they will find the one gap and get pinned.
- Breeding is livebearer stuff (no eggs to find), but it's not a casual home project - you need lots of space, top-tier feeding, and stable water for months. If you ever see a male (claspers) chasing and 'biting' at the female's disc edges, that's normal courtship, but separate them if she looks stressed or gets torn up.
Compatibility
Good Tankmates
- Not recommended to keep with typical aquarium fishes; species is Critically Endangered and species-specific compatibility guidance is not established.
- Calm, open-water fish like larger fairy or flasher wrasses - active but usually not mean, and they stay up in the water column away from the ray
- Peaceful planktivores like chromis or hardy anthias - they cruise midwater and dont mess with the rays disk or tail
- Bigger, chill reef-safe angels (think swallowtail angels, Genicanthus) - generally polite tankmates that wont pick at the ray if well fed
- Docile tangs and bristletooth tangs (kole, tomini, etc.) - good as long as you avoid the super pushy ones and give everyone room
- Non-nippy sand-perchers like a watchman goby (paired with a pistol shrimp is fine) - they hang near the burrow and usually ignore the ray
Avoid
- Triggers (most species) - they love to test-bite stuff, and a rays eyes, spiracles, and tail are basically an invitation
- Puffers and porcupinefish - classic fin and tail pickers, and they get bold fast around a bottom-dweller that cant really get away
- Big aggressive wrasses (like many Thalassoma) - constant cruising plus attitude, and they can harass the ray when it is trying to rest or eat
- Large predatory groupers and big snappers - if it can fit the ray or its tail in its mouth, it will try, and even a failed attempt can wreck the ray
Where they come from
Reticulate round rays (Urotrygon reticulata) are little stingrays from the tropical western Atlantic and Caribbean. You will see them around sandy or muddy bottoms, often tucked into the substrate with just the eyes showing. That burying habit drives basically every decision you make in the aquarium.
This is not a 'pet ray for a reef tank' kind of animal. Think of it more like a specialized predator that needs a big, stable, sand-based marine system.
Setting up their tank
Give them floor space first, not height. A wide footprint lets them cruise and bury naturally, and it also spreads out waste better. I would not keep one in anything smaller than a 6 ft long tank, and bigger is genuinely easier because water stays steadier.
- Tank shape: long and wide beats tall every time (think 180g+ footprints, 6x2 ft or larger).
- Substrate: fine sand, 2-4 inches, no crushed coral. They will abrade on sharp grains.
- Rockwork: keep it minimal and stable. Put rock on the glass or on a solid base, then add sand around it so they cannot undermine it.
- Flow: moderate overall, but leave calm sandy zones so they can settle without being blasted.
- Filtration: oversized skimmer + lots of biological capacity (sump with big media volume). These rays are messy eaters.
- Cover: tight lid. They can startle and slap up water, and you do not want salt spray everywhere.
Avoid exposed heater tubes, powerhead intakes, and sharp overflow teeth where the ray can wedge or scrape. I like heaters in the sump and all intakes guarded.
Water quality has to be boringly consistent. Stable salinity and temperature matter more than chasing a specific number. For most setups, normal reef salinity (around 1.025-1.026) and mid-70s F temps work fine, but pick a target and keep it steady.
Plan your maintenance around the ray: frequent smaller water changes, strong mechanical filtration you actually clean, and siphon the sand surface where food lands. If you let leftovers rot in the sand, you will smell it before your test kit catches up.
What to feed them
They are bottom hunters. In a tank, that means you are the ocean. Do not expect them to live off random pods and leftovers. Mine did best with a varied meaty diet and a consistent feeding routine.
- Staples: shrimp (shell-on sometimes for roughage), squid strips, scallop, clam, marine fish flesh (not freshwater feeders).
- Good variety: live or freshly thawed mysis for smaller individuals, chopped seafood mixes, occasional crab pieces.
- Avoid: goldfish/guppies (fatty and not marine), oily freshwater fish, anything that smells 'off' after thawing.
- Supplements: soak foods in a vitamin/HUFA product a few times a week if you can.
Target feeding makes life easier. Use feeding tongs or a long stick and place food right in front of the ray on the sand. At first they can be shy, especially under bright lights. Feed with pumps turned down so food is not flying around, then bring flow back after they finish.
Watch for them swallowing sand. A little happens, but if you are feeding tiny bits that disappear into the substrate, you will see them 'vacuum' and take in more sand than food. Bigger, easy-to-grab pieces help.
How often? Smaller rays usually do better with smaller meals more frequently. Adults can handle every-other-day heavier feedings, but I still prefer a steadier schedule. The main goal is a ray that stays nicely filled out without the disk edges looking pinched.
How they behave and who they get along with
They are generally calm, mostly nocturnal/crepuscular, and they love to bury. They will learn your routine and come out when you approach with food. Do not confuse that with 'tame' though - they are still a stingray with a venomous spine.
Treat the tail spine with respect. Never hand-feed, never corner the ray with a net, and never reach into the sand blindly. Use containers, not nets, for moving them.
Tankmates are where most people get into trouble. Anything nippy, pushy, or fast at feeding time will stress the ray and steal food. Anything small enough to fit in their mouth is on the menu eventually.
- Good ideas: calm, non-nipping fish that stay off the bottom (some larger angels can work, but choose carefully), peaceful tangs, certain wrasses that are not bullies.
- Bad ideas: triggers, puffers, most large wrasses with attitude, aggressive damsels, lionfish (spines + messy feeding), and bottom-hogging predators.
- Inverts: most clean-up crews become snacks. Snails sometimes last, crabs usually do not.
If you keep more than one ray, give them real space and watch feeding closely. I have seen them pile onto food and the smaller one just gives up. Multiple feeding spots help a lot.
Breeding tips
They are livebearers (like other stingrays), but breeding in home aquariums is not common. The bigger issue is providing enough space and long-term stability for a mature pair. If you ever get a pregnant female, you will notice a thickening body and a heavier appetite.
If pups arrive, separate them if you can. Adults are not always gentle with small rays during feeding, and competition is the fastest way to lose babies.
Pups usually take smaller meaty foods quickly if you offer them right on the sand. Keep the system extra clean because heavy feeding + small volume is a rough combo.
Common problems to watch for
Most losses I have seen with round rays come down to three things: poor substrate, poor acclimation, and slow starvation because tankmates outcompete them.
- Abrasion and infections: red spots, raw edges, or a 'sandpaper' look usually trace back to sharp substrate, unstable rock, or getting pinned against intakes.
- Refusing food: often stress from bright lighting, high flow over their resting spot, or aggressive tankmates. Sometimes it is internal parasites.
- Ammonia/nitrite sensitivity: rays do not tolerate cycling tanks. If your biofilter is not mature, they will pay for it fast.
- Swollen belly or buoyancy issues: can be from gulping sand, constipation, or internal problems. Feeding bigger pieces and adding variety can help, but persistent issues need a vet or an experienced ray keeper.
- Tail spine injuries: can happen during capture/transport. Keep the environment snag-free and do not use nets.
Do not medicate them like a regular fish without researching the drug first. Many common copper-based and harsh treatments are risky for rays. If you need to treat parasites, quarantine planning up front saves you later.
My biggest practical tip: keep a log. Write down what they ate, how fast, and whether they buried normally. With rays, little behavior changes show up before test numbers do. Catching problems early is the difference between an easy fix and a disaster.
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