Caiman Lizard — care sheet

Advanced. This is a large, semi-aquatic, snail-crushing specialist that needs a room-sized, heated, filtered pool AND a warm basking land side, plus high humidity and strong UVB. The water fouls fast, the diet is unusual (shellfish and snails), and adults can top 4-5 feet. It is not a first lizard, or a fifth. Come in with real experience, real space, and a real exotics-vet plan.

A shellfish specialist. In the wild they crush freshwater snails, clams, crayfish and crabs with molar-like rear teeth, plus some fish, amphibians and invertebrates. In captivity feed canned/whole snails (a staple), crayfish/crawfish, shrimp, whole fish, plus superworms, dubia roaches, hornworms and earthworms, with occasional egg or small rodent and small amounts of non-citrus fruit. Prey should be no larger than the lizard's skull. Feed juveniles daily; adults about 2-3x per week.

Think room-sized, not tank-sized. Modern best-practice minimum for one adult is about 8 ft L x 4 ft W x 6 ft H; some older care sheets list 6 x 3 x 4 ft as the floor, but bigger is genuinely better for a swimming, climbing animal. The single most important feature is a large WATER area: a pool taking up roughly one-third to one-half of the floor, at least 12 in deep for adults (20 in is even better) so the lizard can fully submerge and swim, held at about 78 F (range 75-85 F) with a submersible aquarium heater. Water fouls FAST with this messy shellfish-eater: run a large, high-quality external/aquarium filter AND still do full water changes at least weekly, often 2-3x weekly, scrubbing the basin before refilling. On the LAND side, provide sturdy climbing branches under the basking lamp, since wild caiman lizards perch on limbs over water and dive in to escape.

Hot basking spot on the land/branch side. Aim for an air basking zone around 100-105 F; keepers who measure the actual basking SURFACE with an IR temp gun target roughly 120-130 F on the perch under the lamp. Verify with a thermometer/IR gun, never guesswork.

Cool end / ambient roughly 70-80 F, with the warm side sitting 80-90 F, giving a clear thermal gradient across the enclosure.

A mild night drop is fine, but do not let temperatures fall below about 75 F.

Yes, real UVB is required for calcium metabolism and to prevent metabolic bone disease. Use a high-output linear T5 HO tube such as an Arcadia Desert 12% or Zoo Med ReptiSun T5 HO 10.0 (46 in), mounted over the basking branch and replaced on the manufacturer's schedule. Pair it with bright 6500K daytime lighting and run an 11-13 hour photoperiod (shorter in winter, longer in summer).

High: target 70-80%, and do not let it sit below 60%. The large heated pool does a lot of the work; supplement with misting or a fogger/humidifier and good ventilation to avoid stagnant, mold-prone air.

On the land side, a moisture-holding mix such as cypress mulch blended with organic topsoil (and a little sand) works well, kept several inches deep (about 6 in) and fully replaced roughly every 3-4 months. Avoid dusty or dry substrates that fight the humidity you are trying to hold.

Lightly dust feeder items (except whole prey like rodents/fish) with a quality calcium-plus-vitamin-D3 supplement such as Repashy Calcium Plus LoD; some keepers add a multivitamin weekly and calcium a couple of times weekly. UVB does much of the D3 work, so avoid stacking heavy D3 dosing on top of strong UVB.

Large. Females commonly reach about 4 ft (1.2 m) total length; males can grow up to roughly 5 ft (1.5 m) and 8-12 lb, though much of that length is tail. Plan for a genuinely big animal.

Commonly cited at 10+ years in captivity by keeper sources; verified longevity data is thin — the AnAge database lists a maximum recorded captive age of about 9.3 years. Treat ~10+ years as a realistic planning horizon and don't assume more.

See a reptile or exotics vet if you notice: Not eating, lethargy, or noticeable weight loss for more than a week or two - see an exotics vet.; Swollen or soft jaw/limbs, tremors, or reluctance to move (possible metabolic bone disease from poor UVB/calcium).; Wheezing, open-mouth breathing, bubbles or mucus around the nose/mouth (possible respiratory infection).; Retained shed, especially around toes, tail or eyes, or cloudy/swollen eyes.; Runny stool, worms in feces, or a new import that seems unwell (parasites are common - get a fecal check).; Any wound, skin infection, or scale rot from dirty water - clean water problems show up on the skin fast..