Decor
- Climbing branches around the hotspot — different levels to choose from
- Rocks, tubes and other décor for enrichment
- Artificial foliage for a naturalistic look
- Cool-side water bowl for drinking
Lizards · Care guide
Mexican Spiny Tailed Iguana Care Guide
Ctenosaura ssp.
Large Ctenosaura from Central America, Mexico and Guatemala. With regular interaction they often become very tame — but they need a large desert vivarium, strong T5 12% UVB, dry heat, and a mainly vegetarian omnivorous diet.
At a glance
Quick facts
Key parameters for day-to-day husbandry. Full detail is in the sections below.
-
Daytime probe
84–86 °F
29–30 °C · thermostat sensor
-
Night drop
~10 °F
~6 °C · about 74 °F / 23 °C
-
Diet
Mainly plants
Omnivore · some live food · dust every feed
-
UVB
T5 12%
Desert output · ceiling-mounted
01 · Housing
Enclosure & housing
Large desert iguanas need a large vivarium. Provide climbing branches around the hotspot, rocks, tubes and other enrichment, artificial foliage, dry substrate, and a solid temperature gradient. Minimum size is for a single adult.
Adult minimum size
96″ W × 48″ H × 36″ D
For a single adult, or larger if you wish. They are large lizards — plan housing accordingly.
Substrate
- Dry substrate — pelleted straw bedding or coarser desert sand
- Avoid fine mineral sands that can cause impaction
Cleaning
- Daily: spot clean to limit bacteria and odours
- About every six weeks: full clean if kept relatively clean — replace substrate, disinfect decor and vivarium
Housing diagram
Enclosure example
Front view 96″ wide × 48″ tall (depth 36″) · hotspot branches · rocks & tubes · foliage · cool-side water bowl
- Front proportions — 96″ wide × 48″ tall (2:1); depth 36″ — or larger
- Branches — around the hotspot for climbing levels
- Rocks & tubes — enrichment décor
- Foliage — artificial plants for a naturalistic look
- Water bowl — cool-side dish for drinking
- Substrate — pelleted straw or coarser desert sand; daily spot clean, full clean about every six weeks
Setup diagram · 1 of 2
Top-down view
Heat bulb & probe left–right positions · Recommended temps need this layout
Setup diagram · 2 of 2
Front view
Looking into the vivarium · bulb on the ceiling · probe hangs down the back
- Heat bulb — about one-quarter from one side, halfway front to back (on / through the ceiling)
- Probe — one-quarter from the opposite side, hanging down the back, resting a few inches from the floor
02 · Climate
Temperature & UVB
Day/night cycling, a proper gradient, and UVB are essential for metabolism, appetite, and long-term health.
Daytime temperature gradient
When the heat bulb and thermostat sensor are placed as instructed, a probe target of 84–86 °F (29–30 °C) creates this spread. The probe point is not the basking spot.
| Zone | Temperature |
|---|---|
| Cool side | ~82 °F (~28 °C) |
| Probe point (thermostat probe target) | 84–86 °F (29–30 °C) |
| Middle | 94–96 °F (34–36 °C) |
| Warm side | 100–110 °F (38–43 °C) |
| Basking spot (hottest point under bulb) | 110–120 °F (43–49 °C) |
| Night drop | Reduce thermostat by ~10 °F (~6 °C) to approx. 74 °F (~23 °C) |
Photoperiod & night
- Winter: 12 hours light/heat
- Summer: up to 16 hours
- Night: reduce thermostat by ~10 °F (~6 °C) to approx. 74 °F (~23 °C)
- Night drop lets metabolism slow — essential for the lizard
UVB lighting
- Recommended T5 unit with strong 12% UV output on the ceiling
- Mount straight across or diagonally (diagonal often places the power unit toward a rear vent)
- Replace every 12 months — UV output degrades over time
- Match UV on/off to heat schedule (morning on, evening off)
- UVA boosts appetite & activity; UVB enables vitamin D3 / calcium absorption
Climate diagram
Lighting setup
T5 12% UVB on the ceiling (straight or diagonal) · heat dome on the warm side · match UV to heat
- T5 12% UV unit — ceiling-mounted (straight or diagonal); UVA supports appetite & activity; UVB enables vitamin D3 / calcium absorption
- Heat dome — warm side; same on/off routine as UV (morning on, evening off)
- Photoperiod — 12 hours in winter, up to 16 hours in summer
- Replace UV every 12 months — output degrades even if the tube still glows
First power-up tip
Always have the thermostat dial turned down before you plug it into the mains for the first time.
03 · Nutrition
Diet & feeding
Omnivorous but mainly vegetarian — salads are the core of the diet with only small amounts of live food. Dust every feed and gut-load insects well.
At a glance
Feeding cheat sheet
- Type
- Mainly vegetarian omnivore · small amounts of live food
- Plants
- Core of the diet · vary items from the Ca:P lists below
- Dust
- Every feeding · 4:1 calcium : Nutrobal
- Water
- Cool-side bowl · moisture also from food · Reptisafe or bottled
Plant matter
Core of the diet · see lists below
- Salads, weeds and herbs
- Vary items for Ca:P balance
- Dust every feed
Live food
Small amounts only · dust every feed
- Occasional insects only
- Always gut-load before offering
Supplements — every feeding
Dust every feeding with a 4:1 mix of calcium : Nutrobal (4 parts calcium to 1 part Nutrobal). Store the mix in an airtight container and use it to coat food every time you feed.
Settling appetite
New Mexican Spiny Tailed Iguanas often will not eat well for the first day or so. This is perfectly normal. Once settled and happy, appetite usually increases. They are omnivorous but mainly vegetarian — offer salads as the core diet with only small amounts of live food.
Diet balance
- Mainly vegetarian — plant matter is the core of the diet
- Only small amounts of live food — always dust and gut-load
- Vary plant items from the Ca:P lists below
Water
- Cool-side water bowl for easy access
- Moisture also comes from live foods and salads — do not worry if you rarely see them drink
- Reptisafe or bottled water only — never untreated tap
Gut-load insects before offering — variety matters for calcium-to-phosphorus (Ca:P) and vitamins.
Why gut loading matters
Feeder insects must be well fed before offering. In the wild, lizards eat insects that themselves ate a wide variety of foods — providing complete nutrition and a better calcium-to-phosphorus (Ca:P) ratio.
- Use commercial gut-load foods with quality ingredients
- Add fresh reptile-safe vegetables for variety
- A single piece of carrot or potato is not enough — poor Ca:P and limited vitamins/minerals
Hand feeding can help bonding, but excessive hand feeding can lead to obesity. Hunting and chasing food provide exercise and enrichment.
Speak to a member of staff for more feeding advice.
Plant matter & Ca:P lists Supermarket, garden plants, and foods to avoid
Mexican Spiny Tailed Iguanas are omnivorous but mainly vegetarian — salads, weeds, and herbs are the core of the diet (only small amounts of live food). Use as many listed items as possible and alternate often for calcium-to-phosphorus balance. Naturally growing weeds and herbs are excellent when safe. Always dust plant and insect foods with the 4:1 calcium : Nutrobal mix.
Good calcium to low phosphorus (examples)
Apricots, basil, blackberries, bok choy, broccoli tops, cantaloupe, carrots/carrot tops*, chicory, Chinese cabbage, clover, dandelion leaves and flowers, escarole, figs and fig leaves, green onion, leeks, okra, oranges, papaya, parsley, pea pods (not peas), rosemary, sow thistle, turnip greens, watercress, continental lettuces (romaine, cos, frisée, endive, radicchio, lollo rosso), mulberry, grape, ficus, rose, hibiscus, and opuntia cactus leaves. *Carrots/carrot tops not in high concentration (tannins).
Marginal Ca:P
Apple (no pips), aubergine, celery leaf only, pears, radish, sweet potato.
Poor Ca:P / high phosphorus — use sparingly
Asparagus, broccoli, Brussels sprouts, cabbage, cauliflower, cucumber, grapes, peaches, plums, squash, strawberries, tomato.
Generally exclude (oxalates / goitrogens / similar concerns)
Beans, rhubarb, spinach, beet greens, Swiss chard, cauliflower, cabbage, mustard greens, peas, collard greens, soy meal/beans, banana.
Garden plants often listed as safe
Carnations/dianthus, dracaena, echeveria/succulents, ficus, geranium, grape (Vitis), hibiscus, impatiens, maple leaves, nasturtiums, oregano, petunia, phlox, pinks, rose petals, soleirolia, viola/pansy/violets (not African). Always double-check any plant before offering.
Toxic / avoid
Apple bark/leaves/seeds, burdock, buttercup, cherry, clematis, crocus, daffodil, eggplant, elderberry, holly, horse chestnut, hyacinth, hydrangea, iris, lily of the valley, mistletoe, narcissus, oak, oleander, peach, peony, poinsettia, potato, primrose, privet, rhododendron, shamrock, snowdrop, sorrel, sweet pea, tomato plant, tulip, Virginia creeper — and some rosemary/sage varieties (verify before use).
Always dust plant and insect foods with the 4:1 calcium : Nutrobal mix.
04 · Behaviour
Handling & behaviour
Patience first. Settling and regular feeding come before handling.
- Step 1
Settle first
Allow the lizard to settle and begin eating regularly before handling — we recommend at least two successful feeds first. Adapting is stressful; early handling can make it worse.
- Step 2
Short sessions
Initial sessions: 5–10 minutes only. Lengthen as the lizard becomes more comfortable.
- Hygiene
Wash hands
Always wash or disinfect hands before and after handling to prevent bacteria transfer both ways.
- Warning
No aerosols
Do not use aerosols or plug-in air fresheners near the enclosure — the chemicals can harm your lizard.
05 · Welfare
Health & welfare
Prevention starts with correct husbandry — heat, UVB, hydration, and supplementation working together.
Best prevention: good husbandry
Correct temperatures, supplementation, hydration, and UVB keep the immune system and gut working well — supporting essential physiological processes.
Inert substrates Paper, lino, carpet — pros & cons
Pros
- Lower impaction risk
Cons
- Limit natural behaviours such as digging
- Remove natural digging behaviour
- Can increase faecal contamination (waste less absorbed; insects may contact waste)
Questions
FAQ
What size vivarium does a Mexican Spiny Tailed Iguana need?
For a single adult, a minimum of 96″ wide × 48″ tall × 36″ deep, or larger. Provide climbing branches around the hotspot, rocks, tubes and other enrichment, artificial foliage, dry substrate (pelleted straw or coarser desert sand), and a cool-side water bowl. They are large lizards and need a large vivarium.
What temperatures does a Mexican Spiny Tailed Iguana need?
Set the thermostat probe to 84–86 °F (29–30 °C) by day with the heat bulb about one-quarter from one side and the probe one-quarter from the opposite side, hanging down the back a few inches from the floor. That creates a gradient of about 82 °F on the cool side, 94–96 °F in the middle, around 100–110 °F on the warm side, and a basking spot of about 110–120 °F under the bulb. At night reduce the thermostat by about 10 °F to around 74 °F (23 °C).
When can I start handling my Mexican Spiny Tailed Iguana?
Allow the iguana to settle and begin eating regularly before handling. With regular interaction they often become very tame. Initial sessions should be 5–10 minutes only; lengthen as they become more comfortable. Always wash or disinfect hands before and after handling. Do not use aerosols or plug-in air fresheners near the enclosure.
What UVB do Mexican Spiny Tailed Iguanas need?
As a desert iguana they need a T5 unit with a 12% UV tube mounted on the ceiling — straight across the top or diagonally (diagonal often places the power unit toward a rear vent). Replace the tube every 12 months because UV output degrades. Match UV on/off to the heat schedule: about 12 hours in winter and up to 16 hours in summer.
What do Mexican Spiny Tailed Iguanas eat?
They are omnivorous but mainly vegetarian, taking only small amounts of live food. Dust every feed (salads and insects) with a 4:1 calcium : Nutrobal mix. Gut-load insects well. Use a wide variety of plant foods from the calcium-to-phosphorus lists in this guide, alternating often; weeds and herbs are excellent when safe. Provide a cool-side water bowl; they also get moisture from food.
Next steps
Ready to set up your Mexican Spiny Tailed Iguana?
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