🦎 General Info

Grand Cayman Blue Iguanas (Cyclura lewisi) are large, critically endangered lizards native to Grand Cayman in the Caribbean. They are famous for their striking blue coloration, which becomes more vivid in males, especially during breeding season. Adults are 3–5 feet in total length, with males being larger, bulkier, and sporting prominent dorsal crests.

Blue iguanas are intelligent, territorial, and can become accustomed to their keepers with regular, gentle interaction. In captivity, they can live 20+ years with proper care, making them long-term, high-maintenance but rewarding pets.

1. Enclosure

Size

Grand Cayman Blue Iguanas require very large enclosures:

  • Juveniles: Minimum 6 ft x 4 ft x 4 ft

  • Subadults: Minimum 8 ft x 5 ft x 5 ft

  • Adults: Minimum 12 ft x 6 ft x 6 ft or larger

Providing extra space for climbing, basking, and roaming is essential.

Material

  • Sturdy PVC, wooden, or custom outdoor enclosures are preferred

  • Glass enclosures are generally unsuitable for adults due to size and ventilation needs

  • Secure locks are essential—blue iguanas are strong and persistent

Substrate

  • Organic topsoil or coconut coir

  • Cypress mulch or bioactive soil

  • Depth: 6–12 inches for digging and natural behavior

Décor

  • Large, sturdy climbing branches and logs

  • Rocks or flat stones for basking

  • Hides on both warm and cool sides

  • Live or artificial plants for cover and enrichment

2. Temperature & Lighting

Basking Spot

  • 100–110°F

  • Use halogen basking bulbs or ceramic heat emitters

Ambient Temperature

  • 80–90°F during the day

  • Cool side: 75–80°F

  • Night Temperature: 70–75°F (should not drop below 70°F)

UVB Lighting

  • T5 HO 10–12% UVB or equivalent is required

  • Replace bulbs every 6–12 months

  • Proper UVB is essential to prevent Metabolic Bone Disease (MBD)

Day/Night Cycle

  • 12–14 hours of light daily

  • Diurnal species, most active during daylight hours

3. Humidity & Water

Humidity

  • Maintain 60–80% humidity

  • High humidity supports skin health, shedding, and hydration

  • Provide a deep, damp substrate or humid hide

Water

  • Large, shallow water dish for drinking and soaking

  • Change water daily or whenever soiled

  • Blue iguanas often defecate in water, so a durable, easy-to-clean dish is essential

4. Diet

Grand Cayman Blue Iguanas are primarily herbivorous, though juveniles may occasionally accept small insects.

Staple Foods

  • Leafy greens: collard, mustard, dandelion, kale

  • Vegetables: squash, bell peppers, carrots, green beans

  • Occasional fruits: mango, papaya, berries, figs

Occasional Treats

  • Flowers such as hibiscus or dandelion

  • Small insects for juveniles only

Supplements

  • Calcium powder: 3–4× per week

  • Reptile multivitamin: 1–2× per week

All leafy greens should be pesticide-free and well-washed.

5. Behavior & Handling

Temperament

  • Intelligent, curious, and moderately docile when socialized

  • Males can be territorial, especially during breeding season

  • Juveniles are more skittish; adults tolerate careful handling

Handling

  • Start with short sessions

  • Support the full body and avoid sudden movements

  • Regular, gentle interaction helps develop trust, but respect their space

Enrichment

  • Climbing branches and logs

  • Rearrange décor occasionally to stimulate exploration

  • Safe outdoor access in secure, predator-proof areas

6. Health & Lifespan

Lifespan

  • 20+ years in captivity with proper care

Common Health Issues

  • Metabolic Bone Disease (MBD): from poor UVB or calcium deficiency

  • Respiratory infections: from low temps or poor ventilation

  • Parasites: watch for mites and internal parasites

  • Obesity: portion control is important due to voracious appetite

Signs of Illness

  • Lethargy or decreased appetite

  • Swollen limbs or joints

  • Shedding issues

  • Respiratory distress or gaping

  • Sudden weight loss or bloating

Vet Care

  • Seek a reptile veterinarian for any symptoms, especially respiratory issues, sudden weight loss, or difficulty moving

  • Regular check-ups help prevent long-term complications

🦎 Final Notes

Grand Cayman Blue Iguanas are large, intelligent, and highly rewarding reptiles for experienced keepers. They require spacious enclosures, strong UVB lighting, proper diet, high humidity, and consistent interaction to thrive. When properly cared for, they are striking display animals with long lifespans and the potential to form bonds with their keepers.