A Detailed Guide to Pet Iguanas (Iguanidae)

Most iguanas have helmets, or casques — flaps of skin or crests on the head, back, tail, or throat. Such features are mostly seen in males only. If they do occur in both sexes, the ones in females are always less striking than those of males. All anoles have an erectile dewlap. The females of this species also have a dewlap, but it is always smaller and less brilliant in color than that of the male. During the delineation and defense of their territories, during courtship, and during threatening, the dewlap is erected and presented with vigorous head nodding. In some species there are neck and back crests, which are inflated and displayed in excitement. The erecting and flattening of the torso also belongs to the body language of the iguanas.

Like the geckos, all the anole species have adhesive lamellae on the undersides of their toes, by means of which they can even run along a plate of glass. Therefore you need to be particularly careful when working in the terrarium.

On the basis of marking studies of free-living anoles, it has been determined that the lizards of this genus do not become very old. The reason for this lies in their enormous activity. Because anoles are so very busy about their own affairs, they often fail to notice predators. In the studied population, the majority of the marked lizards were no longer to be seen after two years. Considerably older — up to fifteen years — were the larger and less temperamental kinds like the common iguana.

Differences between the sexes: Male basilisks are easy to tell from the females because of their skin flaps and crests. Among the common iguanas both sexes have crests. A grown male of this species is recognizable by its larger skull and the mostly yellow-orange color of its limbs. Spiny iguanas have femoral pores, which are more prominent in the male than in the female. The male of the tropidurine lizards has a black spot on its throat, which is missing in the female. In anole males there are two noticeably larger scales behind the cloaca; females of this species do not have enlarged scales. In the mature males of all the species named, recognizable sheaths containing the hemipenies can be seen at the root of the tail. The sex of the younger lizards can only be determined with a probe.

Reproduction: Some spiny lizard species are ovoviviparous, but all other iguanids bury their eggs in holes of various shapes. The number of eggs varies according to species and range from two to forty. The clutch of eggs must be transferred to an incubator. Only thus can the young animals that hatch later be protected from the usually cannibalistic adult animals. Though the ovoviviparously born spiny lizards are somewhat protected by a differently colored skin, successful breeding nevertheless depends on caring for them separately. General advice for maintenance: In suitably large terrariums with well-constructed decorations, two or more males of the genera Sceloporus, Tropidurus, and Anolis — except for Anolis equestris — can be kept together. Most male common iguanas and basilisks of the same species cannot be kept in one terrarium, however. Besides the physical stress, the psychological stress is too great for the lower-ranked animal and will end in death. But keeping different species in one terrarium is possible.

Basilisks, especially, act extremely frightened during the initial period of being kept in a terrarium. They jump against the glass, which is invisible to them, and injure their snouts. Therefore you should provide extensive cover with suitable decoration or cover the quarantine terrarium.

Iguanas and basilisks love to bathe, so a water bath is essential. In length it should be at least one and a half times the head-torso length of the largest lizard and in width once the head-torso length. Most feces are dropped during swimming, so the water must be changed frequently. Daily water change will be easy if you install a direct water line and drainage system.

Note: The following spiny lizards have no distinguishing English names.

Spiny lizards

Sceloporus poinsetti (Baird and Girard, 1852)

Total length: 10 inches (26 cm). Head-torso length: 5 inches (12 cm).

Distribution and Description: From southwestern North America (Texas and New Mexico) southward to central Mexico.

Habitat: In mountains to 8,200 feet (2,500 m); hot, dry, stony slopes.

Identifying characteristics: Scales that are “keeled,” that is to say, ending in sharp points, spiny.

Behavior: Diurnal. Ground-dwelling. Lives in small groups; dominant males live in privileged areas. Ovoviviparous. Young animals should be separated from cannibalistic parent animals.

Maintenance: Terrarium 60 x 24 x 24 inches (150 x 60 x 60 cm) for two males and four females.

Decoration: Stones, pebbles, sand. Sunning spots and UV lighting. Sun terrarium.

Temperature: By day 104°F (40°C) exactly but the animals must be able to crawl into cooler areas; by night 59°F (15°C). Pseudo-winter rest from November to February at 59° to 68°F (15-20°C; reflector lamp not turned on).

Humidity: 50 to 70 percent.

Food: Insects, spiders, baby mice, also occasionally leaves and flowers. Drinking water will be licked from the decorations or from shallow saucers; spray plants with water once daily.

Spiny lizard

Sceloporus jarrovi (Cope, 1875) Total length: 7 inches (17 cm). Head-torso length: 3 inches (7 cm).

Distribution and Description: From south-western North America (Arizona, New Mexico) southward to southern Mexico.

Habitat: Mountains from 4,900 to 9,800 feet (1,500 to 3,000 m), especially somewhat damp regions.

Identifying characteristics: Scales keeled.

Behavior: Diurnal. Ground-dwelling. Lives in small groups, dominant males on display spots. Ovoviviparous. Young animals must be separated from the cannibalistic parents.

Maintenance: Terrarium, 60 x 24 x 24 inches (150 x 60 x 60 cm) for two males and four females. Decoration: Stones, stumps, sand or sandy soil, not completely dry. Plants from the dry areas of North and Central America. Sunning places and UV lighting. Sun terrarium.

Temperature: By day exactly 95°F (35°C), and the animals must be able to crawl into cooler areas; by night 59°F (15°C). From November to February pseudo-winter rest at 59° to 68°F (15-20°C; reflector lamp not turned on).

Humidity: 50 to 70 percent. Food: Insects, spiders, baby mice, also occasionally leaves and flowers. Drinking water will be licked from the decorations or from shallow saucers; spray plants with water once daily.

Spiny lizards

Sceloporus malachitus (Cope, 1864)

Total length: 8 inches (20 cm).

Head-torso length: 4 inches (7 cm) Distribution and Description: Central America (Mexico, Panama).

Habitat: Mountains 4,900 feet (1,500 m); light woods. Identifying characteristics: Scales keeled.

Behavior: Diurnal. Inhabits ground and tree trunks. Lives in small groups, dominant males on display spots. Ovoviviparous. Young animals must be kept separated from the cannibalistic parents.

Maintenance: Terrarium 60 x 24 x 24 inches (150 x 60 x 60 cm) for two males and four females.

Decoration: Stones, stumps, sand or sandy soil, not completely dry. Plants from the dry areas of North and Central America. Sunning spots and UV lighting. Sun terrarium.

Temperature: By day exactly 95°F (35°C), and the animals must be able to creep into cooler places; by night 59°F (15°C). Pseudo-winter rest from November to February at 59° to 69°F (15-20°C; reflector lamps not turned on).

Humidity: 50 to 70 percent. Food: Insects, spiders, baby mice, also occasionally leaves and flowers. Drinking water will be licked from the decorations or from shallow saucers; spray plants with water once daily.

Tropidurine lizard

Tropidurus torquatus (Wied, 1820)

Total length: 10 inches (25 cm). Head-torso length: 4 inches (10 cm).

Distribution and Description: Northern South America.

Habitat: Mountains to 3,100 feet (1,000 m); the edges of sparse forests in largely dry areas.

Identifying characteristics: Spiny tail scales.

Behavior: Diurnal. Inhabits ground and tree trunks. Dominant males on display spots.

Maintenance: Terrarium 60 x 24 x 24 inches (150 x 60 x 60 cm) for two males and four females.

Decoration: Stones, stumps, sand or sandy soil, not completely dry. Plants from the dry areas of South America. Sunning spots and UV lighting. Sun terrarium.

Temperature: By day exactly 95°F (35°C), and the animals must be able to crawl into cooler places; by night 59°F (15°C).

Humidity: 50 to 70 percent.

Food: Insects, spiders, baby mice, occasionally also vegetarian fare. Drinking water will be licked from the decorations or from shallow saucers; spray plants with water once daily.

Common iguana*

Iguana iguana (Linnaeus, 1758)

Endangered species designation: WA II Total length: 80 inches (200 cm).

Head-torso length: 20 inches (50 cm).

Distribution and Description: Southern Mexico to central South America.

Habitat: Tropical rain forests and savannahs, always in close vicinity to water, with only small populations in the precipitation-poor coastal areas.

Identifying characteristics: Large dewlap with a crest. Crest from neck to tail. Long, sharp claws.

Behavior: Diurnal. Tree-dwelling. Likes to swim. Movements mostly quiet and balanced, therefore requires less space than its size might suggest. Usually lives in large groups. Can become tame; recognized people are greeted with nodding head.

Maintenance: Changing terrarium size because as animals grow, more room is needed. For three juveniles: 40 x 24 x 24 inches (100 x 60 x 60 cm); for one male and two females about 60 inches (150 cm) long: 80 x 60 x 60 inches (200 x 150 x 150 cm).

Decorations: Branches for climbing, at least as thick in diameter as the lizard's torso. Water holders for bathing. Floor surface that can be dampened for constant humidity. No plants. Sunning spots and UV lighting. Sun terrarium.

Temperature: IT to 95°F (25-35°C) during the day; 68° to 72°F (20-22°C) during the night.

Humidity: 60 to 90 percent. Food: Juvenile animals eat animal fare for the most part: insects, earthworms, baby mice; some iguanas also eat fish. Vegetable fare (weeds, grasses, fruit, carrots, rice) is eaten during the growth period of the larger lizards and particularly by sexually mature animals. Many iguanas even give up animal food completely. Provide adequate amounts of vitamin and mineral supplements during the growth period because rickets, convulsive trembling, and other metabolic problems often cause irreparable damage to this species.

Common basilisk

Basiliscus basiiiscus (Linnaeus, 1758) Total length: 32 inches (80 cm). Head-torso length: 10 inches (25 cm).

Distribution and Description: Southern Central America. Habitat: Tropical rain forest, always in the vicinity of water. Identifying characteristics: Male has a casque, back and tail crests. Long extremities. Toes have fringes of skin.

Behavior: Diurnal. Tree-dwelling. Likes to swim. Shy, reacts excitably, fast and powerful jumper, can also move on two legs. Lives in loose groups.

Maintenance: High terrarium, 36 X 36 x 50 inches (90 x 90 x 12 cm) for one male and three females. For every additional animal of another species, add 2 inches (5 cm) more to each measurement.

Decorations: Branches for climbing, stumps, water containers for swimming. Hard-leaved plants (the sharp claws destroy tender leaves) from the rain forest of Central and South America. Sunning spots and UV lighting. Temperature: By day 77° to 86°F (25-30°C); by night 68° to 77°F (20-25°C)

Humidity: 60 to 90 percent. Food: Insects and spiders, freshwater fish, earthworms, baby mice; in the natural habitat also small reptiles, frogs, and baby birds. Some common basilisks also eat vegetable food.

Double-crested basilisk

Basiliscus plumifrons (Cope, 1876)

Total length: 28 inches (70 cm) Head-torso length: 8 inches (20 cm).

Distribution and Description: Central and southern Central America. Habitat: Tropical rain forests, always in the vicinity of water.

Identifying characteristics: Males have crest on forehead, casque, and a back and tail crest; females have only suggestions. Long extremities. Toes have a fringe of skin.

Behavior: Diurnal. Tree-dwelling. Likes to swim. Shy, excitable, fast and powerful jumper, can also move on two legs. Lives in loose groups. Females also respond aggressively.

Maintenance: High terrarium, 36 x 36 x 50 inches (90 x 90 x 120 cm) for one male and three females. For each additional animal, add 2 inches (5 cm) more to each measurement.

Decorations: Branches for climbing, stumps, water containers for swimming. Hard-leaved plants (the sharp claws destroy tender leaves) from the rain forests of Central and South America. Sunning places and UV lighting.

Temperature: By day 77° to 86°F (25-30°C).

Humidity: 60 to 90 percent. Food: Insects and spiders, freshwater fish, earthworms, baby mice; in natural habitat also small reptiles, frogs, and baby birds. Some double-crested basilisks also eat vegetable food.

Banded basilisk

Basiliscus vittatus (Wiegmann, 1828)

Total length: 30 inches (75 cm). Head-torso length: 8 inches (20 cm).

Distribution and Description: Central America. Habitat: Tropical rain forests, always in close vicinity to water.

Identifying characteristics: Males have casque. Shallow back crest. Long extremities. Toes with skin fringe. Behavior: Diurnal. Tree-dwelling. Likes to swim. Shy, reacts excitedly, fast and powerful jumper, also can move on two legs. Lives in loose groups.

Maintenance: High terrarium, 36 x 36 x 50 inches (90 x 90 x 120 cm) for one male and three females; for each additional animal add 2 inches (5 cm) to each measurement.

Decorations: Branches for climbing, stumps, water containers for swimming. Hard-leaved plants (the sharp claws injure tender leaves) from the rain forests of Central and South America. Sunning spots and UV lighting.

Temperature: by day 77° to 86°F (25-30°C); by night 68° to 77°F (20-25°C).

Humidity: 60 to 90 percent.

Food: Insects and spiders, freshwater fish, earthworms, baby mice; in natural habitat also small reptiles, frogs, and baby birds. Some banded basilisks also eat vegetable food.

Carolina anole

Anolis carolinensis (Dumeril and Bibron, 1837)

Total length: 8 inches (22 cm). Head-torso length: 3 inches (7 cm).

Distribution and Description: Southeastern North America.

Habitat: Woods, brush country, and cultivated land; also areas of human settlement.

Identifying characteristics: Adhesive lamellae. Behavior: Diurnal. Inhabits trees and bushes. Lives in colonies.

Maintenance: High terrarium, 16 x 16 x 24 inches (40 x 40 x 60 cm) for one male and two females. For every two additional animals add 2 inches (5 cm) more to each measurement.

Decorations: Branches and plenty of plants from the rain forests of North, Central, and South America. Sunning spots and UV lighting.

Temperature: By day 77° to 86°F (25-30°C); by night 65° to 74°F (18-23°C). Pseudo-winter rest from November to February at 59° to 68°F (15-20°C; reflector lamp not turned on).

Humidity: 50 to 80 percent.

Food: Insects and spiders, ripe fruit from time to time. Drinking water will be licked from plants; spray plants with water once daily.

Knight anole

Anolis equestris (Merrem, 1820)

Total length: 22 inches (55 cm). Head-torso length: 9 inches (20 cm).

Distribution and Description: Cuba, but it has spread, for instance, to Florida.

Habitat: Rain forests.

Identifying characteristics: Adhesive lamellae.

Behavior: Diurnal. Tree-dwelling. More relaxed and less active than other species of anoles. Lives in loose groups.

Maintenance: High terrarium, 24 x 24 x 36 inches (60 x 60 x 90 cm) for one male and two females.

Decorations: Branches and stumps, plants from the rain forests of Central and South America. Sunning spots and UV lighting.

Temperature: By day 77° to 86°F (25-30°C); by night 68° to 77°F (20-25°C).

Humidity: 60 to 90 percent.

Food: Insects and spiders, baby mice; in natural habitat lizards, too. Because these lizards are slow eaters, it is best to feed each one individually, preferably with the help of tweezers; otherwise too many of the food insects escape into the decorations and the food intake cannot be controlled. Drinking water will be licked off the leaves or from the wells provided by the bromeliads; spray plants with water once a day.

Bahama anole

Anolis sagrei (Dumeril and Bibron, 1837)

Total length: 8 inches (20 cm). Head-torso length: 3 inches (7 cm).

Distribution and Description: Orginally only the Bahamas, now also Central America, the Greater Antilles, and Florida.

Habitat: Forest edges, bushy areas, cultivated landscapes, also the vicinity of human settle-ments.

Identifying characteristics: Adhesive lamellae.

Behavior: Diurnal. Lives in trees, bushes, ground, and stones. Lives in colonies.

Maintenance: High terrarium, 16 x 16 x 24 inches (40 x 40 x 60 cm) for one male and two females; for every two additional animals add 2 inches (5 cm) to each measurement.

Decorations: Branches and numerous plants from the rain forests of North, Central, and South America. Sunning spots and UV lighting.

Temperature: By day 77° to 86°F (25-30°C); by night 64° to 73°F (18-23°C).

Humidity: 50 to 80 percent. Food: Insects and spiders, sometimes ripe fruit. Drinking water will be licked from the plants; spray them with water once daily.