Green iguana husbandry — diurnal lizard needs UVB; best kept as a single species per enclosure
The text below is reproduced verbatim from the first-hand source (Merck Veterinary Manual).
> All reptiles, including nocturnal (active at night) and crepuscular (active at twilight) species, benefit from broad-spectrum lighting (see central bearded dragon image). However, UVB light (290–300 nm) is especially important for most diurnal lizards and chelonians for vitamin D3 synthesis and calcium regulation. The best source of lighting is unfiltered sunlight. However, many artificial fluorescent strip lights, compact fluorescents, mercury halide bulbs, and LEDs are available. The quality and intensity of these artificial lights should always be considered second-best to sunlight; however, they can be instrumental in preventing disease. > Different species from different locations must not be mixed. Ideally, only a single species should be kept in any enclosure, and care must be exercised to avoid competition for resources such as food, basking areas, and retreats. In general, the solitary reptile pet is often the healthiest. Most nonbreeding pet snakes and aquatic turtles are best maintained as single pets, because trauma while feeding is common in groups. Some lizards, notably the chameleons (Chamaeleo spp), are so territorial that captive pets must be isolated for long-term survival.
Source: pdf-raw/exotic-b3/reptile_husbandry.txt (first-hand professional veterinary reference, tag-stripped).
Claims (verified C1 substrings of source_file)
All reptiles, including nocturnal (active at night) and crepuscular (active at twilight) species, benefit from broad-spectrum lighting (see central bearded dragon image). However, UVB light (290–300 nm) is especially important for most diurnal lizards and chelonians for vitamin D3 synthesis and calcium regulation. The best source of lighting is unfiltered sunlight. However, many artificial fluorescent strip lights, compact fluorescents, mercury halide bulbs, and LEDs are available. The quality and intensity of these artificial lights should always be considered second-best to sunlight; however, they can be instrumental in preventing disease.Different species from different locations must not be mixed. Ideally, only a single species should be kept in any enclosure, and care must be exercised to avoid competition for resources such as food, basking areas, and retreats. In general, the solitary reptile pet is often the healthiest. Most nonbreeding pet snakes and aquatic turtles are best maintained as single pets, because trauma while feeding is common in groups. Some lizards, notably the chameleons (Chamaeleo spp), are so territorial that captive pets must be isolated for long-term survival.