Giant horned lizard (Phrynosoma asio)
Breeding of Phrynosoma asio at BION Terrarium Center
We keep Phrynosoma asio in BION Terrarium Center since 2011 and start to breed them in 2013. We strongly believe that this unusual and still rare species should take soon the important place in herpetoculture (expecially for desert lizards enthusiasts) together with Uromastyx, Xenagama, Petrosaurus, Ctenosaura, Crotaphytus, Pogona , etc.
We imported the first breeding group from Mexico in 2011; the second group was imported from Switzerland in 2012. For October 2014, we have 6 adult males, 12 adult females and 12 c.b. babies.
The details of keeping
Terrarium: We keep adult lizards in groups (2:4) in horizontal type terrariums 160x60x50 cm. Substrate: thick layer of fine sand (depth from 3 to 12 cm). The bottom’s lay should be kept humid.
Babies and young lizards are kept in open plastic boxes 60x40x40 cm. Substrate: paper towels or wipes.
Decoration & equipment: Water bowls, branches and wood for climbing & hiding, artificial plants.
Lighting (day length): Zoo Med lamp “Reptisun UV.10”; 14 hours at summer, around 4 hours at wintertime (during hibernation) .
Heating: Spot lamp 100 watts;
UV: Full spectrum Zoo Med lamp “Reptisun UV.10”;
Temperature: day time - 28-30°C, night time - 15-22°C.
basking place – up to 45°C
IMPORTANT: We try to keep in hot summer time all our Phrynosoma in outdoor facilities.
Humidity: For adults - spray intensively terrarium every other day before feeding at 3:00 p.m.
For babies – spray box every day 1-2 times (the first time at the morning and the second time before feeding at 3:00 p.m.)
Fresh water is available all time.
Diet: Crickets, Turkestan roaches, ants (must be in the summer) – every day by 5-7 insects per animal. Do not give hard shell mealworms and zophobas (only freshly molt with white color).
It is better to feed animals from 3:00 to 4:00 p.m. after lizards are well heated.
We spray intensively terrarium with water before feeding.
Mineral supplements: Each feeding we sprinkle insects with calcium andvitamins Also we using Repashi Superfood (Formic Cal Plus) 2 times per week when feeding other insects than ants
Breeding
Phrynosoma asio reach their sexual maturity at 1,5-2 years .
Oviparous lizards: lays from 8 to 37 eggs in several clutches per season.
Mating observed in June-August. Eggs are laid in August-October.
Female lays eggs in 7 weeks after mating. Usually a clutch consists of 7-15 eggs.
The incubation period is around 90-100 days at the temperature 25°C.
We keep adult lizards in groups (2:4). Conflicts are not observed . In the hot season (mid-May to the end of August) animals are kept in outdoors facilities. Night time temperature is not lower than 14°C. 
Breeding statistics:
- In 2013 we got 14 babies from 1 female (1 clutch of 15 eggs total).
- In 2014 weobserved mating at the middle of July.
For the moment we got only 1 unfertilized clutch from 1 female (end of September).
Keeping offsprings:
The size of new born lizards are about 3 cm, including tail
We recommend keeping babies in open plastic boxes from hatching till next 60 days. We use plastic boxes 45x30x30 cm. We used paper towels or wipes instead of substrate. After 60 days we put babies in larger boxes 60x40x35 cm. Diet of babies and young lizards should include more ants than diet of adults. Crickets and ants should match 50/50 at the diet.
Veterinary issues:
Rickets (deformation and softening of the bones) may develop in juveniles and adults in case of wrong care.
To prevent problem - the exposure of UV should be increased (“hard” UV over than 280nm during 2 minutes every other day until improvement).
Also dose of calcium should be increased (calcium gluconate in liquid should be offered oraly by 2-3 drops from 2 ml syringe every other day until the situation improves.
Sources:
1.. http://zoofacts.ru/yashherica-ili-zhaba-frinozoma/
2.. http://vivanatura.org/Phrynosoma%20asio.html