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By Audrey Vanderlinden

    The Ornate spiny-tailed lizard ( Uromastyx ocellatus ornatus)  literature indicates that the lizard became sexually mature at around 3 or 4 years of age. This information was derived  from the age of a wild caught hatchling that eventually bred in captivity (Gray 1998).

     In 1995, I acquired a subadult wild-caught female ornate spiny-tailed lizard that was in excellent health and had a nice disposition. In the Spring of 1997, she bred with another imported male, named "King Tut", also purchased in 1995. It was my original thought that the two lizards were similar in age, however, during a visit to my home, herpetoculturist Randall Gray suggested that "Tut" appeared to be a lot older, possibly even eight to ten years old. "Tut's" weight was 240 grams. The female, "Daphne", was a robust 300 grams at the time of conception.

    Since this was my first breeding of this species, I had radiographs taken to confirm the presence of developing eggs and a blood serum calcium level count was performed by Dr. Cheryl Roge. Another female was gravid so lab tests were performed on her as well. My concern was proper calcium levels for proper egg development and for healthy uterine contraction during oviposition. Calcium levels have a direct influence on uterine health and normal to higher calcium levels are necessary for normal egg deposition (Mader 1996)  However, since there was no data documented for Uromastyx ocellatus ornatus, Dr. Roge and I extrapolated our findings from the blood calcium levels for gravid green iguanas ( Iguana iguana ). Calcium levels are based upon a point scale system ranging from 8 to 20 mg/dl. The normal level for a healthy gravid  green iguana is 25 mg/dl.  The blood calcium levels for my two females were only 12 mg/dl which is significantly lower. Whether or not these findings could even construe comparison, it was something to think about. Not wanting to risk losing these lizards in case of egg binding, we chose to provide supplemental calcium.  We chose to administer Calsophan, an injectable calcium once a week, until it came close to the time for the eggs to be laid. Dr. Roge assured me this was a treatment that should not have any adverse affects, but that we should continue to monitor the animals' progress. Whether or not this therapy was effective is uncertain, however I chose this as more of an insurance policy.

     After two and a half weeks of Calsophan therapy, both my females laid their first clutches a day apart. On June 4, 1997, the female "Daphne" laid 18 eggs, twelve of which were fertile. "Titti" on the following day, laid 17 eggs, twelve of which were fertile. The eggs were incubated in a Hovabator Incubator at 90F for approximately 72 days.

     On August 16, 17, & 18, 1997,  twenty four beautiful and robust baby ornatus emerged from their eggs. "Daphne" produced  ten males and two females and conversely, "Titti" produced two males and ten females. Talk about a breeders miracle blessing!

     "Piglet", aptly named for her size and appetite, was the largest baby female. She was very large compared to her litter-mates. Her sibling male, "Bully", was the largest of the male babies. "Piglet" grew to reach 130 grams within 10 months. "Bully" attained a weight of 120 grams in that same period. It seemed appropriate that I house them together, apart from all the other smaller siblings, at least until they reached adulthood.

     Almost immediately, the two copulated. Within days, "Piglet" grew more aggressive towards "Bully" and I had to remove him. She began to grow larger and started to take on the shape of a small ping pong paddle. My suspicions that she was gravid were confirmed when she began digging in the corners of her enclosure. She had reached a weight of 150 grams. I  placed an egg laying site in her enclosure, which is a five gallon Rubbermaid tote filled with 4 to 5 inches of damp play-sand, covered, with a small opening cut out of the side. She immediately took to the egg box and began to search for a dig site. My chief concern was that if she had  developed eggs, was her physical immaturity going to render her eggbound? This was a concern that both Randall Gray and I shared. Again, as an insurance policy, once I suspected she was gravid, I supplemented her with oral drops of Neo-calglucon, a calcium supplement given to premature human babies.

     On July 5, 1998, "Piglet" laid eleven large, adult sized eggs. Her weight after oviposition was 80 grams. At this time, she was offered water from an irrigation syringe, from which she drank gratuitously!  This is the only time my animals drank water. In fact, another breeder female also drank excessively for two days following oviposition. Upon removal of "Piglet's" eggs, they all appeared fertile. However, within one week, three of the eggs must have had micro-tears in them because as they began to expand, they also began to leak. Two eggs became dehydrated during mid-term development. Upon inspection of the dead eggs, I found half formed babies. The only explanation I can offer is that I had placed these two eggs in a different type of container which may have had too much air exchange. The remaining six eggs hatched on September 16, 1998, exactly 72 days post oviposition. The babies were immediately active and alert. The hatchlings weights varied between 6 and 8 grams. They had beautiful markings composed of dark red and orange patterns. Another unusual occurrence  was that the eggs had been an aqua-greenish tint a few weeks before they hatched. This was a pigment-like coloration seemingly developed from inside the egg, rather than outside the egg. When the babies emerged, a couple of the animals had maintained the bluish tint on their tails. Whether or not this is a temporary phenomenon remains to be seen. But, speaking with other breeders (Randall Gray and Greg Gosney, personal communication), this was nothing they had experienced before.

     "Piglet"  has since recovered and has already attained the beautiful maturity speckling that adult ornatus develop. She is a peach and brown colored lizard that has the characteristics of a miniature adult. "Bully" is growing steadily as are all the other males from August of 1997. He is a stunning navy blue with yellow stripes.

    I must note that no brumation had occurred prior to this breeding.  This is another important observation which indicates that a cool down period may not be necessary for captive born ornate spiny-tailed lizards.  However,  I will brumate all my sub-adults and adults this year.

   "Piglet's" mother, Daphne died four months post partum. Cause of death appeared to be kidney failure due to microscopic gout. A  preliminary necropsy showed no obvious cause of death, so tissue samples were sent to Dr. Michael Garner at Northwest ZooPath, an exotics pathology specialist out of Washington which then confirmed the cause of death as microscopic gout, as well as a clot found in her heart suggesting heart failure. She deteriorated quite rapidly and died at approximately four years of age, although her exact age is uncertain. Dr. Roge suggested that the gout may have been secondary to the heart failure.

      All this new information is important documentation on the future breeding of this magnificent animal. It is extremely exciting to know that there are several herpetoculturists working with this species. There is still plenty to learn about Uromastyx ocellatus ornatus,  My observations indicate that sexual maturity can occur as early as 11 months in captivity without any winter brumation.

     As far as the rest of  "Piglet and Bully's" siblings and litter-mates, I have seen some early signs of maturity. All the 13 month old males have reached  full dimorphic coloration and express a lot of posturing around the females. Some of the females are "marked" by the alpha males in the colonies. I suspect these animals will breed in the Spring, following a short brumation. They will be one and a half years old.

     In another breeding related incident, my female, "Titti", double clutched within a year of her first clutch. In April of 1998, she laid 19 eggs, nine months following her first. She was housed with a different male, approximately 4 or 5 years of age, who was somewhat submissive during the post partum period and I had not witnessed any copulation nor aggression. There is no documentation that these lizards retain sperm, so it is more likely that they bred.

   The eggs  were not full and chalky nor oval in shape, as the norm would have them be. They were round and varied in size. Eight eggs went bad within days and were most likely infertile. Eleven eggs  went full term and hatched after 81 days of incubation, and all but four died soon after they emerged. One baby was born completely grey with no pattern and died within a week. The three survivors are now two and a half months old (as of September 1998) and are still the size of hatchlings, weighing a mere 10 grams. They are less active than babies I have hatched in the past,  yet have decent appetites and dispositions. I am administering daily vitamin and Neo-cal glucon therapy to get them over this health hump, so to speak, but their status changes almost weekly. My theory on this is that the female, "Titti", copulated too soon and had not recharged her reproductive system and had not built up her calcium levels for proper egg development. Even though these lizards produce large clutches, they are not necessarily subsequently prolific, and these animals may only clutch once every other year in the wild. The information on breeding behavior in the wild is still largely unknown (Randall Gray, personal communication).

     In closing, I feel hopeful on the future of this beautiful animal in captivity as I will continue to dedicate myself  to the propagation of this species. In my opinion,  there is nothing more magnificent and regal as the ornate spiny-tailed lizard.

Literature cited:

Gray, Randall L. 1998. Captive reproduction of the Ornate spiny-tailed lizard  Uromastyx ocellatus ornatus. Vivarium 8(6):
Mader, Douglas R, M.S,D.V.M. 1996 Reptile Medicine and Surgery.

Special Thanks:

Randall Gray, Greg Gosney, Douglas Dix, Dr. Cheryl Roge, Dr. Stephen Barten and Dr. Byron

About the author:  A Surgical assistant for 17 years, hobbyist/herpetoculturist who has bred Bearded Dragons and Leopard Geckos for many years. Have worked  with Uromastyx since 1995. Living in Chicago, Illinois and an active member on the Board of Directors of the Chicago
Herpetological Society.

Copyright 1998 / Audrey A. Vanderlinden