Radiata2008(3)e

Stephan Böhm vessels

Stephan Böhm vessels forming under the shell or similar developments. The eggs were placed in an incubator after Budde (1980) and half buried in a mix of Cocopeat and Seramis ® as suggested by Schaffer (in Böhm & Schaffer 2006). The degree of substrate moisture was kept high throughout the incubation period, possibly even too high during the first weeks - if I stuck my finger into it, it came out wet. It was only later that Schaffer (pers. comm.) advised me to leave the incubator partly open and so reduce the substrate moisture. Temperatures fluctuated between about 26 and 31 °C. This was actually a fairly wide range, but considering the high probability for sex being determined by GSD (Genotypic Sex Determination) in all species of the family Chelidae (Pieau & Dorizzi 2005), there was no need to worry about sex ratios. By the beginning of December 2006, curiosity got the better of me and I started opening some of the eggs. Most of the twelve eggs were not exactly spoiled, but did not show signs of development either. The first egg I opened appeared to have never started developing. The second contained a baby within an enveloping allantois and was lying on its belly. I opened this egg for about one half. Not even 48 hours later, on 06.12.2006 (corresponding to 125 days of incubation), the baby had hatched by which point of time it had resorbed a substantial portion of its yolk sac. A little more than one week later, I began opening the next eggs. These revealed another live baby. This one had almost slipped off its allantois and was lying on its back, a sure sign that it was ready to hatch. Its yolk sac showed a curious violet colouration and was resorbed at a slightly slower pace. This specimen also developed not quite as rapidly as the first one when both were kept Fig. 10. Juvenile, basking. together initially, but has meanwhile caught up with its sibling. Opening two more eggs did not reveal more babies. The remaining three eggs eventually burst open or were opened after it became clear that they were spoiled. This means that only two juveniles hatched from the first clutch incubated by myself, but these are vital and undemanding as to their keeping requirements. Raising the juveniles The two juveniles were initially accommodated together in a faunabox measuring 40 × 20 × 20 cm with a water level of 15 cm. When I noticed that one specimen was developing better than the other, they were separated and transferred to a 40 × 40 × 40 cm container with a water level of 25 cm and a tub measuring 50 × 40 × 25 (water level 15 cm), respectively. Both tanks were furnished with shelters in the shape of roots and Java moss and offered a basking spot each. As co-inhabitants were chosen a few left-handed pond snails (Physella acuta). Water temperatures ranged around 23 °C during the day. This temperature enabled me to watch the two baby turtles while they were basking outside of the water. Juvenile Phrynops tuberosus are practically copies of their parents. Like these, they like to keep to 50 RADIATA 17 (3), 2008

Near-natural Husbandry of the Tuberose Side-necked Turtle, Phrynops tuberosus sheltered places, but are already able to hunt down small live guppies. So far there have been no problems with their feeding. Most types of food are readily accepted, including freezedried red mosquito larvae, frozen or defrosted Gammarus, guppies, as well as pellets. Their growth rates are satisfactory, too. After two months, both have gained a few grams and a millimetre or two in length. Fig. 11. Juvenile in the initial raising tank. Diet My specimens are fed a wide range of animalian foods. Plant matter has always been ignored even though Souza (2004) stated that fruit would also be consumed during the rainy season. Until now, the following food items have been offered (without a claim to completeness): poultry meat and innards, various species of snails and slugs, crustaceans (shrimp and crayfish), various species of fish (live, dead, or in the shape of fillet), prekilled mice (adults and babies) and rats (babies), insects (crickets, locusts, roaches, Zophobas, grubs), earth worms, and commercial pellets. The predominant constituent of their diet is fish, however. Best suited are defrosted feeder fish such as topmouth gudgeons (Pseudorasbora parva). These can be swallowed whole and contain, besides adequate amounts of calcium and vitamin D 3 , all other substances that are important to the turtles. It is most unfortunate that this food is not available commercially, so that the keeper depends entirely on how many are caught when, for example, a carp pond is emptied. The alternative is less valuable frozen fish such as fish fillet (pangasius, sole, trout). Because this eliminates innards and skeleton from the meal, the Ca:P ratio may be unfavourable. It also requires that attention be paid to the problems associated with thiaminase that concerns various cyprinids (carp). During periods when many frozen fish rich in thiaminase have to be used for feeding, mice should also be offered more frequently in order to improve the calcium and vitamin content of the diet. Cuttlefish shell is available to the turtles at all times anyway. My Phrynops tuberosus unfortunately dislike feeder pellets, which would otherwise be another good source of calcium and vitamins. Depending on the brand, they are either tasted and then spat out, or ignored right from the start. In order to conserve the hunting instincts of my turtles, live foods are offered as often as possible. RADIATA 17 (3), 2008 51