Radiata2010(4)e

Ewald Roddewig Date Male

Ewald Roddewig Date Male 1 Male 2 Carapace length (cm) Weight (g) Carapace length (cm) Weight (g) 15.03.2006 5.7 29 5.1 20 13.04.2006 6.2 34 6.0 26 20.05.2006 6.8 44 6.8 39 18.06.2006 6.9 48 6.9 46 31.07.2006 7.5 60 7.2 56 26.09.2006 7.8 69 7.6 64 12.11.2006 7.8 71 7.6 67 30.01.2007 7.8 70 7.6 67 04.03.2007 8.0 71 8.0 71 22.04.2007 8.0 81 8.0 75 03.06.2007 8.0 89 8.0 79 08.08.2007 8.0 93 8.1 82 21.09.2007 8.0 95 8.1 84 04.11.2007 8.0 92 8.2 82 07.03.2008 8.0 87 8.2 80 07.04.2008 8.0 94 8.2 85 09.09.2010 8.1 96 8.2 91 Tab. 1. Growth of two males (captive-breds from 2005, acquired in 2006). By 2008, the males had become sexually mature at an age of three years. Date Female 1 Female 2 Carapace length (cm) Weight (g) Carapace length (cm) Weight (g) 26.09.2006 4.5 13 3.6 9 12.11.2006 4.5 13 3.9 10 30.01.2007 4.5 13 3.9 10 04.03.2007 4.8 16 4.6 14 22.04.2007 5.5 24 5.3 22 03.06.2007 6.5 42 6.0 34 07.07.2007 7.0 51 6.5 40 08.08.2007 7.6 68 6.8 43 21.09.2007 8.6 100 7.0 51 04.12.2007 8.9 105 7.5 62 07.03.2008 8.9 104 7.5 62 07.04.2008 9.5 130 8.5 87 03.05.2008 9.8 140 - - 16.06.2008 10.6 170 - - 30.07.2008 11.3 193 - - 18.02.2008 11.7 222 - - 19.03.2008 11.7 227 - - 26.08.2008 11.7 224 - - 28.10.2008 11.7 227 - - Tab. 2. Growth of two females (captive-breds from 2006, acquired in September of 2006). Both specimens were passed on in March and May of 2008, respectively. 6 RADIATA 19 (4), 2010

Black-knobbed Sawback, Graptemys nigrinoda nigrinoda Cagle, 1954 Date Breeding female 1 Breeding female 2 Carapace length (cm) Weight (g) Carapace length (cm) Weight (g) 16.06.2008 14.8 484 17.4 671 30.07.2008 14.8 470 17.4 677 26.08.2008 14.8 486 17.4 680 28.10.2008 14.8 497 17.4 690 18.02.2009 14.8 500 17.4 693 13.07.2009 14.9 501 17.4 688 28.10.2009 14.9 554 17.4 699 14.02.2010 14.9 549 17.4 693 16.04.2010 15.1 588 17.4 714 09.09.2010 15.5 649 17.4 693 Tab. 3. Growth of two females obtained in the summer of 2008. No. 1 was about eleven years old at this stage and believed to have come to Germany as a wild-caught specimen. This assessment finds support in the very smooth dorsal shell. Female 2 was captive-bred in Germany and about seven years of age at the time of receipt. The overview shows that the smaller and younger female added somewhat in size and weight, while the older specimen exhibited only minor changes in weight. Both females produced clutches in 2009 and 2010. section that ranges into the water; water level ca. 57 cm). It was, however, notable that the larger female was suppressing the smaller one, which made it imperative that another solution be found. The larger female therefore now shares the mentioned aquaterrarium with a female Graptemys barbouri (22 cm in carapace length). The two turtles are fully compatible and produce clutches of eggs on a regular basis. For her part, the smaller female now lives together with a four year-old female Graptemys ouachitensis sabinensis in another aquaterrarium without any problems being obvious. Outfitting The substrate consists of an about 2-3 cm layer of playground sand that was washed before use. The turtles love to root in the sand and occasionally ingest it in the process. Some 50% of the floor space are covered with natural rock tiles. These tiles have also been used for creating superstructures that enable the turtles to avoid each other if they wish to. The tiles are so heavy and large that the sawbacks cannot displace them. A branch of beech wood lies in the water and does not only serve to please the aesthetic needs of the human eye. It had been stored for two years prior to its use for this purpose. Releasing tannic acid on a constant basis into the water, it is meant to provide the turtles with protection from fungal diseases (Schilde 2004) and increase their feeling of safety by staining the water. With time, algae settle on the branch’s surface, which the sawbacks will graze off together with the bark. Tap water is used for filling the tanks. It is exchanged to an extent of up to 90% every three weeks. Occasionally, but not with every water exchange, 2 g/l iodine-free cooking salt is added to the water for stabilising the electrolyte balance (Schilde 2004). An island made of thick natural cork floats on the water surface as a basking spot. It is fixed so that it is always kept in its place under a UV-floodlight and large enough for all turtles of a tank to find a place for basking at the same time (and avoiding the hottest spot of the cone of light if they so desire). The aquaterraria are covered on top with a wooden box-like extension of about 35 cm in height. It prevents the turtles from escaping, especially in the area of the terrestrial part that serves as an oviposition spot. The box furthermore houses the timer-controlled RADIATA 19 (4), 2010 7