Radiata2010(4)e

Sascha Pawlowski &

Sascha Pawlowski & Christine Krämer Fig. 2. Adult male diamondback terrapin, Malaclemys terrapin. Fig. 3. Portrait of a young Carolina diamondback terrapin, Malaclemys terrapin centrata, with a distinct head and carapace colour pattern. Fig. 4. Adult female diamondback terrapin, Malaclemys terrapin. 20 RADIATA 19 (4), 2010

Diamondback Terrapins, Malaclemys terrapin (Schoepff, 1793) Fig. 5. Portrait of a juvenile diamondback terrapin, Malaclemys terrapin terrapin, with a head pattern that is distinctly aberrant from the normal colouration. winter temperatures, the southern forms do not hibernate, whereas the northern forms (M. t. terrapin and M. t. centrata) are faced with substantially lower winter temperatures and therefore spend several months in hibernation (comp. Brennessel 2006). This necessitates that the origin of specimens be taken into consideration when it comes to captive conditions and possible overwintering (Sachsse 1984, Szymanski 2005). The captive care of Diamondback Terrapins is mostly regarded as rather difficult, which has primarily to do with a high degree of uncertainty as to the required water quality. It is presumed that the terrapins would become susceptible to skin diseases (fungal and bacterial infections) if kept in pure freshwater for which reason salt needs to be added to their water. The fact is, however, that Malaclemys terrapin has adapted to its “salty” natural habitat (brackish water) by developing the ability to excrete excessive salt via specialized glands, i.e., in addition to the desalination capacity of the kidneys (comp. Brennessel 2006). Research conducted on juveniles has shown that these are much less tolerant of salinity than adult specimens and would exhibit optimum growth rates at salinity levels only at less than 8 mg/l (Brennessel 2006). The terrapins are able to adjust both their physiology and activity, and their feeding behaviour in particular, as a response to the salinity of their water (Robinson & Dunson 1976, Brennessel 2006). This entails that specimens living in saltwater bask outside of the water much more frequently than those living in freshwater because the resultant change in osmoregulation reduces their intake of salt. Although life in brackish marsh and mangrove lands is comparatively difficult and requires particular physiological and behavioural psychological adaptation, this environment rewards Diamondback Terrapins with a situation of almost no competition as far as other reptiles are concerned. RADIATA 19 (4), 2010 21