Kyphosis (humpback) spinal deformity has been recorded in the following turtles: Apalone spp. (Stuart 1996), Apalone spinifera (Burke 1994), Chelonia mydas (Rhodin et al. 1984), Chelydra serpentina (Wilhoft 1980), Chrysemys spp. (Plymale et al. 1978; Stuart 1996), Clemmys guttata (Ernst 1976), Glyptemys insculpta (Harding and Bloomer 1979), Lissemys punctata (Duda and Gupta 1977), Sternotherus odoratus (Nixon and Smith 1949; Saumure 2001), Terrapene carolina (Lynn 1937), and Trachemys scripta elegans (Tucker 1997; Tucker et al. 2007). Kyphosis appears to be more common in cryptodiran turtles because only one record has been documented for pleurodiran turtles. Limpus et al. (2006) reported the presence of kyphosis in Emydura macquarii krefftii but provided few details of the specimen. Herein, I report on kyphosis from E. m. krefftii.

During natural history studies of wild E. m. krefftii, three kyphotic individuals were found (Table 1). An adult male was caught 30 August 2001 at the James Cook University Rowing Shed, Ross River, Townsville, Queensland, Australia (19°18′59″S, 146°45′05″E). This individual was recaptured 6 August 2002 at the same site and found to have no difference in carapace length or mass, but the plastron length had increased by 2 mm. An adult female (Fig. 1) was caught 14 April 2003. This individual was recaptured 30 December 2004 and found to have grown 1 mm in both carapace and plastron length. Another male was captured 13 May 2005 at the Palmetum Bridge, Ross River, Townsville, Queensland, Australia (19°18′34″S, 146°45′57″E).

Table 1. Morphometrics of kyphotic Emydura macquarii krefftii from Ross River, Townsville, Queensland, Australia.

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Although kyphosis occurs in many turtle genera, it is a rare occurrence. I documented kyphosis in only 0.36% of the turtles captured during the study (n = 833) in the Ross River. The cause of kyphosis is thought to be a premature asymmetric fusion of the thoracic vertebrae, which results in disproportionate shell growth (Rhodin et al. 1984). Therefore, this allows the vertebral column to dramatically arch, thus permanently deforming the shell (Burke 1994). Although dramatic, kyphosis does not seem to have any affect on either male or female sexual maturity. Both males captured displayed the large tails typical of sexually mature male E. m. krefftii (unpubl. data). Unfortunately, sexual maturity could not be determined by palpation of the female because she was captured in April when E. m. krefftii are not gravid (unpubl. data). However, other turtles with severely deformed shells have been found to be reproductively viable (Burke 1994; Dietz and Ferri 2003) and healthy in most respects (Odum 1985; McLeod 1994), thus, showing that kyphosis may have minimal effects on the turtles.