Siebenrock, 1914
Steindachner's snake-necked turtle
Recognition
This side-necked turtle has a flattened, almost round carapace (to 21 cm) with a medial groove on the 2nd to 4th vertebrals and an unserrated rim. All vertebrals are broader than long. The 1st is slightly flared anteriorly and is the largest; the 5th vertebral is flared posteriorly. There are no neural bones in the carapace. Lateral marginals are not upturned; those over the tail not raised. Carapacial color varies from light to dark brown. The plastron is narrow; the forelobe is broader than the hindlobe. A wide posterior notch is present on the hindlobe. The plastral formula is: intergul > an > fem > hum > pect >< abd > gul. Plastron, bridge, and undersides of the marginals are yellow with black seam borders. The head is small with a protruding snout, an unnotched upper jaw, and laterally placed eyes. The neck is comparatively short and thin and is covered with small granular scales which have a reticulated, wrinkled appearance. Dorsally the head and neck are gray to olive, beneath they are cream colored. Each forelimb has three enlarged transverse scales on the anterior surface. Limbs are gray to olive on the outer surfaces but yellowish beneath.
Bull and Legler (1980) found the karyotype to be 2n = 54.
Males have long thick tails and slightly concave plastra; the females have shorter tails and flat plastra.
Distribution
Chelodina steindachneri is restricted to Western Australia where it occurs in coastal drainages from the DeGrey River system in the north to the Irwin river basins in the South.
Habitat
Over much of its range, Chelodina steindachneri lives in streams that are completely dry for long periods between rains. Apparently the turtles aestivate in the dried-up river beds during these times, and are adapted to prevent desiccation.
Natural History
Male Chelodina steindachneri become mature at about carapace length 12 cm (Kuchling, 1988). No activity occurs in the testes germinal epithelium during the winter, but the spermatogonia multiply in the spring, and spermatocytogenesis takes place in late spring and summer (Kuchling, 1988). Spermiogenesis peaks in January and February, and spermiation begins during the summer and continues through the autumn. Females mature about 15 cm carapace length (Kuchling, 1988). Ovarian follicles begin to enlarge in late spring, but enlargement is arrested for a period during the summer and autumn when the follicles maintain their size without enlargement (Kuchling, 1988). Vitellogenesis is completed in the spring before ovulation; oviducal eggs are present in October (Kuchling, 1988).
Only one clutch of 7-8 relatively small (27.5-31.0 x 17.0-19.5 mm) eggs is laid a year, a pattern apparently adapted to a relatively long period of aestivation. Deposited eggs are white, hard-shelled, and ellipsoidal.
C. steindachneri apparently is carnivorous, as captives feed on chopped meats, fish, and prawns, but Pritchard (1979) reported they also feed on carrion and plants.
IUCN Red List Status (1996)
Not listed.