Brisbane short-necked turtle
The oblong, olive to brown carapace (to 25 cm) is broadest behind the center and is usually posteriorly serrate in smaller individuals but smoother in larger turtles. Posterior marginals are flared, and lateral marginals may be slightly upturned. A cervical scute is present. Juveniles and males may have a medial keel which becomes lower with age; adult females may develop a medial groove. No neurals are present. In adults, the 2nd vertebral may be longer than broad; other vertebrals are broader than long. The 1st vertebral is expanded anteriorly while the 5th is flared posteriorly. Longitudinal striations occur on each carapacial scute, giving it a rugose appearance. The long, narrow plastron does not cover the carapacial opening. Its forelobe is rounded anteriorly and slightly broader than the hindlobe, which gradually tapers toward the rear and contains an anal notch. The intergular scute is longer than broad, and totally separates the gulars. The plastral formula of the two specimens examined was: fem > pect > intergul >< abd > an > hum > gul. Plastron, bridge, and undersides of the marginals are yellow. The head is of moderate size with a slightly projecting snout and an unnotched upper jaw. The mandibular symphysis is broader than the greatest diameter of the orbit. Two chin barbels are present. Dorsally, the head is covered with smooth skin, and the small, blunt neck tubercles are rounded. All skin is gray to olive brown. A yellow to cream-colored stripe runs backward from the corner of the mouth to the neck, passing through the lower third of the tympanum. A yellow spot occurs on each side of the chin.
E. signata has 50 chromosomes (Bull and Legler, 1980).
Males are shorter than females, have more flattened carapaces and longer, thicker tails.
Emydura signata is found in coastal drainages from the vicinity of Brisbane, Queensland, southward to northeastern New South Wales.
This turtle lives in rivers and large streams.
Nesting occurs from late September to early October (Cann, 1978).
Emydura signata is often seen sitting on logs or other emergent sites. Such basking behavior has traditionally been interpreted as thermoregulatory, but body temperatures of eight turtles monitored in winter, spring, and summer by Manning and Grigg (1997) showed a striking conformity with the water temperature rather that that of the air, and revealed no data indicating the turtles routinely elevated their body temperature above that of the water.
Emydura signata is similar to E. macquarrii, of which it is sometimes considered a subspecies. Georges and Adams (1996) were unable to detect genetical and morphological characters separating Emydura krefftii, E. signata, and E. macquarrii, and proposed these species to be synonimized.
IUCN Red List Status (1996)