Turtles House

Description

A small (max. carapace length = 17.6 cm [7 in.]) turtles with a prominent vertebral keel present in all individuals from hatchling to old adult. Carapace light brown to orange, with dark spots or streaks; pattern may become obscure as individuals age. Lacks gular scute of other kinosternids, which typically have 11 plastral scutes. Plastron an immaculate yellow. Skin of head and legs gray to brown or pinkish, with small dark spots. In cross-section, shell has one keel and a sharp slope, shell of stripe-necked Razorback musk turtle one keel with a gentle slope, and shell of the loggerhead Razorback musk turtle has a central vertebral keel, with a pair of secondary lateral keels (Carr 1952, Conant and Collins 1991, Ernst et al. 1994). Based on similarity of pattern and coloration, Razorback musk turtle appears more closely related to flattened musk and loggerhead Razorback musk turtle; stripe-necked and loggerhead Razorback musk turtle were once considered subspecies of Razorback musk turtle. Electrophoretic studies, however, have shown the Razorback musk turtle to be more closely related to the stinkpot (Ernst et al. 1994).

Diet

In captivity, Does well on high quality turtles pellets such as Mazuri and Reptomin, as well as earth worms, crawdads and feeder fish on occasion.

Habitat

Being more aquatic than the closely related mud turtles, razorback musk prefer a greater sized water area. Razorback musk are well able to thrive in deep water habitat. Though infrequent baskers, ample opportunity to do so is important. A spotlight over their basking area will be utilized. This area can be in the form of a rock projecting from the water, or in the case of young specimens, floating aquatic plants are preferred. Razorbacks are more shy by nature than other species of musk turtles, and a substrate of river pebbles seems to give them a greater sense of security.

History

Females mature at a carapace length of about 10 cm, which is reached in 4-5 years; males at 10-12 cm, in 5-6 years. Spermatogenesis begins in June and peaks bymid-August when the testes attain maximum size (Mahmoud and Klicka, 1972). During the last half of August though the middle of September the testes shrink as mature sperm are released to the epididymides. Testes size continues to decline through December when the testes weigh the least. No spermatogenesis occurs from January to April, but mature sperm descend into the vas deferens in March and April. In females, follicular growth proceeds slowly from September to November, and possibly also from December through February (Mahmoud and Klicka, 1972). In March and April follicles are yolked and enlarge, and during May and June grow at their fastest rate. Ovulation and oviposition also occur then. The largest corpora lutea are present when eggs are still in the oviducts, but begin to degenerate to corpora albicantia shortly after oviposition. There is no significant follicular growth during July and August.

Courtship and mating occur in the spring, and the acts are identical to those of Sternotherus odoratus (which see for details).

Presumably, nesting occurs from April through June, as females with oviducal eggs have been found during this period. At least two clutches of two to four white, elongated, brittle-shelled eggs are laid each year. Hatchlings emerge in August and September with carapace lengths of 23-31 mm and often three carapacial keels.

S. carinatus is omnivorous, feeding on insects, crustaceans, snails, clams, amphibians, and aquatic plants.

S. carinatus is a habitual basker; a full sunlight position on steeply angled branches of small diameter was recorded in about 74% of the observations by Lindeman (1996c).

Distribution

Southeastern Oklahoma to southern and eastern Texas, southern Arkansas, Louisiana, south-central Mississippi, and extreme southwestern Alabama. In Alabama, only reported from Escatawpa River (Blankenship et al. 1995). Mount (1975) felt species might be present in Alabama, but at the time of his writing had not been found (Conant and Collins 1991, Ernst et al. 1994, Mount 1975).