Testicles of a snapping turtle
Keywords: turtle, amphibian, testicle, spermatogenesis, gonad, snapping, temperature
Image size: 1704 x 1255px
The testicles of mature male common snapping turtle (Chelydra serpentina) weighing 6.96 kg is submitted for necropsy. The carapace length and width are approximately 33 and 28 cm respectively.
Spermatogenesis starts as day length increases but actually peaks in the early fall (White J.B and Murphy, B.C. 1973 Herpetologica, 29:240-246). Breeding occurs from mid-May to early September. The turtle spermatozoon is vermiform in shape (similar to that of a chicken) with a narrow pointed head that is curved. In general, the turtle sperm contains a typical head, midpiece and tail, similar in morphology to that of birds, amphibians and other reptiles. The differences are discussed by Hess R. A, Thurston R.J. and Gist G.H. in Ultrastructure of the Turtle Spermatozoon Anat. Rec., 1991. 229:473-481.
Snapping turtles are large fresh water amphibians, native to North America. Interestingly, as is the case with many other reptiles and fish, the temperature of egg incubation determines the gender of the hatchling. In this case, cooler temperatures produce more males.
Image modified and posted with the permission of the owner of copyright, Dr S. Martinson, Adjunct & Graduate Faculty Member, Diagnostic Pathology, Atlantic Veterinary College. smartinson@upei.ca
