Spiny Softshell

Naming

Six subspecies of "Apalone spinifera" are recognized, including the nominate subspecies:

⤷ Northern spiny softshell turtle, "A. s. spinifera"
⤷ Gulf Coast spiny softshell turtle, "A. s. aspera"
⤷ Black spiny softshell turtle or Cuatro Cienegas softshell turtle, "A. s. atra"
⤷ Texas spiny softshell turtle, "A. s. emoryi"
⤷ Guadalupe spiny softshell turtle, "A. s. guadalupensis"
⤷ Pallid spiny softshell turtle, "A. s. pallida"

A previously recognized subspecies, "Apalone spinifera hartwegi", has been synonymized to "A. s. spinifera" as of 2011.A rough draft assembly of the A. spinifera aspera genome was completed in 2013 by The Genome Institute at Washington University - St. Louis. The assembly ASM38561v1 can be accessed via its Genbank accession ID APJP00000000.1

Reproduction

Spiny softshells begin mating between ages 8 and 10. A large female turtle may live up to 50 years. The turtles mate in mid-to-late spring in deep water. The male will nudge the female's head while swimming, and if she chooses to mate, the male will swim above the female without clasping her with his claws. A few months later, the female turtle quickly lays her eggs along a sunny sandbar or gravel bank in a flask-shaped cavity she has dug close to the water. The turtle nests more than once during a single season. She can lay between 9 and 38 round, calcareous-shelled eggs. The eggs are laid around August and September, and they hatch in the spring. Unlike in other turtles, in the spiny softshell turtle, the sex of the hatchlings is not determined by temperature variations; it is determined by genetics.