nope, that’s the underlying shell structure! unlike the more familiar hardshell turtles, shoftshell turtles don’t have a solid shell. most of their carapace is actually soft tissue! this gives them a much lower defense than hardshell turtles like box turtles or even pond turtles, but it also makes softshells INCREDIBLY fast and agile. like, faster than some fish!
to pull this incredible speed feat off, their base shell structure consists of a minimal flat bony plate with “ribs” sticking out from the side that help support the leathery soft tissue that makes up their slippery soft carapace.
and because their shell is mostly soft tissue, you can often see the outlines of this bony support right through it! that’s the “ribs” you saw. pretty neat, huh?
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