AN ANATOMICAL MISCELLANY
A starfish’s madreporite
LOOK CLOSELY AT A STARFISH AND YOU might spot a tiny exquisite imperfection in its otherwise flawless five-fold symmetry. This beauty spot is called a madreporite, a roughly circular chalky plate that sits slightly off-centre on a starfish’s upper surface. Dotted with microscopic pores, it works as a seawater intake valve that supplies a system of tubes powering the countless hydraulic tube feet on the animal’s underside.