GENERAL HISTOLOGY

Detailed explanation-1: -Answer: A pedicellaria is a small claw-shaped appendage with movable jaws, called valves, commonly found on echinoderms (phylum Echinodermata), particularly in sea stars (class Asteroidea) and sea urchins (class Echinoidea).

Detailed explanation-2: -Echinoderms possess an unusual suite of appendages on their skeletons, which are used for movement, interaction, and defense. In addition to spines, urchins and sea stars both possess pedicellariae (singular pedicellaria) which are jaw-like structures often at the end of stalks.

Detailed explanation-3: -Pedicellariae are minute stalked appendages that are found in among the spines of echinoids. They consist of a thin stalk, generally supported by a simple calcite rod, and a tulip-like head which is composed of three (rarely two) valves, each supported by an internal calcitic frame.

Detailed explanation-4: -Structure and Function of Echinoderms. Echinoderms are named for their “spiny skin.” However, the spines aren’t on their skin. They are part of the endoskeleton. The endoskeleton consists of calcium carbonate plates and spines, covered by a thin layer of skin.

Detailed explanation-5: -Pedicellariae are found only in echinoderms, particularly sea stars and sea urchins. The type found on collector urchins are known as globiferous, meaning they have a three-pronged jaw and a venom sac at the end of a long stalk.