Arthropod Anatomy
This hard outer covering made of chitin protects arthropods and must be shed for growth.
Exoskeleton
Crabs, lobsters, and shrimp belong in which subphylum
Crustaceans
Adult echinoderms typically display this type of symmetry.
Radial Symmetry
Sea stars belong to this class of echinoderms.
Asteroidea
Echinoderms are exclusively found in this type of environment.
marine environment
These jointed structures allow arthropods precise movement and are a defining feature of the phylum.
Jointed Appendages
This arthropod class includes spiders and scorpions and lacks antennae.
Arachnids
This internal skeleton is made of calcium carbonate plates called ossicles.
Endoskeleton
Sea urchins and sand dollars are members of this class.
Echinoidea
This process allows many echinoderms to regrow lost arms or body parts.
Regeneration
This body plan divides many arthropods into head, thorax, and abdomen or cephalothorax and abdomen.
Segmented Body Plan
These marine arthropods are known for their book gills and ancient fossil record.
Horseshoe crabs
These tiny pincer-like structures help keep the surface of some echinoderms clean.
pedicellariae
This class includes sea cucumbers, which have elongated bodies and reduced ossicles.
Holothuroidea
Arthropods grow by periodically shedding their exoskeleton in this process.
Molting
These specialized mouthparts in crustaceans are used for feeding and manipulating food.
Maxillipeds (mandibles)
This group of crustaceans includes barnacles, which are sessile as adults
Maxillopods
This unique system uses seawater to power tube feet for movement and feeding.
Water Vascular System
Brittle stars, known for their flexible arms and rapid movement, belong to this class.
Ophiuroidea
Some sea stars feed by everting this organ outside their body.
Stomach
This waxy layer on the exoskeleton helps reduce water loss in many arthropods.
Epicuticle
This extinct group of marine arthropods dominated Paleozoic seas.
What are trilobites
This madreporite structure functions primarily to regulate water intake into the water vascular system.
Madreporite
This class includes feather stars and sea lilies, often with many arms used for filter feeding.
Crinoidea
This echinoderm defense behavior involves ejecting internal organs to escape predators.
Evisceration