(updated) Phylum Echinodermata

class Ophiuroidea

Brittle stars, tube feet do not have suckers, madreporite is on the oral surface. passive suspension feeders

passive suspension feeding

animal hides in a crevice and feed by extending their arm, their tube feet aided by mucus trap food particles suspended in the water and pass the food to their mouth

class Echinoidea

sea urchins and sand dollars. aristotle’s lantern and test. sea urchins are herbivories that mainly eat kep and sand dollars are deposit feeders

Aristotle’s lantern

the 5-sided jaw inside the mouths of class Echinoidea

Test (class Echinoidea)

enlarged ossicles that are fused together to form a continuous exoskeleton, has tiny holes to allow for tube feet extension

deposit feeders

sand is passed over small spines on the aboral surface, food particles drop through the spines and become trapped in mucus cilia transport the food filled mucus to the edge of the body and into food groves on the oral surface that is then carried to the mouth by by the tube feet.

class Crinoidea

Sea lilies and feather stars, passive suspension feeders

class Holothuroidea

Sea cucumber, bilateral symmetry, eviscerate to distract their predetor.cuverian tubules that come out their anus and onto predators to deter predation. detritivores

detritivores

eat tiny organic particles (decaying algae and animal feces

class Asteroidea

Sea stars: feed by using their tube feet to grasp their prey(bivalves) and pry their shells open. Then everts its cardiac stomach and release enzymes to start externally digesting its prey

sea star wasting disease

caused by a bacteria infection of the skin and interfering with the body’s gas exchange capacity. often causing limbs to twist and break of the body.

Phylum Echinodermata

deuterostome development, pentaradial symmetry, non cephalized, oral and aboral surfaces. echinoderm larva retain ancestral bilateral symmetry characteristics

deuterostome development

bilateral symmetry, blastopore becomes the anus during embryonic development