BIOL 202 Practical 2: Phylum Echinodermata

Phylum Echinodermata

Sea stars/sea urchins/sea cucumbers

Aboral Side

side opposite from the mouth (Phylum Echinodermata)

Oral side

on the same side as the mouth (Phylum Echinodermata)

Calcite endoskeleton, WVS, mutable collagenous tissue

3 defining traits of Phylum Echinodermata

Calcite endoskeleton

made of ossicles of calcium carbonate, some have spikes and pedicellariae (Phylum Echinodermata)

Ossicles

fused calcium carbonate plates in the Echinodermata endoskeleton

Pedicellariae

pincer-like structures for defense and grooming within the Echinodermata endoskeleton

Water vascular system (WVS)

network of hydraulic canals with madreporite that can be used for locomotion/respiration/feeding/attachment/etc.

Madreporite

Opening for the WVS (Phylum Echinodermata)

Mutable collagenous tissue

allows Phylum Echinodermata to change rigidity of tissues for defense and for them to push out their stomachs for feeding

Class Crinoidea

Echinodermata: sea lilies/feather stars, no spines/madreporite/pedicellariae, feather-like arms

Class Asteroidea

Echinodermata: sea stars, pentaradial, aboral madreporite

Class Ophiuroidea

Echinodermata: brittle/basket stars, long and flexible arms, oral madreporite

Class Echinoidea

Echinodermata: sea urchins/sand dollars, globe-like bodies, aboral madreporite

Class Holothuroidea

Echinodermata: sea cucumbers, internal madreporite