Phylum Echinodermata and Hemichordata Overview

Study Notes

Phylum Echinodermata

Echinoderms are characterized by the presence of calcareous spines on their bodies.
Found exclusively in marine environments.
Exhibit radial symmetry as adults, but are bilaterally symmetrical in their larval stage.
Possess a triploblastic and eucoelomate body structure.
Locomotion is facilitated by tube feet, which are also used for prey capture. Some echinoderms are sedentary.
Their skeleton consists of calcareous spines and/or ossicles (plates).
They possess exceptional regenerative capabilities.
Reproduction is typically unisexual.
Examples include starfish, sea urchins, brittle stars, sea cucumbers, etc.

Phylum Hemichordata

Hemichordates have a tripartite body plan, divided into a proboscis, collar, and trunk.
A notochord is present only in the proboscis region, thus justifying the name 'hemichordate'.
Also known as 'acorn worms'.
Marine animals that reside in burrows within sand.
Possess one or more pharyngeal gill slits.
Reproduction is often unisexual, but some species are hermaphroditic.
Examples include Balanoglossus and Saccoglossus.

Hemichordates and Evolution

Balanoglossus is considered a crucial evolutionary link between non-chordates and chordates due to traits shared by both groups.

Description

Explore the fascinating characteristics of Echinoderms and Hemichordates in this quiz. Learn about their unique body structures, habitats, and reproductive methods. Test your knowledge on examples like starfish and acorn worms.