Marine Invertebrates

What are invertebrates?

Animals that are multicellular eukaryotes with differentiated tissues and lacking a vertebrate or notochord.

What factors drove the Cambrian Explosion?

Oxygenation of oceans, predator-prey dynamics, and competition resulting in niche differentiation.

What methods are used for the classification of animals?

DNA sequencing/barcoding for molecular taxonomy and morphological classification.

What type of body symmetry do sponges exhibit?

Asymmetric.

Which animal groups exhibit radial symmetry?

Cnidarians, Ctenophores, and adult Echinoderms.

What is cephalization?

The concentration of sensory organs at the anterior end of an organism.

What are the key characteristics of Phylum Porifera (Sponges)?

Simplest multicellular animals, benthic, sessile, no true tissues but have differentiated cell types, and filter feeders.

What are the two classes of Phylum Cnidaria?

Cubozoa (box jellies) and Anthozoa (corals, anemones).

What is a unique feature of the life cycle of Cnidarians?

They have a polymorphic life cycle with polyp and medusa forms.

What are the general features of mollusks?

Mantle, foot, radula (except bivalves), complete gut, cephalization, nervous and circulatory systems.

What are the two main marine classes of Phylum Arthropoda?

Chelicerata and Crustacea.

What is the significance of horseshoe crabs in medicine?

They have strong immune systems and blue blood used in medical applications as it reacts with pathogenic bacterial endotoxins.

What are the main characteristics of Phylum Echinodermata?

Exclusively marine, CaCO3 endoskeleton, water vascular system, and tube feet for locomotion.

What are the classes within Phylum Echinodermata?

Asteroidea (sea stars), Ophiuroidea (brittle stars), Echinoidea (sea urchins & sand dollars), Holothuroidea (sea cucumbers), and Crinoidea (sea lillies).

What are some examples of marine worm Phyla?

Annelids (segmented worms), Nemertea (ribbon worms), Platyhelminthes (flatworms), and Nematodes (roundworms).

What are tunicates, and what do they represent in Phylum Chordata?

Barrel-shaped filter feeders that possess a notochord and neural tube in their larvae, precursors to vertebrate features.