Biology 1407- Chapter 30: Protostome Animals

Lophophore

Crest of ciliated, hollow tentacles around the mouth.

Lophotrochozoans

Trochophore

Larval form that moves by beating a wheel-like band of cilia.

Lophotrochozoans

Protonephridia

Simple excretory structures that filter waste and maintain osmotic balance.

Proto-: First

-nephr: Kidney

Phylum Platyhelminthes ("flat worms")

Gastrovascular cavity

Digestive system branched to deliver nutrients directly to cells via diffusion.

Scolex

Anterior end in tapeworms that has suckers to adhere to intestinal lining of hosts.

Class Cestoda

Proglottids

Body sections composed entirely of sex organs

Class Cestoda

Alimentary canal

Digestive tube that extends from the mouth to the anus

Phylum Rotifera- rotifers

(wheel-bearing)

Corona

"Crown" of cilia create water current for feeding

Phylum Rotifera- rotifers

(wheel-bearing)

Mastax

Muscular and jawed organ that breaks the food into smaller particles, unique to rotifers.

Parthenogenetic

Population exists entirely of females that produce more females from unfertilized eggs

Phylum Rotifera- rotifers

(wheel-bearing)

Parapodia

Paddle-like appendages that assist aquatic annelids in locomotion.

Phylum Annelida ("rings")

Class Polychaeta ("many bristles")

Chaetae

Bristle-like chitinous projections

("bristle")

Open Circulation

Hemolymph, or body fluid, leaves vessels of system, percolates between cells and tissues, then flows back into system to be pumped out again by a heart.

Example: Insects, spiders, mollusks

Closed Circulation

Blood is contained within a continuous system of vessels and pumped by a heart

Example: Humans and other mammals, birds, reptiles, fish

Foot

Muscular mode of locomotion in mollusks

Visceral Mass (Phylum Mollusca)

Heart, digestive, excretory, and reproductive organs.

Mantle (Phylum Mollusca)

Fold and tissue that drapes over visceral mass and secretes calcium carbonate shell.

Mantle cavity (Mollusca)

Fluid-filled chamber that houses gills, anus, excretory pores.

Radula

Strap-like organ used to rasp and scrape up food particles

Torsion (Class Gastropoda)

Visceral mass rotates 180 degrees causing anus and mantle cavity to rest above head.

Phylum Mollusca

What are ammonites?

Fossil cephalopods that were dominant marine invertebrate predators for hundreds of millions of years.

When did ammonites go extinct?

In the Cretaceous along with dinosaurs.

To which phylum do ammonites belong?

Phylum Mollusca.

Cuticle

Tough exterior that Ecdysozoans secrete

Ecdysis (molting)

Process of shedding off cuticle.

Ecdysozoans

Chelicerae

Claw-like feeding appendages in chelicerates.

Pincers or fangs that grasp rather than chew.

Mandibles (Myriapods)

Pair of antennae and three pairs of appendages modified as mouthparts.

Myriapods

(many feet).

e.g., Millipedes and centipedes.

Carapace (Crustaceans)

Hardened cuticle that covers head and thorax.

What is incomplete metamorphosis?

A type of development in which nymphs resemble adults but are smaller and lack wings.

What do nymphs do during incomplete metamorphosis?

They go through a series of molts until they reach full size.

What is complete metamorphosis also known as?

Holometabolous

What are the larval stages in complete metamorphosis specialized for?

Eating and growing

What aspects differ between larval and adult stages in complete metamorphosis?

Morphology, food, habitat

Give an example of complete metamorphosis.

Caterpillar to butterfly.

Undergo pupal stage to reach adulthood.