Oceanology Vocab (9.4 - 9.6)

arthropods

largest phylum of animals, segmented and bilaterally symmetrical, jointed appendages (legs & mouthparts)

**exoskeleton**

A skeleton that forms the external surface of an animal, as in arthropods.

**molt**

The exoskeleton that is shed during the molting process.

crustaceans

majority of arthropods (subphylum), barnacles, shrimps, lobsters, crabs

copepods

a group of small crustaceans, found everywhere (plankton, benthic, among sediments, in and on other animals, and seaweeds), extremely abundant and important in the plankton

**carapace**

(1) The shield-like structure that covers the anterior portion of some crustaceans. (2) The shell of sea turtles.

**pereopods**

Paired legs in decapods. (usually for walking)

**maxillipeds**

The food-sorting appendages of some crustaceans.

**cephalothorax**

The anterior portion of the body of many arthropods, which consists of the head fused with other body segments.

**abdomen**

The portion of a decapod body between the cephalothorax and the tail.

**antenna**

A sensory appendage on the head of arthropods.

**compound eye**

An eye that consists of numerous light-sensitive units.

**pleopods**

Specialized appendages beneath the body(abdomen) of a decapod usually used for swimming (also can be used to carry their eggs and food) AKA swimmerets

**nauplius**

A planktonic larva of many crustaceans (copepods & barnacles)

zoea

a planktonic larvae of most shrimps and crabs

**lophophore**

A feeding structure that consists of ciliated tentacles.

**zooid**

Each member of a colony of bryozoans and other colonial invertebrates.

**pentamerous**

Radial symmetry based on five parts.

**endoskeleton**

A skeleton under the external surface of an animal.

**water vascular system**

A network of water-filled canals in echinoderms used in locomotion and food gathering.

**tube foot**

Any of the external muscular extensions of the water vascular system of echinoderms.

**ampulla**

Each of the muscular sacs that extend inside the body opposite the tube feet of echinoderms.

**madreporite**

A porous plate that connects the water vascular system of echinoderms to the exterior.

**pedicellaria**

One of the minute, pincer-like organs of some echinoderms that help keep the body surface clean.

Aristotle’s lantern

an intricate system of jaws and muscles in the mouth of the sea urchin

**evisceration**

The expulsion of internal organs in sea cucumbers.

**respiratory tree**

The branched extensions of the posterior end of the digestive tract of sea cucumbers that are involved in gas exchange.

**regeneration**

The ability of an organism to grow a body part that has been lost.

hemichordates

group of worms that fill the gap between echinoderms and chordates, characteristics: dorsal, hallow nerve cord, openings along anterior part of the gut

Ex: acorn worms (enteropneusts), worm like deposit feeders free or in U-shape