Zoo - Definitions

Annuli

Of Phylum Annelida, circular rings that make up body segments

Setae

Of Phylum Annelida, chitinous bristles that are used for locomotion or as anchors

Cephalization

The concentration of sense organs, nervous control, etc at the anterior end of the body, forming a head and brain, both during evolution and through an embryo’s development

Parapodia

The precursor to paired appendages, they are often fleshy or hair like appendages that are used for locomotion and respiration. Aquatic annelids have gills on them.

Nephridia

Of Phylum Annelida, advanced kidneys

What does the coelom do for an Annelid?

It acts as a hydrostatic skeleton.

Euryhaline

Able to tolerate a wide range of salinity

Atoke

Burrowing adult part of a Palolo worm. Releases epitokes and does not reproduce itself.

Epitokes

Sexually mature part of Palolo worm that breaks off and swims to the surface. It bursts at sunrise, releasing ovaries and sperm.

Peristaltic motion

Undulating/wave motion used for eating. At least earthworms and humans do this.

Calciferous glands

Of earthworms, glands for absorbing/secreting calcium ions to reduce the blood’s Ca level

Clitellum

A raised band encircling the body of oligochaete worms and some leeches, made up of reproducive segments. Secretes mucus that that holds copulating earthworms together, and produces the cocoon that encircles the eggs for development.

Cutting Plates

The jaws of a leech used for getting through the skin of a host.

Ganglia

A structure containing a number of nerve cell bodies, typically linked by synapses.

Tagmata

In the bodies of arthropoads and some other segmented animals, a morphologically distinct region, typicallt comprising several adjoining segments, such as the head, thorax, and abdomen of insects.

Chelicera

Either of a pair of appendages in front of the mouth in arachnids and some other arthropods, usually modified as pincer-like claws

Pedipalps

The secondary pair of forward appendages among chelicerates. They are lateral to the chelicerae and anterior to the first pair of walking legs

Carapace

Hard dorsal outer shell for protection. Present in horseshoe crabs, crustaceans, and turtles.

Telson

The last segment in the abdomen or a terminal appendage to it in crustaceans, chelicerates, and embryonic insects. tail.

Book gills

Found in horseshoe crabs and spiders, respiratory organs that are membranous folds.

Malpighian tubles

Kidney in Order Araneae

Setae

Hair-like structures on living organisms, which in spiders (at least) can serve sensory functions

Spinneret

Any organ through which the silk, gossamer, or thread of spiders, silkworms and certain other insects is produced.

Pectines

On a scorpion, a comb-like structure that is tactile

Repugnatorial glands

Glands on a millipede that emit a bad smell to ward off predators

Rostrum

protective plate on the snout of a crustacean

Antennal Gland

A bean shaped organ next to the antennae in a crustacean that is functionally a kidney.

Three functions of a filter feeder’s gills

Breathe, food, gametes

Statocyst

An organ of equilibrium found in usually aquatic invertebrates that is typically a fluid-filled vesicle lined with sensory hairs which deter the position of suspended statoliths

Statolith

Rocks in the statocysts that stimulates sensory receptors in response to gravity, enabling balance and orientation

Ommatida

Photoreceptors in crustaceans

Metamorphosis

the process of transformation from an immature form to an adult form in two or more distinct stages

ecdysis

Scientific term for molting of any animal

Sclerites

Exoskelton plates made of scleroprotein on an insect.

Wings (for Hexapoda)

Cuticular extensions of the epidermis

Halteres

Unique to an insect, balancers in legs that maintain equilibrium in flight

Spiracles

Of an insect, valved opening that regulates flow, where oxygen goes in and carbon dioxide goes out

Tracheae

Air tubes

Taenidia

Structures that prevent the collapse of tracheae

Tracheoles

H2O filled tubes that carry O2 to cells

Air sacs

Dialated tracheae

Malpighian tubles

Of an insect, kidneys

Spermathecea

Of an insect, sperm storage sacs in females they can use to fertilize eggs when they wish

Instar

Generic name for intermediate stages between molts (specifically metamorphosis