Ch.24

Gastropoda (class)

The snails and slugs. The only class of Mollusca with terrestrial species. Radulla is shaped into a file or rasp like structure used to rake food into the mouth. Most species have a coiled external shell.

Veliger

The shell less larvae of gastropods, and the only stage where bilateral symmetry is present.

Torsion

A developmental event unique to the gastropods, in which internal organs are rearranged in their body as they grow to fit into their shell causing a loss of normal bilateral symmetry.

Cone shells

A family of gastropods native to the tropical pacific. They have the most toxic venom of any known animal species.

Cephalopoda

The octopi, squid, cuttle fish, and the nautilus. All species have a foot that is modified into a series of sucker arm tentacles that are used to capture prey. The radula is a beak-like structure used to tear flesh from prey and in some species, to inject

Siphuncle

A blood vessel extending through the chambers of a nautilus shell, pumping gas into and out of the chambers making it more or less buoyant in the water.

Giant Squid

The largest invertebrate on earth reaching lengths exceeding 60 feet.

Chromatophores

Cells in the skin of cephalopods that allow rapid color change for camouflage or possible communication.

Sepia

An ink-like material released into the water to cloud the vision of a potential threat.

Arthropoda (phylum)

The largest and most diverse phylum of animals on earth. They account for nearly 75% of all animal species. They have an open circulatory system, a complete digestive system. The body is inclosed in a protective covering called an exoskeleton made of the

Trilobita (sub phyla)

The first form of arthropods to have theoretically evolved. Fossils indicate they were once found over most of the earth, and are thought to be the direct ancestors of all modern day arthropods.

Chelicerata (sub phylum)

Arthropods with needle or fang-like mouth parts called chelicerae used to inject venom, stomach acids or a mixture into a food source turning it into a liquid which i then sucked into the stomach through those mouth parts.

Merostomata (class)

The horseshoe crabs. One of the most ancient groups of arthropods, they are scavengers found in most of earths oceans. Their body is covered by a thickened shell-like exoskeleton called the carapace, which features a long spine-like tail called the telson

Anthocyanin

A blue pigment in horseshoe crab blood show to have a positive effect on cancer treatment when added to chemo therapy drugs.

Arachnida (class)

The most common group of chelicerates. All species at some point in their life have eight legs and two body segments.

Cephalothorax

The forward body segment. It contains the brain and sense organs, the mouth parts, and most vital organs. Is also where the legs are attached.

Abdomen

Rear body segment of arachnids, containing the intestine, reproductive organs, and specialized structures.

Aranae (order)

The spiders. The largest group of arachnids in terms of both physical size and species diversity. All species are predators. All species are venomous, though very few are considered harmful to humans.

Silk gland

An internal organ in the abdomen of spiders. It produces a fluid that hardens on air contact to create the material of a spiders web.

Spinnerets

Two muscular appendages on a spiders abdomen that control the release of material from the silk gland and form it into a web.

Funnel Web Spider

Native to Australia. It has the most toxic venom of any spider species known.

Banana Spiders

Native to Central and South America. They are responsible for more human fatalities per year than any other spider species.

Black Widow & Brown Recluse Spiders

The only two species of spiders native to the united states with a venom potentially lethal to humans.

Scorpionida (order)

The scorpions. Predators found in tropical and subtropical regions. They have a multi segmented abdomen that ends with a venomous stinger mainly used as a defensive weapon.

Chelipeds

Pincer-like legs used by scorpions to kill and tear apart their prey.

Pseudoscorpionida (order)

The false scorpions. They are scavengers found in the same environments as the true scorpions. They have a body structure similar to the true scorpions, but the telson is hollow and used to throw acetic acid at the eyes of their enemy `

Opiliones (order)

The harvestmen. Commonly know as the grand daddy longs legs. They are scavengers that feed mainly on decomposing plants.

Autotony

The ability to self sever a limb and regrow it later in order to escape a predator.

Pcynogonida (order)

The sea spiders. Venomous predators found mainly in cold, polar oceans, specifically the southern ocean. They do no posses web spinning structures. They have an extremely thin exoskeleton, giving their body an almost jelly-like appearance. Small, feathery

Acarina (order)

The ticks and mites. Parasites that feed on blood, tissue fluids, or skin tissue cells. Many species are major carriers of disease.

Hypostome

A spine hollow tube inserted into the skin of a host. Used to draw blood and tissue fluid from the host. But also allowing disease organisms to be transmitted.

Mandibulata (sub phylum)

Largest of the arthropod subphyla. Mouth parts form a true biting and chewing jaw.

Myriopoda (class)

Have long, multi segmented bodies with at least one set of legs per segment.

Chilopoda (order)

The centipedes. Predators with one pair of legs per segment and venomous claws on the head used to kill prey.

Diplopoda (order)

The millipedes. Common scavengers in temperate and tropical regions having two pairs of legs per segment.

Crustacea

Characterized by the presence of gills for respiration even in terrestrial species. Most species are covered by a large carapace.

Malacostrica

Crabs, lobster, shrimp, and crate fish. All species have chelipeds for defense. All species have a thick carapace covering the body.

Copepoda

Commonly known as plankton. They are microscopic or barely macroscopic. They are a major link in ocean food chains.

Cirripedia

The barnacles. Sessile crustaceans that survive as filter feeders. They have a hinged carapace that can be opened to allow a flow of water pass through or allow sperm or eggs to be released into the water.

Nauplius.

The free swimming larva of barnacles allowing them to develop in areas away from the parents which reduces competition between generations.

Isopoda

This is the only order of terrestrial crustaceans. They survive in damp areas such as rotting wood.

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The most common class of animals on earth making up roughly 75% of all arthropods. All species at some point have six legs and three body segments.

Head

Forward most body segment containing the brain, mouth parts, and the primary sense organs.

Compound eye

Main sense organ of an insect. Made of separately lensed units called ommatidia that each create a separate image that can be processed by the brain creating a near 360 degree field of view.

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Echinodermata (phylum)

The spiny skinned animals. All species are marine. They all have some degree of spine development extending through their skin. They have no circulatory or muscular system, both of which are replaced by a series of tubes called the water vascular system w

Pentamarous biradial symmetry

Body plan unique to echinoderms, in which bilateral groups of organs are arranged around a central point always in multiples of five.

Asteroidea (class)

The starfish. Largest and most common class of echinoderms. They are predators that feed on shellfish by extending a part of their stomach out of the their body and into the shell of their prey.

Ophidioroidea (class)

Commonly known as the brittle stars. Their arms are long, slender, and snake-like in their appearance and movement. They are nocturnal scavengers that use autotomy for defense.

Echinoidea (class)

The sand dollars and sea urchins. They have long, prominent spines extending from their skin. Sand dollars are scavengers with spines that are soft and hair-like. Sea urchins are predators that feed mainly on coral, their spines are long, rigid needles th

Holothuroidea (class)

The sea cucumbers. They are scavengers on the ocean bottom. Their skin is leathery with only a few extremely small spines. They can be used as a food source by humans

Concentricycloidea (class)

The sea daisies. The most recently descried class of echinoderms. Only found in the Tasman sea which separates Australia from New Zealand. They resemble sea urchins but the water vascular system forms a bulls eye pattern in their body and they survive as

Crinoidea (class)

The sea lilies. Based on fossil evidence, these are the first echinoderms to evolve. They are sessile with their body attached to a flower-like stalk. Extensions of the water vascular system are used to filter feed.

Beadle

Most common type of insects on Earth

Flies and Mosquitoes

Only winged insects with a single pair of wings

Butterflies and Moths

Have powdery scales on the wings to help catch air and provide lift for flight

Grasshoppers, roaches, and mantises

Have multiple joints in the foot giving them a wide range of motion

Fleas

Blood feeding parasites and a major carrier of tape worms

Sucking lice

Have needle like mouth parts including head lice, major carriers of disease

Bitting lice

Includes body and crab lice, they have large chewing mouth parts and are a major cause of infections and disease

Ants, bees, and wasps

All species have an abdominal stinger that may be held internally in their body, most species form complex societies controlled by a queen

- Pheromones

Hormones used to control the actions of a hive

Termites

One of the few types of animals that can digest wood fiber due to a protist in their intestines

Dragonflies/ Mayflies

Major food sources for fish and other animals in lakes and streams

Silverfish

Largest group of wingless insects and major carriers of digestive infections