Bio of Spiders - Quiz 1

Phylum Arthropoda

The largest phylum; animals with a rigid exoskeleton, jointed appendages, and segmented bodies.

Spider classification

Kingdom Animalia‚ Phylum Arthropoda‚ Subphylum Chelicerata, Class Arachnida, Order Araneae.

Kingdom of spiders

Animalia.

Phylum of spiders

Arthropoda.

Subphylum of spiders

Chelicerata.

Class of spiders

Arachnida.

Order of spiders

Araneae.

Order Araneae

The order containing spiders; the largest order in Class Arachnida.

How many spider families are there?

Approximately 120 families.

What habitat have spiders largely not exploited?

Salt water.

Two spider suborders

Primitive spiders and advanced spiders.

Primitive spiders

Larger spiders with longer limbs; chelicerae strike forward; 2 pairs of book lungs. Examples: trapdoor spiders and tarantulas.

Advanced spiders

Chelicerae directed sideways; 1 pair of book lungs; evolution of a tracheal system.

Family

The classification level below suborder/order and above genus; the handout notes that family is responsible for ten.

Genus

A classification level below family and above species.

Species

A classification level below genus.

Binomial nomenclature

The system of naming organisms with two names: genus and species.

Conspecifics

Organisms belonging to the same species.

Heterospecifics

Organisms belonging to different species.

Species definition — four parts

Review the four-part species definition from class; the four blanks were not filled in on the notes provided.

Subphylum Chelicerata

Arthropods that include spiders, scorpions, mites, ticks, and harvestmen.

Chelicerae

Mouthparts; in spiders, the chelicerae include the fangs.

Pedipalps

Appendages used for feeling/sensing; in spiders they also have roles in mating.

How many pairs of legs do chelicerates have?

Four pairs (8 legs).

Typical feeding of chelicerates

Most are terrestrial carnivores.

Class Arachnida

The class containing spiders, scorpions, mites, ticks, and harvestmen.

Order Scorpiones

Scorpions.

Scorpion tagmata

Two tagmata: cephalothorax and abdomen.

Order Acari

Mites and ticks.

Acari tagma

One tagma: the body.

Order Opiliones

Harvestmen, commonly called daddy-long-legs.

Opiliones tagma

One tagma: the body.

Subphylum Crustacea

Crustaceans such as crabs, lobsters, and shrimp; mostly marine, and many have shells.

Subphylum Myriapoda

Millipedes and centipedes.

Subphylum Hexapoda

Insects.

Hexapoda common name

Insects.

Hexapoda tagmata

Three: head, thorax, and abdomen.

Hexapoda legs

Three pairs (6 total legs).

Are all insects winged?

No. Some insects have wings and some do not.

Hexapoda habitats

Insects occur in most habitats.

Habitat largely unexploited by Hexapoda

Salt water.

Millipede legs

Two pairs of legs per segment after the first 3 segments.

Millipede body shape

Generally rounded.

Millipede feeding

Millipedes are detritivores, feeding on dead/decaying organic material.

Millipede defense

Can roll into a ball.

Centipede legs

One pair of legs per segment.

Centipede poison claws

The legs of the first segment are modified into poison claws.

Centipede body shape

Generally flattened.

Centipede feeding

They feed on other living organisms.

Arthropod exoskeleton

A rigid skeleton on the outside of the body.

Ecdysis

Molting; the process of shedding the old exoskeleton to allow growth.

Why does the exoskeleton limit size?

A rigid exoskeleton must be shed and replaced for growth, creating constraints on body size.

Exoskeleton functions

Protection from biotic and abiotic factors; prevention of desiccation; structure and support.

Biotic factors

Living factors.

Abiotic factors

Non-living environmental factors.

Desiccation

Drying out; loss of water.

Apodemes

Internal extensions associated with the exoskeleton that provide structure/support and attachment areas for muscles.

Jointed appendages

Segmented limbs/appendages with joints; necessary for movement in animals with rigid exoskeletons.

Tagmosis

The process in which individual body segments are fused into functional regions.

One tagma examples

Mites, ticks, and harvestmen have one tagma: the body.

Two tagma examples

Spiders and scorpions have two tagmata: cephalothorax and abdomen.

Three tagma examples

Insects have three tagmata: head, thorax, and abdomen.

Spider tagmata

Two: cephalothorax and abdomen.

Spider book lungs

Respiratory organs found in spiders; primitive spiders have two pairs, while advanced spiders have one pair.

Tracheal system

A respiratory system that evolved in advanced spiders.

Book lungs vs. tracheal system

Primitive spiders have two pairs of book lungs; advanced spiders have one pair and a tracheal system.

Web-builder: Orb web spider

Makes a vertical orb web; some have a stabilimentum; has extremely spiny legs.

Stabilimentum

A structure incorporated into some orb webs.

Web-builder: Long-jawed spider

Makes horizontal orb webs in damp areas; has an elongated base and fang of the chelicerae, with long, slim, cylindrical bodies.

Long-jawed spider key note

The chelicerae/fangs are elongated, giving the group its 'long-jawed' appearance.

Web-builder: Sheet web spider

Makes sheet webs; noted as the 2nd largest spider family (>3,700 species); adults are under 3 mm body length.

Web-builder: Cobweb spider

Makes an irregular cobweb; has a globular, tear-drop-shaped abdomen about as tall as it is long.

Web-builder: Cellar spider

Has 6 or 8 eyes, very long legs, carries eggs with little silk in the chelicerae, and exhibits paternal care.

Web-builder: Funnel web spider

Makes a flat sheet with an open-ended funnel; has long posterior spinnerets, about twice as long as the anterior spinnerets.

Spinnerets

Structures used by spiders to produce silk.

Hunter: Jumping spider

Largest spider family (>6,000 species); has large anterior median eyes (AME); stout and muscular; can jump up to 16 cm.

AME

Anterior median eyes.

PME

Posterior median eyes.

Jumping spider eye arrangement note

The notes show the four pairs as posterior lateral, posterior median, anterior lateral, and anterior median eyes; the AME are especially large.

Hunter: Crab spider

Has long front two pairs of legs held out to the side; some can change color; sit-and-wait predators.

Hunter: Wolf spider

Anterior eye row is small and straight; posterior eye row is square with large posterior median eyes (PME); usually brown; provides maternal care; can walk on water and dive for prey.

Wolf spider maternal care

Carries an egg sac on the spinnerets and carries young on the abdomen.

Hunter: Fisher/Nursery web spider

Often found near water; anterior and posterior eye rows are curved; usually brown; carries egg sacs in the chelicerae; can walk on water and dive for prey.

Fisher/Nursery web spider eye rows

Both anterior and posterior eye rows are curved, described in the notes as looking like a smile.

Order Araneae vs. Class Arachnida

Araneae is an order within the class Arachnida; Arachnida also includes Scorpiones, Acari, and Opiliones.

Araneae common name

Spiders.

Scorpiones common name

Scorpions.

Acari common names

Mites and ticks.

Opiliones common names

Harvestmen / daddy-long-legs.