Bio Lab 7 Flashcards

Arthropods are the most successful animal phylum in terms of species diversity, distribution, and sheer numbers

coelomate

body segmentation( modified metamerism)

hard exoskel

jointed appendages

often fuse into three tagmata (anatomical areas) in the adult stage

head- contains segments with feeding and sensory activities

abdomen- contains segments with locomotor and or reproductive activities

head and thoracic segments fused

cuticle

protein and chitin

strong, protects the animal and provides points of attachment for the muscles that move appendages.

thick and inflexible in some regions, such as crab claws, and think and flexible in others, such as joints

in order to grow, an arthropod must molt its old exoskeleton and secrete a larger one

leaves the animal temporarily vulnerable to predators and other dangers

its relative impermeability to water helps prevent desiccation and provides support on land

arthropods moved to land after the colonization of land by plants and fungi

terrestrial arthropods generally have internal surfaces specialized for gas exchange. For example, insects have tracheal systems, branched air ducts leading into the interior from pores in the cuticle.

Limulus- horseshoe crab

Argiope- garden spider

Both contain one pair of chelicerae, one pair of pedipalps. Antennae and mandibles are ABSENT.

Cabarus- crayfish

primarily found in aquatic environments.

contain two pairs of antennae, one pair of mandibles

Romalea- grasshoper

they are found in terrestrial environments.

contain one pair of antennae and one pair of mandibles

feathery gills like under the lateral extensions of a large, expanded exoskeletal plate called the carapace

expanded exoskeletal plate

heart

large digestive glands fill much of the body cavity. the intestine extends from the stomach through the tain to the anus. the green glands lie near the brain in the head.

arteries

open circulatory system

excretory organs

long tubular structures that resemble nephridia but are compacted into a glandular mass.

Waste and excess water pass from these glads to the outside of the body through pores at the base of the antennae on the head.

lies in the midline with nerves extending posteriorly fusing to form central nerve chord

crayfish has 3 distinct parts while the earthworm has septa that divides the body cavity

condition in which body parts are repeated serially along the longitudinal axis of the body.

analids and arthropods

homologous

serial homology

uropods, swimmerets

1 pair on abdomen

biramous appendages that together with the medial telson make up the tail fan which is used in rapid escape movements and in fanning the eggs and young

5 pairs on abdomen

biramous, used for swimming

anterior two pairs are modified as copulatory organs in the male

their grooves direct sperm into the female's seminal receptacle. In the female, the swimmerets are also used t hold the fertilized eggs for incubation

walking legs

maxillipeds

5 pairs on throax

uniramous; all but the last also bear gills

the first pair are the chelipeds and bear the large pincers (chelae)

the second and third pair also possess small pincers at their tips

3 on thorax

biramous; used in food handling and chemosensation. The last two pairs have gills attached

Maxillae

Mandibles

antennae

antennules

2 pairs on head

biramous; used for food handling

second pair bears gill bailers which generate respiratory water currents through the gill chambers

1 pair on head

uniramous

shred food for swallowing

1 pair

biramous; chemosensation

nephridiopore drains the green gland

1 pair on head

biramous

chemosensation

equilibrium

most marine, some freshwater, few terrestrial

free living even though some are parasitic

cephalothorax, abdomen

covered by a caprice and contains appendages used in sensing moving and feeding

contains two pairs of antennae, one pair of mandibles, 5 pairs of walking legs

visceral functions

contains appendages used in moving

2 pairs of antennae, 2 pairs of maxillae, a pair of mandibles, pair of compound eyes

one of the constituents of crustacean mouth parts

lie just behind the jaws and aid with detection and manipulation of food

arthropods evolved from an annelid-like ancestor containing identical appendages

during this evolutionary process some metameres and appendages became specialized to accomplish different roles

the appendages are thus said to have serial homology. they are homologous since they are evolved from the same ancestral structures and serial since they are metameric

grasshopper (romalea)

only winged invertebrates

most successful species are small in size and have a great reproductive capacity

terrestrial

insects have one pair of antennae and crustaceans have 2 pairs

have one pair of antennae and one pair of mandibles

usually has three pairs of walking legs and one or two pairs of wings

most internal organs and specialized structure for reproduction

3 part gut

unbranched appendages

tagmata

head: containing appendages used in sensing and feeding

thorax: containing appendages used in moving

abdomen: containing no appendages and having visceral functions

uses a system of internal tubes- tracheae and sacs delivering oxygen directly to cells. Air is taken in through openings called spiracles (small openings in elastic air tubes)

narrow esophagus leading from the mouth expands into a large crop used for food storage

stomach where digestion takes place

six pairs of these fingerlike extensions that connect to the digestive tract where the crop and the stomach meet.

these pouches secrete digestive enzymes and aid in food absorption.

intestine then into the rectum and out the anus

space between the body walk and the digestive tract

accomplished via Malpighian tubules

blind ending tube like appendages of the intestine that open at the border between the mid and hindgut

as the hemolymph circulates in the hemocoel near these malpighian tubules, the uric acid is actively transported and discharged into the hindgut, from where the excretory products are passed with the feces

named for clawlike feeding appendages called chelicerae which serve as pinchers or fangs. In their cephalothorax they contain one pair of chelicerae. this is followed by one pair of pedipalps and 4 pairs of walking legs.

lack antennae and mandibles

limulus- horseshoe crab

argiope- garden spider

cephalothorax- locomotor, sensory, feeding appendages

abdomen- visceral functions

do not have hemoglobin but rather hemocyanin to carry oxygen in their blood

amebocytes which can be harvested for medical applications

tough and leathery

must be molted periodically as the animal grows

divided into two regions: cephalathorax, abdomen

bears six pairs of spines along the sides and on its ventral side has six pairs of flat, plate-like appendages.

covering the cephalothorax dorsally and laterally

hard

concave below and convex above

small

used for food manipulation

1st pair of appendages

second pair of appendages

next 4 pairs

all appendages except the chelicerae have spiny masticatory processes called this on the basal segments.

the chelae of the appendages pick up food and pass it to the gnathobases.

between the last pair of walking legs is a small rudimentary pair of appendages called the chilaria.

houses openings of the genital pores

2 on the underside of operculum

tail used for bracing when the animal is burrowing or plowing through the sand or in righting itself when turned over

anus located ventrally at the proximal end

leaf like folds

in life the plates and lamellae fan back and forth like the pages of a book in a breeze. because of this characteristic the collective structures are called book gills.

later cpd eyes

median simple eyes

poison from glands on the chelicerae to immobilize their prey which chewing their prey, spill digestive juices into the tissues and suck up the liquid meal

6 pairs of appendages

-4 pairs of walking legs

-pair of pedipalps function in sensing or feeding

chelicerae usually function in feeding

book lungs

produced as a liquid by abdominal glands and spun by spinnerets into fibers that solidify

hard, thin, chitinous, somewhat flexible

cephalothorax and abdomen which includes the pedicel (slender waist)

spiders do not have compound eyes

they have 6 to 8 ocelli (simple eyes) which can't detect motion so they rely more on tactile cues

all parts of body have

2

used to eject poison from its poison gland

6 joined and sed for gripping prey

in the male it is modified as an intermittent organ to transfer sperm to the female

basal parts are used to squeeze and chew food

4 pairs

each leg is made up of seven segments as follows : coxa, trochanter, femur, patella, tibia, metatarsus, tarsus

tarsus has claws and a tuft of sensory hairs at its terminal end

occurs between the blood circulating inside the lamellae and the air flowing in the spaces between the lamellae

opening into a small chamber from which tracheal tubes extend into the body

a chitinous plate which is located on the ventral mid line between the spiracle, conceals the female genital pore

3 pairs of spinnerets on a raised surface

held apart by bars so that there are always air spaces between them

passage through 3 different stages

larva hatches out of the egg

feeds and grows undergoing several molts

after the larva reaches maximum size, it molts and immediately undergoes a transformation into a non feeding stationary pupa.

pupal case splits open and the adult emerges

radical reorganization occurs. most of the larval tissues are broken down completely and replaced by adult structures concurrently formed from the division and differentiation of strategically situated clusters of embryonic cells called imaginal discs.

clusters were formed in the embryo but remain undifferentiated during the larval stage

the immature form that somewhat resembles the adult transforms stepwise with each molt to reach the adult form.

adult never molts

wormlike

resembles the adult but its head is disproportionately large and its wings are rudimentary.

as it feeds and grows it molts and with each molt it more closely approximates the adult form. finally after the last molt it is an adult with fully functional wings and a reproductive system.

in aquatic species the naiad, as the immature stage is called, looks less like the adult and usually has modifications like gills for aquatic life. Otherwise its development proceeds as for terrestrial species.

ex:odonata (dragonflies) and Ephemeroptera (mayflies)

all insects have a exoskel composed of chitin and proteins which have been made tough and rigid through a chemical process called sclerotization.