metamerism

segmentation

tagmatization

specialization of body regions for specific functions

cuticle

an exoskeleton that might be shed for growth

ecdysis

molting

mollusca coelom functions

room for organ development diffusion surface for gases, nutrients, and wastes storage (fat) elimination of reproductive products hydrostatic support

pericardial cavity

the coelom in mollusca; small cavity reduced around the heart, nephridia, and gonads

3 parts of mollusca body

head-foot, visceral mass, and mantle

radula

tongue-like rasping structure that scrapes food off of substrate

what kind of digestive system do mollusks have?

complete

what does the visceral mass contain?

organs of digestion, circulation, reproduction, and excretion

how many chambers in mollusk hearts?

3 (except in snails)

what kind of circulatory system do mollusks have

open: blood leaves vessels and directly bathes cells in sinuses

mantle in mollusks

partially or completely encloses the body, may secrete a calcareous shell in some

functions of mantle cavity

excretion gas exchange elimination of digestive wastes release of reproductive products

function of nephridia in mollusks

excrete nitrogenous wastes filtered from blood into mantle cavity

what is the waste produced by nephridia in aquatic mollusks?

ammonia

what is the waste produced by nephridia in terrestrial mollusks?

uric acid

mollusks: dioecious or monoecious?

dioecious (one class monoecious)

what kind of larvae do mollusks have?

free swimming trochophore in most aquatic members, veliger larvae forms next in snails and clams (first shell)

what is the largest class in mollusca?

gastropoda

aposematism

bright coloration to warn predators that the animal is inedible (many sea slugs)

torsion

class gastropoda; 180 degree twist of visceral mass, mantle, and mantle cavity

advantages of torsion

foot is last structure in shell (not head) allows clean water to enter mantle cavity mantles sensory organs near head

are organs in gastropods single or paired?

most single because shape of shells

operculum

in gastropods, a covering on the foot that closes the shell when the animal draws inside shell

siphon tube

a tube that reaches through the substrate to inhale oxygenated water (gastropods)

pulmonate lung

vascular-rich mantle in land snails used for exchange of gases

how many chambers in gastropod hearts?

two

hydraulic skeleton in gastropods

blood under pressure moves some structures (extends tentacles)

gastropoda nervous system

large cerebral ganglion in head and smaller one in foot eyes with lens and cornea chemoreceptors used to locate food

gastropods: dioecious or monoecious?

marine: dioecious freshwater: monoecious with internal, cross fertilization some terrestrial snails mutually exchange sperm

love darts

organs used by slugs and snails for delivery of sperm to egg

how are bivalves compressed?

laterally

how do bivalves move?

wedge-shaped foot , some creep, some attach to solid objects, some burrow

how do bivalves exchange gas?

thin, plate-like gills that also assist in feeding

how do bivalves eat?

filter feeding

ganglia in bivalves

3 pairs, associated with the esophagus, foot, and posterior adductor muscle

fertilization in bivalves

marine: external fertilization with free swimming larvae freshwater: internal fertilization, brood young in maternal gills

do bivalves have a radula?

no!

glochidia

a parasitic larva of certain freshwater bivalve mollusks, which attaches itself by hooks and suckers to the fins or gills of fish.

anterior foot in cephalopods

modified into circles of tentacles, some with suction cups

mantle cavity in cephalopods

funnel shaped, used for jet-like propulsion

do cephalopods have a radula?

yes!

feeding in cephalopods

beak-like jaws, radula, some have venom

what kind of circulatory system fo cephalopods have?

closed: blood confined to vessels in body

what kind of hearts do cephalopods have?

systemic and branchial; increase blood flow

cephalopod nervous system

extremely complex, extreme cephalization, complex eyes similar to vertebrates

what are the most intelligent invertebrates?

cephalopods

how is the brain formed in cephalopods?

fusion of ganglia

chromatophores

pigment cells in cephalopods that enable color change

spermatophores

sperm packets in cephalopods transferred to the female with a special tentacle (hectocotylus)

hectocotylus

a modified arm used by male octopuses and some other cephalopods to transfer sperm to the female.

what is the largest animal phylum?

arthropods

4 characteristics that contributed to arthropod success

metamerism/tagmatization exoskeleton hemocoel metamorphosis

metamerism/tagmatization in arthropods

external, but not internal permits specialization of body reigons

exoskeleton functions in arthropods

structural support protection slows water loss provides color joint formation

exoskeleton limitations in arthropods

must be shed limits size

what is a hemocoel in arthropods?

an internal cavity for open circulatory system; organs bathed in blood for exchange of nutrients, gases, and wastes

arthropods:dioecious or monoecious?

dioecious

2 body regions of chelicerata

prosoma and opisthosoma

what is the prosoma region?

sensory, feeding, locomotion

what is the opisthosoma region?

digestive, reproductive, excretory, respiratory organs

what are chelicerae?

modified 1st pair of appendages

what are pedipalps?

2nd pair of appendages for sensory, feeding, locomotion, and reproduction

what are class merostomata?

horseshoe crabs

what is the respiratory system in horseshoe crabs called?

book gills

reproduction in horseshoe crabs

intertidal areas; males fertilize eggs externally, eggs covered and unattended

class arachnida legs

four pairs- not chelate

class arachnida chelicerae

modified for piercing or chewing

class arachnida respiratory system

book lungs or tracheae

tracheae

branches system of air ducts; air enters through spiracles and circulates between page-like lamellae

book lungs

like book gills, but are more internal to minimize water loss

main excretion in arachnids

uric acid (semi-solid)

2 organs that can excrete uric acid in arachnids

coxal glands and malpighian tubules

coxal glands

sacs bathed by blood that collect wastes and excrete through pore at base of posterior appendages (expelling through feet)

malpighian tubules

blind-ending tubules of the gut tract that collect nitrogenous wastes and empties them to the gut tract (like nephridia; more for animals in dry habitats)

sensilla

little sense organs

arachnids reproduction

males often transfer spermatophores to females, many tend to developing eggs

order scorpionida body sections

pedipalps modified into large pinchers opisthosoma divided into 2 sections: preabdomen and postabdomen

preabdomen in scorpions

bulk of body; slits for book lungs, chemical receptors, genital openings

postabdomen in scorpions

tail with stinger

scorpion reproduction

mating dance; males position females over deposited spermatophore for uptake of sperm

mode of laying eggs in scorpions

oviviparious (eggs develop inside female) or viviparous (nourishment from mother)

order aranae example

spiders

order aranae specialized legs

chelicerae modified into venom glands and fangs pedipalps leg-like; modified for sperm transfer in males

pedicel

a slender waist; attaches prosoma to opisthosoma

order aranae mating

oviparous, young disperse by ballooning

class opiliones examples

harvestmen

order opilones characteristics

oviparous, no venom glands, many omnivores, some carnivores

order acarnia examples

mites and ticks

class acarnia modified legs

chelicerae and pedipalps modified for piercing, biting, anchoring, and sucking

order acarina body sections

prosoma and opisthosoma fused and covered by single carapace

order acarina general characteristics

oviparous, cause ehrlichiosis (meat allergy), follicle mites

seed ticks

six-legged larvae of ticks

what is in subphylum crustacea?

shrimp, crabs, lobsters, crayfish, and barnacles

hoe many pairs of antennae do crustaceans have?

2

biramous appendages

branched (crustaceans)

class malacostraca members

shrimp, crabs, lobsters, crayfish

what structure does class malacostraca have that protects the soft part of the cephalothorax?

carapace

class malacostraca appendages

1st 2 are 1st and 2nd antennae, 3rd are mandibles, 4th and 5th maxillae, 6-8th are maxillipeds, 9-13 are walking legs, 14-18 are swimmerets