Exam 3 Animal lecture - Panarthropoda and Arthropoda

Panarthropoda

include onychophora, Tardigrada, and Arthropoda

coelomates with reduced coeloms - hemocoel body cavity with hemoplymph

open circulation

ventrolateral legs with claws

Phyulm Onychophora

velvet worms

nocturnal

terrestrial

predators

can spit glue

have lobopods - stub feet

dioecious, internal fert

oviparous

egg laying

ovoviviparous

eggs with yolk sacs, hatch inside parent and emerge

viviparous

placenta like structure for nourishment, young come out of parent

what is the velvet worm glue and what does it consist of

its a glue that spreads as a slime over prey and hardens as water evaporates

comes out as mostly water which keeps proteins from interacting

Phylum Tardigrada

water bears

4 pairs of legs, pair of stylets

moist terrestrial habititats

several molts

have cryptobioosis

have been to space

cryptobiosis

reversible metabolic suspension

can extent life-span from a few months to many years

includes anhydrobiosis, cryobiosis, osmobiosis, and anoxybiosis

allows them to survivee harsh conditions

Anhydrobiosis

severe dehydation

loss of free and bound water

Trehalose replaces bound water, working with CAHS proteins that are unique to tardigrades

cryobiosis

freezing temps

osmobiosis

high salinity

anoxybiosis

lack of oxygen

Phylum Arthropoda

ecdysozoan, protostome, coelomate

“jointed feet” - have jointed appendages

segmented body divided into tagmata

chitinous exoskeleton

open circulatory system and heart with ostia

commonly have tracheae

What are some challenges of dry habitats that arthropoda had to face

dessication: preserving water for cell processes

support: water is dense medium and air is not s dense

movement: the density of water is useful for movement, airs not as dense

excretion: need to conserve water, as it dilutes and removes toxic wastes

gas exchange: something other than gills is needed for respiration

What are some traits that make arthropods the most successful animal clade on earth

versatile exoskeleton for a cuticle

segmentation and appendages - for locomotion and feeding

efficient respiration - many with tracheae

complex behavior

reduced competition through metamorphasis

what do arthropods go through in molting

their cuticle sheds and a new flexible one forms

this allows for growth as the exoskeleton usually llimits growth

biramous appendages

branched appendage, usually into 2 segments

uniramous appendages

unbranched series of segments

Subphylum Trilobita

extinct

distinct head, thorax, pygidium (tail)

biramous appendages

Subphylum Chelicerata

first pair of appendages modified to chelicerae (no mandibles)

pair of pedipalps and 4 pairs of legs

no antennae

fused segments in cephalothorax and abodomen

suck food from prey

includes pycnogonida, merostomata and arachnida

class pycnogonida

in subphylum chelicerata

sea spiders

class merostomata

in subphylum chelicerata

marine

cephalothorax and abdomen

sharp telson

includes hrseshoe crabs and giant water scorpions (Eurypterida)

Clsss arachnida

in subphlum Chelicerata

includes spiders, scorpions, ticks, etc

cephalothorax and abdomen

predacious with sucking mouthparts

harmless

Order Araneae

in subphylum chelicerata, class arachnida

spiders

simple eyes - usually eight

sensory setae

can have fangs venom glands and silk traps

repiratory structures in Order Araneae

book lungs

tracheae

or both

feeding mechanism for Order Araneae

have chelicerae with terminal fangs

inject venom that liquifies and digests tissue

pedipalps handle food

excretion mechanism for Order Araneae

have Malpighian tubules for excretion

K, other solutes, and wastes are secreted into tubules

rectal glands reabsorb K and water wastes and uricc acid left for excretion

Which of the following are toxic: Black widow , Brown recluse, Tarantula

Black widow - neurotoxic venom

Brown recluse - necrotic venom

Tarantulas- harmless, fuzzy kittens

What are some other animals included in the arachinida class other than spiders

scorpions, ticks and mites, harvestmen

Subphlum Myriapoda

includes class chilopoda and diplopoda

have head and trunk tagmata

paired uniramous appendages on all/most trunk segments

1 pair of antennae

breathe using tracheae and spiracles

Class chilopoda

centipedes

have one pair of legs per segment

first appendage modified into pincers with venom glands

active predators

class diplopoda

millipedes

two pairs of legs per body segment

no venom glands

herbivores

subphylum crustacea

mostly aquatic

ecologically and economically important

may have carapace

2 pairs of antennae

biramous appendages

have head, thorax, and abdomen tagmata

2 pairs of maxillae

Class malacostraca

in subphylum Crustacea

includes order Decapoda

largest crustacean group

order Decapoda

includes lobsters, crayfish, crabs, shrimp

primarily aquatic

5 pairs of walking legs, first pair often pincers/chelicerae

cheliped - first legs

how to decapods remove waste

have no malpighian tubes

antennal glands play role in excretion and osmoregulation

ecdysis in decapods

under hormonal control in eyestalks

its a molt inhibiting hormone

Y-organs near mandible make molting hormone that initiates the process

subpylum hexapoda

uniramous appendages

one pair of antennae

mandibles

respiration via tracheae and spiracles

6 legs

head thorax and abdomen tagmata

includes classes entognatha and insecta

Class Entognatha

have entognathous mouthparts - base of mouthparts enclosed within the head

wingless

distribution and roles of class insecta

common in all habitiats

most organisms have as parasites

play major economic and medicinal roles

adaptive traits of class insecta

flight and small size distribute them widely

well protected eggs can withstand harsh conditions

variety of structural and behavioral adaptations

structural modifications in the wings, legs, mouthparts

hard protective exoskeleton - hold in water and protect

order orthoptera

grasshoppers and crickets

in class insecta

order hemiptera

true bugs

in class insecta

order diptera

flies

in class insecta

order coleoptera

beetles

in class insecta

eusociality

social system with cooperative care of offspring division of labor into reproductive and non-reproductive groups

order hymenoptera

bees, wasps, ants

in class insecta

order lepidoptera

butterflies, moths

in class insecta

Class insecta

head thorax and abdomen

3 pairs of legs

up to two pairs of wings

tracheaeal syatem with spiracles for respiration

complex behaviors in many

some have dramatic metamorphosis

batesian mimicry

hamless species mimics a toxic one to avoid predation

mullerian mimicry

two toxic species evolve to be more similar to each other to make their toxic signs more effective

what kind of eyes do class insecta have

convex eyes

what mode of reproduction does class insecta use

prthenogenesis in hymenoptera and hemiptera

sexual reproduction with internal fert is the norm

dioecious

holometabolis metamorphasis

complete metamorphasis

egg → larvae → pupa → Adult

hemimetabolous

more gradual metamorphosis

grasshoppers, cicadas, mantids, true bugs, mayflies, dragonflies

young called nymphs

egg → nymph → adult