arthropoda Flashcards
what are ecdysosoa
moulting clade.
- lack primary larva
how do panarthropods differ from other ecdysozoans?
have segmented bodies with several/many paris of limbs
tardigrada
small, terrestrial.
blunt head, no antennae.
4 body segments, move with slow stepping motion.
tardigrada lack?
circulatory and excretory systems, lack circular muscles.
coelom, cns, sensory of tardigrada
small eucoelom around gonads, main body cavity is haemocoel.
dorsal brain circumesophageal connectives.
- non-image forming eyes in brain
feeding in tardigrada
piercing or swallowing whole.
- pierce: suck out contents with pharynx
repro of tardigrada. 4 ways of sperm transfer
intromission
- traumatic insemination into cuticle
- when female shedding, put sperm between new and old cuticle.
- tickle female to oviposit, then smear sperm over top
eggs and development of tardigrada
eggs very resistant.
cleavge = radial.
development - direct
eutely growth
what is the state in which organism is alive but has no measurable metabolism?
cryptobioses
form when all water is lost from the animal
anhydrobioses
onychophora - features
blunt head, one pair of antennae, 13-43 segments.
soft cuticle, many paillae.
onycophora - differences from tardigrades
body wall includes circular, long and dv muscles
- multiple paire, segmental nephridia
oncyphora: similaties to tardigrades
eucoelom restricted to pockets around gonads, main body cavity is haemocoel.
dorsal brain, circumesophageal connectives.
sensory? gas exchange? feeding?
small light sensing eyes
- gas exchange thru thracheal system
predators. capture prey shooting glue out of glue glands
repro in oncyphorans
separate sexes, direct development, born with full number of segment,
neither spiral nor radial cleavage.
lay eggs ?
brood eggs?
brood young - not in eggs?
oviparous
ovoviviparous - yolk nutrients
viviparous - placental connection.
arthropoda - joint-legged
largest phylum. 4 subphyla: pancrustacea, myriapoda, chelicerata, trilobita
all arthropods ossess?
jointed, semi-ridig exoskeleton & jointed limbs
2 main functions of exoskeleton
protection & structural support including muscle-attachment
feature unique to arthropods?
no cilia on somatic cells
tagma of myriapods
haed + homonomous trunk
trilobites tagma
head, thorax, pygidium
tagma crustaceans
head, thorax, abdomen
chelicerate tagma
cephalothorax, abdomen
names of the rigid plates in exoskeleton
plates called sclerites.
dorsal = tergite.
ventral = sternite
lateral = pleurite
3 main layers of exosksleton
epicuticle - moulted
exocuticle - moutled
endocuticle - resorbed
moulting controlled by ?
ecdysone
process of moutling
epidermis separates from endocuticle. inactive moulting fluid secreted by epidermis to digest old cuticle. endocuticle resorbed. new cuticle deposited beneath protective later. starts out wrinkled. moulting fluid resorbed, epicuticle laid down, old cuticle moutled, ecdysis = animal swallows air to split old skin. new cuticle expands & gets sclerotized.
arthropod limbs
- each segment of limb called?
- project medially vs laterally
- article.
medially = endites
laterally = exited
biramous vs uniramous
limbs - phyllopodous vs stenopodous
phyllo - flattened, flap-like
steno - tubular, walking
infoldings of the cuticle that muscles attach to
apodemes
arthropod coelom
intra lecithal cleavage. panarthropoda coelom reduced and limited to gonads and excretory system.
arthropod gas exchange
aquatic: lmb-branch gills; book gills.
terrestrial: spriacle, trahea, tracheloes = air-filled tubes. or book lungs
arthropod NS
ventral nerve cord. dorsal brain, sircumesophageal connectives. 2/3 lobed brain. libe 1 = innervte eyes. lobe 2: innervate first antenna/chelicera
arthropod eyes
ommatidia - multiple cells per ommatidium, light-sensitive.
light adapted aka?
dark adapted aka?
light adapted = apposition eyes - light entering doesnt leak into adjacent ommatidia. = bright light
dark adapted = superposition. leakage btw adjacent ommatidia = low light.
eyes composed of a single lens?
ocelli. - detect intensity and direction of light.
subphylumm trilobita
all extint. marine. 3 lobed body with antennae, compound eyes, biramous limbs
- coxal endites were often spiny. food processing between gnathobases.
detrivorous/predatory.. large eyes
crustacean - non-hexapod pancrustaceans.
5 pairs of appendages on head. 2 antennae, 1 manidble, 2 maxillae.
have cephalothorax = head covered by shield.
walking legs = pereopods
swimming, egg or sperm transfer = pleopods
crustacean repro
separate sexes. sexual repro - direct sperm tranfer.
- gonopods. fertilization may be internal or external, but frequently brooded.
nauplius larva.
crustacean class remipedia
homonomous segments. tagmata = head and trunk. primitive appearance
crustacean class branchiopoda
freshwater, phyllopodous limbs for swimming/feeding. cyclic parthenogens.
class malacostraca - crustacean
marine, 6 head segments, 8 body segments, 6 abdominal segments.
- stalked or sessile eyes
hoplocariada - within malacostraca
lobster-like. complex predatory + social behaviour. spearing or clubbing thoracic limb.
most malacostracans in order decapoda
crabs, lobsters, shrimp, crayfish.
- mostly benthic, burroug.
5 pairs of walking limbs. carapace.
chelate, subchelate = pinchers
isopoda vs amphipoda differences
i = d-v flat
a - laterally flat, more variable leg morphology. paasitic,
isopods - may have given up gills + exchange gase with spiracle-tracheal system
class thecostraca - barnacles. cirripedia
cerripedia: all marine, sessile filter-feeders. some parasites.
attached to substrate, enclosed in calcareous plates. stalked or ustalked.
- long penis, shorter is high wave force.
hexapoda: crustaceans.
only invertebrates to have evolved powered flight.
hexapod class insecta - morphology
clear segmentation.
- 1 pair of antennae, mandibles. trachea/spiracles for gas exchange.
- uniramous limbs.
3 clear tagmata.
enthognatha = mandibles within cheeks. unsclerotized exoskeletons.
collembola appendage
- ventral projections?
simple eye
furcula = jumping.
- ventral used for water + ion regulation = collophore
insecta - cerci?
sensory organs at the bum.
ectognathous.
insecta archaeognatha
mandibles with one condyl on mandibular joint.
apterygote
pterygota = clade . whats the synapomorphy?
pterygota
palaeopterous condition
unable to swivel wings to lay flat against back.
neoptera condition
flexible wing base.
one wing covers to other wing set.
direct vs indirect flight muscles
direct = attached to wing indirect = attached to thorax
describe dragonfly flights
DV thoracic muscles contract to pull notum down, clicks wing up. wing muscles pull wing down
true flies indirect muscles
DV muscles contract, pull notum down to pop wing up. relax dv muscles, contract longitudinal muscles to downstroke
hexapoda reproduction
separate sexes.
collembola & apterygote = sperm indrectly transferred.
- pterygote - internal ferti with intromission. some haplodiploid. hexapod = intralecithal eggs.
development in which all body segments are present at hatching
epimorphic
three variations of post-hatching life cycle in hexapods
ametaboly
hemimetaboly
holometaboly
juveniles look like small adults except no genitalia
ametaboly
winged insects. wings develop slowly over several moults
hemimetaboly
wings develop all at once in a special stage called pupa
holometaboly
hexapod diets
– when host is killed?
predatores, parasites.
parasitoidherbivorous.
subphylum myriapoda
detrivores, microbivores, herbivoes, predators
2 tagmata. head with ocelli, mandibles, 1 pair antennae.
trunk with a ton of legs. gas x-change = spiracle
class diplopoda
millipedes. 2 pairs of legs per segment.
thick exoskeleton. glandular secretions for dfence
class chilopoda
centipedes. 1 pair of legs per segment. modifies legs behind mouthparts = poisonous claws. aggressive predators.
myriapoda repr + development
se[arate sex. repro = sexually. spermatophore into gonopore. internal fertilization, intralecithal eggs.
epimorphic, anamorphic.
subphylum chelicerata
lack antennae. no mandibles - chelicera instead. tagmatization for most includes cephalothorax (carapace) and abdomen
class pycnogonida
sea spiders. marine.
predatory.
cephalon with proboscis. 4 simple eyes. ovigers. trunk = 6=10 legs. abdomen reduces
pycnogonida - mouth,
trilobed lips.
chelate appendages called chelifores.
pycnogonida - repro
separate sex. external feritlizaiton. male broods.
larva called protonymphon.
class euchelicerata
chelicerae as main mouthparts.
chelicera - evolutionarily a leg.
tagmatization = 6segmented cephalothorax. 6 paris of limbs. compound eyes. sexes separate. eggs yolky
subclass merostomata
order eurypterida: three body tagmata: cephalothorax, mesosoma, metasoma
order xiphosura: carapace looks like horshoe. long tail spine. single lensed eye. scavenge. lay eggs in sand - external fertilization. larvae - planktonic.
*blood clots when single bacteria present
subclass arachnida = order scorpiones
terrestrial. fluid feeding predators.
order scorpiones: segmented chelicerae, pedipalps. obvious segmentation. poisonous stinger. ventral appendages = pectines: vibration, chemoreceptors.
book lungs.
feeding of order scorpiones
crush sting prey. externally digest
repro in order scorpiones
indirectly, fertilization internal. female broods
order araneae:
constriction btw cephalothorax + abdomen. abdomen unsegmented.
2 chelicerae.
spinneretes. 0-4 pairs of ocelli. pedipalps are never chelate.
trachea or book lungs.
fluid feeding. poison glands
repro steps in araneae order
male leaves sperm on web+ puts into pedipalp. - inserts into genital opening of female
acariformes + parasitformes
ticks, mites.
- no segmentation. smallest.
internall fertilization. have chelicerae. fluid-feeders.
