26 -chelicerata Flashcards
Hexapoda
springtails, insects
mostly marine
subphylum Chelicerata
part of anthropoda
Chelicerata habitat
mostly terrestrial some freshwater
and marine arthropods
what do Chelicerata lack
antennae and do not have
mandibles
what do Chelicerata have instead of antennae and mandibles
chelicerae or chelifores
tagmatization most Chelicerata
cephalothorax & abdomen
Pycnogonida
sea spiders
sister to the clade euchelicerata(other chelicerates)
Xiphosura
in the clade Euchelicerata
relationships among chelicerates are
poorly resolved
Class Pycnogonida habiitat
entirely marine
how is Pycnogonida tagmatization unique
have cephalon with ovigers
a trunk w 3-6 pairs of legs
abdomen reduced to tiny stub
eyes Pycnogonida
four simple eyes
ovigers Pycnogonida
additional appendages on walking legs
cephalon
head stem, has proboscis
Pycnogonida where are gonads and gut branches
inside the legs
what is the opening of the mouth at the end of
the proboscis
trilobed(triangle thing) with sclerotized cuticular
ridges
what are the chelate appendages next to proboscis Pycnogonida
chelifores
chelifores homologous to
chelicerae
pycnogonids sexes
separate
pycnogonids fertilization
external
what happens after fertilization Pycnogonida
male gathers the fertilized eggs, holds onto them using his ovigers until larvae hatch
Pycnogonida
what type of parental care
male
larva Pycnogonida
protonymphon
has 3 pairs of appendages
how do protonymphon grow
anamorphic development
legs are added b/w moults
Euchelicerata mouthparts
chelicerae
ancestral chelicerae
3-segmented pincers
what are chelicerae reduced to in some taxa
2 segments
how do chelicerae and mandibles start out as evolutionarily
legs
Mandibulata chelicerae and mandibles evolution
only the leg base (coxa) was retained
Chelicerata chelicerae and mandibles evolution
tip of leg were retained
last articles become the movable digit
Euchelicerata tagmatization
cephalothorax
abdomen- variable in segments
cephalothorax contains
-4 pairs of legs
-chelicerae,
-pedipalps
Subclass Merostomata includes
2 grps marine chelicerates
Eurypterida
Xiphosura
Xiphosura
horseshoe crabs
Eurypterida
sea scorpions extinct
what were most massive arthropod
Eurypterida
Eurypterida tagmata
three body tagmata
cephalothorax
mesosoma
metasoma
Xiphosura spp
4
Xiphosura eyes
compound eyes
Xiphosura body and limbs
-chelicerae, pedipalps
-some walking legs are chelate
-book gills
what doo Xiphosura eat
swallow particles
where are things crushed Xiphosura
gnathobases
fertilization Xiphosura
external
larvae Xiphosura
planktonic
Subclass Arachnida
part of chelicerata
Arachnida spp
112,000
Arachnida what do they eat
fluid-feeding
predators
Arachnida eyes
simple eyes
Order Scorpiones body
3-segmented chelicerae
pincers
comb like pectines
sting
whats obvious in Scorpiones segmentation
abdomen
hoiw do scorpions eat
externally digest, drink fluid
what do pectines do
sense vibrations
what are the pedipalps modified as in scorpions
pincers
young Scorpiones
carried on females back
viviparity
transfer sperm Scorpiones
indirectly
what does merosoma have scorpions
book lungs
Order Araneae
spiders
Araneae spp
52 000
body Araneae
-tight constriction between cephalothorax and abdomen
-spinnerets
abdomen unsegmented
spinnerets
abdominal appendages for spinning silk
how many chelicerae araneae
2-segmented chelicerae
pedipalps Araneae
are never chelate
gases exchange Araneae
tracheae and/or book lungs
ocelli Araneae
image-forming in jumping spiders
and wolf spiders
Araneae what do they eat
fluid-feeding predators
what is on fangs of chelicerae Araneae
venom glands
silk usage Araneae
to capture prey
or line burrows and wrap eggs
sperm transfer Araneae
sperm sucked through pedipalp
Araneae mating and relationships
often complex courtship
maternal care of eggs, and
sometimes young
Acariformes & Parasitiformes
the mites, including ticks
are Acariformes & Parasitiformes considered orderAcari
no, ‘mite-ness’ has evolved
twice independently
Acariformes & Parasitiformes body
-no clear cephalothorax or abdomen
-almost no external evidence of abdominal segmentation
-among the smallest of all
animals
how many chelicerae mites
2 or 3 segmented chelicerae
where do mites live and eat
-do everything, live everywhere
-most are fluid-feeders
-many detritivores can ingest solid
particles
fertilization mites
internal
sperm transfer mites
all imaginable modes of sperm transfer
mites parental care
no/rarely idk it says seldome
young mites lets
3 pairs of
legs
wack ass life-cycle in some mites
greatly shortened in some
live until adults in mother
crustaceans Ecological importance in ocean
-food for many aquatic vertebrates
-commensals or parasites
bottom-trawling
-destroys benthic habitat
-75% bycatch, which is
discarded
collembolans importance
important detritivores
insects importance
detritivores
-food for many invertebrates and vertebrates
-commercial farming of insects for protein
pollination
colony-collapse disorder
disaster
Chelicerata importance
-venoms dangerous, explored for their potential
pharmacological uses
-biomimicry of spider silk
-horseshoe crab blood
horseshoe crab importance
haemolymph coagulates if bacteria present tests for contamination of vaccines and medical equipment
economically important arachnids
crop pests
biocontrol agents
medically important
medical importance arachnids
allergies and dermatitis vectors for viruses and bacteria
Demodex mites
-two species
-live in the pores and follicles of
human facial skin
