Exam 3 Ecdysozoans Phyla Nematoda and Arthropoda Flashcards
Ecdysozoans
ecdysis – molting of cuticle
•Cuticle - tough layer outside of the skin
•Have to shed cuticle to grow
phylum nematoda
nematodes, roundworms
body covered in tough cuticle
complete digestive tract
0.1-2.5mm long
most abudant type of animal
nematodes!
found in marine, freshwaters, soils, tropics, and polar regions
nematodes can be
free living or parasitic
-free living species feed on algea, fungi, small animals, fecal matter, decaying matter, bacteria
-parasitic individuals feed on plant or animal tissues
harmful nematodes
heart worms, elephantiasis, crop pests
-encysted in muscle tissue
beneficial nematodes
natural pest control
decomposers
phylum Arthropoda
insects, arachnids, centipedes, millipedes, crustaceans
characteristics of Arthropods
segmented body, exoskeleton, paired, jointed appendages (“jointed foot”)
all arthropods have
a cuticle/ exoskeleton of protein and chitin
purposes of exoskeleton
attachment for muscles
prevents drying out
Arthropod senses
well developed
simple eyes-detect light
compound eyes- form images
olfactory receptors- smell
antennae- touch/smell/taste
arthropod respiration
terrestrial arthropods breathe through holes called spiracles that lead to trachea
aquatic arthropods breathe with gills
phylum arthropoda
subphylum Chelicerata
horseshoe crabs (marines) and arachnids (terrestrial)
2 body regions: Cephalothorax and abdomen
simple eye (single lens)
chelicerates have
6 pairs of appendages
Chelicera- pincers/fangs
pedipalps- sensing, feeding, defense, reproduction
4 pairs walking legs
Horseshoe crabs
not true crabs
living fossils
Arachnids
harvestman, spiders, mites and ticks, scorpions, tailless whip scorpion, whip scorpion, camel “spider”
most common arachnids
spiders
-pierce prey with hollow chelicerae
secrete digestive juices, suck up fluid
make silk for webs, dispersal, escape
well developed eyes
types of webs
orb webs, sheet webs, cob webs, funnel webs
Phylum Arthropoda
subphylum Myriapoda
millipedes and centipedes
“many legs”
all terrestrial
body regions: head, many body segments
millipedes
2 pairs legs/ segment
live in humid conditions, forest floor, leaf litter, dead wood, soil
most can burrow into soil
Detritivores- eat decaying plant matter
important decomposers
Centipedes
1 pair legs/ segment
also found in soil, leaf litter, logs
predators, stab prey with poison fangs, eat other arthropods
phylum arthropoda
subphylum crustacea
(paraphyletic)
msot are marine, freshwater
3 body regions : head, thorax, abdomen
lots of appendages
rolly pollies are terrestrial crustaceans
crustaceans appendages
head
-sensory appendages- antennae
-feeding appendages
== mandibles- jaws
==Maxillae- tasting, manipulating food
== Maxillipeds- feedings
crustacean appendages
Thorax
-chelipeds- pinchers, defense
-walking legs- locomotion
Abdomen
-swimmerets- locomotion