Ecdysozoa Flashcards
(16 cards)
Ecdysozoa
- ecdysis : molting
- cuticle provides support and protection
- some species undergo metamorphosis
- internal fertilization; amoeboid sperm: allows colonization of dry environments
- Nematodes & Arthropods most common
Ecdysozoa - Nematodes
- abundant, habitat or host specific
- small predators (eat decomposing organic matter)
Nematoda exmaples and features
- roundworms
- non-segmented, generally colorless worms
- parasitic roundworms infect humans, animals, plants
- molt cuticle
- only longitudinal muscles
Water Bears
- very small
- mosses, surface films, aquatic algae, barnacles
dorsal brain, gangilonated nerve cord - singular gonad
- mating/egg laying during molting
- direct development
- Cryptobiosis: extreme inactivity in response to harsh enviromental conditions
Water Bears can survive in extreme conditions
- temperatures up to 150 C
- deep sea
- frozen vacuum of space
- radiation from outer space
- heat and pressure around volcanic ocean vents
- being fired out of a gun
- up to six times the pressure of the deepest part of the ocean
Arthropoda general features
- freely movable jointed appendages
- rigid jointed exoskeleton: chitin
- segmented
- head, thorax, abdomen
- well developed nervous system
Arthropods - Crustaceans
Shrimp, lobsters, crayfish, crabs, barnacles
- 5 pairs of walking legs
- head and thorax fused into cephalothorax
- 2 prs. antennar
- 1 pr. compound eyes
- abdominal segments with swimmerets; tail = uropods
respiratory system = gills
Arthropod - Chelicerata
Spiders, scorpions, ticks, mites, horseshoe, crabs, sea spider
- body divided in prosoma ( equivalent to cephalothorax generally smaller) and opisthosoma (abdomen, generally larger)
- all appendages attached to prosoma; on head
- first pair are feeding organs
- second pair function in feeding sensory
Anthropods - Myriapoda
- multiple pairs of legs
- appendages attached to thorax and abdoment only have one branch
Anthropods - Myriapoda: Centipedes
- pair of legs per segment
- flattened dorsoventrally
- fast carnivores
- poison glands
Anthropods - Myriapoda: Millipedes
- 2 pairs of legs per segment
- rounded body
- herbivores and detrtivores
Arthropods - Hexapoda
- appendages attached to the thorax and abdomen only have one branched
- 3 pairs of legs; 0-2 pairs of wings
- head appendages include:
one pair antennae
one pair of mandibles
one or two pairs maxillae - live on land and breath by trachae
Insect metamorphosis
- no metamorphosis
- change little form as they develop
- just keep getting bigger
- wingless
Ametabolous defenition
No metamorphosis
Hemimetabolous definition & examples
Gradual (incomeplete) metamorphosis
ex. dragonflies, damselfies, stoneflies, mayflies, grasshoppers, cicadas, cockroaches, termites
Holometabolous
complete metamorphosis (88% of insects)
egg - larva - pupa - adult
