BIOL 202 Practial 2: Group Ecdysozoans

Ecdysis

have a exoskeleton and molt it

Phylum Nematoda

contain only longitudinal muscles and move by thrashing

Phylum Arthropoda

tagmata, “jointed foot”, 4 subphylums: Chelicerata, Myriapoda, Hexapoda, and Crustacea

Tagmata

body segments (head/throax/abdomen)

Cephalothorax

example of tagmata: head and thorax together

Group Ecdysozoans

Phylum Nematoda and Anthropoda

Subphylum Chelicerata

Anthropoda: 1 pair of chelicerae and pedipalps, 4 walking legs and no antennae, Classes Arachnida and Merostomata

Chelicerae

feeding appendages (Phylum Arthropoda)

Pedipalps

modified legs for reproduction/sensory/defense (Phylum Arthropoda)

Class Arachnida

Subphylum Chelicerata: spiders/scorpions, book lungs

Class Merostomata

Subphylum Chelicerata: horseshoe crabs, used in medical field

Subphylum Myriapoda

Phylum Arthropoda: “myriad” = many legs, Classes Diplopoda and Chilopoda (millipedes and centipedes)

Class Diplopoda

Subphylum Myriapoda: millipedes, 2 pairs of legs per segment, detritivores

Detritivores

Feed on decaying matter

Class Chilopoda

Subphylum Myriapoda: centipedes, 1 pair of legs per segment, carnivores

Subphylum Hexapoda

Phylum Arthropoda: “hex” = 3 pairs of legs

Class Insecta

Subphylum Hexapoda: adapted mouthparts for feeding, spiracles, metamorphosis, malpighian tubules

Spiracles

holes in exoskeleton for gas exchange (Class Insecta)

Malpighian tubules

for excretion (Class Insecta)

Complete metamorphosis

goes through life forms that look different

Incomplete metamorphosis

goes through life forms but baby looks like a small adult

Subphylum Crustacea

Phylum Arthropoda: crayfish/lobsters, carapace and green glands, Classes Malacostraca and Cirripedia

Carapace

protective shell covering cephalothorax (Subphylum Crustacea)

Green glands

Glands for excretion of wastes (Subphylum Crustacea)

Class Malacostraca

Subphylum Crustacea: lobsters/shrimp/crayfish (things people eat)

Class Cirripedia

Subphylum Crustacea: barnacles, mobile larvae and sessile adults