biology lab 12: the ecdysozoa
DESCRIPTION
Bio 12; Lab reviewerTRANSCRIPT
7 - CLADE ECDYSOZOA
- most species-rich
- secrete exoskeleton
- ECDYSIS (molting/shedding of old exoskeleton)
I. Phylum Nematoda
eg. Trichuris trichiura, Trichinella spiralis, Ascaris lumbricoides
II. Phylum Arthropoda
1. Subphylum Chelicerata
a. Class Xiphosura/Merostomata
eg. Tachypleus
b. Class Arachnida
eg. Daddy longlegs, spider
2. Subphylum Myriapoda
a. Class Chilopoda
eg. Scolopendra (CENTI)
b. Class Diplopoda
eg. Spirobolus (MILLI)
3. Subphylum Crustacea
a. Class Malacostraca
eg. Portunus (sharp)
Scylla (blunt)
Penaeus (small shrimp)
Machrobrachium (big)
Pagurus (hermit crab)
b. Class Cirripedia
eg. Balanus
Lepas
4. Subphylum Hexapoda
a. Class Insecta
Order Blattodea - cockroaches
Order Coleoptera - beetles
Order Diptera - flies, mosquitoes
Order Hymenoptera - ants, bees, wasps
Order Lepidoptera - butterflies, moths
Order Odonata - dragonflies, damselflies
Order Orthoptera - grasshoppers, crickets
Order Phthiraptera - lice
Order Isoptera - termites
I. PHYLUM NEMATODA
-vermiform (worm-like)
- Symmetry: bilateral
- not segmented
- PSEUDOCOELOMATE (body cavity not lined by mesodermal derivatives)
- body TAPERED at both ends
- covered with COLLAGEN cuticle
- CHEMOSENSORY organs:
***chemosensory - responsive to chemical stimuli
1. amphids - paired, head/anterior
2. phasmids - posterior
- wall DOES NOT HAVE CIRCULAR MUSCLES; move in whip-like, undulating
manner
- COMPLETE: Digestive System
- LACKING: Circulatory and Respiratory
- Nervous System: GANGLIONIC
- Excretory System - w/ renette cells (for OSMOREGULATION)
- free-living or parasitic
- SEXES USUALLY SEPARATE
eg.
Trichuris trichiura
male