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

male

egg

Trichinella spiralis

Ascaris lumbricoides

II. Phylum Arthropoda

1. Subphylum Chelicerata

Tachypleus

Daddy longlegs

Spider

Subphylum Myriapoda

Class Chilopoda

eg. Scolopendra (Centipede)

Class Diplopoda

Spirobolus (Millipede)

Subphylum Crustacea

Scylla

Class Cirripedia

Balanus

Lepas