5. ECDYOSOZOA SUPERPHYLUM

3 Phylas (Nematoda, Tardigrada, Anthropoda)... NOT CHORDATES

Animal Phylogeny

ECDYSOZOA Superphylum (3)

3 Phyla, 1 Monophyletic Group:

Cuticle (Exoskeleton)

1. Nematoda (roundworms)

2. Tardigrada (tardigrades)

3. Anthropoda (arthropods)

NEMATODA

• Epidermis with one cell layer (syncytium)

• Cuticle: Collagen + Chitin

• Cylindrical

• Triploblastic

• Bilateral

• Pseudocoelomates

• External rings do not reflect true internal body segmentation

• Renette Cells: Excretory cells

NEMATODA ANATOMY

Nervous System:

• Four longitudinal nerve cords

  • Ventral is better developed

• Pharyngeal nerve ring

  • Nerve cells fusion around pharynx

TARDIGRADA (“Water bears”)

• CRYPTOBIOSIS

  • Go into dormant state in response to environmental stress

    • Able to survive loss of up to 99% of water content

ANTHROPODA CHARACTERISTICS (“Jointed Feet”)

“Jointed feet”

• Jointed appendages

• Body segmentation

• MOLTING followed by ECDYSIS

  • Molt then shed

ANTHROPODA SUBPHYLA (5)

TCMCH

1. Trilobita

   • All extinct

2. Chelicerata

3. Myriapoda

4. Crustacea

5. Hexapoda

ANTHROPODA MORPHOLOGY (5)

1. Tagmata

2. Appendages

3. Hemocoel

4. Nervous System

5. Respiratory System

ANTHROPODA TAGMATA (3 Types, 3-2-2)

Body regions

• Head, thorax, abdomen

• Cephalothorax and abdomen

  • Fused body region

  • Head + Thorax

• Head and trunk

ANTHROPODA APPENDAGES (2)

SEGMENTAL PAIRS

Walking, jumping, digging, swimming

ANTENNAE:

• Sensing environment

MANDIBLES/MAXILLAE:

• Capturing and manipulating food

ANTHROPODA HEMOCOEL

HEMOCOEL:

• Blood cavity

• Hemocoel liquid

N EXCRETION:

Excretion of toxic nitrogenous waste from protein metabolism

• Terrestrial: Uric acid; conserve water

  • Malpighian tubules (insects)

• Aquatic: Ammonia

  • Green glands (crustaceans)

ANTHROPODA NERVOUS SYSTEM

ALL SEGMENTS

• Larger Ganglia

  • Segments with sensory structures

• Ganglia

  • Connected by ventral nerve cord

ANTHROPODA RESPIRATORY SYSTEM (4 Types)

TRACHAE:

• Insects & Myriapods

GILLS:

• Crustaceans

BOOK LUNGS:

• Terrestrial chelicrates

BOOK GILLS:

• Aquatic chelicerates

CHELICERATA (Scorpions)

CHELICERAE:

• Specialized claw-like or fang-like mouthparts

  • MODIFIED LEGS

TAGMATA (2):

1. Prosoma

   • Cephalothorax

2. Opisthosoma

   • Abdomen

PEDIPALPS:

• Sense environment

• NO ANTENNAE

OPEN CIRCULATORY SYSTEM:

• Heart pumps blood into hemocoel

• Exchange both matter (nutrients/waste) and energy (heat/light) with surroundings

MYRIAPODA (“Ten thousand”)

Myriad = Ten thousand

Chilopoda (Centipedes)

• Numerous legs

• Pair of legs per segment

• Mandibles as mouthparts

CRUSTACEA

• Krill, shrimp, lobsters, crabs, crayfish

• Marine and terrestrial

• EXOSKELETON with Chitin + CaCO3

• Two pairs of antennae

• Mandibles as mouth parts

CRUSTACEA TAGMATA

TAGMATA (2):

1. Cephalothorax

2. Abdomen

CRUSTACEA OPEN CIRCULATORY SYSTEM

HEMOLYMPH:

Hemocyanin and Hemoglobin

DORSAL HEART

CRUSTACEA APPENDAGES (2)

2 Branches appendages

CRUSTACEA Blue Crab Anatomy

HEXAPODA (Insects)

HEXA = SIX

Ants, beetles, cockroaches, butterflies, crickets, flies

SIX LEGS (3 Pairs)

TAGMATA (3):

1. Head

2. Thorax

3. Abdomen

Winged or wiingless

Metamorphosis

Social/Use pheromones

HEXAPODA Anatomy