1. Annelid characteristics

   1. Body metameric or segmented; bilateral symmetry

   2. Body with circular and longitudinal muscles

   - Often with chitinous setae

   1. coelom well developed, except in leeches

   2. closed circulatory system

   3. complete digestive tract

   4. gas exchange across gills, parapodia, or body wall

   5. excretion through paired nephridia in each segment

   6. sensory system of tactile, taste, and photoreceptors, and eyes with lenses in some

   7. hermaphroditic or dioecious

Polychaeta ("many long hairs"

Many setae (bristles), usually protruding in bundles. Pronounced differentiation of some body segments, well-differentiated head with sensory appendages.

Parapodia (lateral fleshy extensions) on most segments. Used for primitive gills or respiratory organs, anchors while in tubes, crawling, and swimming.

1.  

   1.  

       Hermaphroditic, but have sex.

      1. Go head to toe with each other.

      2. Both clitellums create mucus to assist with sperm transfer.

      3. Sperm is dumped out of seminal vesicles along ciliated lines into the seminal receptacle of the other. 

      4. Slime tube goes up the body; passes the oviduct. The eggs are fertilized in the slime tube. Next hits its own fertilized eggs. Slime tube continues off the body, becomes cocoon.

       

Hirudineans = leeches

1.  

   1.    most closely related to oligochaetes, so have similar reproductive system.

   2. Filled in coelem

   3. Very advanced digestive tract.

      4.           Can be predatory or parasitic.  

What are the characteristics of arthropods?

1) Segmented (or metameric body); but segments fused into functional units called tagmata.

2) Jointed appendages- one pair per segment

3) Rigid exoskeleton with cuticle

4) Complex muscles for moving the exoskeleton

5) Reduced coelom

6) Complete gut (but only absorb from midgut)

7) Open circulatory system

8) Various respiratory structures: gills, tracheae, book lungs

9) Fully developed excretory systems

10) Highly developed nervous systems

11) Separate sexes, internal fertilization, often larval stages and metamorphosis

What are the arthropod growth and size issues? How is molting a factor in size?

The exoskeleton is a major size constraint.

1. In order to molt, must detach muscles from old exoskeleton and grow new (and larger) one underneath. The old exoskeleton is shed, then soft new exoskeleton is hardened.

2. The larger the animal, the longer it takes for the new exoskeleton to harden.

3. During this time, very vulnerable to predation and parasites.

4. Terrestrial insects breath through pores in the side of their body. Too large = too little oxygen.

What are the major subphyla of Arthropoda?

Trilobita (trilobites; all extinct)

Chelicerata (spiders, horseshoe crabs, etc)

Crustacea (crustaceans)

Uniramia (insects, centipedes, and millipedes)

What are the characteristics of Subphylum Trilobita? Give an example.

3 lobed body

Extinct

Example: Trilobite.

What are the characteristics of Subphylum Chelicerata? Give an example.

Have chelicerae (limbs modified into pincers for eating. In some species, poisonous "fangs")

No antennae

aquatic and terrestrial

Examples: horseshoe crabs, spiders, mites, scorpions.

Interesting

 Male scorpions will do mating dance, male grabs females peldipalps and they dance. Once he thinks he has a shot, he drops a spermatophore (sperm packet). Rest of the dance is to get her to stand over it and accept his spermatophore.

What are the characteristics of Subphylum Crustacea? Give an example.

 2 pairs antennae; biramous appendages; often calcified skeleton; primarily aquatic

Examples: crayfish, lobsters, isopods, crabs

Interesting:

Hermit crabs will sometimes communicate with each other via a system of shell-tapping to exchange if a smaller crab has a larger shell than the larger crab.

Horrifying:

    Some barnacles will parasitize crabs and take over their genitals.

Some isopods will eat the tongue of fish, then attach themselves to the tongue root. 

What are the characteristics of Subphylum Uniramia? Give an example.

 1 pair antennae; uniramous appendages; primarily terrestrial

3 classes: Chiliopoda (centipedes), Diploda (millipedes), Insecta (insects)

Major anatomy and characteristics of Insecta

Head w/ 1 pair antennae

Thorax with 6 legs and wings

Abdomen.

Different features may be lost, reduced, or very morphologically different

What are the types of insect mouthparts? Give an example of each (fig 20.19a-e)

Parts of the insect jaw: mandible, labrum, maxilla, labium

Biting/chewing mouthparts: grasshoppers, roaches, chewing lice, etc. Mouthparts are designed for chewing/biting

Piercing/sucking: labrum mandible, maxilla, labium are all elongated and thin. Mosquitoes, etc.

A. Labium is flexible part outside, labrum, mandible, and maxilla are inside, called fascicle.

B. When biting, the fascicle springs out of the channel in the labium which is progressively bent out of the way.

Sucking: Butterflies, moths. Their maxillae acts as a straw.

Sponging: Flies. Use labial lobes (look like ping pong paddles). Lay on soft, semisolid food, get stuff on labial lobes, bring them back in, then lick it off.

  Horseflies, etc, hurt more b/c they have to slash to expose blood, then sponge it up.

How do indirect and direct flight muscles work to produce flight?

Direct flight. Dragonflies and locusts. Wing muscles connect directly to base of wings so small contraction of flight muscles lifts the wings upwards. Like rowing. (see fig 20.13a)

Indirect flight: Most other insects; flies and midges. Wings move because flight muscles deform the exoskeleton, flexing the wings up or down. (see fig 20.13b)

What is hemimetabolous and holometabolous development in insects?

 Hemimetabolous development: incomplete/partial metamorphosis. Adults look pretty much like larvae

Holometabolous development: full metamorphosis. Distinct body forms in each stage.

 sedentary → don't tend to move around a lot. Live in burrow, may build tube, or tube in burrow.

errant → moves around, “does errands”

Predators have large jaws.

Deposit feeders: Tentacles that are exposed to the surface on terrebellid polychaete. There are grooves that bring and draw food to mouth. Some have mucus on tentacles. They rub them on the sediment, then suck them off.

Filter feeders: Many sabellid polychaetes are have feathery radioles. They look like the spiralling fungus in Avatar. Also called Christmas tree worms

Some filter feeders build burrows with 2 holes. The worm uses peristaltic contractions to move water though the tube. Act somewhat like marine earthworms.

  Synchronized spawning: all go off at the same time in tune with lunar cycle and season.

Adults (atokes) live hidden in coral. In preparation for breeding, they bud more copies of themselves (epitokes).  The epitokes actually leave the coral, spawn, then die.

Not the method I would choose, personally.