Biology Lab #24 Invertebrate Coelemates
Terms in this set (31)
Marine and freshwater molluscs consist of:
Three-part body plan
1. Muscular foot - locomotion
2. Visceral mass - internal organs
3. Mantle - thin tissue that encloses the visceral mass and may secrete a shell.
Development of a head region.
Anatomy of a Clam
- No head
- Muscular foot
- Filter feeders
- Hinge ligament
- Umbo (beak)
- Growth ring
- Adductor muscles (hold the valves together on both sides)
- Labial palps channel food
Channel food into the mouth
Paricardial sac (Pericardium)
Contains the heart
Contains the digestive and reproductive organs (simply internal organs)
True or False?
The intestine is the clam's only evidence of a coelem?
Do clams have an open or closed circulatory system?
Open circulatory system, it is not closed within blood vessels, diffuses out.
Incurrent and excurrent siphons
- Water enters and exits these siphons
- Located on posterior end
- Incurrent siphon right underneath gills
- Excurrent siphon located right above gills (closest to adductor muscle)
Anatomy of a Squid (Cephalopods)
- No external shell (Fin)
- Captures prey with tentacles and eats with radula
- Three hearts
- "Jet propulsion" as locomotion
- Well-defined head (cephalization)
- Water enters mantle cavity by way of a space that encircles the head and exits by means of the funnel
Posterior Vena Cava
Carry collected blood from the posterior body regions into the bronchial hearts
Endoskeleton that gives the mantle definite shape and structure
Siphon (or Funnel)
Allows for jet propulsion, respiration, and discharge of wastes.
Receive digestive food from stomach and absorbs it to the bloodstream for use
Do squids have an open or closed circulatory system?
Closed circulatory system
Arthropods (Phylum Arthropoda)
- Jointed appendages
- Hard exoskeleton (chitin)
- Crabs, shrimp, and lobsters, crayfish
- Three to five pairs of legs
- Two pairs of antennae
- 3 pairs of legs
- With or without wings
- Three distinct body regions
- Comprise 95% of all arthropods
- Well-developed digestive tract
- Dorsal, anterior, and posterior arteries carry hemolymph (blood plus lymph) to tissue spaces (hemocel) and sinuses
- Open circulatory system
Anatomy of a Crayfish
The head and the thorax together
Cephalothorax is covered by the carapace
- Hard upper shell
Antennae and Green Glands
Project from the head
- At the base of each antennae there is a small, raised nipple containing an opening for green glands, or the organs of excretion.
Composed of many individual units for sight
- Crayfish demonstrate cephalization
A swelling located between the bases of the third and fourth pairs of walking legs.
- Sperm from the male are deposited in the seminal receptacles.
- Opening of sperm duct located at the base of the fifth walking leg.
Five pairs of swimmerets on the abdomen. Use them to swim and move water over their gills.
- For males, swimmerets are claspers that aid in the transfer of sperm during mating.
- In females, clusters of eggs and larvae attach to the swimmerets
- Together with a terminal extension of the body, uropods form a tail.
Last segment in the abdomen