1. Marine Mammals without a Backbone
Marine Biology: Chapter 7

2. Lets Get Started… Kingdom Animalia
Organisms of this kingdom must hunt/find their own food
Two major groups;
Vertebrates: have a backbone
Invertebrates: lacking any backbone
At least 97% of all species of animals are invertebrates

3. Suspension vs. Deposit
Suspension feeders- animals that eat food particles suspended in the water
Filter feeders
Deposit feeders- animals that eat detritus that settles on the bottom
Detritus- dead “stuff” which sinks to the bottom of the sea-floor

4. Sponges Sponges do not form true tissues and organs
Among the structurally simplest organisms
Sponges are sessile
Come in all shapes, sizes, and colors, but all have a relatively simple body plan
Phylum Porifera; “pore bearers”
Contain numerous tiny pores, or ostia

5. Sponge Anatomy Pinacocytes- flat cellson the outer surface
Porocytes/pore cells- allows water to enter
Choanocytes/collar cells- uses a flagella to create a current and trap food particles
Osculum- water exits from this point
Spicules- support structures (siliceous/calcareous)
Spongin- skeleton of tough elastic fibers
Amebocytes- secrete spongin and spicules

6. So what’s it look like??

7. The Awkward Part.. Asexual reproduction Sexual reproduction
Branches and buds of the sponge break off and grow into separate sponges
Sexual reproduction
Produce gametes, large nutrient-rich eggs and smaller sperm cells that have flagellum
Broadcast spawning- sperm are released into the water and enter a sponge containing eggs

8. Growing Up! Early stages of development occur within the sponge
Larva is released into the water
Carried by currents until it settles on the bottom and develops into a cute tiny baby sponge

9. Just a little more… 6,000 known species of sponge
Mostly inhabit shallow tropical waters
Branching, tubular, round, volcano-like
Encrusting- thin growths on rocks/dead coral
Glass Sponges- anchored in deep-water, have lace-like structures
Boring Sponges- bore channels in CaCO3
Coralline Sponges

10. Cnidarians Coelenterates Sea anemones, jelly fish, corals
Radial symmetry

11. Body Parts Tentacles- finger-like extensions to collect food
Gut- food is digested, connected to the mouth
Nematocysts- stinging structures
Polyp- sessile stage
Medusa- upside down polyp adapted for swimming
Planula- Larva, consisting of 2 layers of cells
Epidermis- 1 of the two layers, the outer part
Gastrodermis- Internal layer, lines the gut
Mesoglea- gelatinous middle layer

12. Hydrozoans Hydrozoans Siphonophores Wide range of forms
Many consist of colonies of tiny polyps
Do not always consist of a polyp stage, and some lack a medusa stage
Siphonophores
Drifting colonies of polyps
Portuguese Man-O-War

13. Scyphozoans Scyphozoa Larger jellyfishes, with larger medusae
Planktonic- easily carried by currents
Have a bell-shaped ‘head’
Swim with contractions of the bell
Some of the most dangerous marine creatures

14. Anthozoans Anthozoa Solitary/colonial polyps that lack a medusa stage
More complex than hydrozoans or scyphozoans
Septa- within the gut, used for support and help with digestion
Sea anemones, corals

15. Corals Calcium carbonate skeletons Tropical waters
Gorgonians- Secrete a tough branching skeleton (Sea fans)
Precious Corals- gorgonians with red/pink spicules as well
Black Corals- Secrete a hard black protein skeleton
Black and precious carved into jewelry

16. Feeding and Digestion Almost all are carnviores
Capture and digest food larger than that of filter feeders
Use their nematocysts primarily to capture prey

17. Behavior No brain or true nerves They do have specialized nerve cells
These cells interconnect to form a nerve net that transmits impulses in all direction
Statocysts- Small calcareous bodies in fluid-filled chambers surrounded by sensitive hairs- give them a sense of balance

18. Worms… Bilaterally Symmetrical Anterior Posterior

19. Flatworms Platyhelminthes
Have a central nervous system where information is stored processed
Have a SIMPLE brain- just an aggregation of nerve cells in the head
More complex tissues than that of cnidarians
Turbellarians- free living carnivores
Flukes/trematodes(largest group)- parasites
Tapeworms/cestodes- parasites, looooong body

20. Ribbon Worms Nemertea More complex degree of organization
Have a circulatory system
Proboscis- a long fleshy tube used to entangle prey

21. Nematodes Also known as roundworms
Hardly ever seen, but are often found in sediments
Many are parasitic
Small with cylindrical bodies which are pointed at both ends
Feed on bacteria and organic material
Sushi- OH NO!!!

22. Segmented Worms Annelids Consists of segments
Earth and marine worms
Consists of segments
The gut goes through all the segments and lies in the cavity known as a coelom
Polychaetes
Closed circulatory system
Have gills

23. Polychaetes

24. Polychaetes Trocophore- band of cilia around the body, larval stage
Live in temporary or permanent tubes