1. Chapter 7
Marine Animals
sans Backbone

2. Where are we in geologic time?
As a class, we’ve moved from bacteria to plankton, and through
some algae (seaweed).
Now we’ll examine primitive animals without vertebrae.

3. How are we related??

4. Introduction
Most (97%) of the amazing life located within the oceans (or anywhere else, for that matter) doesn’t have a backbone.
Animals without backbones are called invertebrates (without vertebrae).
In every class of invertebrate we can find a marine example.

5. 1. Sponges
Sponges are really nothing but a loose aggregation of specialized cells.
Of the 6,000 known spp. nearly all are marine.
Amazingly enough, these cells don’t actually form organs, but do serve similar functions, keeping the animal(s) alive.

6. Porifera-Sponges (the pore bearers)
Spicules are like calcium carbonate or silica re-bar for sponges, providing support for a larger congregation.

7. Sponges Do they “sits and thinks, or do they just sits??”
Sponges are sessile and remain permanently attached to the substrate they alight upon.

8. if you carve ‘em up, they come back!!
It’s more amazing than that. If you mix groups of sponges together, they will usually reorganize into their original groups.
if you carve ‘em up, they come back!!

9. Suspension feeding: natural water purification

10. Reproduction: Asexual vs. sexual
Damage to a sponge can actually promote asexual reproduction, as “parts” can land elsewhere and form new sponges.

11. Sexual reproduction
Many sponges are hermaphrodites, containing male and female reproductive capabilities. They do not self-fertilize.
Tube sponges, such as this Verongia Archeri which is common in Caribbean waters use broadcast spawning to disperse sperm and eggs in a flurry of activity that is often coordinated with lunar cycles.

12. General Sponge Types
Sponges fall into several basic categories, mostly depending on shape:
branching
tubular
round
encrusting
glass
boring (destructive)
Hawaiian encrusting sponge
Sclerosponge (CaCO3)
Ceratoporella nicholsoni

13. Sea anemones, jellyfishes, coral, etc.
2. Cnidarians
Sea anemones, jellyfishes, coral, etc.

14. Cnidarians
Cnidarians actually exhibit radial symmetry in which similar body parts can be grouped around a central axis.
Here we also observe a large jump on the evolutionary scale: tissues that perform specific functions.

15. General Cnidarian Structure and Function
Macrorhynchia phillipina
General Cnidarian Structure and Function
Centrally located mouth
Oral surface (mouth)
Aboral surface (“mouth side” vs.“aboral side”)
Tentacles
Gut
Nematocysts
Polyp and Medusa: reproductive stages
Beautiful, but deadly! This colonial
hydrozoan still contains cnidae.

16. Discharged nematocysts( stinging cells) used for defense
and prey capture, have been the plague of more than fish.
Stings from certain jellyfish have resulted in death in a matter of hours, especially
for infants.

17. Carukia Barnesi: the bad-est of the bad!
A sting from this little guy can cause Irukandji Syndrome:
“It begins with a mild sting, followed by severe lower back pain, muscle cramps in arms, legs, stomach and chest. It causes sweating, anxiety, nausea, vomiting, headaches and palpitations, and has also been known to cause cardiac failure.”

18. Shapes
1. Polyp: a sac-like attached stage with a mouth and tentacles (mostly sessile)
2. Medusa: a mobile bell-like upside down polyp (jellyfish).

19. Types of Cnidaria Cnidaria come in all shapes and sizes:
Hydrozoans- feathery hydroids
Siphonophores- man-o-war
Scyphozoans- large jellyfish
Anthozoan-sea anemones and coral
Almost all Cnidaria are carnivores.
Sea fan

20. Similar to cnidarians in most respects.
3. Ctenophores
Similar to cnidarians in most respects.
Nearly 100 spp. contain ciliary combs which assist in prey capture and mobility.

21. Ctenophora vs. Cnidaria
Characteristic
Cleavage
Nematocysts
Sexuality
Ciliation
CTENOPHORE
Determinate
Usually None
Typically Hermaphroditic
Multiciliated Cells
CNIDARIA
Indeterminate
Typically Single-Sex
Monociliated Cells

22. 4. Marine Worms, etc.
Marine worms, and organisms hereafter, kick it up a notch, evolutionarily, exhibiting bilateral symmetry (just like humans).
They have anterior, posterior, dorsal, and ventral sections.
Bilateral symmetry, and all that goes with it, results in enhanced motion and sophisticated behaviors.

23. Flatworms: Platyhelminthes
These simple organisms contain organs and systems.
Nearly 20,000 spp. exist
The most common are turbellarians, like this Pseudoiceros gratus from the Great Barrier Reef (lower right.)
About 6,000 spp. are parasitic, like flukes (trematodes) and tapeworms (cestodes)

24. Ribbon worms look like tapeworms, however they exhibit a complete digestive tract and a circulatory system.
~900 spp. exist

25. Nematode Roundworm numbers are staggering in the marine world.
Many animals have them.
Some even find their way into fish (which we ingest when we eat sashimi).

26. Segmented Worms 20,000 spp. known as Annelids
First example of segmentation.
Allows for flexibility and excellent burrowing ability.

27. Polycheates-many bristles (setae) ~10,000 spp. Exhibit parapodia
Evolution of gills!!!
Fireworm
Hermodice carunculata

28. Sandworm Nereis

29. This feather-duster worm, Sabella melanostigma, is a perfect example of beauty, form, and function.

30. Soft Bodied Marine Organisms
5. Molluscs
Soft Bodied Marine Organisms

31. Molluscan Variety
Molluscs (mollusks) include snails, octopuses, clams, etc.
Nearly 200,000 spp. exists. Many of them are eaten as food.
Most have a common body design (or variations of it)
CaCO3 shell, mantle (tissue), foot (locomotion), and a radula (rasping teeth) .

32. Essentially, a mollusc is a coiled mass of vital organs wrapped
in a dorsal shell.

33. Gastropods (Gastropoda), or stomach foot,
are the most common molluscs.
Snails, abalone, and nudibranchs.
75,000 spp.
red abalone
Haliotis rufescens
giant keyhole limpet
Megathrua crenulata
Cooper’s nutmeg snail
Cancellaria cooperi
nudibranch, Phidiana crassicornis
Cone snail, Conus geographus

34. Bivavles

36. Clam or Mussel? In general, clams burrow and mussels don’t.
Clams burrow (foot) for protection and
feeding- filter feeding (incurrent siphons).
Mussels and oysters attach to
whatever they can find, often
causing destruction of bridge
and pier pylons.

37. Scallops also filter feed. Many have striking color patterns.

38. Pearls Natural pearls are still found.
Occurs when irritating particles are lodged within the mantle cavity and covered by secretions (CaCO3) from oyster.
Many other pearls are cultured (seeded).

39. “Putting Your Head and Feet Together”
Cephalopods
“Putting Your Head and Feet Together”

40. Cephalopod (General Morphology)
While still following the basic body plan of a mollusc, octopuses, cuttlefish, squid, etc. are highly specialized.

41. Cephalopod All cephalopods (650 spp.) can be considered as predatory.
Some have venomous bites which can be extremely painful.
Octopuses lack a true shell,
while other “cephs” have
internalized it (squid-pen).

42. Some cephalopods like this Pacific giant octopus, Octopus joubini,
reach amazing proportions (>30 ft).
Octopus, squid, and cuttlefsh use suckers to help capture prey items.

43. 7. Arthropods: Crustaceans Crabs, Lobster, Shrimp, Barnacles

44. Arthropods exhibit bilateral symmetry and an chitinous exoskeleton
Arthropods exhibit bilateral symmetry and an chitinous exoskeleton. Crustaceans (68,000 spp.)
To grow they must shed the exoskeleton and absorb water to grow
before the new exoskeleton hardens.

45. Barnacles

46. Amphipods and Isopods Orchestoidea, a beach hopper
are often found on marine
mammals.
Sea louse: a marine pill bug

47. Decopods: Ten legs never tasted sooo good!

49. Other decapods

50. Male vs. female When choosing a crab, females exhibit a “U” shaped
abdomen while males exhibit
a “V” shape.

51. Sea stars, brittle stars, urchins
8. Echinoderms
Sea stars, brittle stars, urchins

52. General Structure Echinoderms
Echinoderms are examples of animals with pentaradial symmetry (although not all are pentaradial).
Unlike arthropods, they have an endoskeleton (internal).
They also evert their stomach to eat.

53. Nearly 7,000 spp. of sea stars exist.
Tube feet along ambulacral grooves assist the starfish in moving.

54. Other Echinoderms Brittle star Ophiothrix oerstdii Sand dollar
Sea Urchin
Strongylocentrotus drobachiensis
Sand dollar
Mellita sexiesperforata