Compare feeding mechanisms and prey types in Cephalaspidomorphi with those of Myxini.
What ecological disaster sometimes occurs when lampreys are introduced to lakes and rivers that they did not formerly inhabit?
List/briefly describe the three major evolutionary changes that occurred after the lampreys but prior to the Chondrichthyes (i.e. for the “Gnathostomes”.)
What is the likely structural origin of jaws? Of fins?
What material comprises most of the shark’s skeleton? Which parts of a shark’s skeleton are mineralized?
What feature of shark teeth makes them the most common vertebrate fossil? Also, describe the two general morphologies of shark teeth and how they differ in function.
Describe the attachment of the upper jaw to the skull in a shark. In what ways does this affect the shark’s feeding behavior?
What is a spiral valve (location/appearance/function), and in which type of fish are they found?
Describe the scales of Chondrichthyes: Elasmobranchii. What role do the scales play in swimming?
Describe three mechanisms that help a shark maintain approximately neutral buoyancy.
List and describe the three patterns of respiration in Chondrichthyes: Elasmobranchii (i.e. “ram jet”, etc…)
Describe the solute concentration of Elasmobranchii compared to seawater and describe the mechanisms by which it maintains its osmolarity.
Name the major orders of the Elasmobranchii, key characteristics that place sharks in the particular order, and representative members. (NOTE: On an exam, you will need to recognize the names of the major orders of sharks as well as the key features/members, with a focus on those we studied most intensively.)
Great white sharks!
Briefly explain the bite-and-spit hypothesis of Tricas and McCosker (1984), including the evidence they used to develop their hypothesis.
Describe how evidence from actual shark attacks witnessed and videotaped by Klimley, Pyle and Anderson (1996) appears to contradict this hypothesis.
Describe at least three major differences observed for great white shark attacks on phocids (true seals) vs. otariids (eared seals, i.e. sea lions) by Klimley et al. (1996) and provide an explanation for these differences based on adaptive value to the shark, differences between seals and sea lions, and other relevant factors.
Explain how basking sharks and whale sharks feed, pointing out similarities and differences in feeding mechanisms and prey. Also indicate to which Order each belongs.
Describe the process of countercurrent exchange of oxygen uptake in fish gills and countercurrent heat exchange in the great white shark. In addition, explain the significance of this mechanism to each animal. You must include a diagram with each
What do angelsharks eat, and which sensory modality do they use to detect their prey? Also, briefly describe how they capture their prey.
Provide at least two hypotheses to explain the odd-shaped head of the hammerhead shark. (Two distinct hypotheses were provided in class.)
How is it possible for several species of closely-related reef sharks, all predatory, to be associated with the same reef?
Explain how the relatively slow-moving cookie-cutter shark is able to take bites out of fast-moving fish such as tuna.
What is the defining difference between skates (Order Rajiformes) and rays (various orders)? NOTE: Don’t worry about more subtle differences…
Which fish are in the Class Chondrichthyes, Subclass Holocephali? Describe several ways they differ from the Subclass Elasmobranchii.
What key characteristic distinguishes the Class Osteichthyes from Class Chondrichthyes? (Note that there are several differences, but one feature in particular defines the Osteichthyes and the rest of the vertebrates beyond this branchpoint.)
Describe the initial the position and connections of the lung/swim bladder to the intestine, and describe how these have changed through time among different groups of fish. Also, indicate which best exemplifies the tetrapod condition.
Briefly compare the skull/cranium of Osteichthyes to that of Chondrichthyes.
Which group(s) of fish has fins that are most similar to the limbs of tetrapods?
List/describe the key features of coelacanths, making comparisons to other groups of fish as you do so. Key features you discuss should include:
Vertebral column and any other unique skeletal features (as compared to either Chondrichthyes or Osteichthyes: Actinopterygii)
List/describe several features of the marine iguana that are adaptations to the marine environment.
What do marine iguanas eat? If you did not already do so for the previous question, describe adaptations that help them feed in on this particular type of food.
Martin Wikelski and Corina Thom discovered that marine iguanas shrunk by up to 20% in body length during two separate El Niño events. What was the environmental cause of this shrinkage?
Describe several adaptations of true sea snakes (Family Hydrophiidae) to the marine environment.
Are sea snakes always solitary?
In what way(s) are sea snakes better-adapted to the marine environment than sea turtles?
How do sea kraits differ from sea snakes in terms of their adaptations to the marine environment?
Compare the structural components of the carapace and plastron of sea turtles in the Family Cheloniidae with those in the Family Dermochelydae.
Describe the differences in beak structure among different turtle species and explain how these differences in beak morphology are related to feeding behavior/food type.
How are the limbs of sea turtles specialized for swimming? Which bones support the main portion of the flipper (i.e. what are they equivalent to in your own arms/hands and legs/feet?) Compare the size and role of the forelimbs vs. the hindlimbs. How do the limbs of sea turtles compare to those of land turtles and freshwater turtles?
Given that sea turtles are ectothermic, how are they able to maintain body temperatures sufficient to allow for efficient swimming (several mechanisms)? What happens to sea turtles in the water when they are unable to maintain the body temperature needed for swimming?
What is “basking”? When/where does it occur and what are its functions (both definite and hypothesized)? When basking on land, how do sea turtles keep from overheating?
Describe how sea turtles keep from ingesting excess water with their food, including key structures.
What is the function of salt glands and where are they located in sea turtles? How effective are they? Why do hatchlings have larger salt glands in proportion to their body size than adults?
Describe the key anatomical/physiological adaptations of sea turtles for diving.
What species of sea turtle holds the diving depth record? Approximately how deep was the deepest dive recorded for this species, and what marine mammal has similar capabilities? Does this species have any particular adaptations that make it better-suited for diving than other turtle species?
Which species of sea turtle has the longest recorded dive?
How is sex (gender) determined in sea turtles? What changes in sex ratios are likely to occur with increases in global temperatures?
In studies on leatherback turtles that examined the consequences of skewed sex ratios:
What aspects of reproductive success were measured?
What were the key results?
Did the results suggest that the low proportion of male hatchlings had a deleterious effect on reproductive success? Explain.
Explain how it is possible for there to be 2-3 males/female at the breeding grounds even though ≥3 times as many females initially hatch (>1 possible reason).
Which species of sea turtle grows the most quickly and reaches sexual maturity most rapidly? Which species of sea turtle grows the slowest and also does not reach sexual maturity until at least its late twenties? What factors might help explain this difference in the two species?
Describe several ways that leatherbacks can be considered the “record holders” of the sea turtle world.
How far north are leatherbacks found (northern hemisphere), and why are leatherbacks better able to deal cold temperatures than members of Family Cheloniidae?
Explain the seemingly paradoxical ability of leatherback turtles to be the fastest-growing sea turtle despite the fact that it primarily preys on jellyfish that are 97% water.
Why do nesting leatherbacks sometimes appear to have a pinkish tinge?
Why are hawksbill turtles important to the reef ecosystem and how might their loss affect the reef ecosystem?
What makes the meat of hawksbill sea turtles toxic?
What makes green sea turtles green?
What is an “arribada” and which species of sea turtle participates in these? (Note that another, closely-related species does this as well.)