Assignment I: Warm blooded animals (homeotherms) dominate the terrestrial environment, but cold blooded animals (poikilotherms) are most abundant in the aquatic environment. Given the differences between the two environments and speculate on why this is so.




Assignment IIA: What is the P_N2 in the fish's blood in A, B, and C




Assignment IIB: Find a living fish you can observe, a large aquarium specimen like an oscar is ideal, if you don't have an aquarium at home, go to a public aquarium or retail store. Observe the respiratory pump and answer the following questions. Do the mouth and opercula have to close entirely for the buccal and opercular valves to operate? Is the expansion phase of the buccal and opercal cavities simultaneous or offset? What is the respiration rate (respiratory cycles/minute) of your specimen? Speculate on what might cause the respiration rate to change.




Assignment IIC: Speculate on why it might be adaptive for fish to sometimes direct more or less of the lamellar blood flow into the central compartment and away from active blood/water exchange in lacunar spaces.




Assignment IID: How would the length of the countercurrent flow affect exchange? Lampreys are sometimes parasitic hanging onto their host with their sucker mouth and hagfish often feed deep inside dead fish, why would bidirectional flow be adaptive?




Assignment IIE: Why don't fish at very cold temperatures succumb to carbon monoxide poisoning? What is the difference between hemoglobin's capacity and affinity? Different fish have Hbs with different affinities, why don't they have different capacities (except when Root shifted)?




Assignment IIF: When a fish is engaged in exceptionally strenuous activity (high metabolic rate) CO₂ increases in the blood and O₂ falls. On a percentage basis, would you expect the increase in partial pressure of CO₂ to be more, less or the same as the decrease in parital pressure of O₂. Explain.




Assignment III : The assignments for all the labs will be same. Obtain a freshly dead fish and dissect it. How does the gross anatomy compare to the rainbow trout pictured in the labs? What is the same and what is different? Did you find all the features? If not, why not? Did you find anything not pictured?

Since every lab has this same assignment, you might wish to wait until you completed all the labs and hand all the assignments in together. This way you will need only one fish. You can obtain a whole, fresh fish from someone who fishes, or a large fish market or even use an inexpensive goldfish from a pet store. If you need to kill your own fish, you can do so with no damage to the body by putting the fish on wet ice for an hour or so, or by putting a few drops of clove oil from the drugstore into the water. Clove oil is a general anesthetic for fish. The only tools you will need will be some small, sharp scissors, a sharp knife (an Exacto knife makes a fine scalpel), and a dull instrument to tease tissue apart.




Assignment IVA: Explain why it would be adaptive for fish to minimize blood pressure pulses through the gill and why they would tend to synchronize heart beat and opercal pump under hypoxic conditions.




Assignment IVB : Explain why fish that swim continually have more red muscle than sedentary fish.




Assignment VA: Explain how the Root and Bohr shifts are able to raise gas pressures in blood that already has a partial pressure of oxygen far in excess to 150 mm Hg.




Assignment VB: If a fish had a rigid gas bladder instead of an elastic one, how might this change the performance of the bladder? Speculate on why evolution did not lead to a rigid bladder?




Assignment VC: While most air breathing fish live in habitats where dissolved oxygen would be expected to be low at times, some live in well oxygenated waters. Speculate on the adaptive significance of air breathing in well oxygenated habitats.




Assignment VI: Speculate on adaptive advantages/disadvantages of the parthenogenic life cycle found in Mexican mollies.




Assignment VII: The assignments for all the labs will be same. Obtain a freshly dead fish and dissect it. How does the gross anatomy compare to the rainbow trout pictured in the labs? What is the same and what is different? Did you find all the features? If not, why not? Did you find anything not pictured?




Assignment VIIIA: Describe all the changes that would occur in the gut and the gill as a euryhaline fish move from fresh water to salt water.




Assignment VIIIB: If a FW adapted euryhaline fish was immediately immersed in full strength sea water, what changes in their water/ion balance would occur? If the fish survived and adapted to salt water, in what sequence would the imbalances be corrected?




Assignment IXA : The illustration features a carnivorous fish. If the fish was omnivorous what would be different? What would be the same?




Assignment IXB: The middle graph showing activity effects on metabolic rate is not quite accurate because of the limits of my animation ability. What is wrong?




Assignment X: Why do carnivores dominate the aquatic environment and omnivores and herbivores the terrestrial environment? (Hint: start at the source of primary production, the plants, in each ecosystem).




Assignment XI: The assignments for all the labs will be same. Obtain a freshly dead fish and dissect it. How does the gross anatomy compare to the rainbow trout pictured in the labs? What is the same and what is different? Did you find all the features? If not, why not? Did you find anything not pictured?




Assignment XIIA: Some otoliths (not the ones used for hearing) are used by fish to detect gravity and determine which way is up. These otoliths rest on sensory hairs in semicircular canals above the auditory chambers. If the fish tips over, the otolith slides over different hairs and this information is sent to the brain. If these otoliths are removed, fish can still usually stay upright. What cues might allow them to accomplish this? What if these secondary cues were removed or altered? What might happen?




Assignment XIIB: Compare and contrast the functional value of the lateral line sense with the weakly electrical sense. What would be the advantage of one over another and why?




Assignment XIII: Suggest an experiment that would confirm the statements regarding control of the gas bladder made in this section. Be specific.




Assignment XIV: The assignments for all the labs will be same. Obtain a freshly dead fish and dissect it. How does the gross anatomy compare to the rainbow trout pictured in the labs? What is the same and what is different? Did you find all the features? If not, why not? Did you find anything not pictured?