Lab 4 Pre-teleosts and early teleosts Goals




Дата канвертавання17.04.2016
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Zoo511 2006

Lab 4 --Pre-teleosts and early teleosts
Goals:

  • To review the characteristic morphological structures of early fishes and early teleosts.

  • To identify specimens to genus and species


Readings

Moyle and Cech. 1996. pp. 209-212, 231-235, 238-239, 242-245, 247-249.


Introduction:

In this week’s lab we will look at some relict fish species and start looking at some teleost fishes. The first 5 families you will be looking at this week are very distinct. Agnathans are jawless fishes, the most ancient of vertebrates. Sturgeons, paddlefish, gars, and bowfin are relict fishes, all quite different in morphology than anything else you will see in the fish collection. Among the earliest teleosts are superorders known as Osteoglossomorphs, Elopomorphs, and Clupeomorphs. Each of these superorders is represented in Wisconsin, although there are not many different species.


Identification:

Order Petromyzontiformes

Family Petromyzontidae

1. Practice identifying the genera Icthyomyzon, Petromyzon, and Lampetra.

2. Practice identifying the following species (adult and ammocoete):

sea lamprey (Petromyzon marinus)

American brook lamprey (Lampetra appendix)

chestnut lamprey (Ichthyomyzon castaneus)

Order Acipenseriformes

Family Acipenseridae

3. Practice identifying lake sturgeon (Acipenser fulvescens)

and shovelnose sturgeon (Scaphirhynchus platorynchus)

Family Polyodontidae



  1. Practice identifying paddlefish (Polyodon spathula)

Order Lepisosteiformes

Family Lepisosteidae


  1. Practice identfying shortnose gar (Lepisosteus platostomus)

and longnose gar (Lepisosteus osseus)


Order Amiiformes

Family Amiidae


  1. Practice identifying bowfin (Amia calva)

Order Clupeiformes

Family Clupeidae

7. Practice identifying the genera Alosa and Dorosoma

8. Practice identifying alewife (Alosa pseudoharengus)

and gizzard shad (Dorosoma cepedianum)

Order Anguilliformes

Family Anguillidae



  1. Practice identifying American eel (Anguilla rostrata)

Order Osteoglossiformes

Family Hiodontidae

10. Practice identifying mooneye (Hiodon tergisus)


As you are working on these specimens, review the morphological differences that characterize phylogenetic groups: In the space provided below, list the differences between groups


Agnatha—Chondrostei

Chondrostei—Neopterygii

Early Neopterygii— Teleostei


QUESTIONS (Answer in a few short sentences and turn in next week)
1. Name two characteristics common among members of the Clupeidae, and speculate as to the advantage of possessing these traits.

2. Look at the fins and caudal-peduncle region of the gars. Given your observations, and what you’ve learned this semester so far, how would you expect a gar catches its food? (The answer is not just “in its mouth”; think about the gar’s swimming behavior as well!)



3. Current methods to control sea lamprey involve killing the larval lampreys (ammocoetes) in the spawning streams using the lamprey-specific toxin TFM. Questions concerning the specificity of TFM and the impact of TFM on native lampreys have led some researchers to look for alternative methods of control. Think about the life history of sea lamprey, and suggest some other methods that might be used.


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