Thursday, March 12, 2009

Tree of Fish Life

After spring break we will continue to describe a few groups of bony fishes, the Teleostei. These fish are definded by the homocercal tail and the specialized bones that support the symmetrical caudal fin. Hence the name Telesotei which literally means "end bone" The groups that I will use to introduce the Teleostei include the Osteoglossomorpha, Elopomorpha, Clupeomorpha, which are specialized offshoots of the main Teleostei line of evolution. The group in the main line of Teleostei evolution ( i.e, Euteleostei) that I will discuss is the Ostariophysi, a large group of fishes which include the Gonorynchiformes, Cypriniformes, Characiformes, Siluriformes, and Gymnotiformes.

The photo above is the Piraucu (or Arapaima), a member of the Osteoglossidae (bony tongues) that is sometimes referred to as the "Tarpon of the Amazon." Click on Osteoglossomorpha above to take you to a section of the Tree of Life that deals with this fish group. Here you can read more about this group and click on the phylogenetic tree to move up or down and see the interrelationships among the fish groups. I will not present this level of detail for other fish groups because I know you can read those chapters (15 through 26) and investigate further as your prepare your presentations on Fascinating Fishes.

We will then move on to some fundamental questions that people have about fish: What do fish eat? How do fish grow? How do fish breed? How do fish smell? How do fish taste? How do fish see? How do fish hear? How do fish behave in response to environmental change? How do fish communicate?

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