ANSC 3300 Prelim 1 Lecture 1
How much water do the Earth be?
70% (97% salt 3% fresh)
Basic structures of early chordate evolution evolved to:
CNS, sensory organs, mechanical structures, complex internal organs
Time periods of importance for fish
Cambrian, Devonian
Sturgeon genome
No sexual dimorphism, slow maturation
Chondricthyes
Sharks, skates, rays, chimeras (cartilaginous fish)
Amphioxus (lancelet)
ancestor of fish and all verts
Other features of most fish
are aquatic free-swimming vertebrates, swim using paired fins, breathe with gills rather then lungs, covered in protective scales, unable to regulate internal body temperaure
Herbivores and carnivore intestines
carnivores is shorter
Cambrian
first fish
Basic fish design
food and waste tube
Exceptions to fish characteristics
hagfish aren't vertebrates, some fish don't have scales, lampreys don't have paired fins, mudskippers can live outside water, lungfish use lungs, tuna swordfish and sharks can elevate body temp
Pre-teleost fishes (Limited extant species)
hagfish, lamprey, reedfish, lobe-finned fishes, sturgeons, lungfish
What is a fish
have a brain protected by braincase and obvious head region
Devonian
increased fish diversity
lancelet structure (left to right)
oral hood w/ tentacles, gill slits in pharynz, notochord, gonad, atrium, dorsal nerve cord, atriopore, intestine, anus
Genome duplication events
role in diversification, FSGD, whole or partial, 1R (Cambrian explosion), 2R (second duplication), 3R (FSGD)
Sustainable aquaculture feed
sustainable, abundant protein, low carbon footprint, scalable to site size, cheap (Possible is insect protein)
How many fish species we got?
~35,000, 95% modern