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