Science & Nature
What a Gem!
Shark!
You Do The Math
Anagrammed Birds
400
In the U.S., alligators & crocodiles co-exist only at the southern tip of this state
Florida
400
This greenish-blue gem is so popular in the Southwest that it has its own museum in Albuquerque
Turquoise
400
Almost all sharks have 5 of these "slits"; & some don't have to swim constantly to pump water over them
Gills
400
Number of U.S. states divided by the number of noncontiguous states
25
400
It's often atop a statue:
ONE PIG
A pigeon
800
In 1991 radar images hinted that there was ice at the north pole of this inner planet
Mercury
800
AKA chrysoberyl, this gem produces a streak of light resembling the pupil of a certain animal when cut a certain way
Cat's eye
800
It's the type of shark seen here named for obvious reasons 
A hammerhead shark
800
It's the square root of the square root of 81
3
800
It's big in Africa (heck, it's big everywhere):
CHRISTO
An ostrich
1200
17th century Dutch scientist Christiaan Huygens developed the wave theory of this
Light
1200
Often a lemony color, this variety of quartz has a name derived from the type of fruit that a lemon is
Citrine
1200
The largest living fish, it often grows to be 30 feet long but reportedly may reach twice that
A whale shark
1200
Number of sides on a pentagon multiplied by the number of sides on a hexagon
30
1200
He'll send you a large bill:
CAP LINE
Pelican
1600
Dinosaurs died out in this geological era that means "middle life"
The Mesozoic era
1600
Silent screen star Mary Pickford bequeathed the Star of Bombay, a 182-carat one of these gems, to the Smithsonian
A sapphire
1600
One specimen of this shark variety seen here was 21 feet long & 7,300 pounds--no wonder it gets all the press
A great white shark
1600
49 plus 22 minus 33 plus 11
49
1600
I may gulp when I say its name:
LOW LAWS
A swallow
2000
In 1766 this English chemist discovered the properties of hydrogen, which he called "inflammable air"
Henry Cavendish
2000
Utah's official state gem is this stone that's often golden but can be pink or blue
The topaz
2000
Galeocerdo cuvier, this shark retains its eggs until its young hatch; they're grrreat!
The tiger shark
2000
An $80 shirt reduced in price by 20% would cost this
$64
2000
It's probably long-tailed:
HEAT SNAP
Pheasant