13.1. Crotalus ruber: Red Diamond Rattlesnake http://www.ck12.org
Habitat
The range of this species can be found in southwestern California and throughout the Baja California peninsula. It
also lives on some islands in the California Gulf. It often inhabits and rests inside rock outcrops.C. rubercan be
found in desert scrub, coastal sage scrub, mesquite cactus and pine or oak forests.
Biology
Cell Biology
Like all reptiles,C. ruberhas eukaryotic cells, which have many organelles, and are found in all plants, animals,
and even fungi. Examples of these organelles are the nucleus, vacuoles and vesicles. Another organelle called
the mitochondria provides energy needed to power chemical reactions. An example of an organelle that is very
important is called the ribosomes, where proteins are made. The part of the cell that takes care of waste is known as
the lysosome. Endoplasmic reticulum is a folded membrane that transports proteins.
Cells multiply through mitosis, or when the nucleus divides, and each new cell contains a copy of the DNA in the
cell before it. Another way cells multiply is through meiosis for reproduction. In meiosis, the cell divides to make
gametes, with half the chromosomes of the parent cell.C. ruberhas red blood cells, which transport oxygen around
the body, and nerve cells, among other specialized cells.
Evolution
The earliest reptiles, or amniotes, evolved around 350,000,000 years ago. Then 30 million years later is when they
would separate into two groups, synapsids and sauropsids. Ancestors of modern snakes were sauropsids.
Ecology
C. ruberis hunted by birds of prey like hawks. It uses scrub and cactus for shelter and will also hide in rock
outcrops.C. rubermates in spring, delivering three to twenty young in summer. Its diet consists mainly of small
rodents. Examples are woodrats, small birds, rabbits, other reptiles and ground squirrels. Also, ground squirrels are
immune to the snake’s venom, and they will attack threatening rattlesnakes.
Anatomy and Physiology
C. ruberis cold blooded, which means it relies on the environment to control its body temperature. They have scales
covering the entire body.C. ruberhas a forked tongue used for smelling. The snake will hunt at night with pit organs
that allow for thermal vision. Another set of organs, called Jacobson’s organs, are connected to the nose and let the
snake “taste” the air. Even after death, this snake should still be treated as a dangerous threat, due to neurological
reflexes that allow the snake to bite. The venom, which is a complicated mixture of proteins that affects blood tissue,
can be fatal. The rattle is made of keratin. During each shedding, a new segment is added to the rattle. Depending
on how much the snake sheds, rattles can vary in size.