From Wikipedia, the free encyclopedia. Calcitonin (also known as thyrocalcitonin) is a 32-amino acid linear polypeptide hormone that is produced in humans primarily by the parafollicular cells (also known as C-cells) of the thyroid, and in many other animals in the ultimobranchial body.t acts to reduce blood calcium (Ca 2+), opposing the effects of parathyroid hormone (PTH). Calcitonin has been found in fish, reptiles, birds, and mammals.
The timber rattlesnake is 1 of 2 venomous snakes in Minnesota, the other being the eastern massasauga (Sistrurus catenatus). While the eastern massasauga also has a gray to tan rattle, it is a smaller snake (47-76 cm; 18.5-30 in.
Also see our Venomous Snakes of Southeast Texas poster. *Note: Although there are only 4 species of venomous snakes in Texas, there are several subspecies of these snakes (11 rattlesnakes, 1 cottonmouth, 3 copperheads, 1 coral snake). The Southeast Texas poster displays the subspecies found in that area.lso see our Venomous Snakes of Southeast Texas poster. *Note: Although there are only 4 species of venomous snakes in Texas, there are several subspecies of these snakes (11 rattlesnakes, 1 cottonmouth, 3 copperheads, 1 coral snake). The Southeast Texas poster displays the subspecies found in that area.