Sperm, beluga, and pilot are all types of what?
Flora and fauna of Greenland many as two million seals are estimated to inhabit Greenland's coasts; species include the hooded seal ("Cystophora cristata") as well as the grey seal ("Halichoerus grypus"). Whales frequently pass very close to Greenlandic shores in the late summer and early autumn. Species represented include the beluga whale, blue whale, Greenland whale, fin whale, humpback whale, minke whale, narwhal, pilot whale, sperm whale. Whaling was formerly a major industry in Greenland; by the turn of the 20th century, however, the right whale population was so depleted that the industry was in deep decline. Walruses are to be found primarily in the
Sperm heteromorphism Sperm heteromorphism Sperm heteromorphism is the simultaneous production of two or more distinguishable types of sperm by a single male. The sperm types might differ in size, shape and/or chromosome complement. Sperm heteromorphism is also called sperm polymorphism or sperm dimorphism (for species with two sperm types). Typically, only one sperm type is capable of fertilizing eggs. Fertile types have been called "eusperm" or "eupyrene sperm" and infertile types "parasperm" or "apyrene sperm". One interpretation of sperm polymorphism is the "kamikaze sperm" hypothesis (Baker and Bellis, 1988), which has been widely discredited in humans. The kamikaze sperm hypothesis states that