Mongooses and Fossa: Herpestidae
Mongooses are a family, Herpestidae, of small to medium-sized, mainly carnivorous Old World mammals. Their overall appearance suggests a small, generalized mammalian carnivore. They have long bodies, short but powerful legs, and long, often bushy tails. In some ways, they converge with (resemble) the mustelids (mammal family Mustelidae: weasels, badgers, skunks, otters, wolverines) of the New World.
Family Herpestidae, including species in Madagascar, includes about thirty-five species and seventeen genera (JEN-uh-ruh), although not all taxonomists, or classifiers of animal types, agree as to the exact number of genera and species. The large island of Madagascar, off the southeast coast of Africa, has eight mongoose species arranged in four genera, probably all descended from a single founder species that rafted on floating vegetation from Africa. The Malagasy mongooses are classified in a subfamily of their own, the Galidiinae. All other mongoose species are classified within subfamily Herpestinae.
Adult head-and-body length throughout family Herpestidae runs 9 to 25.5 inches (23 to 65 centimeters), tail length 9 to 20 inches (23 to 51 centimeters), and weight just under 1 pound to 9 pounds (0.4 to 4.0 kilograms). The exception to these measurements is the fossa of Madagascar, the largest of the Herpestidae and the most un-mongoose-like of all mongoose species. A fossa can grow up to 31.5 inches (80 centimeters) head-and-body length, with a tail just as long, and an adult weight of 20 pounds (9.1 kilograms).
Fur colors in herpestids are various shades of brown and gray, with lighter, sometimes white, fur on the underside. Some species carry stripes or stipplings on their darker fur. The fur can vary in texture as well, from soft to coarse, short to long. There are five clawed digits on each of the four paws, the claws of the forefeet long, sharp, and curved. Except for the fossa, the claws are not retractable, meaning they cannot pull them back into the paw. The small head and face taper to a pointed muzzle, sometimes with a straight bridge from crown to the end of the snout, or there may be a distinct, sloped forehead where the head and muzzle join. The ears are short and rounded.
Herpestids carry glands for scent-marking in their cheeks and near their anuses. Some species can shoot out a foul-smelling fluid from the anal glands.