Antechinus

From Wikipedia, the free encyclopedia

iAntechinuses

Antechinus flavipes

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Dasyuromorphia
Family:	Dasyuridae
Subfamily:	Dasyurinae
Tribe:	Phascogalini
Genus:	Antechinus Macleay, 1841

Type Species

Antechinus stuartii
Macleay, 1841

Species

See text.

Antechinus is a genus of dasyurid marsupial that is indigenous to Australia (including Tasmania and some outlying islands) and New Guinea. The majority of Antechinus species occur in Australia and only two (currently with a putative third) species have been described in New Guinea. Members of this species have been called broad-footed marsupial mice, pouched mice, or antechinus shrews. However, these common names are to be considered either regional or archaic and the modern common name for animals of this genus is 'Antechinus'.

Antechinuses are small, carnivorous, shrew-like animals, that primarily prey on invertebrates such as spiders, beetles (including larva), and weevils. Some are strictly terrestrial and hunt only at ground level while others are highly scansorial (climbing) in nature. Most species nest communally in tree-hollows.

Antechinuses are semelparous, which means that an individual will usually only live long enough to breed once in its lifetime. Breeding occurs in winter (usually August-September) at a time when there is little food available in the environment, and in order to ensure breeding success, male Antechinuses strip their body of vital proteins and also suppress the immune system so as to free up additional metabolic energy. In this way an individual male trades away long term survival in return for short term breeding success, and following the breeding season there is a complete die-off of physiologically exhausted males. Breeding is intensely competitive. Males produce large amounts of testosterone and mate-guarding occurs in the form of protacted copulation (up to twelve hours in some species).

The females can store sperm for up to three days in specialized sperm-storage crypts in the ovary and do not ovulate until the end of the breeding season. Many litters have multiple-paternity (i.e. several fathers contribute to a single litter). Females can live for 2-3 years, however this is unusual, and most females die following the weaning of their first litter. Litters size depends on the number of teats in the pouch. There are as few as 4 teats, usually 8, and in some populations up to 10 can occur. It is currently unknown why teat number varies, however it is likely that in food-poor environements selection has tended towards fewer teats so that there is a greater parental investment per offspring.