wilson@csli.Stanford.EDU (Nathan Wilson) (10/24/90)
Do male marsupials have pouches? My strong guess is that they don't, but I can't find anything that says one way or the other. Nathan Wilson Teleos Research nathan%teleos.com@ai.sri.com
kuento@kuhub.cc.ukans.edu (10/24/90)
In article <15975@csli.Stanford.EDU>, wilson@csli.Stanford.EDU (Nathan Wilson) writes: > Do male marsupials have pouches? My strong guess is that they don't, > but I can't find anything that says one way or the other. > > Nathan Wilson > Teleos Research > nathan%teleos.com@ai.sri.com No, they do not. The marsupial pouch is an integral part of the female reproductive system. Monotremes (platypus and echidna) also have a pouch, and this is where the eggs are generally kept during incubation. The young monotremes receive nutriment from modified sweat glands inside the pouch (called mammary glands, though a much more primitive version than in other mammals). Marsupial reproduction is basically similar, except that the shelled-egg stage is deleted, and the young marsupials must crawl unaided (while blind and poorly- developed) from the birth canal forward (or up) into the pouch, where they attach to the mother's nipples. In a general sense, then, the marsupial pouch is an analog (if not a homolog - I'd have to check on that) of the uterus of a placental mammal. Male marsupials have no corresponding structures, though they *do* have hemipenes like reptiles (at least in the possums). Amazing critters, indeed. ---------------------------------------------------------------- Doug Yanega (Snow Museum, Univ. of KS, Lawrence, KS 66045) My card: 0 The Fool Bitnet: Beeman@ukanvm Disclaimer? Ha! Have opinion, will travel...
andrewt@cs.su.oz (Andrew Taylor) (10/25/90)
In article <26295.2724b2f1@kuhub.cc.ukans.edu> kuento@kuhub.cc.ukans.edu writes: > No, they do not. The marsupial pouch is an integral part of the female > reproductive system. Monotremes (platypus and echidna) also have a > pouch, and this is where the eggs are generally kept during incubation. One clarification, many of the smaller (female) marsupials do not have pouches and I don't think platypuses have pouches (though I'm not certain about that). Andrew