At 10:07 AM 3/25/99 -0800, you wrote:
>This old wives' tale about earthworms' ability to regenerate is quite
>overblown. Only the head end can survive and then can only partly
>regenerate the missing segments. Different species regenerate to different
>degrees, but the anterior end has the brain, hearts (6 of them),
>reproductive organs and gizzard.
Gates 1972 ("Burmese Earthworms", Trans. Amer. Philosophical Soc.) reports
that regeneration in Perionyx excavatus can take place at either end,
including decapitation. In such cases, let us say removal of the first
twelve segments, including many of the reproductive organs and other
head-only parts, these worms can regenerate all the lost parts. Other
species may have lesser or greater regenerative powers. Gates studied
regeneration very extensively, and the reference given contains lots of
information on E. fetida as well as other worms.
>E. fetida (correct spelling apparently) makes excellent compost worms
>except for their smell and a tendency to swarm out of the container. Fish
>tend to avoid them so they don't make good bait.
"Worm crawls" are probably an environmentally-induced phenomenon. Mary
Appelhof may have more details on the causes.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~ Sam James ~
~ Dept. of Biology ~
~ Maharishi Univ. of Mgmt. ~
~ 1000 N. 4th St. FM 1056 ~
~ Fairfield, IA 52557 ~
~ sjames at mum.edu ~
~ 515-472-1146 ~
~ Systematics and Ecology ~
~ of Earthworms ~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- ANNELIDA
Discuss = annelida at net.bio.net = talk to all members
Server = biosci-server at net.bio.net = un/subscribes
Archives = http://www.bio.net:80/hypermail/ANNELIDA/
Resources = http://biodiversity.uno.edu/~worms/annelid.html
--
