http:www'biosci'ohio

1
annual infection rate said to be 1500 million
cases!
egg L1
http//www.path.cam.ac.uk/ schisto/Nematodes/Asca
ris.html
4th
xxx
these worms are not very oxygen-tolerant....so
how do they survive in their hosts? They have
special hemoglobins that bind O2 25,000X
stronger than human hemoglobin, using NO to soak
up the oxygen, thus protecting
themselves. (Minning et al. 1999. Nature 401
497-502.)
(1.5 mm long L4)
(250 µm long L2)
http//www.biosci.ohio- state.edu/parasite/lifecy
cles/ ascaris_lifecycle.html
2
more on Ascaris lumbricoides
L2 hatching from the egg
adult worm
http//www.dpd.cdc.gov/dpdx/HTML/ImageLibrary/Asca
riasis_il.htm
3
Priapulids
Ottoia, a campbrian priapulid
from Hyman, 1951
http//www.geo.utexas.edu/students/ cmcfar/burgess
-shale/ottoia.htm
4
a hawaiian chaetognath baby!
5
Cape Cod fiddler crabs!!! (Uca pugnax?)
6
A competitive male that outsignals or outfights
other males will mate with more females and thus
sire more offspring, even if his actions lead to
a reduction in each mated females reproductive
output.
from
The dark side of sexual selection by Brooks
and Jennions (1999) Trends in Ecology and
Evolution 14 336-7
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the fiddler crab Uca annulipes, from Mozambique
http//www.specola.unifi.it/mangroves/ fauna/inv/c
rabs/ocypodidae.htm
regenerated claw
unregenerated claw
http//www.anu.edu.au/BoZo/backwell3/research.htm
8
When compared with males with un-regenerated
claws of the same claw size, the males with the
regenerated claws (which can be as many as 44
of the males in a given population!)
1. ...are just as scary to potential burrow
stealers 2. ...are just as as attractive to
females 3. but, in the event of a burrow
contest, lose their burrows more often 4.
Still, they end up finding burrows as quickly,
and might actually benefit from having
lighter claws, since such claws would be
easier to wave.
Patricia R.Y. Backwell, et al. (2000) Dishonest
signalling in a fiddler crab. Proc. R. Soc.
Lond. B 267, 719-724