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Scorpion Races: Reference and
Abstract
Shaffer, L.R. and D. R. Formanowicz, Jr. 1996. A cost of viviparity and
parental care in scorpions: reduced sprint speed and behavioural compensation.
Animal Behaviour 51:1017-1024.
Abstract:
Current reproductive effort may often be at the expense of future reproduction.
One way in which future reproduction of viviparous animals may be affected
is by increased risk of predation resulting from decreased mobility associated
with pregnancy. The common striped scorpion, Centruroides vittatus,
may experience considerable risk of predation associated with reproduction
because it is viviparous, with an eight-month gestation period. C.
vittatus also carries the newborn young on its back during their first
instar. The purpose of this study was to establish a cost of viviparity
and parental care in these scorpions by determining sprint speed at three
reproductive stages: pregnant, carrying offspring and post-dispersal of
offspring. Post-dispersal speed was used as a best estimate of non-pregnant
speed. Pregnant speeds averaged 84% of post-dispersal speeds. Lower speeds
were correlated with absolute and relative measures of litter size. Speed
while carrying offspring averaged 61% of post-dispersal speed, and was
correlated with mass of the litter and number of individuals in the litter.
Sixty-five per cent of the females carrying young could not be induced
to run; these females instead assumed a defensive posture. Results indicate
that female scorpions experience a cost (in decreased running speed) to
viviparity and parental care, and that some females may reduce this cost
by using an alternative defensive strategy.
© 1996 The Association for the Study of Animal Behaviour.
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