WILD MATING OF NURSE SHARKS
Summary by Deependra Chhabra
In this paper, we are going to look at the mating habit of the nurse
shark. This research has been going on since 1992, and this is
the
first time scientist have documented in detail the sex life of shark.
This study was done near the Florida area.
Nurse sharks are relatively sluggish. Adults range from seven
to ten
feet's in length and weight between 250 to 400 pounds. Nurse
shark
spends most of their time in the caves. But, during the five-month
mating season, a group of about 20 shark congregates in one small area.
They do not seem to be aggravated by the presence of humans around
them.
Scientists could come as close as two feet while the sharks were mating.
The mating starts by an acceptance or rejection dance by the males.
The
males struggle to arch his body over the female. Often one of
his
penis-like clappers will poke out pointing skywards. Male sharks
possess two claspers to deliver sperm. Only one is used, depending
which
side of female he is able to grip. Sometimes as many as six males
will
work together to ambush a female. The males would literally inhale
the
female's fins and tow her in the deeper waters. The females can
resist
males by arching her body to keep her fins away from the male.
Successful male is the one who can have the tightest grip on the female.
The male can then roll the female over, flick her tail underneath to
brace himself and insert a clasper. A successful copulation lasts
for
one to two minutes after which the male collapses to the bottom of
the
sea. The fatigue is due to the lack of oxygen as the male has
the whole
fin deep in his mouth. The female fins will have "love bites"
which may
look serious. But there thin, tough skin quickly heals.
Reference:
Harold, L. Pratt, Jr. and Jeffrey, C. Carrier. (1995, May). Wild Mating
of the Nurse Sharks. National Geographic, pp. 46-49.