GREAT WHITE SHARK
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Great Whites Sharks – Anatomy & Reproduction
Anatomy
At the pinnacle of evolution the blood circular pathways of the Lamnids
have adapted a unique heat exchange and conservation system whereby
body heat is not lost as it is with other shark families.
In most sharks, blood from the heart is oxygenated at the gills and
transported via the large dorsal aorta and finally returned to the
heart via post cardinal and abdominal veins. In the case of the lamnids,
blood from the gills is dispersed to the muscles and returned to the
heart via a bed of small arteries and veins that are in contact with
each other and also in direct contact with the heat generating swimming
muscles. The muscles warm the veins and the veins warm the arteries
and body heat is retained rather than being continuously lost at the
gill filaments. Body mass to surface area ratios also plays a part
in heat conservation.
The benefits of this heat conservation system is that warm muscles
give improved performance in the pursuit of prey. The same benefits
that their cousins the mako, porbeagle, thresher, and non-related
tuna gain.
Reproduction
Great whites grow at a rate of approximately one foot a year and reach
maturity at the age of nine to ten years at a length of between 11 and
14 ft. They have small litters of seven to nine pups with a length between
2ft and 4ft / 60cm - 120cm each.
Great whites are ovoviviparous whereby the young are borne live and
nourished in the uterus not only by the yolk of the egg, but also by
gland secretions from the wall of the oviduct when they leave the egg.
Intrauterine cannibalism, which produces a smaller number of larger
babies, is also likely with great whites.
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