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hark
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How the most successful predators of all time do
it.
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So just HOW do marine CARNIVORES manage
INTERNAL FERTILIZATIONwith NO HANDS???
Let's watch and see...
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Recommended Reproduction Notes Videos

• http//www.elasmo-research.org/education/ecology/i
  ntertidal-nurse.htm

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So whats the big deal with Twilight? Male sharks
have been biting females for millions of years!
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NOT your average hickey!
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So Now What?
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Egg - Laying

• 1. Extended Oviparity paired eggs are laid, one
  from each oviduct embryos derive nourishment
  solely from yolk in external yolk sac and undergo
  most of their development outside the mothers
  body the egg membrane is sclerotinized to form a
  collagenous, sulphur-rich case that often has
  antifouling properties. Found in skates
  (Rajiformes).

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Egg Developing

• 2. Ovoviviparity - eggs are packaged in thin
  cases and retained until development is complete,
  whereupon parturition occurs embryos derive
  nourishment solely from yolk supply in external
  yolk sac. Found in cow sharks (Hexanchiformes),
  dogfishes (Squaliformes), angel sharks
  (Squatiniformes), some catsharks (Galeus spp.),
  shovelnosed guitarfish (Rhynchobatiformes),
  Bowmouth Guitarfish (Rhiniformes), sawfishes
  (Pristidae), electric rays (Torpediniformes), and
  stingrays and eagle rays (Myliobatiformes).

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Live Birth 1(Eat your eggs, now!)
3a. Matritrophic Viviparity with Oophagy
embryos feed initially on yolk in external yolk
sac after yolk sac is absorbed, embryos feed on
unfertilized ova produced and shed by their
mother. Found in all mackerel sharks
(Lamniformes) except the Sandtiger (Carcharias
taurus).
Great White Embryo 4.9 ft long!
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Live Birth 2(Eat your little brother, now!)

• 3b. Matritrophic Viviparity with Adelphophagy -
  embryos feed initially on yolk in external yolk
  sac, then unfertilized ova produced and shed by
  their mother, then cannibalize siblings, Found in
  the Sandtiger (Carcharias taurus).

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Live Birth 3 4 (Got Milk? or a belly button?)

• 3c. Viviparity with Oophagy and Histotroph
  embryos feed initially on yolk in external
  yolksac, then unfertilised ova produced and shed
  by their mother, these ova are consumed by
  embryos to replenish the external yolk sac
  vilified embryonic surfaces indicate absorption
  of histotroph (uterine milk). Found in false
  catsharks (Pseudotriakidae).
• 3d. Matritrophic Viviparity with Placenta also
  termed viviparity or placental viviparity
  embryos feed initially on yolk in external yolk
  sac, then depleted yolk sac interdigitates with
  endometrial tissues (lining of mothers uterus)
  to form a direct placental blood vessel link to
  mother some species may also supplement
  placental nutrition with histotroph vilified
  surfaces on the embryo or placental stalk
  (appendiculae) allow absorption of histotroph
  in addition to nutrients transferred via the
  placental link. Found, with some exceptions, in
  smoothhounds (Triakidae), weasel sharks
  (Hemigaleidae), whaler sharks (Carcharhinidae),
  and hammerhead sharks (Sphyrnidae)

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How Long does it Take?
1278 days (3.5 years)

Frilled Shark(Chlamydoselache anguineus)
70 days (2.3 months)
Grey Bambooshark(Chiloscyllium griseum)
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When do sharks mature?

• Mosquitofish 1month/1.5 years
• Largemouth Bass 16months/5 years
• Great Hammerhead 10-15yrs/25-30yrs
• Spiny Dogfish 20 yrs/70 yrs
• Great White - ??/??