An Overview on Shark and rays

1. A PRESENTATION ON
SHARK AND RAYS
PRESENTED BY-
Md. Nazmul Islam
1

2. Shark and Rays: The special types of fish which are cartilaginous that means their
skeleton are made of cartilage.
Common Features:
No swim bladder.
Rigid dorsal fin.
Small placoid scales.
Teeth's are in several series.
Five to Seven pairs of gill slits.
2

3. Differences Between-
Shark Ray
1.Most sharks have
streamlined body.
1. flattened, disk like body.
2.The tail of shark is small. 2.The tail of rays is
generally long.
3.Swim by creating a
wave and starts at head
then ripples down rest of
body.
3.Swim by moving fins up
and down.
4.Oviparous. 4.Ovoviviparous.
5.Example:Hammerhead
shark.
5.Manta rays.
3

4. Distribution: Tropical and temperate seas,
as well as some cold
and polar seas and freshwater lakes.
Habitat: shark-Usually found in pelagic surface.
Rays-Usually found in demersal areas.
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5. Diet: Shark-They can eat fish,crustaceans,mollusks,
plankton, marine mammals, krill and other sharks.
Rays- They can eat bundles of sea worms ,
shrimp and clam, eat soft shelled animals.
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6. Reproduction: Claspers are modified inner edges
of the pelvic fins of male shark and rays.
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7. Regulating the quality and health of other
species of fish
and invertebrates that helps to keep the
ecosystem balance.
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Economically:Fishing,tourism,Herbal
medicine ,food.
Importance:
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8. By –catch.
Habitat destruction.
Climate Change.
Marine debris.
Unregulated tourism.
Threats:
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9. Improved management is needed to avoid
extinction and promote population recovery.
Overall chondrichthyan extinction risk is
substantially higher than
for most other vertebrates.
One –quarter are threatened according to
IUCN Red list criteria due to Overfishing
Conservation Status:
9

10. https://www.wiseoceans.com/seasense/sharks-rays
https://www.wcs.org/our-work/wildlife/sharks-skates-rays
https://en.wikipedia.org/wiki/Chondrichthyes
References:
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