Class Chondrichthyes

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Class Chondrichthyes
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Classification

• Kingdom Animalia
• Phylum Vertebrata
• Class Chondrichthyes
• Subclass Holocephali
• Subclass Elasmobranchi

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Kingdom Animalia

• Heterotrophs
• multicellular
• eukaryotic

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Class Chondrichthyes

• Have appeared in the fossil record for over 450
  million years
• All have
• Jaws
• paired fins
• cartilage skeleton (except teeth and some
  vertebrae)
• All aquatic

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Subclass Elasmobranchi

• External gill slits
• Examples
• Sharks
• Skates
• Rays

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Subclass Holocephali

• All have an operculum gill covers
• Examples
• Chimera
• Ratfish

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Classification

• Kingdom Animalia
• Heterotrophs, multicellular, eukaryotic
• Phylum Vertebrata
• Have spinal chord and vertebrae
• Class Chondrichthyes
• Jaws, paired fins, cartilage skeleton (except
  teeth)
• Subclass Holocephali Chimeras
• Operculum gill covers
• Subclass Elasmobranchi Sharks, Skates, Rays
• External gill slits

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• They have a disproportionately huge head
  (Holocephali means 'whole head') pocked with
  large, well-developed eyes.
• They have an odd, rabbit-like mouth filled with
  plate-like grinding teeth.
• The tail is tiny and often streamer-like, so for
  propulsion chimaeras rely instead on flapping
  their large, wing-like pectoral fins.
• Chimaeras in 'flight' resemble a kind of weird
  cross between a fish and an angel.

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Class Agnatha

• Jawless fish
• Cartilage skeletons
• No scales

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Hagfish

• Can tie themselves in knots
• Used to escape predators, remove excess slime, or
  gain leverage to feed
• Also called slime eels
• Eat prey by entering
• either mouth or anus and
• eating the animal inside out
• Uses slime to escape
• predators by gumming
• up their gills

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Lampreys

• Attaches to prey using the suction-cup like mouth
  called an oral disk
• Uses tongue with toothlike plates to rasp hole in
  prey
• Sucks fluids and
• tissue out hole

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Class OsteichthyesBony fish

• Swim bladder
• Bone
• Bony scales
• Fin rays
• 95 of all fish
• Homocercal tail
• Backbone ends
• where tail begins

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Cartilaginous Bony

• No swim bladder
• Cartilage
• 5-7 gill slits no covering
• Non-overlapping denticles
• Fins have no rays
• gt5 of all fish
• Heterocercal tail
• Backbone continues to end of tail

• Swim bladder
• Bone
• Operculum covers gills
• Overlapping bony scales
• Fin rays
• 95 of all fish
• Homocercal tail
• Backbone ends
• where tail begins

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Class Chondrichtyes Elasmobranches

• Sharks
• Streamlined bodies
• Gill slits behind head
• water enters mouth and exits gill slits
• Skates and Rays
• Flattened bodies
• Gill slits under body
• Water enters spiricle near eye and exits slit

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Skates

• Swim by creating wave on forward edge of the fin
  and sweeps down edge to back of fin
• Allows fish to glide along bottom
• Tails have small fins, no spines, fleshier than
  rays
• Smaller than rays
• Oviparous (lay eggs) in
• case called Mermaids Purse

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Guitarfish

• Have shark-like body with ray-like pectoral fins
• Gills on underside of body
• Eat crabs and other bottom dwelling org.

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Rays

• Swim by moving fins up and down like bird wings
• Tails streamlined and have poisonous spines
• Some species grow to 7 meters
• Ovoviviparous (give birth to live young)

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Electric Rays

• The fish are stunned with an electrical charge
  which is concentrated as the ray wraps its disc
  around the prey. This electric organ discharge
  (EOD) can measure up to 50 volts in a large
  animal, and with low internal organ resistance
  can produce a power output of 1 kilowatts.
• Second strongest shock to Electric Eel

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Sawfish

• Belong to ray family because gill slits are
  located under the body
• At night, they scull slowly through the shallows,
  using their sensitive saw to find buried prey,
  which are then raked from the sediment to be
  consumed. It is useful to view the sawfishes'
  unique rostrum like a metal detector combined
  with a clam rake.

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Manta Ray

• Adults are easily recognized by their large
  triangular pectoral fins and projecting cephalic
  fins, forward extensions of the pectoral fins
  that project anteriorly on either side of the
  head.
• Each cephalic fin is about twice as long as its
  base is wide. The length of each cephalic lobe,
  from tip to the mouth, is 14 of the disc width.
  They are rolled like spirals when swimming and
  flattened when eating.
• This ray has smooth skin, a broad, rectangular
  terminal mouth located at the front of the head,
  and a tail that lacks a spine.

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Manta Ray

• Distribution
• Size
• 22 ft. long
• 3500 lbs
• Swim near surface
• Give birth to 1 baby
• (5 ft, 20 lbs)

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Stingrays

• Shallow water bottom dwellers
• Well camouflaged
• Distribution

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Stingray

• Distinctive Features
• round body.
• well developed caudal fin that extends around the
  tip of its tail.
• tail spine is located just anterior to the caudal
  fin.
• stingray lacks a dorsal fin.

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Types of Stingrays

• Butterfly Rays
• Short tail and underdeveloped stinger
• Spotted Eagle Rays
• Bird-like extension of head and body
• Well developed stinger
• Round Rays
• Short tail with well developed stinger
• Responsible for most US human injuries on west
  coast
• Whip Rays
• Long whip-like tail with 1 or more barbed spines

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Shark StructureDorsal View
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Ventral View
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Whale Shark

• Largest Living Fish
• Plankton Feeder
• Identifying Char.
• Great Size 60 ft
• Pattern of yellowish spots and stripes
• 1000s of tiny teeth
• Mouth at front of head

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• Distribution
• Habitat In contrast to most sharks from the same
  order (Orectolobiformes), which are benthic (live
  on or near the bottom) species, the whale shark
  is a pelagic (open sea) species. Studies reveal
  that this shark prefers warm waters, with surface
  temperature around 21-30º C, marked by high
  primary productivity (much plankton). It is often
  seen offshore but commonly comes close inshore,
  sometimes entering lagoons or coral atolls

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Basking Shark

• 2nd largest living fish
• 500 gal. of oil in 1 liver
• Commercial fishermen
• Get 40 females/1male
• Identifying Char.
• Great size 40 ft
• Gill slits longer than most
• Body entirely gray
• Has mouth under snout

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• Distribution
• Habitat
• The basking shark is typically seen swimming
  slowly at the surface, mouth agape in open water
  near shore. This species is known to enter bays
  and estuaries as well as venturing offshore

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Nurse Shark

• At some point after fertilization (no one is sure
  when), as many as 12 eggs hatch in each of the
  two horns of the uterus. Then, from day one, it's
  a fight for survival. The bigger, stronger
  embryos cannibalize their brothers and sisters
  until there are only two left. This process takes
  about a year, and it takes another year for the
  mother to recover sufficiently to go through it
  all again.