CHONDRICHTHYES

COMPARING FISH TO FISH  OSTEICHTHYES  CHONDRICHTHYES  BONY  SINGLE GILL OPENING  SINGLE ROW OF TEETH  SCALES  SWIM BLADDER  NO BONES  5-7 GILL OPENINGS  MANY ROWS OF TEETH  DERMAL DENTICLES  LIVER OIL

SHARK ANATOMY

CRANIAL AREA

Cranial area  Rostrum-pointed snout of at the end of head  Ampullae of Lorenzini

ELECTRORECEPTION  All living things (even you) produce an electric field, given off by each heartbeat and muscle movement. Special receptors located around the head that detect electric fields. Special receptors located around the head that detect electric fields. Help find a fish hidden under the sand by detecting its heartbeat. Help find a fish hidden under the sand by detecting its heartbeat. Also uses this sense to position its head and mouth when moving in for the final attack. Also uses this sense to position its head and mouth when moving in for the final attack. This is the only sense a shark has that you don't share. This is the only sense a shark has that you don't share.

Cranial area  Rostrum-pointed snout of at the end of head  Ampullae of Lorenzini  External nares-nostrils.

SENSE OF SMELL Nostril for smelling only! Nostril for smelling only! Particles in the water trigger signals that are sent to the brain. Induces exploratory behavior. Particles in the water trigger signals that are sent to the brain. Induces exploratory behavior. Detect the scent of prey that are up to several hundred yards away, depending on the speed and direction of the water current. Detect the scent of prey that are up to several hundred yards away, depending on the speed and direction of the water current. Some sharks can smell as few as 10 drops of liquid tuna in the volume of water it takes to fill an average swimming pool! Some sharks can smell as few as 10 drops of liquid tuna in the volume of water it takes to fill an average swimming pool!

Cranial area  Rostrum-pointed snout of at the end of head  Ampullae of Lorenzini  External nares-nostrils.  Mouth

MOUTH  Teeth Many rows of teeth Many rows of teeth Tooth shape varies from shark to shark-indication of diet Tooth shape varies from shark to shark-indication of diet  Taste Many choose what they eat depending on how it tastes. Many choose what they eat depending on how it tastes. A shark's mouth is lined with taste buds. A shark's mouth is lined with taste buds. Some sharks will eat anything; others will reject food because they don't like the taste (which may include the taste of humans). Some sharks will eat anything; others will reject food because they don't like the taste (which may include the taste of humans). For a shark to use its taste sense, food needs to be close enough for it to take a bite. For a shark to use its taste sense, food needs to be close enough for it to take a bite.

Cranial area  Rostrum-pointed snout of at the end of head  Ampullae of Lorenzini  External nares-nostrils.  Mouth  Eyes

VISION Excellent! ten times more sensitive to light than your eyes. Tapetum lucedum Excellent! ten times more sensitive to light than your eyes. Tapetum lucedum Can see colors, may prefer bright or shiny objects. (Keep this in mind the next time you shop for a swimsuit!) Can see colors, may prefer bright or shiny objects. (Keep this in mind the next time you shop for a swimsuit!) Most see their prey when it's about away. Most see their prey when it's about 70 to 100 feet away.70 to 100 feet To protect their eyes from a thrashing victim, some sharks (such as tiger sharks) cover their eyes with a lid, while others (such as white sharks) simply roll their eyes back into the sockets To protect their eyes from a thrashing victim, some sharks (such as tiger sharks) cover their eyes with a lid, while others (such as white sharks) simply roll their eyes back into the sockets

Cranial area  Rostrum-pointed snout of at the end of head  Ampullae of Lorenzini  External nares-nostrils.  Mouth  Eyes  Spiracle-may or may not present  Gill slits-5 vertical slits that allow water to exit after passing over the gills  Ears

HEARING a shark can hear sounds up to 0.6 miles away -- about the length of ten football fields. a shark can hear sounds up to 0.6 miles away -- about the length of ten football fields.0.6 miles0.6 miles Sharks are particularly sensitive to the irregular, low- frequency sounds made by a sick or wounded fish, and prey in this state is an easy target. Sharks are particularly sensitive to the irregular, low- frequency sounds made by a sick or wounded fish, and prey in this state is an easy target.

MEDIAL AREA

Medial area  Pectoral fin-paired  Doral fin-unpaired  Dorsal spine-may or may not be present  Lateral line-runs length of body

LATERAL LINE Detects water movement made by fish or other swimming prey. Picks up the vibrations in the water. This narrow strip of fluid-filled sensory cells runs along the sides of the body and into the head. Picks up the vibrations in the water. This narrow strip of fluid-filled sensory cells runs along the sides of the body and into the head. Use to detect the erratic motions of sick or wounded prey (easy-to-catch meals) when they are about three to 10 feet away. Use to detect the erratic motions of sick or wounded prey (easy-to-catch meals) when they are about three to 10 feet away.three to 10 feetthree to 10 feet Also aids in maintaining balance Also aids in maintaining balance

Medial area  Pectoral fin-paired  Doral fin-unpaired  Dorsal spine-may or may not be present  Lateral line-runs length of body  Pelvic fin-paired  Claspers-may or may not be present

REPRODUCTION  INTERNAL FERTILIZATION  CLASPERS FOUND ON MALES  COURTSHIP IS OFTEN ROUGH  VERY LITTLE HAS BEEN OBSERVED

3 WAYS OF DEVELOPMENT  OVIPAROUS EGG LAYING EGG LAYING CASING IS HARD LEATHER=AKA MERMAID’S PURSE CASING IS HARD LEATHER=AKA MERMAID’S PURSE TENDRILS-HELP ATTACH TO ROCKS, PLANTS, AND OTHER SUBSTRATES TENDRILS-HELP ATTACH TO ROCKS, PLANTS, AND OTHER SUBSTRATES EMBYRO FEEDS OFF OF A YOLK EMBYRO FEEDS OFF OF A YOLK

3 WAYS OF DEVELOPMENT  VIVIPAROUS LIVE BIRTH LIVE BIRTH NOURISHED THROUGH PLACENTAL ATTACHMENT (MODIFIED YOLK SAC) NOURISHED THROUGH PLACENTAL ATTACHMENT (MODIFIED YOLK SAC) HAVE UMBILICAL CORD HAVE UMBILICAL CORD

3 WAYS OF DEVELOPMENT  OVOVIVIPAROUS HATCH FROM EGGS HATCH FROM EGGS REMAIN NOURISHED FROM OWN YOLK SAC REMAIN NOURISHED FROM OWN YOLK SAC NOT ATTACHED TO FEMALE NOT ATTACHED TO FEMALE EXAMPLE: GREAT WHITE SHARK EXAMPLE: GREAT WHITE SHARK  OVIPHAGUS CANNIBALISM OF UNHATCHED EGGS AND SMALLER/WEAKER SIBLINGS CANNIBALISM OF UNHATCHED EGGS AND SMALLER/WEAKER SIBLINGS EXAMPLE: SAND TIGER SHARK EXAMPLE: SAND TIGER SHARK

CAUDAL AREA

Caudal area  2 nd dorsal fin-may or may not be present  Anal fin-may or may not be present  Caudal fin-heterocercal.

Heterocercal tails

DORSAL SIDE

DERMAL DENTICLES  TOOTH-LIKE STRUCTURES  SHED AS SHARK GROWS REPLACED BY LARGER DENTICLES  LAYERS CREATE A ROUGH SURFACE- COMPARED TO SANDPAPER  SHAGREEN= UNTANNED SHARK SKIN USED TO SAND AND POLISH FURNITURE

RAYS/SKATES  Locate the following: Dorsal fin Dorsal fin Pectoral fin Pectoral fin Spiracle Spiracle Pelvic fin Pelvic fin Bucklers (thorny scales) Bucklers (thorny scales) Mouth Mouth Gill slits Gill slits

VENTRAL SIDE

INTERNAL ANATOMY  Stomach-”J” shaped organ  Liver- 3 lobes (2 large and 1 small) Gall bladder located within smaller lobe Gall bladder located within smaller lobe Stores bile Stores bile  Spiral Intestine has extensive arteries and veins over surface has extensive arteries and veins over surface  Heart  Reproductive system