Did You Know?Did You Know?That the Sand Tiger Shark is not able to close its mouth, because of That the Sand Tiger Shark is not able to close its mouth, because of its long and sharp teeth.its long and sharp teeth.

- That the Great White Shark, which can be more than 6 metres - That the Great White Shark, which can be more than 6 metres long and weight more than 2 tons, only has a brain at the size of a long and weight more than 2 tons, only has a brain at the size of a thumb.thumb.

- That 30 species of sharks are known to have attacked humans.- That 30 species of sharks are known to have attacked humans.

- That the Nurse Shark sucks meat out of shells and it crushes - That the Nurse Shark sucks meat out of shells and it crushes lobsters on the ocean bed.lobsters on the ocean bed.

Monday 4/16Monday 4/16

Objective: Learn about marine fishes and Objective: Learn about marine fishes and the class chondrichthyes, and their the class chondrichthyes, and their physical characteristics.physical characteristics.

Agenda:Agenda:– Begin shark notesBegin shark notes

Marine FishesMarine FishesPhylum Chordata

Subphylum Vertebrata

CharacteristicsCharacteristicsBackboneBackboneBilateral symmetryBilateral symmetryEndoskeletonEndoskeletonFish-simplest & oldest of all living Fish-simplest & oldest of all living vertebrates (Fossils date back to 400 vertebrates (Fossils date back to 400 million years ago)million years ago)Most abundant-over 22,000 species of fish Most abundant-over 22,000 species of fish in worldin world58% are marine58% are marine

Jawless FishesJawless Fishes

class Agnathaclass AgnathaMost primitiveMost primitiveNo jaws- feed by No jaws- feed by suctionsuction

Cartilaginous Cartilaginous FishesFishes

class Chondrichthyes class Chondrichthyes (Con-dric-thees)(Con-dric-thees)Sharks, rays, skates, Sharks, rays, skates, & ratfishes& ratfishesSkeleton is made of Skeleton is made of cartilage cartilage – Lighter & more flexible Lighter & more flexible

than bonethan bone

Mouth is ventral (underneath head)Mouth is ventral (underneath head)Sandpaper like skinSandpaper like skinMay have well developed teethMay have well developed teeth– Constantly are replacedConstantly are replaced

MovementMovementFins more rigid than bony fishFins more rigid than bony fishRely on pectoral fins to “lift” them in order to Rely on pectoral fins to “lift” them in order to prevent sinking (no air bladder)prevent sinking (no air bladder)Large, oily liver that increases buoyancyLarge, oily liver that increases buoyancyStreamline body shape – moves quickly b/c Streamline body shape – moves quickly b/c of large muscles in the caudal fin.of large muscles in the caudal fin.Asymmetric caudal fin improves stabilityAsymmetric caudal fin improves stability

SharksSharks

Smallest = pygmy shark (25cm)Smallest = pygmy shark (25cm)Largest = whale shark (15 meters)! These Largest = whale shark (15 meters)! These are filter feeders.are filter feeders.Bottom dwellers = nurse & leopardBottom dwellers = nurse & leopardMost aggressive = Great WhiteMost aggressive = Great WhiteOther dangerous sharks = Tiger and Other dangerous sharks = Tiger and HammerheadHammerhead

SensorySensory

Sensitive receptors to detect stimuli: Sensitive receptors to detect stimuli: Lateral LineLateral Line organ organ– Hair-like sensors that pick up sound Hair-like sensors that pick up sound

vibrations up to ½ km awayvibrations up to ½ km away

Ampullae of LorenziniAmpullae of Lorenzini in the snout – in the snout – senses electric fields generated by the senses electric fields generated by the muscles of potential prey.muscles of potential prey.2/3 of the sharks brain is devoted to 2/3 of the sharks brain is devoted to sense and smellsense and smell

Did You Know?Did You Know?

The flying fish is capable of continuing its The flying fish is capable of continuing its flight, they have been recorded stretching flight, they have been recorded stretching out their flights with consecutive glides out their flights with consecutive glides spanning distances up to 1,312 feet (400 spanning distances up to 1,312 feet (400 meters).meters).

Tuesday 4/17Tuesday 4/17

Objective: I will learn about bony fishObjective: I will learn about bony fish

Agenda:Agenda:– Bony fish notesBony fish notes– Fish Food Group: if you have a digital copy of Fish Food Group: if you have a digital copy of

your guided notes I can print them for you, but your guided notes I can print them for you, but I need it tomorrowI need it tomorrow

Homework: NoneHomework: None

ReproductionReproductionInternal fertilizationInternal fertilizationMale sharks = Claspers that hold onto female for Male sharks = Claspers that hold onto female for transfer of sperm into reproductive tract.transfer of sperm into reproductive tract.Some (mostly aggressive) have internal development Some (mostly aggressive) have internal development and live births (viviparous) and live births (viviparous) -- -hammerheads-hammerheadsSome start predation early by devouring their siblings Some start predation early by devouring their siblings before they hatch!before they hatch!Other sharks and skates have external development – Other sharks and skates have external development – develop in a black, leathery case called a “mermaids develop in a black, leathery case called a “mermaids purse” – take over a year to develop. (oviparous)purse” – take over a year to develop. (oviparous)

Whale Shark- largest fish in existence

Bull Sharks

Very AggressiveFresh and Saltwater

Sharks must swim to force water over their Sharks must swim to force water over their gillsgills– If caught in nets they will drownIf caught in nets they will drown

Some exceptions: nurse sharks- gills can Some exceptions: nurse sharks- gills can contain enough oxygen w/o swimmingcontain enough oxygen w/o swimming

Bony FishesBony Fishesclass Osteichthyes (Osti-ich-thees)class Osteichthyes (Osti-ich-thees)Skeleton partially boneSkeleton partially boneHave an operculum-gill cover to protect Have an operculum-gill cover to protect gillsgillsCaudal fin usually same size (top & Caudal fin usually same size (top & bottom)bottom)

Bony fish have fin Bony fish have fin rays vs. cartilaginous rays vs. cartilaginous finsfins& a swim bladder& a swim bladder

Sunfish-largest Bony fish1996, Japan9.6 ft long

Biology of FishesBiology of FishesStudy of fishes: Study of fishes: IchthyologyIchthyologyBody ShapeBody ShapeDirectly related to lifestyleDirectly related to lifestyleFast swimmers=streamlined Fast swimmers=streamlined

Coral reef fish=laterally Coral reef fish=laterally compressedcompressed

Elongated bodies fit into rocks & other Elongated bodies fit into rocks & other narrow spacesnarrow spaces

Truncate, short-Truncate, short-

Laterally compressed-Laterally compressed-at beginning of life one at beginning of life one eye on each side then eye on each side then migrates to same sidemigrates to same side

Irregular shapes help with concealment-Irregular shapes help with concealment-

Countercurrent exchange Countercurrent exchange Heat

exchange: legs of birds, body heating of fish such as Tuna and

Mako shark

FinsFins

Pairs = Pectoral & PelvicPairs = Pectoral & PelvicSingle = Dorsal, Anal & Symmetric Caudal Single = Dorsal, Anal & Symmetric Caudal (have air bladder for stability)(have air bladder for stability)SkinSkin – slimy mucus coating acts as a – slimy mucus coating acts as a barrier against infection and frictionbarrier against infection and friction

Pelvic Fin Anal Fin

1st Dorsal Fin

2nd Dorsal Fin

Pectoral Fin

Caudal Fin

S.T.A.RS.T.A.R

1. What type of skeleton do cartilaginous fish 1. What type of skeleton do cartilaginous fish have?have?2. What type of symmetry do marine fishes 2. What type of symmetry do marine fishes have?have?3. What type of reproduction do sharks have?3. What type of reproduction do sharks have?4. What adaptation do male sharks and rays 4. What adaptation do male sharks and rays have to aid in reproduction?have to aid in reproduction?5. Answer questions 1-4 on page. 5-665. Answer questions 1-4 on page. 5-66