Fish Taxonomy & Charateristics
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata (Back bone present)
Supraclass Agnatha (Jawless Fish)
Class Myxini (Hagfish)
Class Cphalospidomorphi (Lamprey)
Supraclass Gnathostomata (Jawed Fish)
Class Chondrichthyes (Cartilaginous Fish)
Class Osteichthyes (Bony Fish)
2. CLASSIFICATION
• KINGDOM ANIMALIA
• PHYLUM CHORDATA
• SUBPHYLUM VERTEBRATA (BACK BONE
PRESENT)
• SUPRACLASS AGNATHA (JAWLESS FISH)
• CLASS MYXINI (HAGFISH)
• CLASS CPHALOSPIDOMORPHI (LAMPREY)
• SUPRACLASS GNATHOSTOMATA (JAWED FISH)
• CLASS CHONDRICHTHYES (CARTILAGINOUS
FISH)
• CLASS OSTEICHTHYES (BONY FISH)
3. PHYLUM CHORDATA
FIVE CHARACTERISTICS OF CHORDATES
• 1. HOLLOW NERVE CORD- IN VERTEBRATES IT
DIFFERENTIATES INTO BRAIN AND SPINAL CORD
• 2. NOTOCHORD- FLEXIBLE ROD PRESENT AT ONE STAGE IN ALL
CHORDATES; IN VERTEBRATES IT DIFFERENTIATES INTO
VERTEBRAL COLUMN THAT FORMS AROUND THE NERVE CORD
• 3. PHARYNGEAL SLITS - POUCHES THAT CONNECT PHARYNX
WITH OUTSIDE (BETWEEN MOUTH AND ESOPHAGUS). GILLS IN
SHARKS, FISH; PRESENT IN TERRESTRIAL ANIMAL EMBRYOS
BUT DISAPPEAR LATER EXCEPT EUSTACHIAN TUBE
(CONNECTING THROAT AND MIDDLE EAR)
• 4. POSTANAL TAIL- EXTENDS BEYOND ANUS; PRESENT AT
LEAST IN EMBRYO; REGRESSES INTO TAIL BONE IN HUMANS
• 5. SEGMENTATION- REFLECTED IN ARRANGEMENT OF
MUSCLES & IN VERTEBRAL COLUMN
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4. SUPRACLASS AGNATHA
(JAWLESS FISH)
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Class Cephalspidomorphi (Lamprey)
• Parasite
• attaches to other fish & sucks their blood
• lives in ocean
Class Myxini (Hagfish)
• Scavenger
• lives in the ocean
• known for its slimy secretions
Both have cartilaginous skeletons
and sucker-like mouths
7. CLASS CHONDRICHTHYES
(SHARKS & RAYS)
• HAVE SKELETONS MADE OF CARTILAGE NOT BONES (HAVE
BONE JAW).
• MOST SALTWATER/ VERY FEW FRESHWATER
• HAVE NO OPERCULUM (GILL COVER)
• SOME MUST KEEP MOVING TO BREATHE & OTHERS CAN PUMP
WATER OVER THEIR GILLS
• SPIRACLE- A MODIFIED SLIT BEHIND THE EYE, ASSISTS THE
SHARK WITH TAKING IN WATER DURING RESPIRATION AND
PLAYS A MAJOR ROLE IN BOTTOM DWELLING SHARKS.
• HAVE DIFFERENT KINDS OF SCALES THAT FEEL AND LOOK
MORE LIKE SANDPAPER.
• MULTIPLE ROWS OF REPLACEMENT TEETH THAT STEADILY
MOVE FORWARD LIKE A CONVEYOR BELT. SHARKS CAN LOSE
UP TO 30,000 OR TEETH IN THEIR LIFETIME.
• MOST SHARKS ARE COLD BLOODED
• CONTROL BUOYANCY WITH LARGE LIVERS THAT EXCRETE OIL
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8. CLASS CHONDRICHTHYES
(SHARKS & RAYS)
REPRODUCTION
• VIPAROUS- LIVE BIRTH
• VIVIPAROUS- EGGS HATCH INTERNALLY
• OVOVIVIPAROUS- LAY EGG CASES EXTERNALLY
(CALLED MERMAID’S PURSE)
• SEPARATE SEXES
• MALES HAVE CLASPERS
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9. CLASS CHONDRICHTHYES
(SHARKS & RAYS)
SENSORY
• AMPULLAE OF LORENZINI- ELECTRORECEPTOR
ORGANS USED TO DETECT THE
ELECTROMAGNETIC FIELDS ALL LIVING THINGS
PRODUCE. THEY NUMBER IN THE HUNDREDS TO
THOUSANDS.
• LATERAL LINE SYSTEM- DETECTS MOTION OR
VIBRATIONS IN WATER
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20. CLASS OSTEICHTHYES
(BONY FISH)
• BACKBONE MADE OF BONE
• FRESHWATER & SALTWATER
• GILLS WITH OPERCULUM (FEW HAVE LUNGS)
• FINS - DORSAL, CAUDAL, PECTORAL, PELVIC,
ANAL.
• SWIM BLADDER- A GAS FILLED SAC THAT HELPS
THE FISH MAINTAIN BUOYANCY. SHARKS DON’T
HAVE A SWIM BLADDER
• LATERAL LINE SYSTEM
21. TYPES OF OSTEICHTHYES
RAY FINNED:
– MOST FISH ARE THIS TYPE
– FINS ARE SUPPORTED BY BONY
STRUCTURES CALLED RAYS.
LOBE FINNED:
– FINS ARE LONG, FLESHY,
MUSCULAR, SUPPORTED BY
CENTRAL CORE OF BONES.
– THOUGHT TO BE ANCESTORS OF
AMPHIBIANS.
– EXAMPLES ARE: COELACANTH,
LUNGFISH
25. RESPIRATION
• WATER FLOWS OVER GILLS
AS FISH OPENS MOUTH AND
SWIMS.
• WATER FLOWS OPPOSITE
DIRECTION OF BLOOD FLOW.
• O2 DIFFUSES FROM THE
WATER INTO THE BLOOD.
• GILLS ARE MADE OF
THOUSANDS OF GILL
FILAMENTS.
• GILLS ARE COVERED BY THE
OPERCULUM.
26.
27. CIRCULATION
• FISH HEART HAS 2 CHAMBERS
• SINGLE LOOP CIRCULATION
• BLOOD FLOWS INTO GILLS, PICKS UP O2, GOES TO THE
BODY, RETURNS TO THE HEART.
28. REPRODUCTION
• MOST FISH REPRODUCE SEXUALLY, AND
FERTILIZE THEIR EGGS EXTERNALLY
• SPAWNING IS THE PROCESS OF
FERTILIZING EGGS.
• BABY FISH ARE CALLED FRY.
