characteristics of fishes

3. Body of a fish:Body of a fish:
• Body is divided into three regions as:Body is divided into three regions as:
- Head- Head
- Trunk- Trunk
- Tail- Tail
• Fishes do not have neck.Fishes do not have neck.

4. Characteristics of fishes:Characteristics of fishes:
• Unlike mammals, fish areUnlike mammals, fish are cold-bloodedcold-blooded. .. .
ExceptExcept TunaTuna andand pacific salmonpacific salmon..
• True fish have a backbone and fins.True fish have a backbone and fins.
• Most breathe with gills.Most breathe with gills.
• Have scales that cover their bodies.Have scales that cover their bodies.
• Lateral line ,have swim bladder.Lateral line ,have swim bladder.
• Streamline body.Streamline body.
History:History:
It is currently believed that fish began to evolveIt is currently believed that fish began to evolve
about 480 million years ago. There are 22,000about 480 million years ago. There are 22,000
known species of fishes.known species of fishes.

5. Types of fishes:Types of fishes:
jawlessjawless lampreylamprey
hagfishhagfish
sharkssharks
fishes cartilaginousfishes cartilaginous
raysrays
lungfishlungfish
lobe finned coelacanthlobe finned coelacanth
bonybony chondrosteanchondrostean
ray finned holosteanray finned holostean
teleostteleost

6. Size of fishesSize of fishes
• World smallest fish:World smallest fish:
Paedocypris progenticaPaedocypris progentica
female (female (7.9mm7.9mm))
• Large fishes:Large fishes:
Marine:Marine:
whale shark (whale shark (17m17m && 37tones)37tones)
Fresh water:Fresh water:
mekong giant fish (mekong giant fish (2.7m , 293kg2.7m , 293kg))

7. Fins of fishes:Fins of fishes:
A fish's A fish's finsfins are used for: are used for:
• balance.balance.
• propel and steer through the water.propel and steer through the water.
types of fins:types of fins:
• Pectoral finsPectoral fins
• Pelvic fins/ ventral finsPelvic fins/ ventral fins
• Dorsal finsDorsal fins
• Anal finsAnal fins
• Adipose finsAdipose fins
• Caudal fins/ tail finsCaudal fins/ tail fins
• caudal keelcaudal keel
• FinletsFinlets

8. 1:Pectoral fins1:Pectoral fins
• The paired The paired pectoral finspectoral fins are located on each are located on each
side, usually just behind the operculum.side, usually just behind the operculum.
• FunctionsFunctions::
Dynamic lifting in sharks.Dynamic lifting in sharks.
Flight in flying fish.Flight in flying fish.
Walking in mudskipper.Walking in mudskipper.
• Modifications:Modifications:
Cephalic fins: horns of manta rays.Cephalic fins: horns of manta rays.
Finger like projections,Finger like projections,
in sea robins & flyingin sea robins & flying
gurnards.gurnards.

9. 2:Pelvic fins/ ventral fins2:Pelvic fins/ ventral fins
The paired The paired pelvicpelvic or or ventral finsventral fins are typically are typically
located ventrally below and behind the pectorallocated ventrally below and behind the pectoral
fins.fins.
• Functions:Functions:
assists the fish in going up or down.assists the fish in going up or down.
turning sharply.turning sharply.
stopping quickly.stopping quickly.
• Modifications:Modifications:
Single sucker disk. (Single sucker disk. (Gobies)Gobies)
• w.r.t position:w.r.t position:
Abdominal (minnows)Abdominal (minnows)
Thoracic (sunfish)Thoracic (sunfish)
Jugular (burbot)Jugular (burbot)

10. 3:Dorsal fins3:Dorsal fins
Dorsal fins are located on the back. A fish canDorsal fins are located on the back. A fish can
have up to three dorsal fins. have up to three dorsal fins.
• Functions:Functions:
protect the fish against rolling.protect the fish against rolling.
assist it in sudden turns andassist it in sudden turns and
stops.stops.
• Modifications:Modifications:
Illicium/ esca (anglerfish)Illicium/ esca (anglerfish)
The bones that support the dorsal fins areThe bones that support the dorsal fins are
called called Pterygiophore.Pterygiophore.

11. Modification of Dorsal fin inModification of Dorsal fin in
angler fishangler fish

12. 4:Anal fins4:Anal fins
The The anal finanal fin is located on the ventral is located on the ventral
surface behind the anus.surface behind the anus.
• Functions:Functions:
to stabilize the fishto stabilize the fish
while swimming.while swimming.

13. 5:Adipose fins5:Adipose fins
The The adipose finadipose fin is a is a
soft fin found on the backsoft fin found on the back
behind the dorsal fin andbehind the dorsal fin and
just forward of the caudal fin.just forward of the caudal fin.
(Salmonidae and catfishes)(Salmonidae and catfishes)
• Functions:Functions:
Sensory ( Canadian research)Sensory ( Canadian research)
Detect and response to stimuli.Detect and response to stimuli.
(touch, sound, change in pressure)(touch, sound, change in pressure)

14. 6:Caudal fin (tail fin)6:Caudal fin (tail fin)
(Latin (Latin caudacauda =tail)located at the =tail)located at the
end of the caudal peduncleend of the caudal peduncle
• Function:Function:
PropulsionPropulsion
DefensiveDefensive
• Types:Types:
- - Heterocercal:Heterocercal: vertebrae extend into the upper lobe of thevertebrae extend into the upper lobe of the
tail, making it longer (sharks).*tail, making it longer (sharks).*
- - Protocercal:Protocercal: vertebrae extend to the tip of the tail and thevertebrae extend to the tip of the tail and the
tail is symmetrical but not expanded (amphioxus)tail is symmetrical but not expanded (amphioxus)
- - Homocercal:Homocercal: fin appears superficially symmetric butfin appears superficially symmetric but
vertebrae extend for a very short distance into the upper lobevertebrae extend for a very short distance into the upper lobe
of the fin.of the fin.
- - Diphycercal:Diphycercal: vertebrae extend to the tip of the tail and thevertebrae extend to the tip of the tail and the
tail is symmetrical and expanded (bichir, lungfish)tail is symmetrical and expanded (bichir, lungfish)

15. • homocercalhomocercal • hetrocercalhetrocercal
• diphylcercaldiphylcercal • protocercalprotocercal

16. 7: Caudal keel*7: Caudal keel*
Some types of fast-swimmingSome types of fast-swimming
fish have afish have a
horizontal horizontal caudal keelcaudal keel just just
forward of the tail fin.forward of the tail fin.
• Functions:Functions:
provides stabilityprovides stability
and support toand support to
the caudal fin.the caudal fin.

17. 8: finlets8: finlets
FinletsFinlets are small fins, generally behind are small fins, generally behind
the dorsal and anal fins (in bichirs, therethe dorsal and anal fins (in bichirs, there
are only finlets on the dorsal surface andare only finlets on the dorsal surface and
no dorsal fin)no dorsal fin)
• Function:Function:
Drag reduction.Drag reduction.

18. Mouth shapes of fishes:Mouth shapes of fishes:
Mouth shape depends on the feeding habit of a fish:Mouth shape depends on the feeding habit of a fish:
• terminal:terminal: if a fish eats otherif a fish eats other
fish.fish.
• superior:superior: if fish is a hiddenif fish is a hidden
predator.predator.
• Inferior:Inferior: if fish is a bottomif fish is a bottom
feeder.feeder.

19. Terminal: Superior:Terminal: Superior:
Inferior:Inferior: Protrusible:Protrusible:

20. Sucker:Sucker: mouth is a property ofmouth is a property of
inferior mouth fishes.inferior mouth fishes.
Elongated:Elongated:
Beak like:Beak like:
Protrusible:Protrusible:

21. Scales in fishes:Scales in fishes:
small rigid plate like structuresmall rigid plate like structure
grows out of animal skin.grows out of animal skin.
These overlap in rows.These overlap in rows.
• FunctionsFunctions
help protect the fish against injuries andhelp protect the fish against injuries and
infections. (mucus covering)*infections. (mucus covering)*
reduce friction, allowing the fish to move easilyreduce friction, allowing the fish to move easily
through the water.through the water.
• Fishes vs reptilesFishes vs reptiles
Scales of fishes are derived from mesoderm,Scales of fishes are derived from mesoderm,
while in reptiles they evolve from epidermiswhile in reptiles they evolve from epidermis

22. • Types of fishes on the basis of scales:Types of fishes on the basis of scales:
Scale present (cyprinid).Scale present (cyprinid).
Scales absent ( silurids).Scales absent ( silurids).
• Uses of scales :Uses of scales :
 use in making glue.use in making glue.
 For making jewelry.For making jewelry.
 Making artificial bones due to theirMaking artificial bones due to their
hardness.hardness.

23. Types of scales:Types of scales:
• Placoid scales ( sharks, rays)Placoid scales ( sharks, rays)
• Leptoid scalesLeptoid scales
cycloid (salmon, carp)cycloid (salmon, carp)
ctenoid (perch like fishes)*ctenoid (perch like fishes)*
• Ganoid scales (sturgeon)Ganoid scales (sturgeon)
• Cosmoid scales (earlier lung fish)Cosmoid scales (earlier lung fish)
• Thelodond scalesThelodond scales
( fossil fishes)( fossil fishes)

24. Shapes of fishesShapes of fishes

28. Gills of fishes:Gills of fishes:
In order to breathe underwater, fishIn order to breathe underwater, fish
have developed special organs calledhave developed special organs called
gillsgills..
• found on the side of thefound on the side of the
fish just behind the head, contain lotsfish just behind the head, contain lots
of capillaries. Water is constantly pumped over the gills.of capillaries. Water is constantly pumped over the gills.
• A gill cover, called theA gill cover, called the operculum,operculum, is a flexible bony plateis a flexible bony plate
that helps protect the sensitive gills.that helps protect the sensitive gills.
• Functions:Functions:
excretion of waste products, particularly ammonia, from theexcretion of waste products, particularly ammonia, from the
fish's bloodstream.fish's bloodstream.
filter the oxygen out of the water and directly into the fish'sfilter the oxygen out of the water and directly into the fish's
blood.blood.

29. Swim bladder:Swim bladder:
• Fish have a unique internal organFish have a unique internal organ
known as the known as the swim bladderswim bladder or or
air bladderair bladder. It is usually found in. It is usually found in
the abdomen having flexible wallsthe abdomen having flexible walls
impermeable to gases.impermeable to gases.
Functions:Functions:
• Buoyancy creation.Buoyancy creation.
• In some fish, the swim bladder is also used to produceIn some fish, the swim bladder is also used to produce
sounds due to sonic muscles.(sounds due to sonic muscles.(common carp, catfishcommon carp, catfish))
• Sonar activity.Sonar activity.
information:information:
Elasmobranches* do not have a swim bladder.Elasmobranches* do not have a swim bladder.

30. Mechanism:Mechanism:
• Gas gland secrete lactic acid,Gas gland secrete lactic acid,
produces CO2produces CO2..
• In result heamoglobinIn result heamoglobin
release Orelease O22 which fills swimwhich fills swim
bladder, creating buoyancy.bladder, creating buoyancy.
• Reverse process occurs toReverse process occurs to
release buoyancy.release buoyancy.

31. Lateral line:Lateral line:
organ of senses unique to fishorgan of senses unique to fish
is called the is called the lateral linelateral line,,
located along the side of thelocated along the side of the
fish, consisting offish, consisting of
electroreceptor (ampullae) &electroreceptor (ampullae) &
mechanoreceptor (neuromast)mechanoreceptor (neuromast)
FunctionsFunctions
• It contains small sensory hairs that help detectIt contains small sensory hairs that help detect
underwater vibrations and determine theirunderwater vibrations and determine their
source.source.
• enabling fish to navigate even in low light orenabling fish to navigate even in low light or
murky water.murky water.
• Detect gravity, equilibrium, audition.Detect gravity, equilibrium, audition.

32. Presented by:Presented by:
• RabiaRabia
• Aqsa yosufAqsa yosuf
• Arifa AsadArifa Asad
• Fozia shaheenFozia shaheen
• Mubashra akramMubashra akram