FISH DISSECTIONFISH DISSECTIONFISH DISSECTIONFISH DISSECTION

12

3

45

1 - ANTERIOR DORSAL FIN

2 - POSTERIOR DORSAL FIN

3 - CAUDAL FIN

4 - PELVIC FIN

5 - ANAL FIN

FISH

DISSECTION

1 - GILLS

2 - HEART

3 - LIVER

4 - PYLORIC CAECA

5 - SMALL

INTESTINE

6 - STOMACH

7 - SWIM BLADDER

ANTERIOR PORTION

1 - SWIM BLADDER

2 - GONAD

3 - LARGE

INTESTINE

4 – URINARY

BLADDER

5 - ANUS

POSTERIOR PORTION

ANTERIOR DORSAL FIN

(Balance, some protection)

How fast is your fish?

Dorsal fin may

show you.....

POSTERIOR DORSAL FIN

(Balance)

CAUDAL FIN

(Locomotion, Power)

Forked = fast

Paddle = slow

PECTORAL FIN

(Steering, brakes)

PELVIC FIN(balance, locomotion)

ANAL FIN

(Balance)

EYE (No Lids?)

Open wide!

Look at & feel teeth

What is the fish’s feeding

strategy?

LATERAL LINE (sensation, schooling)

Where does the fish live

in the water column?

•Look at its coloring

•Countershading?

ANUS

UROGENITAL OPENING

OPERCULUM (bony structure protects gills)

Fish open

mouth to take

in water & pass

over gills

GILL ARCHGILL ARCH

(Bony structure holds gill filaments & rakertogether)

GILL FILAMENTS(4 gill rakers on each side = 8 rows of gill filaments)

Filaments – draw O2

Rakers – clean H2O

GILL FILAMENTS(4 gill rakers on each side = 8 rows of gill filaments)

Filaments – draw O2

Rakers – clean H2O

SWIM BLADDERSWIM BLADDERSWIM BLADDER

Aids in vertical

movement & floating

STOMACH – Digestion (breakdown food)

•What’s inside?

•Was your feeding strategy hypothesis correct?

STOMACH – Digestion (breakdown food)

•What’s inside?

•Was your feeding strategy hypothesis correct?

INTESTINE – Nutrient Absorption

SPLEEN

(Destroys worn out blood cells)

SPLEEN

(Destroys worn out blood cells)

LIVER (Detoxification)

GONAD (one on each side)

•Ovary – yellow (lots of blood vessels)

•Testis – white

HEART

(2 Chambered)

BRAINBRAIN

CEREBRUMCEREBRUMOPTIC LOBESOPTIC LOBES

DISSECTION OF THE SQUID

SQUID

DISSECTION

MANTLE

•Protects inner

organs

•Takes in H2O for

propulsion &

breathing

FINS

•Steering &

Stabilization

8 ARMS + 2 TENTACLES

•All arms have suction cups

•Used for clutching &

manipulating prey

•Tentacles grab prey

•Only have suction cups

at ends

DORSAL

VIEW

SUCTION

CUPS

CHROMATOPHORES

•Color cells in the squid's

skin

•Contract & expand to

produce different colors

& patterns

•Squid can use this

ability to hide

Give your squid a Give your squid a Give your squid a Give your squid a

good rub & watch it good rub & watch it good rub & watch it good rub & watch it

change color !change color !change color !change color !

FINDING THE BEAK

•Spread the arms & tentacles

to see the Buccal Mass

•You will see the Beak (pair of

dark colored jaws)

1 - SUCKER

2 - BUCCAL MEMBRANE

3 - BUCCAL MASS

4 - SALIVARY GLAND

5 - ESOPHAGUS

START YOUR

INCISION

OPEN THE SQUID

LIKE THIS

1 - TENTACLE

2 - GILL

3 - INTESTINE

4 – GILL

HEART

5 – POSTERIOR VENA CAVA

6 - CAECUM

Internal Anatomy

1 - SYSTEMIC

HEART

2 - GILL HEARTS

3 - GILLS

4 - POSTERIOR

VENA CAVA

5 - ANTERIOR

VENA CAVA

6 - SIPHON

RETRACTOR

MUSCLE

7- SPERMATOPHORIC

GLAND

8 - ANUS

9 - INK SAC

1 – COLLAR (prevents H2O

escape)

2 - SIPHON

3 - EYE

4 - SIPHON RETRACTOR

MUSCLE

5 - ANUS

6 - CARTILAGE RIDGES

SIPHON

•Discharges water taken

in by the mantle

•Jet-propelled movement

•Site of waste removal

Backwards Propulsion

GILL HEARTS

•Pump blood to gills

•CO2 eliminated & O2

gained

•1 Gill heart for each

gill

GILLS

•2 Gills

•Location of CO2 & O2

exchange

FINDING THE INK SAC(INK SAC IS BLACK)

INK SAC

• Squid squirts out ink

when disturbed

• Confuses predator &

allows squid to

escape

• Small dark sac near

the siphon

• Gently pull up & cut

connective

membrane

• Pull sac off liver

(don’t puncture it)

1 - SIPHON

2 - RECTUM

3 - RETRACTER MUSCLE

4 - GILL

5 - INK SAC

6 - NIDAMENTAL GLANDS7 - GILL HEART

8 - OVARY

FEMALE MORPHOLOGY

May need to remove Ovary

& Nidamental Glands

FEMALE ORGANS

•Nidamental Glands:

•Secrete gelatinous

material over eggs

•Gelatinous covering

hardens, protecting

the eggs in the sea

Eggs, if present, appear as

a large granular mass

(may be hundreds of eggs)

NIDAMENTAL

GLANDS

(may need to

remove)

1 - SIPHON

2 - MANTLE

3 - FINS

4 - TENTACLES

5 - ARMS

6 - GILLS

7 – CAECUM

8 – PEN

MALE SQUID

No Nidamental Glands or eggs

MALE MORPHOLOGY

Testis (Produce sperm): White fluid-filled sac at

end of mantle

•Males take a small package of sperm

with the sex arm

•Fit it under the mantle of a female, next

to her eggs

Spermatophoric Gland:

Stores

sperm in

elongated

sac behind

1 gill

Locating & Removing the Pen

•A Chitinous structure beneath

viscera (“guts”)

•Squid are molluscs = their

“internal shell”

•Gives squid structure &

support

•To expose pen, lift viscera &

pull back gently

•Lift & pull gently to remove pen

Use the PEN & squid’s INK to

write your name on your lab !

THE EYE

•SQUID EYES ARE SIMILAR IN

STRUCTURE TO HUMAN EYES

•IT CAN FORM IMAGES

•CUT INTO THE EYE & TO

REMOVE THE LENS

LOOK THROUGH IT!

QUIT COMPLAINING,

YOU COULD BE

CUTTING UP THIS ONE.

24 FOOT LONG SQUID

(WITH ITS TENTACLES

EXTENDED)

LARGEST SQUID EVER

FOUND

WAS 57 FT. LONG

Do a good job with your squid &

you can help dissect this one!

THE END

OPTIC LOBESOPTIC LOBESCEREBELLUMCEREBELLUM

MEDULLA MEDULLA

OBLONGATAOBLONGATA

CAECUM

•Where Digestion

(Absorption) is completed

•Posterior to Stomach

CAECUM

1 – SYSTEMIC HEART

2 - GILL HEARTS

3 - GILLS

4 – MEDIAN MANTLE

ARTERIES

5 – MANTLE

ARTERIES

6 - CAECUM

Internal Anatomy

1 - ARM

2 - SIPHON

3 – ANTERIOR

VENA CAVA

4 - MANTLE

5 – SIPHON

RETRACTOR

MUSCLE

6 - ANUS