SBB3023 - Biodiversity And Evolution Of Protista And Animalia

NAME MATRIC NO

NABILAH BINTI KOMARUDDIN D20101037466

NUR SYAFIQAH BINTI ABD KADIR D20101037567

NAZRATUL ILYANA BINTI MOHAMAD D20101037470

YANTIE BINTI MAKLIN D20101037471

RIDWAN BIN SHAMSUDIN D20101037472

MARIAMAH BINTI ARON D20101037477

INTRODUCTION TO

CEPHALOPODA

SQUID NAUTILUS

CUTTLEFISH

OCTOPUS

CLASS CEPHALOPODA

1.Most advance, intelligent invertebrates (squid,

nautilus, octopus, cuttlefish)

2. Included squid,octopus,nautilses and cuttlefish

3. have well developed senses and large brain (larger

than those of gastropods)

4.All marine

5.All predators (giant squid is the largest invertebrate)

CHARACTERISTIC

CLASS CEPHALOPODA6. They can also change texture and body shape

7. Cephalopods have advanced vision, can detect gravity

with statocysts, and have a variety of chemical sense organs

8. cephalopods lack a cornea, and have an everted retina

9.Most cephalopods possess chromatophores that is, coloured

pigment

10.cephalopods have an ink sac, which can be used to expel a

cloud of dark ink to confuse predators

11. closed circulatory system.3 heart

12.Nautiluses are the only extant cephalopods with

an external shell

13.Shell variable –

Nautilus –multi-chambered gas-filled shell

Cuttlefish -cuttlebone –internal shell

Squid –internal shell (pen)

Octopus –no shell

14.Reproduction -Dioecious, internal fertilization,

eggs fertilized by males then leave oviduct of

female and land on sea floor

Shell

• The earliest shells were straight cones.

• Others had curved or coiled shell such as ammonoids and nautiloids.

• The early nautiloid and ammonoid shell are heavy cause buoyancy by a series of gas chambers. (eg: Nautilus)

• This enable the animal to swim while carrying its shell.

• The shell of Nautilus is coiled but quite differ from gastropod.

• Transverse septa divide the shell into internal chambers.

• The living animal inhibits only the last chamber.

• As it grows, it moves forward, secreting behind it new septum.

• The chambers are connected by a cord of living tissue called siphuncle.

Cuttlefish have a small, coiled or curved shell, but it is entirely enclosed by the mantle.

Squids have no shell. But leaving only a thin, flexible strip called a pen, which the mantle enclosed.

Octopus have no shell.

Cuttlefish

squids

Octopus

Body and Mantle

NAUTILUS the head with its tentacles can be extruded

from the opening of the body compartment of the shell.

Its 60-90 or more tentacles have no suckers but adhere to prey by secretions.

The tentacles search for, sense and grasp food. The head is the funnel.The shell shelters the mantle, mantle cavity and

visceral mass.

Other than NautiloidsHave only one pair of gills.Octopuses have 8 arms with suckers.Squids and cuttlefishes have 10 arms (8 out of

10 with suckers and the other 2 is retractile tentacles.)

Thick mantle allowing water to be taken into the mantle cavity

CephalopodsThey have a closed circulatory system with a

network of vessels.Blood flows through the gills via capillaries.Branchial (gill) hearts, or accessory hearts increase

the blood pressure in the gills which permits more rapid gas exchanges.

Have well-developed nervous systems-most complex brain among invertebrates.

Nautilus has simple eyes but others have elaborate eyes with cornea, lens, chambers and a retina.

COLOUR CHANGES

Cephalopods has special numerous pigment-filled bags called chromatophores in the skin.

Chromatophores are found in the skin, and expand and contract to reveal or conceal small dots of color.

Color changes in cephalopods is controlled by the nervous system and hormones.

The color changes are used for camouflage or to startle and warn potential predators in their undersea realm.

Cephalopods are believed has lack color vision, it is proven in the experiments.

The photoreceptor of cephalopods are rhabdomere cells. Hence, their ability to see color depends on the number of pigments present.

The fluid is released through the anus to form a “smokescreen” to

confuse an enemy.

Most cephalopods have an ink sac that empties

into the rectum.

INK PRODUCTIO

N

The sac contains an ink gland that secretes a

dark fluid containing the pigment melanin.

Locomotion

Swim by force expelling water from mantle cavity through ventral funnel.Funnel is mobile ( to control direction, forced expulsion of water determined speed)

Squid and cuttlefish

In Squid (Loligo) and cuttlefish ( Sepia )Streamlined (for speed)Lateral fins – acts as stabilizer, rapid swimming

NautilusIn Nautilus - Gas filled chambers keep shell uprightMove slower compared to squid

OctopusHas globular body, no finsSwim backward by spurting water from their

funnelAid to crawling over rocksSuction disc at arm- to anchorSome deep water octopus- have fins,arm

webbed like umbrella, swim in medusae-likeLarge octopus- have flatten body and swim by

undulation

Reproduction of

Class Cephalopoda

Sexes are separateInternal fertilizationinvolves elaborate color changes

cuttlefish

OctopusMales changes in skin pigmentation and

patterningAttract towards females and against rival

malesundergo copulation process

Copulation processAdult males produces a

special arm or modified arm called a hectocotylus

Then transfers a sperm packet to the female's pallial cavity

plucks a spermatophores from his own mantle cavity and inserts it into the mantle cavity of female near the oviduct opening

Arrow 1 :The spermatophore groove of the inserted hectocotylus. Arrow 2 :An oviducal gland

The female lays a number of eggsSome octopuse tends their eggs - guard their eggsThey clean them, provide them with fresh water and

defend them against enemiesThe female octopus does not eat as long a she guards the

eggs. Often she dies after her offspring's hatching, because she is too weak to defend herself against her enemies

1 2

3 4

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Phylogeny and Adaptive

diversification

Phylogeny

Adaptive diversification

Cephalopoda have a greatly expanded visceral mass. In cephalopoda the mantle cavity was extended ventrally. Evolution of chambered shell in cephalopodo was are very important contribution to their freedom from the substrate and their ability to swim. Elaboration of their respiratory, circulatory, and nervous system is correlated with their predatory and swimming habits. Diversity is related to their adaptation to different habitat, feeding methods and mode of life.

END