mollusca dunia hewan

1

ANIMALIAStandar KompetensiSiswa mampu memahami prinsip-prinsip pengelompokkan makhluk hidup.

Kompetensi Dasar2.6 Mendeskripsikan ciri-ciri filum dalam dunia Hewan dan peranannya bagi kehidupan

Indikator Mengenal ciri-ciri umum animalia. Mengidentifikasi karakteristik berbagai filum anggota kingdom

animalia. Menyajikan data (gambar, foto, deskripsi) berbagai ivertebrata

yang hidup di lingkungan sekitarnya berdasarkan pengamatan.

Phylum MOLLUSCA Class Polyplacophora - Chiton

Phylum Mollusca

Class Scaphopoda – Tusk Shells

Phylum Mollusca Class - Gastropoda

Phylum Mollusca Class Gastropoda - Nudibranch

Phylum Mollusca Class – Gastropoda - Nudibranchs

Phylum Mollusca Class – Sea Hare

Class Gastropoda

whelks

Class - Gastropoda ConchConch

Class GastropodaClass Gastropoda Limpets and Periwinkles

Class - Gastropoda Abalone

Class - Gastropoda Land Snail

Class Bivalvia Clams, Mussels,Scallops

Class - Cephalopoda

Octopus

Squid

Class Cephalopoda

Octopus

Class Cephalopoda

Nautilus

Characteristics of Molluscans Size – Millimeter to 60 Feet (18M)

Major Food source

Lifestyle

Simple - Limpets

Complex – Squid and Octopi

Molluscan Body Plan

Visceral Mass

Foot

Adductor Muscles

Siphons

Gills

Circulatory System

Open Circulatory System

Means that not all the blood is contained in vessels but rather vessels AND open chambers called sinuses

Sinuses take place of the Capillaries

3 chambered heart

Body Systems

RespirationRespiration – this is accomplished thru the circulation of oxygen-rich water by the MANTLE

ExcretionExcretion – this is accomplished by Kidneys that double as a passageway for eggs or sperm

Nervous SystemNervous System – varies with species. Limpets and Bivalves are simple, Cephalopods are well developed.

Comparison of Body Plans

Specialized Structures

RadulaRadula – Horny-toothed structure found within the pharynx

Used for “Rasping” or “Scraping” plant or animal tissue

Bivalves are filter feeders and have lost this structure

Cephalopods, in addition, have a “Beak” which work together to kill prey

Specialized Structures

OperculumOperculum – A protective plate that covered the opening to the shell of some gastropods

SiphonSiphon – A tube that allows for water to enter/leave the body of a Mollusc. Bivalves and Cephalopods

Siphuncle – Siphuncle – a cord of tissue that connects all the chambers of the Nautilus and used for boyancy

Specialized Sturctures NacreNacre – secretion around sand particles

by oysters resulting in a pearl.

HectocotylusHectocotylus – a special structure on one of the arms of an Octopus (male) that allows it to deposit sperm packets into the females mantle cavity

Hectocotylus

Specialized Structures

Shells – Not all mollusc’s produce them

Make of calcium carbonate which is obtained from water or soil.

They can grow through the lifetime of the animal

Reproduction

Varies tremendously from external fertilization to internal, dioecious and hermaphrodidic

Changing Sex – some such as oysters change back and forth from male to female releasing sperm and eggs accordingly.

Spermatophores – packets of sperm