echinodermata and mollusca

1. Echinodermata and Mollusca
Presented By
Md.Wasif Fuad Md. Al-Amin
Roll:ASH1819031M Roll:ASH1819040M
Easa Datta Saleha Akter
Roll:MUH1819036F Roll: MUH1819012F

2. Echinodermata
Sea star• Echinodermata literally
means “spiny or prickly
skinned “.
• Echinodermata are also the
largest phylum that has no
freshwater or
terrestrial(land-based)
representative.
• This phylum contains about
7000 living species.

3. General Characteristics
• The outer body is made of lime, calcareous and thorns of ossicle
• The larve is bilaterally symmetrical
• In outer part of the body there has 5 ambulacral groove
• On the both side of the ambulacral groove in the rows of the tube
feet are present
• Triptoblastic ceolomate
• Head and specific respiratory organs are absent.Prolonged Papule
from thorax works respiratory organs
• The nervous system and the sensory system of the elderly and
backward

4. Classifacation
Asteroidia
• Anus aboral
• Example:Sea Starts
Ophiuroidea
• No anus
• Examle:Brittle stars
Echinoidea
• Gonads usually or less
• Examle:Sea urchins
Holothurodia
• No arms,no spines
• Examle:Sea cucumbers
Crinoidia
• Mouth and anus on oral
surface
• Examle:Sea lilies

5. Reproduction of Echinodermata
Asexual Reproduction Sexual Reproduction

6. Special Features
• External skeletons
• There is no head
• Usually have mouth on the underside
• Anus usually on the top

7. Economic Importance
• Ecological role
• Important step of ocean food chain
• Echinoderms as medicine
• Echinoderms in farming

8. Mollusca
• Mollusca is derived from Latin
word " Mollis"which means soft
bodied.
• Mollusca is the second largest
phylum of invertebrates animals
and also the largest marine
phylum.
• The members are known as
molluscs or mollusks.Around
85,000 extant species of molluscs
are recognised.

9. General characteristics
• Triploblastic, coelomate,unsegmented (except
in Monoplacophora) and bilaterally
symmetrical.
• Body divisible into head,mantle,foot.
• Shell,when present,usually univalve or bivalve.
• Coelom reduced and represented mainly by
pericardial cavity, gonadial cavity and kidney.
• Digestive system complete with a digestive
gland or liver ; a rasping organ,the radula,
usually present.
• Circulatory system mainly of closed type.
• Respiration direct or by gills or lungs or both.
• Excretion by paired metanephiridia(kidneys).
• Nervous system of paired cords .

10. Classification of Mollusca
Monoplacophora
•Segmented
•Example: Neopilina galatheae
Amphineura
•2 pairs of interconnected nerve
cord
•Examples:Neomenia,Chiton
Scaphopoda
• Conical food and tubular shell
•Examples:Cadulus,Pulsellum
Gastrophoda
• Coiling body and univalve shel
•Examples: Patela,pila globosa
Pelecypoda
•Bivalve shell
Examples: Nucula, Spondylus
Cephalopoda
•Body elongated dorsoventrally
•Examples: Octopus,Sepia

11. Reproduction of Snail
Asexual Reproduction Sexual Reproduction

12. Special Features Of Mollusca
Pearl culture : pearl is a result of
an injury to molluscs.It is secreted
by the mantle as a means of
protection against some foreign
body.When a foreign body gets
between the mantle epithelium
secrete nacre.Japanese have
developed a technique of
producing pearl artificially.

13. Pearl farming video of Bangladesh

14. Economic Importance
• As Food
• As Bait
• Money
• Ornamentation
• Useful dyes and ink
• Buttons and pearls
• In art and medicine
• In literature
• Animal inventions

15. Reference
o www.wikipedia.com
o www.biologydiscussion.com/invertebratezoology/molluscs/mo
lluscs-characters-and-ecpnomic-importance
o www.snail-world.com/life-cycle-of-a-snail
o Modern text book of zoology invertebrates-R.L.Kotpal
o www.toppr.com/animal-kingdom/echinodermata
o www.onlinebiologynotes.com

16. Thank You Everybody
Any Question???