Molluscs - Snails, Octopus And Squid Flashcards
What type of species to molluscs include?
Name 6
Snails, slugs, bivalve, shellfish, octopus and squid
What makes molluscs unlike any other phylum?
Three main parts
They have three main parts: a foot, mantle and visceral mass
What is a visceral mass?
The body is contained with the shell, it holds the bulk of the digestive tract, reporductive, excretory and respiratory system
What type of body cavity do mullsucs have?
They are coelomates !!!!!!!
Molluscey coeloey
Give three points about the digestive system:
Mouth
Digestive tract
Gut
It has a radula - kinda of like a tongue to scrape algae and food
A complete digestive tract - mouth to anus
Has a one way gut
What type of circulatory system to molluscs have?
What does this mean?
They have an open circulatory system
This means blood is pumped into a hemocoel (body catvity) with the blood diffusing back to the circulatory system between cells. The tissues are surrounded by blood
Tell me about the reproduction methods of molluscs
Two points - how they reproduce and their offspring
They are mostly dioecious two sexes mate - opposite of monoecious
They give birth to trochoplamore larvae (swimming plankton offspring)
What are the three classes of molluscs we are looking at
Class Gastropoda - snails, slugs Gastropod snails
Class bivalvia - clams, pipis, mussels (bivalvia gains for muscles)
Class Cephalopoda - octopus, squid, cattlefish (cepha squida)
What is an annelid?
Annelids are segmented worms. Think earthwerms
Tell me some features about annelids Body shape Body cavity Habitat Organs
Body has bilateral symmetry
Its is a coelomates
They are segmented with basic metamerism (linear series of body segments)
Habitat is the sea and damp soils
Well developed organs - tentacles, eye spots and palps
What is the circulation system of an annelid like?
They have a closed circulation system. This means the blood is closed within vessels at all times and the heart pumps the blood
What are the excretory tubules called in annelids? What is it?
Metanephridia - it opens like a pipe to the nepridopore to excrete waste
Think metanephridia is like a meth pipe
Nepridopore is like nep rid pore (hole that gets rid of stuff)
What are the 3 classes of annelids?
Polychaeta
Oligochaeta (earth worms)
Hirvdinea (leeches)
What is a nematode? How are they different to annelids?
They are NON SEGMENTED worms (annelids are segmented worms) and are pseudocoelomates (annelids are coelomates)
What are some cool features of nematodes?
Habitat
Skin/skeleton
They live in aquatic habitats
They have an exoskeleton that is known as the cuticle
They shed their skin as they grow !!
