Invertebrates

Why phylum are sponges in?

Porifera

What are some important characteristics of sponges?

Asymmetrical

No tissues

Hermaphrodites (function as male and female)

Mesohyl

Where you would find spicule

Choanocytes

Flagellated collar cells which engulf bacteria

Amoebocytes

Totipotent cells within the mesohyl which digest food

Cnidarians

They have a digestive system with a single opening

What are some characteristics of Cnidarians

Radial symmetry

No brain, but have a non-centralized nerve net to react to stimuli

Medusa

A body plan of a hydrozoan

Medusozoa

All cnidarians which produce medusa; Free-swimming cnidarian with a bell shaped body and a mouth on the underside

Anthozoa

All cnidarians which only appear in polyp form

Polyp

Sessile body plan that adheres to the substrate by the end opposite the mouth

Nematocyst

Organelle which ejects a stinging thread (ex: tentacles of a jellyfish)

Lophotrochozoa

MOST have a lophophore (crown of cilia used for feeding)

SOME have a trochophore larval stage

Bryozoans

Ectoprocts

Radula

A rasping tongue

Molting

Activity shared by Ecdysozoans

Cuticle

Tough but flexible external coat of ecdysozoans

Arthropoda

Phylum with the most species

Chelicerates

Spiders, Ticks, Mites

What are Chelicerates named after?

the pincer appendages, chelicerae

Pedipalps

Function in sensing, feeding, defense and reproduction

Book Lungs

Stacked platelike structures at the base of the body which aid in gas exchange

Myriapods

Invertebrates with a pair of antennae and 3 pairs of appendages (Millipedes and Centipedes)

Pancrusteans

Paraphyletic group including insects, lobsters, and shrimp

What do most Pancrusteans have?

Highly specialized appendages including walking legs, antennae, and swimming appendages, and separate sexes

Complete Metamorphosis

Larva to adult stages occur in clear stages with specialized functions

Incomplete Metamorphosis

The young resemble adults but are smaller and go through a series of molts until they reach full size

Deuterostomia

Radial cleavage of the blastula; Formation of the anus from the blastopore

Water Vascular System

This characteristic is unique to the echinoderms; a network of internal hydraulic canals

What are characteristics of a water vascular system?

Network of canals whch branch into tube feet; Function in movement and feeding