Phylum Poriferia

Protist

unicellular eukaryotes, no undergo gastrulation or tissue development

Basal Metazoans

Early development

Metazoans

multicellular eukaryotes undergo gastrulation and tissue development

Porifera

Sponges

Benthic organism

Live on sea floor

Characteristics of Porifera

Multicellular, cell-cell communication, and animal like reproduction with larval stage

Aquiferous System

Water current channel powered by flagellated cells called choanocytes

Nutrients

Bring water containing food through the sponge where cells can phagocytize food particles

Respiration

Water containing oxygen where individual cells can carry out gas exchange

Waste management

Metabolic and digestive waste carried out through water currents

Cellular level

Specialized cells that carry out life functions

Totipotent and Aquifers

Important for making up cells

Pinacocytes

Form outer layer of sponge

Amoebocyte

Digestive and transports nutrients through the body

Porocyte

Single cell, creates pores for water flow

Choanocyte

All purpose cell; water flow in, feeding, gas exchange, and waster

Asconoid Sponge

Simplest

Syconoid Sponge

Bit more complex

Leuconoid Sponge

Most complex

Ostia

Water flows through

Spongocoel

Large cavity in the middle

Osculum

Water flows out through

Choanocyte ( body type)

Line the spongocoel

Channels

Line choanocytes

Dermal pore

Water flow through (Ostia)

Hexactinellid Sponge Characteristics

Greater degree of radially symmetry, no pinacoderm, cellular distribution is sparse and form trabecular network

Spicules

Help give sponge form, shape, and support

Spicules Type

Silicious, Calcareous, and Spongin

Porifera Feeding characteristics

Filter feeder, digestion carried out by individual cells, phagocytosis, pinocytosis

Sensory Capabilities

No evidence of use of neurons or sense organs, rely on cell response

Reproduction

Mostly sexual

Zygote

Free swimming larvae ( they land somewhere can take root)

Budding

Asexual, clone themselves and spread off

Archaeocytes

Totipotent cells capable of becoming anything

Gemmules

Packets of archaeocytes protected by skeleton

Taxonomy

Class Calcarea, Demospongia, Hexactinellida

Class Calcarea

Spicules of calcium carbonate, in all 3 body types, and all marine

Class Demospongia

Spicules of silicon or sponging, Leuconoid, marine, brackish and freshwater

Class Hexactinellida

Spicules of silicon 3 or 6-ray, trabecular network, glass sponge, all marine