Kingdom Animalia

Kingdom Animalia

• Animals are multicellular, eukaryotic, heterotrophs whose cells lack cell walls. At some point in their development, animals can move (are motile).

• invertebrates—animals with no backbone or vertebral column

• Animals can carry out the following functions: feeding, respiration, circulation, excretion, response, movement, and reproduction.

Body Symmetry

• All animals have some type of symmetry EXCEPT SPONGES.

• radial symmetry: around a central point or axis (ex. sand dollar)

• bilateral symmetry: on two sides of a central plane (ex. butterfly)

• asymmetry: no symmetry (sponges)

Body Symmetry

Body Terms to Know

• anterior: front end

• posterior: back end

• dorsal: upper side

• ventral: lower side

• cephalization: concentration of sense organs and nerve cells at anterior (front) end of body

Phylum Porifera

“the sponges”

General Characteristics

• Porifera means “pore-bearing”

• Multicellular

• Two tissue layers

– Endoderm (inner layer)

– Ectoderm (outer layer)

– Mesenchyme – jellylike material between the layers

• Benthic

• Sessile

Vase Sponge

Another Popular Sponge

Sponge Structure

Injestion & Digestion

• Food particles and plankton enter ostia (pores)

• Ostia surrounded by pore cells

• Water and wastes exit through large opening, the osculum, at top of sponge

• Collar cells (choanocytes) beat flagella, coordinated movement causes water flow

• Collar cells trap food particles

• Passed to food vacuoles in amebocytes

• Digestion is intracellular - inside the cells

Gas Exchange

• Water coming through ostia contains dissolved oxygen

• Oxygen diffuses into cells in passing

• Carbon dioxide diffuses out

• Water with wastes exits osculum

Response to Stimuli

• Lack nervous system

• Myocytes – musclelike cells

• When myocytes contract, ostia close

• Possible protection from toxins in water

Reproduction (sexual)• Adult sponges release sperm and egg into

water

• Fertilized egg cell results from union

• Cell division occurs

• Morula forms (latin for raspberry)

• Blastula develops

• Blastula forms flagella, now called larvae

• Larvae exists as plankton until it makes contact with a substrate

• Attaches and grows into adult sponge

A Sponge Spawning

• Sponges can be male or female

• Hermaphrodites

– Produce sperm and eggs at different times to avoid self fertilization

Reproduction (asexual)

• Fragmentation

• Regeneration

Sponge Diversity

• Hardy creatures

• Found in variety of environments

• Unique spicules– Calcium carbonate

– Silicon dioxide

– Protein fibers, spongin

Red Beard Sponge

Piggy Nose Sponge, surrounded by encrusting sponge that typically grows on

dead areas of coral reefs

• Cliona (yellow boring sponge)

• Barrel Sponge