cephalopods (ii)
DESCRIPTION
Cephalopods (ii). By Sasha Georgiev Biology 9A. Phyla . Belongs to phyla called mollusca cephalo+poda = head+foot Octopus, squid, cuttlefish . Specific features. About 800 classified species 11,000 extinct species Found in all oceans of earth Do not tolerate freshwater - PowerPoint PPT PresentationTRANSCRIPT
By Sasha Georgiev
Biology 9A
Cephalopods (ii)
Belongs to phyla called mollusca cephalo+poda=head+foot Octopus, squid, cuttlefish
Phyla
About 800 classified species 11,000 extinct species Found in all oceans of earth Do not tolerate freshwater One exception Greatest diversity towards the equator Occupies abyssal plain to surface Advanced vision Good camouflage More than one heart
Specific features
Nautiloids – earliest cephalopods in fossil record Late cambrian period Simple shell shapes
Fossils
Ocassionally long lived Mostly short life spam Gain 12 percent body mass per day They reproduce After 1 to 2 years they die
Life cycle of a cephalopod
Semelparous reproduction Iteroparity Sexual reproduction
Reproduction in cephalopods
Two part beak or radula Symbiotic digestive juices Digestive gland: crop, stomach, caecum and intestine Radulae description
Feeding of cephalopods
Pericardial cavity filters waste Delivered to renal sac Inflation and deflation of branchial hearts Release through pore
Excretory system of cephalopods
Exchange of gasses with seawater Water enters the cavity outside the gills Contraction of the water Jet propulsion Deplasation depends on respiraton
Respiratory system of cephalopods
Only molluscs with closed circulatory system Two gill hearts A single systematic heart Use of hemocyanin
Circulatory system of cephallopods
Most intelligent invertebrates Brain to body mass ratio Cartilageous cranium Nerve fibers use Highly adaptable
Nervous system of cephalopods
Advanced vision (color blind) Smell Tentacles use Hearing Use of light (coloration) Ink to confuse predators
Sensory system
?????????????????????????????????????????????????????????????????????????????????????????????????????????
Any questions????