Download
1 / 15
150 likes | 154 Views
mighty. Molluscs!. Scraping teeth. Body of Mollusc. Molluscs The life cycle of many marine mollusks includes a ciliated larvae, the ____trochophore___________ . This larva is also found in marine __annelids_____ (segmented worms). A trochophore larva.
E N D
mighty Molluscs!
Scraping teeth Body of Mollusc
Molluscs The life cycle of many marine mollusks includes a ciliated larvae, the ____trochophore___________. This larva is also found in marine __annelids_____ (segmented worms) A trochophore larva.
Class of Polyplacophora - chitons • Marine; oval shapes and shells divided into eight dorsal plates. • Muscular __foot_ grips the rocky substrate tightly and creep. • Grazers; use _radula__ to scrape and ingest algae.
Class ______Gastropoda____ • More than 75,000 species; mostly marine, but also many freshwater species. • _Some Terrestrial___ • Garden snails and slugs have adapted to land. In place of the gills found in most aquatic gastropods, the lining of the mantle cavity of terrestrial snails functions as a lung
Class of Gastropoda • Most gastropods are protected by _______shells_____ into which the animals can retreat if threatened. • Other species have lost their shells entirely and may have _chemica_ defenses against predators (They can handle the nematocysts from anemones). Shell-less nudibranchs
Queen Conch Class of Gastropoda • Many gastropods have distinct heads with ___barbs__ at the tips of tentacles.
Class ____Bivalvia__ • ____Two_ shells connected with a hinge. • Clams, oysters, mussels, and scallops. • Bivalves have shells divided into two halves. • The two parts are hinged at the mid-dorsal line, and powerful adductor muscles close the shell tightly to protect the animal. • When the shell is open, the bivalve may extend its hatchet-shaped foot for digging or anchoring.
Class Bivalvia • The mantle cavity of a bivalve contains gills that are used for feeding and gas exchange. • Most bivalves are filter feeders, trapping fine particles in mucus that coats the gills. • The Palp conveys the particles to the mouth. • Water flows into mantle cavity via the incurrent siphon, and passes over the gills, and exits via the Excurrent siphon.
Class of __Cephalopoda____ • __head_-Footed MolluscsUse quick movements to dart toward their prey which they capture with several long tentacles. • Squids and octopuses use beaklike mouths to bite their prey and then inject poison to immobilize the victim. • A mantle covers the organs; shell is reduced and internal in squids, missing in many octopus. Onlychambered-nautilus has external shell.
Cephalopods • Fast movements by a squid occur when it contracts its mantle cavity and fires a stream of water through the excurrent siphon. • By angling the siphon in different directions, the squid can rapidly move in different directions. • The foot of a cephalopod (“head foot”) has been modified into the muscular siphon and parts of the tentacles and head.
Nautilus This is the chambered nautilus, a type of Cephalopod, with up to 90 short tentacles used to capture prey A series of gas-filled chambers serve as a bouyancy device
Cephalopods • Unique among mollusks, cephalopods have a closed circulatory system to facilitate the movements of gases, fuels, and wastes through the body. • They have a well-developed nervous system with a complex brain and well-developed sensory organs. • This supports learning and problem solving behavior.
