Phylum Mollusca 5 Classes Policemen censor gals in

Phylum Mollusca (5 Classes) Policemen censor gals in scant bikinis! Polyplacophora – Many plates on a foot Cephalopoda – Head foot Gastropoda – Stomach Scaphopoda – Tusk shell Bivalvia – Hatchet foot

Typical questions for Mollusca How many of these specimens posses a radula? Which ones are filter feeders? Which have undergone torsion? Detorsion? What is the function of the mantle? Name a class used for currency Which specimens lungs vs. gills? have think of which live on land vs. in water…… Oldest part of a univalve shell? Bivalve? Just

Answers…maybe • Gastropods, Cephalopoda, Mono-, A- & Polyplacophora • Bivalvia (Scaphopoda…. have a captacula) • Gastropods Opisthobranchia (sea hares & sea slugs) and the land slugs of the Pulmonata • Mantle secretes the shell • Scaphopoda • Pulmonata – their name gives this away • Apex for Univalve, Umbo for bivalve but often the terms are used interchangeably

Anus Mantle Radula in mouth Gills in mantle cavity Head Chitons radula, 8 plates Class Polyplacophora

My tentacles (2) & arms are derived from the Gastropod foot Cephalopoda - Octopuses, Squid, Nautilus, Cuttlefish…beak, pen, ink sac, chromatophores, jet propulsion………. dissection. Class

Apex Prosobranchia Aquatic –marine. Generally they have thick pointed shells, with spines. Many have opercula. Subclass Gastropoda WORDS TO KNOW: snails, conchs, torsion, coiling, radula, operculum & egg sac Subclass Pulmonata Aquatic –freshwater. Shells are thin, rounded, with no spines, and have no opercula.

Pulmonata Slug Subclass Detorsion… If something looks strange, chances are…. ……. it is something from Class Gastropoda (…or your roommate!) Subclass Opisthobranchia Nudibranch

This is correct! Class Gastropoda Sinistral ‘POP’ Subclass Prosobranchia - Aquatic snails (“shells”) - Have gills Subclass Opisthobranchia - Marine - Have gills - Nudibranchs / Sea slugs / Sea hares - Mantle cavity & shell reduced or absent Subclass Pulmonata - Terrestrial Slugs and terrestrial snails - Have lungs Dextral

Class Scaphopoda - “tusk shells” Currency for Wampum Indians. Head in sand. Respire through mantle (no gills. ) Captacula for feeding on foramniferans

Name of oldest part? D A Cla. Bivalvia V P or Pelecypoda - clams, scallops etc. filter feeders, bivalved shells…… dissection

Umbo D A Cla. Bivalvia V P or Pelecypoda - clams, scallops etc. filter feeders, bivalved shells…… dissection

Path of water (O 2) Dorsal (hinge) Heart Ventricle Auricle Bulbus arteriosus Anterior (Umbo) Adductor muscles Area of gastric & /digestive glands Mouth Gills or ctenidium – Each = 2 demibranchs Gills Visceral Mass Foot Mantl e. Ventral Posterior (siphons) Excurrent & Incurrent siphon – (hairs & papullae) Schematic Diag. of a Clam Very