Marine Worms Flatworms, Nematodes, Annelids, General Characteristics of Marine Worms bilateral symmetry Cephalization (Has a head) Hydrostatic skeleton (no bones) most are benthic Flatworms 2 types No body cavity=flatbodies _No_ segments, No_ circulatory system, No Respiratory system _Type 1_:Turbellarians (Non Parasitic) _Type 2_: flukes and tapeworms (parasitic) Swimmers itch Flatworms Most turbellarians are _carnivorous __Chemoreceptors_: detect prey unique prey-capturing mechanisms – _Stab__ – _Suffocate_ pharynx secretes enzymes and pulls in food food is digested in the gastrovascular cavity = which functions as a mouth and an anus__. Reproduction Flatworms – _Asexually through regeneration – _Sexually_: Penis Fencing (flatworms are male and female. They fight with their penis’s the winner becomes the male, looser becomes the female) Nematodes _round worms, tapered at both ends _No segments___ _They have a body cavity_: Hence why round in shape __Most numerous animals on the planet__ – Handful of sediment may contain 3 million nematodes http://www.youtube.com/watch?v=gofmShLJIPM&safety_mode=true&persist_safety_mode=1 Nematods Nonparasitic species are scavengers and are small in size__ Parasitic and carnivorous species are larger_: Annelids Bodies divided into _Segments_ ↑ common marine polychaetes Has _a closed circulatory system__ ↓ deep sea vent tube worms “more advanced” worm Setae: used for locomotion and defense Polychaetes (Not a bird) are the main type of marine worm: For example, earthworm is an annelid, but it is not a polychaete ← errant polychaete featherduster→ Annelids Polychaetes Annelids 2 Types: – _Type 1: Sedentary polychaetes that burrow or built tubes of sand, calcium carbonate, proteins. They filter feed_with cilia that extend from tubes and the aid of chemoreceptors. My Favorite Sedentary Polychaetes: _Christmas Tree Worms_; Also used in Avatar; IN Real Life Use their gills to capture plankton Polychaetes Annelids 2 Types: Type 2: _Errant (swim)_polychaetes have jaws with teeth_ and nocturnally hunt small invertebrates. Many are poisonous and have a painful bite. Sexual Reproduction in Polychaetes _Epitoky_ is a form of reproduction ,The worms undergo a transformation into an _Epitoke, a pelagic morph capable of _Sexual Reproduction. Often an epitoke is the end part of the worm, which separates from the head. The end then releases the eggs or sperm. Other Marine Worms _Peanut Worms_: Filter Feeder that burrows in the sand, sticking out its head to feed Other Marine Worms _Spaghetti worms__: lies hidden in sediment or rocky crevices while its foodgathering tentacles wave overhead. Other Marine Worms Fire worms have bristles that are filled with venom and easily break when touched to discourage predators. They also inflict a painful rash on any human who handles them Aliens or Marine Worms? New Species, of marine worms Yet still to be named…….. Marine Worms 1.Name the three types/classifications of worms 2.List them from simple to complex 3.List three characteristics of each type of worm 4.Give two examples of sexual reproduction for worms 5.Describe two ecological roles of marine worms. 6.What is swimmers itch? 7.Define: Sedentary, Cephalization, Benthic, Errant, Polychaete and gastrovascular cavity 7.