Ch 26 Identification Practice

Portuguese Man-o-War Colonial Cnidarain

Elephantiasis Caused by a parasitic roundworm - filaria

Crown Jellyfish - medusa - Cnidarian

Marine Flatworm Platyhelminthes - showing bilateral symmetery

Roundworms are EVERYWHERE !! Nematoda

Platyhelminthes ( flatworms)- have simple organs and exhibit simple cephalization Planarian (left) showing it’s ocelli (eyespots) and marine flatworm (right)

Soft Coral Polyps Cnidarian - showing radial symmetry

c. Proglottid - flatworm (Platyhelminthes - Tapeworm Platyhelminthes (flatworms) are the first animals on the phylogenetic tree that have simple organs. They have very primitive “brains” in their “heads”-called cephalization

a.Sac Body Plan – only one opening for food to enter and wastes to exit Planarian on left (Platyhelminthes) and Hydra on the right (Cnidaria) What do these animals have in common?

Roundworm infection Heartworm Guinea Worms - Break out of skin when mature Parastic Roundworms

Acoelomates (left), Pseudocoelomates(right), and Coelomates(middle)

Hydra - a polyp cnidarian - may be showing budding the the bottom right corner

Found in the tropics Nearly ¼ of the population are infected with hookworm The eggs hatch and develop outside the body of the host Burrow into un- protected skin (often the feet) and enter the blood stream Travel from the lungs up to the pharynx and are swallowed They dig into the intestinal wall and suck the blood of the host cause weakness and poor growth Hookworm

Sea anemones (polyp Cnidaria)

Regeneration - asexual repro. Exhibited by Planaria (Platyhelminthes Flatworm

Sexual Reproduction of a Jellyfish - is a medusa Cnidarian (adult) - shows sperm, egg, planula swimming larva (with bilateral symmetry), the young and then budding polyp stage, and the adult medusa

Sea Anemones - a polyp, sessile Cnidarian

Clownfish and Sea Anemone – symbiotic relationship –tentacles protect clown fish from predators, clownfish protects tentacles from being eaten

Trends in Animal Evolution - Body Plans

Sea anemones

Platyhelminthes - planaria top right and left, marine flatworm bottom right

` Tapeworm (a parasitic Flatworm) Life cycle

Porifera Sea Sponge

A Polyp Cnidarian - showing its nerve net

Acoelomate - exhibited by Platyhelminthes (Planaria top left)

Planaria - Pharynx Protruded (ready to eat) (Platyhelminthes - Flatworm)

Parasitic Flatworm - You can tell because this is not really a mouth - it is just a “hook” to stick to the intestinal wall Deceiving because it looks round

 loaded Discharged  What is this? Nemaotcyst Of a Cnidarian’s Stinging Tentacles

Flatworm showing its nervous system (you can just see the two ventral nerve cords) and the gastrovascular cavity (larger branching network)

Blood Flukes - Parasitic flatworm Have two different hosts in their life cycle Found in tropical areas Female lives inside the male in a groove Often kills human host

Nematocysts - on the stinging tentacles of Cnidaria

Blood Fluke life cycle - parasitic flatworm - snail is intermediate host - often kill human host

Trichinella worm CYSTS - Parasitic Roundworm (but very difficult to tell the difference between this and tapeworm (a flatworm) cysts) Food or water contaminated with eggs is ingested by an intermediate host (cow, pig, fish) Larvae from eggs burrow into muscle tissue of host and create a cyst

Asexual Reproduction - budding - Hydra - a Polyp Cnidarian

Tapeworms showing proglottids and the scolex

Anatomy of a Roundworm Simplest animals with a digestive system with two openings – a mouth and an anus Have several ganglia-groups of nerves-but lack a brain Muscles run in strips along the length of the body walls Breath and excrete their metabolic wastes through their body walls

Parasitic Roundworm

Top - Pseudocoelomates,shown by roundworms Bottom is comparing acoeloms, pseudocoelo ms and coeloms mesoderm

Trends in Animal Evolution - Symmetry

Sponges! (Porifera carcasses!)

Trends in Animal Evolution – Cephalization - flatworm on left, Roundworm on right