BIO 120 Objectives 9 Pseudocoelomates Rise of Hollowness General Zoology BIO 120 Lecture NOVA Loudoun Campus Fall 2013 Chapter 9 Objectives Please respond to the following questions in preparation for the lecture evaluation on this material 1 What are acoelomate pseudocoelomate and eucoelomate animals NOTE students should know the terms pseudocoel coelom peritoneum mesenteries and somatic visceral tubes 2 What are Pseduocoelomates What are Lophotrochozoans and Ecdysozoans 3 To which superphylum and phylum do rotifers belong How many species are there What are four general characteristics of Rotifera NOTE students should refer to pp 194 195 Where do rotifers live What type of symmetry do they possess How many germ or tissue layers do they possess What type of gut do they possess Do they possess a coelom How do they feed What is the corona 4 To which superphylum and phylum do nematodes belong How many species are there and how many may be unidentified What are four general characteristics of Nematoda NOTE students should refer pp 200 201 Where do nematodes live What type of symmetry do they possess How many germ or tissue layers do they possess What type of gut do they possess Do they possess a coelom How do they feed NOTE students should be able to illustrate a generalized nematode see Figure 9 8e and include the terms amphid phasmid pseudocoel mouth pharynx and anus 5 Do nematodes possess a digestive system circulatory system respiratory system or nervous system 6 What is the cuticle What is ecdysis BIO 120 Objectives 9 1 Coelom Pseudocoelomates Rise of Hollowness a Acoelomate no body cavity b Pseudocoelomate functional body cavity false cavity c Coelomate peritoneum derived from mesoderm to support other organs 2 Pseudocoelomates a Pseudocoelomate i False coelom ii Functional body cavity between mesoderm and endoderm iii i e nematodes and rotifers b Lophotrochozoan wheel to bear i Trochophore larvae on ciliated oral cavity ii Lophophore ciliated mouth iii Found in bottom of freshwater iv Shape reflects lifestyle v Variety of shapes and colors c Ecdysozoan i Removal or shedding of outer cuticle ii Most abundant group on earth 3 Rotifers a Superphylum lophotrochozoan b Phylum rotifer c 1 800 species d Characteristics i Aquatic or semi terrestrial ii Pseudocoelomate iii Cuticle iv Complete digestive system 1 Corona variable ciliated arrangement for movement and feeding v Free floating active swimming fix themselves to things by toes vi Unsegmented vii Protonephridia excretory system viii Lack respiratory and circulatory system ix Have brain and nervous system x Cyclomorphosis changes in body form from seasonal or nutritional changes xi Dioecious xii Parthogenesis xiii Banded cilia 4 Nematodes a Superphylum ecdysozoans b Phylum nematode c 25 000 identified species d 500 000 unidentified BIO 120 Objectives 9 Pseudocoelomates Rise of Hollowness e Characteristics i Simple body plan outer and inner body wall ii Microscopic iii Thin iv Unsegmented v Complete digestive system vi Cuticle must be molted throughout lifetime vii Lack cilia viii Lack circulatory and respiratory systems ix Dioecious x Nervous system nerve ring and spinal cord like feature xi Free living xii Detritivore xiii Live everywhere xiv Parasitic xv Have longitudinal muscles xvi Have excretory system 5 Nematode Body Systems a Complete digestive system b Lack circulatory and respiratory systems c Nervous system consists of nerve rings 6 Cuticle a Cuticle outer layer protection from elements and or host digestion system b Ecdysis the process of molting