Note: Exercise 1 should be completed before your assigned lab time.

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1 Keying and Animal Taxonomy Lab Learning Objectives: 1 - Become familiar with the construction of an identification key 2 - Accurately use a key to identify unknowns 3 - Accurately apply common name, phylum and subsidiary ranks (subphylum, class) to each of the included animals 4 - Identify visible features of an animal that are unique to each taxonomic grouping Note: Exercise 1 should be completed before your assigned lab time. Exercise 1 Introduction of Identification Keys A key is a tool for the identification of unknowns, be they organisms or objects. If the item under consideration is included in the key, then a combination of accurate observation and correct decision making will lead to a correct identification. There are multiple ways to construct keys. In this lab, we will be using a dichotomous, numbered, nested and indented key. Dichotomous means divided into two. In a key, this means that the user will be reading couplets composed of two paired, alternative statements which are identified by the same number (ex.: 1. and 1'). These paired statements are mutually exclusive and parallel (that is, they describe the same characteristics, but only one statement could be correct for any given unknown). Thus, for each dichotomy, the user will need to correctly choose the statement which accurately describes the unknown. This choice may lead the user to yet another dichotomy or may lead to an identification. Brief examination of the sample key on the next page should enable you, the student, to explain what the terms nested and indented mean in the context of a key. Nested means: Indented means:

2 Sample key to common plane figures Begin by reading statements 1. and 1'. Which one accurately describes shape A? The number at the end of that line tells you which couplet to read next. When a line ends with a word, you should have accurately identified the shape. 1. Figure with straight sides, the sides joining at an obvious sharp angle 2 2. All four sides of equal length Square 2' Opposite sides of equal length, adjacent sides of different lengths Rectangle 1' Figure with no obvious sides or the sides curved, any junctions with rounded angles 3 3. Obvious sides indistinct, the length and width of the figure equal Circle 3' With two sides, the length and width of the figure not equal Oval Now, use the key to correctly identify shapes B, C and D. Using other paper, rewrite the key logically, following the pattern above, such that it also includes triangle and ovate (egg-shaped). Be prepared to compare your key to those of other students. Your lab instructor may have you turn in your key. Exercise 2: Identification of adults of common animal phyla and subgroups. Animal specimens for you to observe and identify are set up throughout the lab. There is at least one sample animal from each group in the key. As you identify each, fill in the tables. Learning objectives 3 and 4 apply to these specimens.

3 1. Symmetry radial or lacking 2 2. Appendages lacking; filter-feeders, body perforated with pores and often with one or several immobile openings (osculum/a) for release of filtered water that may superficially resemble mouths Porifera 2' Appendages present, these tube feet or tentacles; feeds by ingestion through a mouth 3 3. String-like tentacles present, surrounding the mouth; tube feet lacking; epidermis with stinging cells Cnidaria 3' Tentacles absent, flexible 'arms' may extend from a central disc; tube feet present, arranged in radial lines; stinging cells absent, macroscopic spines may be present Echinodermata 1' Symmetry bilateral 4 4. Lateral appendages lacking; shell lacking; body cylindrical to flattened, worm-like 5 5. Body distinctly segmented 6 6. Mouth absent, but hooks and/or suckers at anterior end; segments (other than at anterior end) identical and independent Cestoda 6' Mouth present; segmentation evident only in body wall, not in enclosed organs 7 7. Microscopic; mouth surrounded by cilia Rotifera 7' Size variable; mouth not surrounded by cilia 8 8. Setae present; body cylindrical, suckers 0 Oligochaeta 8' Setae absent; body flattened, 1 sucker present at each end Hirudinea 5' Body lacking obvious segments 9 9. Body cylindrical; mouth at anterior end; digestive tract complete Nematoda 9' Body flattened; mouth near anterior end or middle of body; digestive tract incomplete Epidermis ciliated; body lacking suckers Turbellaria 10' Epidermis not ciliated; body with a sucker at anterior end Trematoda 4' Lateral appendages present or shell present; body variously shaped, including worm-like shapes Body covered by chitin exoskeleton, segmented; appendages jointed, bending at thin portions of exoskeleton Walking legs distributed along length of body Myriapods 12' Walking legs restricted to thorax (or area between head end and abdomen) Antennae lacking; with 4 pairs of legs and only 2 other pairs of appendages (chelicerae and pedipalps), these located around mouth Chelicerata 13' Antennae present; with 3 or more pairs of legs and variable numbers of other appendages, these variously located (mouth area, thorax, abdomen) Body sections 3; 1 pair of antennae; 3 pairs of legs, 0-2 pairs of wings Insecta 14' Body sections 2; 2 pairs of antennae; legs or similar appendages 8 to numerous, of variable types but never wings. Crustacea 11' Body covering variable (shell, scales, feathers, skin) but not a complete chitin exoskeleton, segments present or absent; appendages jointed or not, if jointed then by means other than thin areas of exoskeleton Body strongly segmented, worm-like; lateral appendages with clusters of coarse hairs Polychaeta 15' Body with few or no obvious segments, if worm-like then lateral appendages fleshy, without clustered hairs Muscular post-anal tail present during development, often retained in adult; endoskeleton of cartilage or bone present in most, external shell lacking Chordata 16' Post-anal tail lacking; endoskeleton lacking, external shell often present Tentacles with suckers present; eyes 2, often large Cephalopoda 17' Tentacles and suckers absent; eyes 0-many, small Body covered by 8 plates on dorsal surface Polyplacophora 18. Body enclosed by 0-2 shells Body enclosed by 0-1 shells Gastropoda 19' Body enclosed by 2 shells Bivalvia

4 Taxa included in this lab Phylum Porifera Cnidaria Rotifera Platyhelminthes Annelida Mollusca Nematoda Arthropoda Echinodermata Chordata Subgroups Turbellaria, Cestoda, Trematoda Polychaeta, Oligochaeta, Hirudinea Bivalvia, Gastropoda, Cephalopoda, Polyplacophora Myriopoda, Insecta, Chelicerata, Crustacea use your text to identify the major lineages if they are unfamiliar to you

5 As you identify each animal, fill in this table: Common Name Phylum Visible characteristics unique to this phylum Subgroup Visible characteristics unique to this sub-group

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