EC BiologyName ______

How are organisms classified?

Biologists group organisms according to structural similarities. The classification groups in biology are: kingdom, phylum, class, order, family, genus, and species. The branch of science that deals with classifying organisms on the basis of their natural relationships is called taxonomy. A mnemonic device to help you remember this is: Kissing Pink Cats Or Frogs Gets Sick. Can you think of a better one? If so, turn it in to your teacher for extra credit.

Part A.

Cut out the figures below. Assemble the figures into two groups based on a common characteristic. Record what criteria you used to create the two groups. Continue doing this with each new group until you have finally reached the point where each organism is in its own group of one. On your data sheet record your "tree" of divisional groups. You have just made a classification key.

Part B.

Look at the drawing of one of the fish. Read the first and second choice statements on the classification key. Choose which one best fits your fish. Now go to the numbered choices referred to at the end of the line and choose again. Do this until you find the name of the fish. Repeat for each fish. You have just used a biological classification key. Your write-up should include a title, your classification key from part A and the identification of fish 1-24.

(see fish diagram at end for term identification)

  1. a) Pelvic fins present or small with spine……………………….……………………………………………....2

b) Pelvic fins absent; body snake-like; dorsal, caudal, and anal fins continuous…..Common Eel Anguilla rostrata

  1. a) Pelvic fins abdominal (near anus) or distinctly behind pectoral fins.………………………………………...3

b) Pelvic fins just below or in front of pectoral fins...... ………………………………………...... 16

  1. a) Adipose fin present...... …………………………………………...... …4

b) Adipose fin not present...... …………………………………………...... 6

  1. a) Barbels present.…………………………………………...... 5

b) Barbels absent...... ……………………………………………...... 25

  1. a) Scattered spots on sides; caudal fin forked...... …....Channel catfish Ictalurus punctatus

b) Upper body dark-colored; caudal fin not forked...... …...... Bullhead catfish Ictalurus melas

  1. a) Snout much longer than head or barbels on underside of mouth only………………………………………..7

b) Snout short, barbels not present…………………………………………………………………………..…10

  1. a) Caudal fin heterocercal (top & bottom half not even) or fin rounded…………………………………...... 8

b) Caudal fin homocercal (top & bottom half identical)...... ………………………………………...... 10

  1. a) Caudal fin rounded (not lobed); snout slender and long.....……………..…...... Longnose gar Lepisosteus osseus

b) Caudal fin true heterocercal...... …………………………………………...... 9

  1. a) Snout long and shovel-like, nearly 1/2 the length of body; body naked (no visible scales)………………….

……………………………………………………………………………………..Paddlefish Polyodon spathula

b) Snout shorter; body covered with bony shields extending all the way to the tail...... ………..…………

………………………………………………………………………..…….Pallid sturgeon Scaphirhynchus albus

  1. a) Dorsal fin beginning about center of body...... …………………………………………...... 12

b) Dorsal fin far back near tail, usually above anal fin...... ………………………………………...... 11

  1. a) Spots on dark background; fins spotted; 5 or less pores under mouth ...(see note)...... Northern pike Esox lucius

b) Opercle scaled; body striped not spotted; 6-8 pores under mouth…(see note).….MuskielungeEsox masquinongy

  1. a) Mouth opening upwards...... ……………………………………………...... 13

b) Mouth opening downwards...... ………………………………………..…...Silver redhorse Moxostoma anisurum

  1. a) Dorsal and anal fins with spine; barbels present on mouth; scales large...... …….European carp Cyprinus carpio

b) Dorsal and anal fins without spines; barbels not present...... …………………………………………...... 14

  1. a) Dorsal fin recurved downward in center...... …………………………………………...... 15

b) Dorsal fin not recurved but with black spot at base of first soft rays....……....Creek chub Semotilus atromaculatus

  1. a) Anal fin longer at base than dorsal fin, eye large…………………………………….....Mooneye Hiodon tergisus

b) Dorsal fin longer at base than anal fin..………………………………………..…..Buffalofish Ictiobus cyprinellus

  1. a) Dorsal fin preceded by several unconnected spines; small pelvic fins with spine…Stickleback Eucalia inconstans

b) Dorsal fin single or divided into anterior and posterior parts.....………………………………………...... 17

  1. a) Caudal fin slightly-to-deeply forked...... …………………………………………...... 18

b) Caudal fin not forked; lateral line extending on to the caudal fin...... …….....Sheepshead Aplodinotus grunniens

  1. a) Distinct dark spot on opercle...... ……………………………………………...... 19

b) No dark spot on opercle...... ……………………………………………...... 22

  1. a) Body three times as long as deep; mouth large; small spot on opercle; dorsal fin separated into two parts or

nearly so...... ……………………………………………………………………………………....20

b) Body only about two times as long as deep; mouth opening even or in front of eye; spot on opercle large....21

  1. a) Mouth large, opening near back of eye; dorsal fin separated into anterior spiney part and posterior soft ray

part...... ……………………...... ……...... Largemouth bass Micropterus salmoides

b) Mouth smaller, opening near middle of eye; dorsal fin not completely separated into two parts; color pattern

of vertical bars...... ……………………...... ……...... Smallmouth bass Micropterus dolomieui

  1. a) Distinct black blotch near base of last dorsal rays; large spot on opercle; color pattern vertical bars…………. ………………………………………………………………………….……...... Bluegill Lepomis macrochirus

b) No distinct black blotch on dorsal fin; spot on opercle not as large; color pattern spotted…………………….

..………………………………………………………………………...... Orangespot sunfish Lepomis humilis

  1. a) Dorsal fin separated into anterior spines and posterior rays...... …………………………………………....23

b) Dorsal fin not separated; body covered with dark spots; anal fin a network of dark lines……………………...

……………………………………………………………...... ……...... Black crappie Poxomis nigromaculatus

  1. a) Posterior rays of dorsal fin larger than anterior spiney part; body pattern of horizontal stripes………………...

………………………………………………………………...... …...White or striped bass Roccus chrysops

b) Posterior rays of dorsal fin equal or smaller than anterior spiney part.……………………………………….24

  1. a) Bars on sides of body, eye medium...... …………………………………………...….....Perch Perca flavescens

b) Black spot at base of last dorsal spines...…………………………………………….Walleye Stizostedium vitreum

  1. a) Rose-colored streak and black spots on sides; caudal fin not forked……………...Rainbow trout Salmo gairdneri

b) Sides grey with yellowish spots; caudal fin forked………………………………Lake trout Salvelinus namaycush

NOTE: Pike has 5 or less mandibular pores; Muskellunge has 6-8 or more)

Part B:

1 / 2
3 / 4
5 / 6
7 / 8
9 / 10
11 / 12
13 / 14
15 / 16
17 / 18
19 / 20
21 / 22
23 / 24
25

Part B:

1 Shovelnose sturgeon / 2 Stickleback
3 Paddlefish / 4 White bass (striped bass)
5 Muskielunge (muskie) / 6 Long-nose gar
7 Black crappie / 8 Bluegill
9 American eel / 10 Carp
11 Northern pike / 12 Small-mouthed bass
13 Rainbow trout / 14 Large-mouthed bass
15 Walleye / 16 Orange-spotted sunfish
17 Lake trout / 18 Yellow perch
19 Redhorse / 20 Freshwater drum
21 Mooneye / 22 Channel catfish
23 Smallmouth buffalo / 24 Black bullhead
25 Creek chub