My Key to Manitoba Fish

Transcription

1 My Key to Manitoba Fish Outcome: : Develop a system to classify common objects or living things into groups and subgroups, and explain the reasoning used in the system s development. Materials: large paper (e.g. flip chart paper) colouring utensils scissors glue ruler Teacher s Instructions: 1. Make a class set of pages 3 and 4. For this activity students may work individually or in groups. Hand out copies of pages 3 and 4 to each student or group of students. 2. If students have already completed the Fish Parts activity then ask them to recall the fish features discussed previously. If not, review the different external features of fish using the diagrams on page 3. Be sure to discuss the uses of some of the more unusual features. 3. Ask students to colour and cut out the fish cards on page Students will observe the appearance of the different fish species and categorize them into two categories according to a physical characteristic. This can include the presence (or lack) of a body part (e.g. teeth, barbels, fins), the appearance of body markings, or the shape of a body part like the tail fin to name a few. 5. Once students have created two categories, instruct them to sub-categorize each group of fish cards according to a different physical characteristic. 6. Once students are satisfied that their fish cards are categorized appropriately, ask them to glue their fish cards onto the large piece of paper, using coloured pencils or markers to link the categories and sub-categories. Instruct them to label their key by writing the physical characteristic/rationale on or near the lines linking the categories. 7. After students have completed their keys, ask them to present their keys to the class. 8. The actual Key to Manitoba Fish Species is provided on page 5. You may use this key as a reference tool. It is not important that the students key resemble the actual key (and most likely they will not). What is important is that students demonstrate the reasoning behind their choices and justify their categorization of the fish species. If you intend to follow this activity with Key to Manitoba Fish Species under Outcome , do not show this key to students. 1 of 5 Teacher Background Information on page 2

2 Teacher Background Information: Fish are animals - they move, they have sensory organs (eyes, mouth, barbels), and they have body structure (skeleton, skin). They eat other organisms to survive. They also breathe oxygen, however they "breathe" by inhaling water through their mouths. The water is then passed over special structures called gills. The gills absorb the oxygen from the water as it flows over the gills and then exits the fish's body. The gills are protected and covered by a gill cover or operculum, just behind the cheek (yes, fish have cheeks!). While they do not use them to breathe, fish do have nostrils that they use to smell. Fish have fins to help them swim. They may have one or two dorsal fins (fins on top of the fish's back). If they have two, they may be separate or joined together. Some fish have an adipose fin on their back, which is actually a fleshy lobe that is a "leftover" of a more developed dorsal fin that was lost as the particular fish species evolved. Fish have pectoral fins (fins along the side of their body where their "arms" would be) and pelvic fins (fins underneath their bodies). They also have an anal fin just behind the vent where they excrete wastes. Their tail fin or caudal fin may be lobed or club-shaped. Depending on what they eat, fish may or may not have teeth. Fish that are carnivores or piscivores (i.e. they eat other fish) will have well-developed teeth (like a northern pike). They will likely have mouths at the end of their snout, or even above it, which helps them grasp their prey. Fish that feed off the bottom of a lake or river often do not have teeth. Their mouth may be located underneath their head to help them "vacuum" up their food (like a sucker). Some fish have barbels or fleshy feelers ("whiskers") that hang in front of the mouth (such as the catfish). These barbels are sensory structures that help the fish detect its food as it swims along the bottom of a river or lake. Fish have a lateral line. This is a system of holes along the sides of a fish that is actually a sensory organ. Similar to sonar, fish use it to detect vibrations and sense what they cannot see. Manitoba has many different species of fish. Some of them look very unusual and are easy to distinguish, such as the prehistoric-looking lake sturgeon. Sturgeon have an outer armour of bony plates called scutes and a heterocercal (shark-like) tail which are vestiges of earlier times. These features have disappeared in most modern-day freshwater fish. Other Manitoba species look very much alike, such as the various species of trout. All of these species have adipose fins and are distinguished from each other primarily by their body colouration. Other species also have adipose fins but can be distinguished from trout because they lack teeth (such as the whitefish). Other species with adipose fins are obviously different from trout because they have barbels (like the bullhead). Some fish have spines while other species have no spines. Fish may have spines in their dorsal fins, like a walleye, or along the leading edge of their pectoral fins, like a catfish. Goldeye and northern pike do not have any spines. Fish have scales, which may be very large or barely visible to the naked eye, depending on the species of fish. For example, goldeye scales are very large. On the other hand, catfish scales are so small, these fish look like they have a smooth skin. Some fish do not have scales, such as a burbot. All of these features - spines, teeth, barbels, tail shape, fins - can be used to help classify and identify fish species found in Manitoba. The size and shape of the mouth, body colouration, and markings (spots or stripes) can also be used to sub-classify similar species. Encouraging students to develop their own system of classification and provide their rationale for the system assists them in developing both their observation and classification skills. In addition to creating their own classification key, students develop their own understanding of existing keys - what they are used for and how they work. 2 of 5

3 Dorsal Fin Catfish Adipose Fin Tail Fin Anal Fin Pelvic Fin Pectoral Fin Barbels Walleye Spines Dorsal Fin Gill Cover Nostral Pectoral Fin Lateral Line Pelvic Fin Anal Fin Tail Fin 3 of 5

4 A B C D Walleye Perch Rainbow Trout Brook Trout E F G H Sturgeon Catfish Bullhead Carp I J K L Sucker Goldeye Rock Bass Northern Pike

5 Manitoba has many species of fish, from the huge lake sturgeon to the tiny spottail shiner; the colourful brook trout or the drab bullhead. In fact, Manitoba has 80 species of fish. In all of Canada, only Quebec and Ontario have more kinds of fish. Even fisheries biologists have difficulty in identifying all 80 of the species, so it is only natural many people are confused by Manitoba's bountiful fish species. This key helps people identify fish they catch. The key concentrates on the 30 species anglers are most likely to catch when fishing. To use the key, simply start at the beginning and see which of the two alternatives apply to the fish you have. Then move to the second two alternatives and so on, until the fish is identified. White edge on lower fins Tail deeply forked Red spots with blue circles on sides Lake Trout Brook Trout Dorsal fin near tail Light spots on dark body Light body and spots if present are dark Northern Pike Muskellunge Tail square or slightly notched Pink, yellow or white spots on side Arctic Char Front of dorsal fin ahead of anal fin Mooneye Pale red spots and slightly notched tail Splake Teeth Dorsal fin behind front of anal fin Goldeye Teeth No white edge on fins Body light or silver colour Kokanee Pink flash on side and small black spots Rainbow Trout Dorsal fin centered No teeth Single stiff spine on dorsal and anal fin Carp Body dark colour Large dark spots on yellow-brown background Brown Trout Scales No spines on fins Sucker Large dorsal fin Arctic Grayling No scales Burbot Tail fin. Upper lobe larger Sturgeon No teeth No Barbels Adipose fin long and thin an d connected to tail fin Normal dorsal fin Stonecat Mouth above end of snout Mouth below end of snout Tullibee Whitefish No spines in anal fin Strong sharp teeth Spiny dorsal fin a series of black spots Spiny dorsal fin solid light colour, dark spot at rear base Sauger Walleye S T A R T Tail fin. Even or symmetrical Adipose fin Barbels Adipose fin small and distinctive Tail fin deeply forked Tail fin square Channel Catfish Bullhead Soft dorsal fin Teeth not as pronounced and dark vertical bars Dorsal fins separate and body light in colour Dark lateral lines No lines Perch White Bass Freshwater Drum No adipose fin Spines in anal fin Mouth extends to eye Smallmouth Bass Spiny dorsal fin Dorsal fins connected and body dark in colour Notch in dorsal fin Mouth extends past eye Largemouth Bass Eye red Rock Bass Continuous dorsal fin Key to Manitoba Fish Species Eye yellow Black Crappie 5 of 5