Animal Adaptations & Behavior By Krista Granieri

Transcription

1 Animal Adaptations & Behavior By Krista Granieri The Kingdom Animalia is divided into many distinct groups of organisms. There are 9 major phyla based primarily on characteristics related to embryonic development, body symmetry and gut-shape. Each phylum contains organisms that are genetically related and share a variety of other physical and behavioral characteristics. Figure 1: Nine major phyla of the Kingdom Animalia Porifera: Sponges species-no true symmetry, no gut, no organs systems, marine habitats, eat plankton and other small items by moving water through pores and trapping food items, which are then phagocytized. Reproduce asexually and sexually depending on water temperature. Figure 2: A sponge (Porifera) and a coral, a jellyfish and an anemone (Cnidarians)

2 Cnidarians: Jellyfish, Coral, Sea Anemones- 10,000 species - radial symmetry, simple tissues, sac-like gut, marine habitats, carnivorous, fairly well developed sensory and nervous system, reproduce sexually and asexually. Eat by trapping prey with tentacles, digesting them in their sac and then expelling undigested material. Platyhelminthes: Flatworms (Planarians, Tapeworms, Flukes) - 25,000 species - bilateral symmetry, dorsoventrally flattened, organs and organelles, blind gut (mouth/no anus), kidney-like excretory organs, rudimentary nervous system, sexual reproduction as hermaphrodites, feed on animals and other smaller life forms, many are parasitic, some are free-living. Figure 3: A fluke and a tapeworm (Platyhelminthes); Filarial worms (Nematodes) Nematoda: Non-segmented Roundworms - 80,000 known- up to a million species possible - bilateral symmetry, tissues and organs, hydrostatic skeleton, tube gut with anus, nervous system, no circulatory system, reproduce sexually, diet varies, many are parasitic, few are free living, live in moist or wet habitats. Mollusca: Snails & Slugs, Octopi, Clams-110,000 species bilateral symmetry, tissues and organs, tube gut with mouth and anus, may possess a dorsal or lateral shells of protein and calcareous spicules, nervous system, true closed circulatory system with a heart and respiration via gills, sexual reproduction, diet is varied, live in moist environments, mostly marine and aquatic habitats. Annelida: Segmented worms - 9,000 species bilateral symmetry, tissues and organs, tube gut, nervous system, true circulatory system, no respiratory organs, sexual reproduction, can be hermaphroditic, diet varied, habitats mostly terrestrial and aquatic. Figure 4: A snail and an octopus (Mollusks); a centipede, a feather worm and a leach (Annelids)

3 Arthropoda: Insects, Spiders, Crabs- 874,000 species - bilateral symmetry, exoskeleton made of chitin, tissues and organs, tube gut, segmented body, 3 to 400+ pairs of jointed legs, well developed nervous system with brain, respiratory system, circulatory system with heart, sexual reproduction, diets and habitats extremely varied. Figure 5: A moth and a tarantula (Arthropods); a sea star and a sea urchin (Echinoderms) Echinodermata: Sea stars, Sea urchins, Sea cucumbers- 6,000 species - mostly radial symmetry, tissues and organs, tube gut with anus, non-cephalized, rudimentary nervous system, rudimentary circulatory system, has a water vascular system, which hydraulically operates the tube feet or feeding tentacles, has a sub-epidermal system of calcareous plates, sexual reproduction, feeds on detritus and small particles/animals in water, all live in marine environments. Figure 6: A chimpanzee, a hummingbird, coyote, clown fish and a Komodo dragon (chordates) Chordata (subphylum vertebrata): Fishes, Amphibians, Reptiles, Birds, Mammals 50,000 species bilateral symmetry, complex tissues and organ systems, tube-gut with mouth and anus, true cephalization, vertebrae of cartilage or bone, complex nervous system with brain, endoskeleton of cartilage or bone (or both), endocrine system, sexual reproduction, terrestrial, marine, aquatic habitats, diets also extremely varied. Thanks to Gordon John Larkman Ramel at for much of the phyla information Activity 1: Animal Diversity Observe the posters and specimens for each animal phylum. Examine the basic morphological adaptations that allow them to survive in their environments. For each group look for characteristics such as body symmetry, gut type, feeding behavior, cephalization, locomotion and reproductive behavior.

4 Complete the following chart with your observations from the various stations Animal Characteristics by Phyla Animal Phylum Symmetry (rad/bilat/none) Ceph (Y/N) Gut (tube/sac) Reproduction (aex/asex/both) Locomotion Snail Fish Earthworm Anemone Frog Jellyfish Sea Star Alligator Crayfish Ant Elephant Spider Coral

5 Activity 2: Focus on Mammals - Skulls, Jaws and Teeth Mammals are found in a variety of terrestrial, marine and aquatic habitats from the polar region, dry and wet temperate areas and in the tropics. The teeth of mammals are often specialized to use specific types of food. Compare the teeth of the mammal specimens on the board and match each one to one of the following diet types: A. General herbivore- generally have flattened molars for grinding plant material B. Carnivore- often have blade-like incisors for slicing meat C. Insectivore- frequently have procumbent lower incisors (most anterior teeth stick straight out instead of up) to aid in grasping prey. D. Gnawing herbivore- Usually large, self sharpening incisors. E. Omnivore- generalized tooth pattern, typically has pronounced canines for prey capture, insicors for meat slicing, and rounded molars for grinding. F. Piscivore- homodont dentition- all teeth the same- usually for catching and eating fish Complete the following chart with your observations from the Skulls station Animal Dentition Chart Animal DentitionType Habitat Likely Food Habit Opossum Frog Human Monkey Fish Beaver Dog Sheep Rabbit

6 Activity 3: Focus on Birds Beaks and Feet Look at the various birds at this station and infer what sort of diet they have by looking at their beaks. Look at their feet and infer what type of habitat they might live in and they might use their feet for. Use the diagrams below to help you complete the Bird Beaks and Feet chart in your lab. Bird Feet Adaptations Bird Beaks and Feet Chart Bird Beak Shape Likely Food Habit Foot Shape Likely Habitat

7

8 Activity 4: Focus on Animal Locomotion- Snail Races & Taxis Introduction to Garden Snails (adapted from wikipedia) Helix aspersa (garden snail) is one of the most wellknown terrestrial mollusks, native to the Mediterranean region and western Europe from northwest Africa and Iberia east to Asia Minor, and north to the British Isles, and widely introduced and naturalized elsewhere. The adult bears a hard, thin calcareous shell, with four or five whorls. The shell is somewhat variable in color and shade but is generally dark brown or chestnut with yellow stripes, flecks, or streaks. The body is soft and slimy, brownish-grey, and is retracted entirely into the shell when the animal is inactive or threatened. During dry and cold weather, the aperture of the shell is sealed with a thin membrane called the epiphragm, which helps the snail retain moisture. During times of activity the head and foot emerge. The head bears four tentacles, two of which have eyes, and two of which are smaller, tactile sensory structures. The tentacles can be retracted into the head. The mouth is located beneath the tentacles and contains a chitinous radula which the snail uses to scrape and manipulate food particles. The snail's muscular foot contracts to move the animal, and secretes mucus to facilitate locomotion by reducing friction against the substrate. It moves at a top speed of 1.3 centimetres per second (47 metres per hour), and has a strong homing instinct, readily returning to a regular hibernation site. Helix aspersa is a hermaphrodite, producing both male and female gametes. During a mating session of several hours, two snails exchange sperm and after a few days each will dig a nest in the soil and deposit fertilized eggs in it. The young snails emerge from the eggs after about two weeks, and take one to two years to reach maturity. In today s lab we will investigate snail locomotion and taxis. Locomotion is the way an organism moves. Taxis is when an organism moves toward (positive taxis) or away (negative taxis) from a specific stimulus. Materials: Obtain the following materials and return to your lab bench: Red tray Glass observation bowls Ruler Lettuce A snail Substrate kit -Glass plate -Sandpaper -Cloth -Sand Procedure: Take your glass bowl and select a snail from the jar. Try to choose one that looks healthy and alert. You may have to gently wake your snail up. They are generally nocturnal. To wake up a

9 snail give it a quick dip in some fresh water and then place it in your glass bowl. It should be alert and moving in a few minutes. If not, return it to the container and select a new snail. PART 1: Race Your Snail on Various Substrates 1. Draw your snail. Place your snail on the glass plate. Use the dissecting microscope to see details of the snail s anatomy. Identify the shell, foot, eyestalks, tentacles and mouth. You may even see the snail s anus if it poops while you are drawing it. The anus is located at the superior and anterior aspect of the snail s shell (yes, right over its head!). 2. Watch your snail move on the glass plate and describe what the foot looks like from underneath. 3. Describe what you think causes the snail to move. 4. What is the function of the snail s mucus? MAKE A PREDICTION Predict the relative speediness of each substrate. Use 1 for the fastest and 5 for the slowest. Plexiglass Fabric Dry sand Wet sand Sandpaper

10 SNAIL RACES Using a centimeter ruler determine how far your snail travels on each substrate in 2 minutes. This will give a speed unit of cm/min. It might be necessary to coax your snail by holding a piece of lettuce just in front of him/her. Record the distance (cm) traveled by your snail in 2 minutes- then divide by 2 to get a rate in cm/min. Record the data from other groups snails and determine who s snail won the races. Snail Plexiglass Fabric Sandpaper Dry Sand Wet Sand cm cm/min cm cm/min cm cm/min cm cm/min cm cm/min Part 2: Chemotaxis & Snail Control Garden snails are herbivorous and have a wide range of host plants. They can damage numerous types of fruit trees, vegetable crops, garden flowers, and cereals. It has been introduced to many regions around the world, including southern Africa, Australia, New Zealand, North America and southern South America. It was introduced to California as a food animal in the 1850s and is now a notorious agricultural pest here, especially in citrus groves. Many areas have quarantines established for preventing the importation of the snail in plant matter. They are themselves a food source for many other animals, including small mammals, many bird species, lizards, frogs, centipedes, and predatory insects. The decollate snail (Rumina decollata) will capture and eat garden snails, so it is sometimes introduced as a biological pest control agent. There are a variety of snail control measures that gardeners and farmers can use to reduce damage. Traditional pesticides are still in use, as are many less toxic control options. Some of the natural control measures that supposedly work to control snails include the use of garlic, wormwood and copper metal bands. In this part of the lab we will test the efficacy of these control measures in deterring snails by observing what type of taxis, if any, the snails exhibit towards the various stimuli. Some common type of taxis include chemotaxis (chemical), geotaxis (gravity) and phototaxis (light). Materials: Keep your snail and supplies from the previous activity.

11 Obtain: Garlic preparation Copper strip Wormwood preparation Lettuce preparation Procedure: You have already observed your snail s general locomotion on various substrates and you have probably already observed positive chemotaxis with respect to a piece of lettuce. 1. Place your snail on the glass plate and tilt the plate completely sideways (on edge). Hold it that way for a few minutes and see how your snail responds. Lay the glass plate back down and record your observations. Based on your observations, how would you describe your snail s geotaxis behavior? 2. Now, place a piece of lettuce on the plate about 10 cm away from your snail. In between the snail and the lettuce you will place a path about 1 cm wide of each of the chemical stimuli - one at a time. This way you can determine whether the snail has positive, negative or neutral chemotaxis towards each of the items. Sample of substance being tested Lettuce ~10 cm

12 If the snail will not cross the substance to get the lettuce or moves away from it, that is negative chemotaxis. If your snail moves toward the substance and stops to lick or otherwise engage the substance, that is positive chemotaxis. If the snail simply travels over it to get to the lettuce, that is neutral chemotaxis. Chemotaxis Behavior of Snails Material No Material Lettuce Juice Water Copper Wormwood Garlic Snail s Response (pos/neg/neutral) 1. Did your snail exhibit negative chemotaxis to any of the substances? If, so which ones? 2. What does this indicate about the use of these substances as snail control measures?