Animal Diversity Lecture-5 11 Nov 2024 PDF

Exam format Short questions (4 questions, 5 marks each) Long questions (2 out of 3, 15 marks each) Short question doesn’t mean short answers!  Quiz - Covers lectures from 1 to 3 (Animal Diversity-1, 2 and 3). Animal Diversity-3 (slide 1-42). Anything before the costal habitat w...

Exam format Short questions (4 questions, 5 marks each) Long questions (2 out of 3, 15 marks each) Short question doesn’t mean short answers!  Quiz - Covers lectures from 1 to 3 (Animal Diversity-1, 2 and 3). Animal Diversity-3 (slide 1-42). Anything before the costal habitat will be included in the quiz. - 30 multiple choices in 30 mins - Date: 18 Nov (Week 12) - Venue: LT 12 - Time: 10:00-10:30 Adaptations of organisms to the marine environment The marine environment presents many challenges to organisms because seawater: 1. Has high viscosity 2. Variations in salinity 3. High transparency 4. Change of pressure with depth Marine organisms have various adaptations for the conditions of the marine environment Warm blood flowing out of the core of the seal’s body and towards its flippers dumps heat to cool blood returning from the flippers to the core of the body. This ensures that valuable heat isn’t lost while blood is in the seal’s flippers. This process is called counter-current heat exchange.  Mostly Spray or Splash Zone shelled orgs High Tide Zone Middle Tide Zone Many soft Low Tide Zone bodied orgs and algae  From Stream to River to Sea rain and snow plankton tributary bass source region transition zone floodplain ocean trout estuary great blue heron catfish Animal Diversity-5 Prof. Eddie Ma 11 Nov 2024  (3) Understory Layer Animals The understory layer is below the canopy, consisting of the shorter and/or younger trees, long-stemmed plant species and various shrubs. Light is at a limited due to the canopy overhead blocking most of it out. It is darker and is more hot and humid than the canopy. Insects abound as well as spiders. Bats have the ability to fly more easily through this layer and they as well as birds will come to it to pursue bugs. Many kinds of amphibians such as tree frogs and salamanders live in the trees at this layer of the rainforest. Snakes such as the emerald tree boa and the Wagler's pit viper inhabit the branches. Predators such as jaguars and leopards will use the lower branches to launch attacks on passing prey.  Reptiles and Amphibians Snakes thrive in the understory layer of many rain forests. Snakes feed on everything from reptiles and insects to smaller mammals. Although most shrub layer snakes are constrictors, such as pythons and boas, some hunt using various kinds of poisons. Frogs also do very well in rain forest shrub layers. The best known rain forest frog is the Poison Dart Frog. This frog produces a protective poison that has been used for centuries by local populations to make poison darts and arrows for hunting.  Backward-curving teeth http://science.howstuffworks.com/zoology/reptiles- amphibians/snake4.htm End Arid and Desert Deserts in the World  Arid – severe lack of available water Hindering or even preventing the growth and development of plant and animal life. As a result, environments subject to arid climates tend to lack vegetation. A desert is a landscape or region that receives very little precipitation. Deserts are defined as areas with an average annual precipitation of less than 250mm/yr, Cover 20-30% of landmass.  Extreme arid: 30°C mean annual temperature Highest 50°C 500 species 70 species of mammal, 20 of which are large mammals. 90 species of resident birds, and around 100 species of reptiles. Arthropods are also numerous, especially ants. Animals may loose 30 to 60 percent of their body mass and are still able to recover. Many of the animals obtain their water only through metabolic processes. These kinds of adaptations have allowed them to survive in such an inhospitable environment.  Insects When a desert insect breathes, it does not exhale continuously like human beings do. It waits until the level of carbon dioxide is enough in its body, before exhaling once. The outer covering of a desert insect is hard and made up of a tough waterproof substance known as 'chitin'. Long legs allow them to move rapidly and elevate their bodies above the hot sand  Yellow Scorpion Red Scorpion Black Scorpion Giant Scorpion  Scorpion Habitat/Behavior Scorpions are nocturnal creatures, preferring to hunt in the dark of night. During the day Scorpions sleep in burrows under the ground or under the desert rocks. It is rare that you will see a Scorpion out in the light of day, unless it has been roused from its burrow, awakened by the noise of larger predators. Diet Scorpions hunt for their food, using their long stinging tails to kill or immobilize their prey. The Scorpion feeds on various invertebrates, particularly insects, during the mild hours of the warm night. Depending upon the size of the Scorpion, they can eat lizards of medium and small sizes, small snakes, rodents and even other Scorpions. Glow under UV  http://www.youtube.com/watch?v=HXy5Deh VTBE http://www.youtube.com/watch?v=ugO73eUt qv4 Thorny Devil  http://www.youtube.com/watch?feature=play er_embedded&v=JoduGti4G_k#!  Once the water lands on them they will begin “drinking” which causes the water to move towards their mouth using a capillary action generated by the water’s adhesion to tiny grooves in the surface of the scales. This mechanism might afford the lizard a drink from dew or sporadic showers. Hides its real head and exposes a fake, spike-filled head which is located on their back. The predator will be very surprised if it tries to attack the ball of spikes. Horned Lizard  http://www.youtube.com/watch?v=gEl6TXrkZ nk https://www.youtube.com/watch?v=xodVcgJ8bc0  Convergent evolution Convergent evolution refers to the evolution in different lineages of structures that are similar or ‘analogous’, but that cannot be attributed to the existence of a common ancestor. Distance relative to the Australian Thorny Devil. Development of similar traits in two separate species in distinctly different environments. Inflate their bodies to protect themselves from predators. Absorb water through networks of tiny tube-like channels beneath their scales, which cover their entire body.  Divergent evolution Divergent evolution is the opposite of convergent evolution. Divergent evolution occurs when two species share a common ancestor and evolve one or more characteristics that make them different to each other. modern elephant and the extinct woolly mammoth Development of different traits in distinctly different environments. They both evolved from a common ancestor, but experienced different environments. Exposed to a cold climate, mammoths adapted by growing warm, furry coats. Frill-necked lizard  http://www.youtube.com/watch?v=fKMtUOw 3Uxw https://www.youtube.com/watch?v=rLY2gNiO Fzk  The frill-necked lizard is so called because of the large ruff of skin which usually lies folded back against its head and neck. The neck frill is supported by long spines of cartilage which are connected to the jaw bones. When the lizard is frightened, it gapes (wide open) its mouth, exposing a bright pink or yellow lining; the frill flares out as well, displaying bright orange and red scales. This reaction is often used to discourage predators or during courtship. Bipedal locomotion when running. Why it is an advantage?  Raises the head to have better field of vision Front limbs become free for other uses The field research to date shows about an 11% advantage (in terms of stride length) for bipedal locomotion based on tracks left in the sand. Irschick DJ, Jayne BC. 1999. Comparative three-dimensional kinematics of the hindlimb for high-speed bipedal and quadrupedal locomotion of lizards. Journal of Experimental Biology. 202:1047-1065. Irschick DJ, Jayne BC. 1999. A field study of effects of incline on the escape locomotion of a bipedal lizard, Callisaurus draconoides Physiological and Biochemical Zoology. 72:44-56  Estivation Estivation, also known as ‘summer sleep’, is a state of animal dormancy somewhat similar to hibernation Estivation protects these animals from high temperatures and drought. Just as animals hibernate in order to stay alive in cold places, animals estivate [or aestivate] in hot, dry places. The bodies of estivators will slow down. Breathing and heartbeat get very slow. The animal doesn't need as much food and water to live since food is fuel for energy and they aren't using much. Use 90-95% less energy when they are estivating. Animals don't move, grow or eat during this time. Spadefoots estivate (enter a state of torpor during summer dryness) and hibernate (spend the winter sleeping) in a burrow for up to eight months of the year.  Spadefoots Toad With a bit of rain they surface, feed (largely on termites and ants), breed if they can, then dig themselves back under the sand to wait. During aestivation, the skin of frog and toads can become impermeable to moisture loss. The spadefoot gets its name from the presence of a sharp, black spade on its hind feet. The spade serves as a cutting edge that allows the spadefoot to dig through the soil rapidly. They are primarily nocturnal which allows them to avoid the heat and low humidity of daytime, and consequently, the chance of desiccation  http://www.youtube.com/watch?v=D4i3AB32 0zk http://www.youtube.com/watch?v=ZUsARF- CBcI  Mohave Ground Squirrels Can sleep for about seven months!  Ground squirrels have a unique defense against rattlesnakes Resistant to snake venom. They can heat their tails and wave them at the snakes in order to intimidate them. Since the tails are warmer than normal, the rattlesnake goes on the defensive, and no longer sees the squirrel as food. Rattlesnakes, which are a type of pit viper, have a highly evolved organ that senses infrared heat. The organs are much more sensitive than the heat sensors in boas and pythons, thus able to detect the variation in the tail temperature and core body temperature of the squirrel. Snakes without heat sensing capabilities do not elicit this tail heat defense response. When they find rattle snake skins, they chew them up into a paste that they spread on their tails. When a rattle snake enters close to their burrow, they will swish their tail around and fool the snake into thinking this is another snake, no food here. Shake their tails high above their body, producing heat and making themselves seem much larger and more intimidating. Adult squirrels have also been known to eat snake skin and lick their offspring to mask their scent. http://www.youtube.com/watch?v=1xOqYrkATV Q Rattlesnake 32 known species of rattlesnake. Even dead rattlesnakes can be fatal, because if you step on their fangs you could be in contact with the venom. Venomous bite rather than by constricting. Causing >80% fatality. Bite only when provoked. It's rattle (a group of up to a dozen hollow, dried-skin shells on the end of it's tail) to warn other bigger animals that it is near. The noise of the rattle is produced by segments of the rattle bumping against each other. When rattling, the rattle may rotate up to 60 or more times in a second!  Pit vipers are snakes with two pits under their nostrils to detect heat (infrared radiation), thus enabling them to hunt warm-blooded prey. The pits are so sensitive that the snake can determine the size of the warm-blooded animal and can even detect prey in complete darkness. Snakes are not as heat tolerant as lizards. They avoid hot daytime temperatures by hiding underground, in rodent burrows or in rock crevices, and emerge only at night or during cloudy and cool days. Forked tongue flicks in and out, picking up odor particles from the ground and passing them over a special smelling organ in the roof of the mouth.  http://www.youtube.com/watch?v=p-nj_iOBDqA http://www.youtube.com/watch?v=lySW2-eYilg Oryx The summer coat of the oryx is short, sparse and very white – reflecting solar radiation. Shade under the canopy of desert trees for most of the day, thereby avoiding direct sunlight. Oryx can survive without drinking water, as they are able to extract sufficient moisture from their diet and have various morphological adaptations. Allows its body temperature to rise up to an incredible 45°C. This will kill other mammals. Why isn’t the oryx killed by it? http://openlearn.open.ac.uk/mod/oucontent/view.php?id=398612&section=3.4  Oryx In order to survive temperatures of up to 45°C, the Oryx allows its own body temperature to rise accordingly to prevent the loss of water through sweating. “Hot blood” is passed through a network of carotid veins along its nasal passage, before entering the brain. The blood is cooled by air flowing in and out of its nose. Oryx also has highly efficient kidneys which eliminate waste products with a minimal loss of moisture by concentrating the urine. To offload the "stored heat" in their bodies, Oryx often move to the highest points in their range - for example a sand dune - where they stand side-on (not facing directly) to maximize on the cooling effect of even a slight breeze. Ostrich  Ostrich Ostriches are the second fastest animal in the world and can run at 40 miles per hour. They can maintain this speed for at least 30 minutes. Ostrich the world's fastest two-legged animal. Ostrich kicks can kill a human or a potential predator like a lion. Each two- toed foot has a long, sharp claw. Wings are used for balance and speed control during running. Two of the wing fingers have claws on them. These claws are spur like, and can be used as defense mechanisms if the ostrich is provoked by a predator. Long and thick eyelids Ostriches can kick up to 2,000 pounds (141 kilograms) per square inch. That's twice as powerful as the best boxers. Ostrich Kicks can kill humans, dogs or even a fully-grown lion.  http://www.youtube.com/watch?v=1r- b8uY7C9E&playnext=1&list=PL98B567B3BFD9 7611&feature=results_main Collared Lizard Jackrabbit  Morphological and Behavioral Adaptations Behavioral thermoregulation related to the shape or color of an animal’s body, are also important for living in the desert. The collared lizard has long legs and toes that keep its body away from the hot ground, reducing heat absorption. Ground squirrels will use their bushy tails as a shade umbrella, and the long ears of the jackrabbit aid in dispersing body heat. This lizard must “thermal” dance to stay alive! https://www.youtube.com/watch?v=1rkkKyYCxio Dromedary Camel Last three months without water, a special adaptation for desert living. Store fat in the hump, not water. The fat can be metabolized for energy and water. Unlike most mammals, body temperature fluctuates throughout the day from 34°C to 41.7°C.This allows the camel to conserve water by not sweating as the environmental temperature rises. Camels have nostrils that can open and close, protecting the respiratory tract from blowing sand. Long eyelashes Bactrian Camel A camel can lose 30% of its body water and retain it back in 10 minutes. For other large mammals a 12-14% weight loss is lethal. A very thirsty Camel can drink 30 gallons (135 liters) of water in only 13 minutes. Oval-shaped blood cells, which are more elastic, they can easily change shape to retain more water allowing camels to consume large amounts of water. large and flat toe prevent sinking into sand Originated from one or two humps ancestor?  General adaptive feature of desert animals 1. A nocturnal lifestyle, which keeps them out of the heat of day (and out of human sight as well). 2. Living in burrows, which are cooler and more humid. This often goes along with #1, the burrow becomes a place to sleep during the hot day. 3. Slender bodies with long limbs - these are better for shedding heat. 4. Adaptations for reducing water loss - specialized snouts, waxy body coatings, efficient kidneys, etc. are all part of this strategy. Some animals - i.e. the kangaroo rat - are so efficient that they never need to drink liquid water; they get all their water from the food they eat (including the water released when sugars are respired to form CO2 and water). 5. Eyes protected from the sun (for diurnal species). Long eyelashes or deep- set eyes not only reduce harsh sunlight but reduce evaporation from the eyes. Note that the animals shown here all bear with one or more of these adaptations.  Two types of nephron, distinguished by the length of their loops of Henle http://www.answersingenesis.org/articles/cm/v26/n3/kangaroo-rats  Consultation Professor Eddie Ma Department of Neuroscience (NS) Director of the Laboratory Animal Research Unit (LARU) Office: TYB, Room 1A-203 Lab: G1701 Tel: 3442 9328 Email: [email protected] End