Crayfish are Crustaceans, which is a type of Arthropod. Crayfish has five pairs of legs which are jointed, counting the pinchers it has to pick up food and defend itself. The other four pairs are used for walking legs. They have a hard exoskeleton and as aforementioned, two, big pinchers. They have two small pairs or smaller antennas to sense food in the water and find a mate, while the bigger antennas are used for touch and making sure it doesn’t bump into things. They have two eyes which are on stalks so they can rotate around, and lastly they have a tail to help with steering and swimming. Crayfish will use their pinchers to catch food and also defend themselves if attacked or threatened. Crayfish are closely related to crabs, lobsters, and shrimp. Some species of crayfish are signal crayfish, red swamp crayfish, and rusty crayfish. Crayfish only live in freshwater and can live in moving or standing water. Crayfish are omnivore, so they eat both plants and animals. Most fossils records of crayfish come from the last 30 million years, but there are some …show more content…
fossils that date back to the Jurassic period 150 million years ago. One behaviour that helps the crayfish survive is it’s instinct to defend itself when it feels threatened.
That way, whatever is trying to eat it would back off or get hurt while trying to eat the crayfish. One of the most important body structures of the crayfish is it’s hard exoskeleton, which looks like plates of armor. Without it, it would just be exposed and without protection from being hurt. Bumping into things would cause much more damage. Another important bodily structure are the cheliped, or the ‘pinchers’, which look like pinchers. They enable the crayfish to catch and eat food, and defend itself against animals wanting to eat it. As with the exoskeleton, they would be stripped of protection. Additionally, the gastric mill is important for the crayfish to digest food. The gastric mill is teeth inside the stomach, and without it the crayfish wouldn’t have the food properly digested, and be unable to
eat. Crayfish that we know today aren’t the same as they were 150 million years ago. They went through evolution; mutations in the gene pool; to get to the Crayfish we know today. For example, if at some point in the many years that crayfish have been around the predators have increased or if they got a new predator they would have had go through natural selection. Another example is if Crayfish didn’t have anntenes, then it wouldn’t have that necessary touch receptor and their detection of nearby food. Crayfish without antennas would die off while others with antennas would live through natural selection.
The documentary Blackfish by Gabriela Cowperthwaite is a gripping documentary about orca whales in captivity at SeaWorld and other sea parks around the world that shows the disturbing effects that can be caused from having these animals in a place where they shouldn’t be.
“Taxonomically speaking, a lobster is a marine crustacean of the family Homaridae, characterized by five pairs of jointed legs, the first pair terminating in large pincerish claws used for subduing prey…. Moreover, a crustacean is an aquatic arthropod of the class Crustacea, which comprises of crabs, shrimp, barnacles, lobsters, and freshwater crayfish” (Wallace, 55). This is an example of Logos since the author uses scientific facts to convey the message he wants to communicate in an objective way. Wallace also uses logos as a persuasive device by presenting facts on the science of the lobster’s neurological system and its ability to feel pain. The Maine Lobster Promotion Council states “The nervous system of a lobster is very simple, and is in fact most similar to the nervous system of a grasshopper. It is decentralized with no brain. There is no cerebral cortex, which in humans is the area of the brain that gives the experience of pain”. Wallace counter-argues this statement by mentioning the fact that since lobsters have a simpler nervous system compared to humans, they are unable to produce their own natural opiates. “One can conclude that lobsters are maybe even more vulnerable to pain, since they lack mammalian nervous systems’ built-in analgesia, or, instead, that the absence of natural opioids implies an absence of the really intense
Cephalopods are known to be exceptionally intelligent by invertebrate standards and in some respects even rival “higher” vertebrates. These animals have many highly evolved sensory and processing organs that allow them to gain a greater understanding of their environment and their place within it. Due to their advanced structures, many of which are analogous to vertebrate structures, and abilities they have been widely studied. Their methods of learning have been of prime interest and many experiments have been conducted to determine the different ways in which octopuses can learn. From these experiments four main kinds of learning have been identified in octopuses: associative learning, special learning,
Name – Arius felis Name – Hardhead catfish Description – Hardhead catfish have six rounded barbels that stick out from their chins like whiskers. These barbels help the catfish find crabs, fish and shrimp in the muddy bays where they live. The dorsal and pectoral fins each are supported by a sharp, slime-covered barbed spine. The catfish is covered in a mildly toxic slime, that causes severe pain, and swelling, should the catfish cut you. The dorsal spine normally is held erect when the fish is excited, and a tennis shoe or even a leather-soled shoe offers little protection.
There’s No Real Good Guy In the movie, “Blackfish” we are exposed to the fact that the way orcas are treated at SeaWorld is worse than we are lead to believe. We see how they are forced to swim in tiny pools and how they can only be fed if they preform well. After seeing this it makes you feel like the only way to help these poor creatures is to jump on the animal activist wagon and to free all the whales like in “Free Willy”. But is that really the right way to go?
The Red Lionfish (Pterois volitans) is an invasive saltwater predator that is increasing exponentially in the tropics of the western Atlantic (Benkwitt, 2013). The Lionfish invasion is causing a dramatic decline in native marine reef species due the gluttony of the lionfish.
The normal weight of M. salmoides is one kilogram; however, certain largemouth basses have gotten weights of over ten kilograms. Males usually do not surpass 40 cm, while females can reach up to 56 cm in length. The largemouth bass has a large, slightly sloping mouth. Its body is slender to robust, slightly compressed laterally, and oval in cross section. The corner of the mouth extends past the eye, hence its common name. (Bailey, et al., 2004; Boschung, et al., 2004) Immature Micropterus salmoides feed on zooplankton and marine insects. As they grow their diet shifts to crayfish
The body of the shrimp is two parts the thorax which is the body and the head , the body pieces are connected by the cephalorax and a narrow abdomen. The mouth if the shrimp works with the gills so they can be used. Shrimp have a hard shell that keeps everything together and protects them, its legs, eyes, and rostrum grow out of the hard shell. The use their nose or a sharp peak which there there basically the sing thing to protect their self from all the bigger and other animals it come in contact with and it sticks them with and it has a length that the shrimp lets out to be able to reach where the shrimp wants to get the other animals. Shrimp have some similarities to fish like when they travel, breed, and eat its usually done in schools (schools area group of the species). A (shrimp) single female is capable of producing a large number of offspring, one shrimp can lay up to one million eggs in a single session, take two weeks to hatch it takes two weeks to
An English naturalist Charles Darwin (1802-1882) developed a theory of biological evolution. He studied variation in plants and animals during his five years’ voyage around the world in the 19th century. Darwin studied hundreds of species, which he researches variations between locations. His theory states that all species of organism arise and develop through natural selection. Natural selection is the process of organisms that adapt to their surrounding environment, which tend to survive and produce more offspring. Killer whales are remarked to have evolutionary links from land dwelling organisms, millions of years ago. This paper will display the evolution and natural selection of the killer whale.
Moore, Paul. “Agonistic Behavior in Freshwater Crayfish: The Influence of Intrinsic and Extrinsic Factors on Aggressive Encounters and Dominance.” 2007. PDF file.
When someone says the word octopus, an image of an eight legged invertebrate comes to mind. The body structure of a mature octopus is very interesting. Octopuses are extremely intelligent. They have excellent memory can use tools, and are great problem solvers. Only birds and mammals are known to be smarter. Each one of their tentacles, which are used for prying open clam shells, has two rows of suckers that can give them a pretty good grip. An octopus also tastes with its tentacles. An octopus’s third right arm, also called hectocotyli, is also its penis which a male octopus will use to mate at one or two years of age. The only part of an octopus that cannot move or squeeze through small spaces is its beak where it consumes food. This is used for biting and also breaking things apart. Did you know that octopi have three hearts? This is because these sea creatures have extra legs and three hearts are necessary for better bl...
In The Rainbow Fish by Marcus Pfister tells how a beautiful, extraordinary, yet, self-centered blue fish learns that being beautiful isn’t the key to happiness. The blue fish came to find this lesson when he lost his friends. Pfister takes a simple ocean setting and explores the consequences of an individual’s arrogance toward their peers, the process of humbling of oneself, and the tremendous reward one feels when they learn to share. The story achieves these morals by the author’s use of detailed imager and also, the influence of minor characters on the antihero in order to reveal to the audience the true thematic message; selfish actions bring true happiness.
In Chinese tradition, Shark fin soup is called as “a celebration soup”, which people eat it to celebrate in various occasions. Moreover, people also believed that shark fin consisted of diverse nutrition values which provide them virility, wealth, and power(Wolchover, 2011). These beliefs lead to the beginning of poaching for sharks, the top of food chain in the sea world. Surprisingly, although people are aware of the decreasing number of sharks since the old days, around hundred million of sharks are still hunted each year(Heltus, 2013), to be served on luxury tables surrounded by those believers in things that they do not even prove whether the belief is reliable. Therefore, in the generation that people are mostly educated, sharks should no longer have to be continuously killed for their fins.
To start off, the horseshoe crab lived 200 million years before dinosaurs. What’s astounding is that while dinosaurs have become extinct, the horseshoe crab is still alive and well today (Horseshoe Crab:Saint Louis Zoo). Next is that it might not seem like it, but this critter is actually a predator. The crab likes to feed on things such as small clams, crustaceans, worms, algae, and other animals (Steel). Furthermore this animal is also known as the king crab. Finally the male horseshoe crab is actually shorter than the female the crab. The male is about 14-15 inches long from head to tail, while the female is measures in to be 18-19 inches long (Horseshoe Crab
Introduction One particularly interesting sea creature is the whale shark, formally known as Rhincondon typus; it was first discovered in 1828 by Andrew Smith (Rowat 2012). This large fish is found globally in warm tropical oceans and prefers to stay within 200 meters of the ocean’s surface in waters ranging from 4.2 to 28.7 degrees Celsius (Stevens 2006). This creature can be found all across the globe in warm tropical seas. Aggregations of whale sharks have been seen off the coast of Australia at times, although it is primarily a creature of solitude. Whale sharks are filter feeders that consume plankton as well as small fish and are harmless to humans.