When I imagine a fish that resembles a sea monster, I immediately picture a sea lamprey (Petromyzon marinus). These fish are jawless and can grow up to 80 cm as an adult. An adult lamprey’s mouth has teeth arranged in circular rows like something from a nightmare. When it comes time to feed, sea lamprey latch on to a host and drill a hole to obtain nutrient-rich blood. If that weren’t enough, they only have two dorsal fins and one caudal fin and lack pelvic and pectoral fins, which gives them an eerie, eel-like appearance. Lamprey even have a lateral line system that enhances their sensory abilities underwater. Since lamprey do not have any bones, they have a cartilaginous skeleton to help support cardiovascular, neural and respiratory systems. In addition, sea lamprey are semelparous, so they only have one mating opportunity to procreate. Juvenile lamprey go through a process of metamorphism to mature into adults. Larval lamprey or ammocoetes burrow in …show more content…
sandy/silt substrates that filter feed algae. These juveniles are distributed through a stream dependent on habitat and water quality (Young et al, 1990). Females during mating can lay up to 102,000 eggs (Lewis and McMillan, 1965). Despite these seemingly freaky and primitive morphological adaptations, lamprey have proved successful. Evidence suggests lamprey have been around since ~545 million years ago (Janvier 1999). How a fish can survive lacking a jaw seems counterintuitive to me. Humans would not last very long without a maxilla to help break down food for digestion. Sea lamprey’s mouths are shaped like a buccal funnel and have sensory papillae that help form a seal to stay attached to an unsuspecting host. Once attached, they use their lingual and horny teeth to dig a hole into the host to access blood for sustenance. There are a series of muscles that attach to the cartilage in the buccal funnel that allow the funnel to contract and expand, which creates suction for feeding (Dawson 1905). Since sea lamprey suck blood for nutrition they do not have stomachs. Their esophagus is connected directly to the intestine where nutrients are then absorbed. In order to continue respiration sea lamprey use what’s called a velum to breathe while feeding. Their esophagus and breathing tubes are close together, so without this morphological characteristic they would suffocate. The velum acts as a valve to close the breathing tube during feeding, and the passive movement of water in and out of the gills allows lamprey to still breathe. Sea lamprey, unlike more advanced fishes, have seven pairs of external gill slits. This higher number of slits suggests less-efficient oxygen absorption. They obtain oxygen by allowing water to pass through their mouth and gills through counter-current exchange. Counter-current exchange works by pumping blood in the opposite direction of the water flow. Sea lamprey’s gill slits contain hemibranches that have highly vascularized gill lamellae that intake oxygen and dispel carbon dioxide and other waste products. Sea lamprey are anadromous, so they spend time in freshwater as juveniles and migrate to salt water to fully mature. Since lampreys spend time in salt- and freshwater, they have chloride cells in their gills to help regulate salt concentrations. Along with regulating salt, chloride cells serve as a site for ammonia excretion as well. Lamprey, like other cartilaginous fish, have a lateral line system that contains cells that allow electroreception, mechanoreception, and photoreception.
Electroreception is the process of locating prey by detecting weak electrical signals in the water produced by organisms. Chondrichthyes use this system to locate nearby potential prey, and it is assumed lampreys do the same (Bodznick and Northcutt, 1981). Electrophysical responses can be sensed in lampreys in the dorsal medulla, a portion of their brain (Bodznick and Northcutt, 1981). It is assumed lampreys use mechanoreception to detect changes in pressure in the water, but its exact use is largely unknown. The caudal region of the lateral line contains most of the photoreceptors. Tests have shown that when the tail was illuminated it causes the animal to swim forward or perform left and right turns (Deliagina et al, 1995). The purpose of this is thought to be a way to keep the animal out of bright areas to prevent being predated upon (Deliagina et al,
1995).
Seaworld is a giant marine life theme park. The greatest attraction to these many theme park would be those killer whales. In fact, these killer whales are the face of the park. As gigant as these mammals are, seaworld is keeping them in some pretty tight quarters. Mr. Jett and Mr.Ventre says “Wild killer whales can swim a hundred miles daily as they socialize, forage, communicate, and breed. In stark contrast, with little horizontal or vertical space in their enclosures, captive orcas swim only limited distances, with most spending many hours surface resting.” The animals don't have the freedom they need. Also when taking the whales out of their natural habit the whales tend to be depressed and not as heath in that situation. They need their freedom in the big ocean blue. Bring them into the small living units, breeding whales in captivity all for the entertainment of humans. At young ages the calves are taken away from their mothers on to a new seaworld park. Mothers of the calves have even been seen denying their offspring.
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.
Barlow (1953) first postulated the existence of feature-sensitive ganglion cells in a frog’s retina based on an inhibitory-surround structure of the receptive field. He maintained that the “on-off” units of these cells triggered by the presence of a particular stimulus corresponded to certain behaviour in the frog. For example, presenting a spot of light in the visual field would cause certain neurons to fire in a particular ganglion cell, and in a live frog, would cause the frog to snap at the stimulus. Barlow concluded that these cells must be “fly detectors”. Lettvin et al. (1959) further examined the visual mechanisms of the frog and discerned fo...
...s in the water, as well as quick change in pace and direction. This again is to evade predation.
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.
Whales living in captivity become aggravated and have been known to take out anger on themselves by self harming. In the pools they live in, metal bars are placed in between the pools to prevent the killer whales from swimming to another pool. On several occurrences, the whales have attempted to bite and break the metal bars. This leaves the whales with broken teeth and a risk of infection. Infections in killer whales can lead to death in many cases. If a whale gets an infection, they have to be taken out of the pool and placed into another pool by themselves to prevent any problems with other killer whales they live with. In many cases, whales with infections need serious care from whale specialists.
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.
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.
The most unique feature of the platypus is the soft and pliable bill. The bill surface is perforated with openings that contain nerve endings, which allow the animal to locate food and aid movement under water. These pores contain two types of sensory receptors: mechanoreceptors, which respond to tactile pressure, and electroreceptors, which respond to electric fields. The eyes and ear openings are located behind the bill in a muscular groove, which contracts and closes as the platypus dives (Griffiths, 1998). The nostrils are positioned towards the tip of the bill and are slightly elevated upwards to allow breathing whilst the body is beneath the surface (Figure 1).
“The Shocking Predatory Strike of the Electric Eel” by Kenneth Catania addresses electric eels (Electrophorus electricus) have the ability to sense desired preys and fight against undesired predators. Since the body of these fishes are composed of electrolytes, they are capable of this action by releasing high voltage electrical discharges. The discharges then invade the targeted prey’s muscles and causes involuntary actions. Kenneth Catania conducted an experiment to see how the electrical eels carry out the electric discharge mechanisms on targeted preys and the effects it has on the prey. According to Catania, electrical eels “emit three distinct types of electric organ discharges” (Catania, 2014, p. 1231).
A big change that has occurred in the oceans all over the world is the Coral Reefs are dying and are predicted to be dead by the end of the century due to the rising acidity of the oceans caused by many different threats to marine ecosystems. Coral reefs cover less than 0.2% of our oceans but they contain 25% of the world’s marine fish species according to Endangered: Biodiversity on the brink, 2010: pg.45). If this is the case that means by the time the end of the century comes around we will have lost close to 25% of the worlds marine ecosystems.
Whitaker, David J, Rachael King, and David Knott. "Jellyfish." Sea Science. Web. 7 Jan. 2014. .
The morphology of whale sharks is mostly similar to aquatic fish species, but many specific traits help differentiate them from the rest. Whale sharks are the largest fish in the world and can reach a size of around 20 meters (Martins, C., and C. Knickle). This is often compared to the size of a school bus. The shark has a very large transverse mouth. They have 5 very large gill slits and have a larger first dorsal fin compared to the second one (Whale Shark). They have a distinctive spotted “checkerboard” pattern with stripes (Martins, C., and C. Knickle). It is not exactly known why they have this specific body marking. It is believed that the body markings act as a camouflage. The strange thing about whale sharks is that they have 300 rows of teeth that play no role in feeding (Martins, C., and C. Knickle).
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 any 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. The whale shark is a species with a fascinating ecology, life history, behavior, anatomy