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 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
Its body and dorsal surfaces have patterns of light spots and stripes over a dark blue background. The whale shark’s length ranges from 12 meters up to 20 meters on average. Females typically grow to be bigger than the males and weigh anywhere from 47,000lbs to 66,000lbs as adults. It is estimated that this species average lifespan is around 70 years, though accurately measurements have proven difficult (Stevens 2006). Rhincondon typus is known to be primarily a loner traveling by itself the majority of the time, although they are known to seasonally aggregate in specific areas.
Life cycle Due to the large expanse and sheer size of the whale shark much of the species lifecycle is unknown. Although in recent years some aquariums have created exhibits large enough to contain the whale shark enabling more thorough research. It is largely speculated that the ratio of male to female whale sharks dictate the structure of their mating system (Martin 2007). Rhincodon typus are oviparous giving birth to live young and have been documented to carry up to 300 embryos at one time. Female whale shark’s will give birth to numerous batches of pups in short succession and may rest up to a year after giving birth before mating again. The large size of the litter and rate of birth suggests a very high rate of neonatal mortality. Young pups will stay with their mother for an undetermined amount of time until they are
At maturity males are typically close to nine meters in length with the females being slightly larger. Throughout its adult life the whale shark is mostly solitary traveling alone and staying to itself. Due to the size of it doesn’t have many predators though on occasions killer whales have been known to attack Rhincodon typus (Rowat 2012).
Structure and Function The lorenzini is a pit-like organ located on the head of the whale shark that senses weak electrical and magnetic fields. This is an area that is currently being researched extensively and is largely unknown. It is speculated that this organ is used by the whale shark as a navigational aid through using the earth’s magnetic force (Rowat 2012).
Evolution
Studying the evolutionary history and adaption for this species is difficult and an ongoing struggle for scientists. It is classified in the order of Chondrichthyes suborder Elasmobranchii and family of Rhincodontidea. The difficulty in tracing this species evolutionary history stems from the fact that its ancestry dates back 245 million year ago to the Jurassic and Cretaceous
The Great Shark debate – to cull or not to cull, has been at the forefront of the minds of conservationists, as well as the general population for many decades now. The opinions of everyone are divided, according to their personal experiences, and views on what is right and wrong for the environment.
Monodon Monoceros, Latin for “one tooth, one horn”#; or Narhval, Norwegian for “corpse whale” , because of it mottled coloration suggests a bloated corpse#.Narwhals are in the white whale family, along with the beluga, but are actually covered with spots of black, white, gray-green, and cream. Newborns are dappled gray-brown, white spots come with age#. At birth the calves are about 5 feet long and 180 pounds. Male Narwhals can reach 16 feet long, not including the horn which is 8 to 9 feet long, and weigh around 3000 pounds. Females are around 13 ft. long, do not have tusks, and weight around 2000 pounds. Adult males and females are usually dark in the area of the head, especially top of the head and upper and lower jaws#. Unlike most other whales, Narwhals have no dorsal fin, instead they have a low bumpy ridge that begins at about the midpoint of the back and continues to the fluke#.
One of the things this company claims is that the killer whales actually live longer in their care. According to the website Sea World of Hurt, this is completely false, killer whales in the wild have a similar life span to humans, they can live from anywhere to 50-100 years. Held captive, these animals hardly live past twenty-five years. In the wild, an orcas dorsal fin is straight, which is the way it should be. In captivity, you will mostly see their dorsal fins flopped over or completely collapsed.
In warmer waters Bull Shark mating occurs year-round while mating females usually receive mating scars on their dorsum, “the back or outer surface of an organ…” (“dorsum”). They typically carry from one to thirteen pups at one time for ten to eleven months. When the female Bull Sharks gives birth it gives birth to free swimming, live young in their nursery grounds that are again, in areas with low salinity and shallow waters (Curtis). The Pups that survive will be around 56 to 81 centimeters long at birth, and grow approximately to be around 340 centimeters when fully matured (Simpfender & Burgess). Female Bull Sharks are typically larger than males when fully grown and mature; the lifespan for both males and females is around 16 years (Curtis). Females on average are around 180 to 230 centimeters long and 285 pounds, and males on average are around 157 to 226 centimeters and 209 pounds, but the biggest known Bull Shark was reported to be 11.5 feet and 500 pounds (Simpfender and Burgess; Curtis). “Bull sharks are pale to dark grey [on their dorsal, and fade] to white on their [ventral, but on] younger individuals the fins have black
Orcinus orca is the scientific name for the massive marine mammal. Orcas are not rare, but have declining numbers in some areas (Martin.) Orcas are found from the Artic Ocean to the Antartic Ocean. (Britannica) They belong to the Delphinidae, or dolphin family, which is the largest of their species. Female orcas grow to be at the most 15 feet, and weigh up to 4 tons, but the males can grow as large as 20-30 feet, and weight up to 8 tons. (Martin) The color of the orca is white in some spots, black on the majority of the body, and gray just behind the dorsal fin. It is white on the chin, belly and the eye. The white patch above the eye is usually mistaken for the eye, and may confuse their prey, but acts as a camouflage for the eye. The name “killer whale” makes people tend to believe that this is a viscious man-eating mammal, yet it is one of the most shrewd, docile and playful species of the marine mammals. The orca is sexually mature at 10-15 years of age, much like humans, which is 12-13 years of age. They tend to mate year round, and is able to have a calf every two years. It is interesting to know that lactation of the mother lasts 12 or more months (Wynne.) The life expectancy of orcas is 45-50 years of age.
Their dorsal fin is extremely long, tampered and pointed in a triangular shape or rounded and curved towards the end. The skull is oval shaped and the beak is extremely short and rounded at the end. The killer whale’s jaw is powerful with teeth that are able to tear apart flesh of their prey. They can withstand the jolting, wiggling and hurtling movements of prey that are trying to escape. The killer whale is born with a single blow hole instead of two. Their flippers are paddle shaped with rounded ends and flukes are tapered back and pointed at the end resembling to a triangle/pyramid
Orca whales are the largest members of the dolphin family. Orcas are very curious creatures, they like to sky hop, which is when they poke their heads out of the water and look around, and they can also dive to as much as a hundred feet. These social animals live in pods and stay with them for their whole lives. They are so family oriented that they can may sleep together in a tight circle and have synchronized breathing. Orcas can grow up to thirty-two feet and can weigh nine tons. They typically eat five percent of their body weight and are amazing hunters. The lifespan of an orca in their natural habitat is about fifty years. This lifestyle for them is wonderful because they can swim as far as they want to and are free. Orcas should not be held captive because the capture process is dangerous, it is not good for their health, and their trainers are at risk. Free Willy. Dir Simon Wincer. 1993.Video. Warner Bros Home Video
Shirihai, H. and B. Jarrett (2006). Whales, Dolphins and Other Marine Mammals of the World. Princeton, Princeton University Press. p.185-188.
As shown in the figure A, a blue whale has a mottled bluish with broad flat head and a small dorsal fin located near the tail. Figure C furthers shows the morphology of a blue whale. A blue whale can have about “320 black baleen plates in the mouth, 2 blowholes, and many blue-gray white spots” (ZoomWhale). A blue whale is toothless, and this can be a problem when scientist tries to date the age of animal based on it’s teeth. However, it is estimated that a blue whale can expected to live past 50 years (NOAA and World Wildlife).
Orcas, or killer whales are majestic giants of the sea. They are actually the largest type of dolphin. They have long black bodies with distinct white patches near their eyes. A killer whale can be up to 32 feet or more in length, and weigh up to 12,000 pounds. Females are a bit smaller, but live longer (Gorman). The name “killer whale” apparently came not because it is a vicious whale, but because it preys on whales. They do not have any natural predators, and they are considered the “top dog” of the ocean. Not even the great white shark stands a chance against these superb killers. “Unlike sharks, killer whales are cautious hunters, sometimes spending hours harassing a 1,000-pound sea lion so it can easily be drowned” (Francis). Orcas use many hunting tactics that are unique to their species, which is what makes them invincible.
In 2015 only 59 shark attacks have occurred around the world compared to the millions of sharks killed by humans every year. Due to these accidental shark attacks people tend to think that sharks, especially Great Whites are evil creatures with malice intentions when attacks do occur; but, on the contrary that is wrong. Sharks are not the only beautiful and unique creatures in the ocean, they also play a vital role in our ecosystem; however, due to human interference they might not be around much longer, through awareness sharks can be protected from endangerment.
Thesis: Sharks should be conserved because they are an important part of the ocean, attacks are often incidental, and human behavior influences the behavior of sharks.
Most people think that sharks are large, fast-swimmers, and savage predators. This is true of some species and groups should be interested of the appealing aspects of biology found within it: all sharks have an excellent sense of smell; some can detect electrical discharges; some sharks give birth to one of the
Whale sharks were named Rhincodon typus by Andrew Smith, in 1828. The naming was hard due to the similarities between the family Ginglymostomatidae and the family Orectolobiformes. The closest relatives to the whale shark are nurse and zebra sharks. The whale shark is the only species in their family, Rhincondontidae. Whale sharks...
When Indo-Pacific Humpback Dolphins are first born, they are dark gray and get lighter as they grow older, sometimes this will cause spots (WCD). According to Whitfield on page 114, when the Indo-Pacific Humpback dolphin is young it has a normal streamlined body figure, but when it grows older it start to form fatty tissue humps. They have the average lifespan of 40 years (WCD). The Indo-Pacific dolphin can be between 6 ½ feet to 10 feet long with 120 teeth in their long beak. Using their long beak to eat, these dolphins swim up to the shallow waters and hunt for fish (Whitfield 114). Indo-Pacific dolphins are not the only type of dolphins that pray on the