Is the whale shark an upper-level carnivore?
An upper-level carnivore — such as the Shortfin Mako (Isurus oxyrinchus) — is removed from the tiny, planktonic photosynthesizers at the base of the epipelagic food web by four or five trophic levels. In comparison, the Whale Shark feeds primarily one or two trophic levels above the phytoplankton.
What is a whale shark?
The whale shark ( Rhincodon typus) is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of 18.8 m (61.7 ft). The whale shark holds many records for size in the animal kingdom, most notably being by far the largest living nonmammalian vertebrate.
What is a trophic level?
A trophic level is the group of organisms within an ecosystem which occupy the same level in a food chain. There are five main trophic levels within a food chain, each of which differs in its nutritional relationship with the primary energy source.
What is the habitat of a whale shark?
The whale shark inhabits all tropical and warm-temperate seas. The fish is primarily pelagic, and can be found in both coastal and oceanic habitats living in the open sea but not in the greater depths of the ocean, although it is known to occasionally dive to depths of as much as 1,900 metres (6,200 ft).
Are whale sharks carnivores?
Habitat and diet Though Whale Sharks have several hundred teeth, they don't use them to eat. Instead, these fish are filter feeders, swimming forward to swallow prey. They are carnivorous, eating krill, crab and fish larvae, small schooling fish, and jellyfish. Humans are not on the menu.
Are whale sharks Planktivores?
The Whale Shark is the largest species of extant shark. Unlike most sharks, they are planktivores: slow-moving filter feeders that feed exclusively on microscopic plankton.
What are whale sharks adaptations?
The whale shark is well adapted to its environment. Its monumental size is its greatest protection and adults have little to fear from natural predators except for humans. It has a very efficient feeding mechanism and its somewhat opportunistic diet provides a broad base of food supply.
Are whale sharks found in coral reefs?
Whale sharks have a broad distribution in tropical and warm temperate seas, usually between latitudes 30°N and 35°S. They are known to inhabit both deep and shallow coastal waters and the lagoons of coral atolls and reefs.
What family is the whale shark in?
RhincodontidaeWhale shark / Family
Has a whale shark ever killed a human?
No, no whale shark has ever killed a human. There has been no record of these fish attacking human beings. Apart from the naturally calm demeanor, whale fish do not use their teeth. So, they cannot bite humans or kill them. Neither can they eat dead human flesh.
How many whale sharks are left 2021?
No one knows for sure how many whale sharks are in these waters, but the best estimate is 1,400. The global whale shark population may number in the hundreds of thousands.
What eats whale shark?
Although adult whale sharks don't have much to fear from predators, juveniles and old or sick whale sharks are preyed upon by a variety of fish, including sharks and blue marlins. They are also vulnerable to predators such as killer whales and humans also hunt them in some areas of the world.
Is whale shark a whale or shark?
They're not whales, but the world's largest fish These huge creatures can grow up to 39 feet long. But despite their size, whale sharks are often referred to as "gentle giants."
What role does the whale shark play in the ecosystem?
Whale sharks are plankton-patrollers – these toothless sharks can eat more than 20 kilograms a day! When ocean waters are rich in plankton, it shows the water is full of nutrients and the ecosystem is healthy.
Is it illegal to touch a whale shark?
It's easy to get focused on the sharks that are in front of you but don't forget to notice the ones behind you. It is illegal to touch a whale shark, so make sure to swim out of the way if one swims toward you. There's no mistaking their large size and tremendous power, especially of their tail!
Are whale sharks mammals?
Unlike whales, sharks are not mammals but belong to a group of cartilaginous fishes. The whale shark (Rhincodon typus) earns the name “whale” solely because of its size.
Where are whale sharks found?
The largest aggregation of whale shark ( Rhincodon typus Smith, 1828) in the world occurs in the north of the Mexican Caribbean from Holbox to Contoy Island, and includes the Marine Protected Area Yum-Balam and the Whale Shark Biosphere Reserve (de la Parra et al., 2011 ). The greater abundance of whale sharks occurs from May to September, near Cabo Catoche, the northernmost point of the Yucatan Peninsula. This aggregation coincides with an increase in primary productivity caused by an upwelling that occurs when the Yucatan stream hits the continental slope and emerges as a water mass, producing a high saturation of nutrients (Merino, 1997; Cárdenas et al., 2010; Ramírez et al., 2012 ). As a result, this part of the continental shelf becomes a zone of high biological activity with an abundances of diet items for R. typus, such as fish eggs, larvae of gastropods, sergestid, chaetognaths, appendicularians, and squid (Compagno, 1984, 1998; Cárdenas et al., 2010 ).
What is the trophic level of Rhincodon typus?
Rhincodon typus reached a trophic level of 3.13 , close to that obtained by M. birostris (3.03) which feeds also on zooplankton. MTI results showed that R. typus propagated negative effects on hogfish, large pelagic fish, and seabirds, and positive effects on snappers, groupers, and omnivore fish. On the other hand, the groups that produced higher negative direct and indirect effects on R. typus were soft corals, small benthic epifauna, and medium carnivorous reef fish 1. In contrast, the groups that enhanced positive effects on whale shark were zooplankton, phytoplankton and detritus. Ecosim ’s simulations showed that when whale sharks are disturbed, resilience of the system is equivalent to 55 years of SRT under a mixed control scenario, and 9 years under a bottom-up control scenario (Table 3; Supplementary Appendix D).
How many functional groups are there in the trophic model?
The trophic model was built with 28 functional groups and eight individual species ( n = 36). The functional groups of fish were based on their habits (pelagic, benthic or associated to coral reefs), trophic groups, diet, caudal fin shape and size, maximum-minimum length and weight (Randall, 1963; Opitz, 1991 ). Species of commercial and tourist interest were considered separately to analyze their functional role in the ecosystem. Biomass ( B) for fish, corals, sea grass, and macroalgae were obtained from field observations. Field surveys were carried out from April of 2006 in five locations identified with local names as Corsario, Punta Mosquito, Piedra Corrida, Boca Nueva, and Cuevones. At these sites, 60 visual census were performed for the quantification of fish (50 × 2 m) and invertebrates (20 × 5 m), and 30 video-transects to record benthos (50 × 0.4 m). Biomass of dolphins, birds, snook, shark, some carnivorous fish, octopus, whale shark, spotted seatrout, Manta birostris, schooling fish, lobster, turtles, and manatee were taken from published literature, or well, estimated from fishing mortality and catches. Other input parameters as production ( P ), consumption ( Q) and diet items were taken from the scientific literature, while catches ( Y) were obtained from official statistics published by the federal agency SAGARPA (Secretariat of Agriculture, Livestock, Rural Development, Fisheries and Food). Supplementary Appendix B shows the functional groups and their corresponding species (Supplementary Appendix Table B1), as well as data sources used to build the Ecopath model (Supplementary Appendix Table B2).
What is mixed trophic impacts?
The mixed trophic impacts (MTI) is an Ecopath subroutine that analyzes the direct and indirect trophic relationships between functional groups, and assesses the impact of increased biomass of one group over the other functional groups and the potential cascading effects within the ecosystem (Ulanowicz & Puccia, 1990 ). Short-term dynamic simulations of Ecosim were used to assess the propagation of direct and indirect effects through the network (Supplementary Appendix A). Ecosim took into consideration the criteria of Ortiz et al. ( 2009) with the following flow controls: bottom-up ( v = 1.0), mixed ( v = 2.0), and top-down ( v = 6.0). The purpose of these criteria was (i) to test scenarios with different flow control perturbations; (ii) to assess the propagation of instantaneous direct and indirect effects; and (iii) to calculate the system recovery time (SRT), in response to increased total mortality ( Z) (i.e., Z = M + F, where Z is total mortality, M is natural mortality and F is fishing mortality) equivalent to 30% of total production ( P ), where P = B * Z. The impact was caused between the second and the third year of the simulation. Consequently, the instant effects propagation was calculated as the change in biomass of all functional groups in the third year, i.e., one or two years after increased fishing mortality occurs. This was useful to estimate and analyze the resistance of the system and the SRT and, thus, providing an internal measure of stability of the system (Ortiz et al., 2009 ). For details see Supplementary Appendix A.
What is a trophic level?
Trophic Level Definition. A trophic level is the group of organisms within an ecosystem which occupy the same level in a food chain. There are five main trophic levels within a food chain, each of which differs in its nutritional relationship with the primary energy source. The primary energy source in any ecosystem is the Sun (although there are ...
Which trophic level is herbivore?
The second trophic level consists of herbivores, these organisms gain energy by eating primary producers and are called primary consumers.
How do apex predators affect the ecosystem?
Apex predators play an extremely important role in an ecosystem; through predation they control populations of the lower trophic levels. If apex predators are removed from an ecosystem, organisms such as grazing herbivores can over-populate, therefore placing intense grazing and browsing pressure on the plants within a habitat.
What happens to the ecosystem if there are fewer available plant resources?
If there are fewer available plant resources, other organisms that depend on the plants (although are not hunted by the apex predator), such as insects and small mammals, will suffer population declines, and in turn can affect all trophic levels within an ecosystem.
What are some examples of disruption within one of the trophic levels?
However, disruption within one of the trophic levels, for example, the extinction of a predator, or the introduction of a new species, can have a drastic effect on either the lower or higher trophic levels.
What is the term for an organism that gains a portion of its energy intake from the tissues of other animals?
Carnivore – An organism that gains a portion of its energy intake from the tissues of other animals. Herbivore – An organism that obtains its energy solely from plant material. Trophic cascade – The occurrence of a predator suppressing the population size of lower trophic levels.
Do trophic levels have a uniform chain?
It is important to note that organisms within the trophic levels of natural ecosystems do not generally form a uniform chain, and that many animals can have multiple prey and multiple predators; the non-linear interactions of trophic levels can therefore be best viewed as a food web rather than a food chain.
How big are whale sharks?
Most whale sharks observed are 6 to 12 m (19.7 to 39.4 ft) in length. As is the case with many shark species, females tend to be larger than males. Diet. It is interesting that the largest fish in the world utilizes small food items for its nutrition.
What is the temperature of a whale shark?
It prefers warm tropical water, in a range of 21 to 25 o C (69.8 to 77 o F), but is more content when the warm water is interspersed with cooler, nutrient-rich upwellings that provide a good source of food.
Why do whale sharks have checkerboard pigmentation?
One reason given for the unique checkerboard pigmentation of the whale shark is an adaptation for radiation shielding, an advantage in animals that spend a significant amount of time near the surface of the water where they are exposed to high levels of ultraviolet radiation.
Why are whale sharks declining?
Populations have declined largely due to harpoon fisheries and bycatch. The whale shark is listed by the IUCN Red List as vulnerable. It is listed in CITES Appendix II. It is protected in Australia, the Maldives, the Philippines, and the United States.
How do sharks feed?
This filter-feeding shark may feed passively by simply opening its mouth while it is swimming. It may also feed actively by jutting out its jaws, gulping water into its mouth, closing the mouth and forcing the water through the filtering system and out the gill slits. These sharks have been observed hanging vertically in schools of baitfish while sucking the baitfish into their mouths.
Why do whale sharks migrate?
Their movement has been attributed by some researchers to timing with plankton blooms and changes in water temperature. They are primarily solitary animals, but on rare occasions are observed in aggregations of 100 or more individuals. The reasons for the aggregations are not well understood.
What color are shark fins?
The underbody is white or cream colored. The sides and back have a darker base color with shades of blue, gray, and brown. Vertical and horizontal lines of cream or white create a checkerboard appearance with round spots in the squares giving the impression of checkers on a board ready for play. The dark shaded fins are irregularly marked with round, light colored dots.
What is the first trophic level?
The first trophic level consists of primary producers gathering energy from the sun, which will be passed up to herbivores, then multiple levels of carnivores (source: nau.edu). Food webs are often pretty short, which confused many scientists for a long time.
What do whales eat?
With all of this in mind, it still may not make sense as to why such a large animal would feed on some of the smallest organisms in the ocean. Blue whales, which can be 20-30 meters long, feed on shrimp-like krill that are a mere 2-3 centimeters long. As stated above only ten percent of the energy obtained from one trophic level gets passed along to the next trophic level. For this reason, ecosystems with longer food chains are proven to be, on occasion, less stable than those whose food chains are shorter (Sinclair et al. 2003). Therefore, it is more advantageous for the whale to eat animals on a trophic level in which there is more energy available to be taken in. Hill et al. 2018’s textbook Animal Physiology describes this concept in more depth. In it, they contrast two different possible mechanisms by which a whale can obtain food. One is for the whale to eat fish that are somewhat smaller than themselves. These fish can potentially eat fish that are slightly smaller than themselves, and so on. In this case, there are many trophic levels that the energy will have to pass through before reaching the whale. To apply the ten percent rule directly, we can say that the primary producer produces 10,000 units of energy obtained from the sun. The crustaceans that feed on the producer will generate 1,000 units of energy, from which the small fish that feeds on them will produce only 100 units of energy. The larger fish that feeds on this fish will produce only 1 unit of energy, which may not be enough to sustain the large whale. This is why Baleen whales have evolutionarily evolved into suspension feeders, using Baleen plates to take in large amounts of water and sift through to find small krill. The Baleen whales can eat organisms much smaller than themselves, which can cut down the trophic levels between primary producer and the whale itself, making the energy available to the whale population 1,000 units, as opposed to only 1. In summation, shortening the food chain will in turn increase the food energy available to the whales by a factor of 1,000 (Figure 3) (Hill et al. 2018).
Why is krill important to the Blue Whale?
For example, now that it is known that krill play an extremely important role in the survival of the Blue Whale, agencies can implement new ecological management strategies to be sure that krill populations are not significantly affected by anthropogenic impacts.
Can whales eat fish?
One is for the whale to eat fish that are somewhat smaller than themselves. These fish can potentially eat fish that are slightly smaller than themselves, and so on.
What do whale sharks eat in captivity?
Whale sharks are feed in captivity diet the same diet as they are in the wild; planktons, lots and lots of them.
What do whale sharks eat?
Whale sharks feed primarily on zooplankton such as krill, crab larvae, fish larvae, copepods, shrimp, fish eggs and chaetognaths. They also feed on phytoplankton such as algae and other plant materials when their primary food items are unavailable.
What is the process of whale sharks filtering food from water?
Researchers believe that whale sharks use a method of filtering known as cross-flow filtration to separate food from water.
What happens when whale sharks cough?
Every so often, the lower filtering pads of the fish gets clogged by food particles blocking the spaces, and the whales sharks rise to the surface of the water and cough, releasing bolus of whiteish substances (or rather food particles) from its mouth.
How do whale sharks quench their thirst?
Whale sharks naturally quench their thirst by absorbing little water through their gills, “by means of osmosis ; because they are naturally more salty that their surrounding environment”.
How do baleen whales feed?
In the method, the whale goes below the surface of the ocean and swim forward with its mouth wide open in order to gulp plankton bearing water. No suction involved.
How fast do whales swim?
In this mode of feeding, the whale simply lurks onto the surface of the ocean and swims forward (at a speed roughly about 1.2m/s) ramming plankton bearing water into its mouth and filtering out the food using its gills.
What is the trophic pyramid of a great white shark?
Biomass is the amount of living or organic matter present in an organism. This is the trophic pyramid for the great white shark. The great white shark trophic pyramid starts with kelp, that then gets eaten by different kinds of zoo plankton. After the zoo plankton come the small fish which get eaten by the bigger fish.
What is the trophic pyramid?
Trophic Pyramid Information that is in video: An ecological pyramid (also trophic pyramid, energy pyramid, or sometimes food pyramid) is a graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem. Biomass is the amount of living or organic matter present in an organism.
What happens after the zoo plankton?
After the zoo plankton come the small fish which get eaten by the bigger fish. The tip of the pyramid is the shark which eats the big fish. The energy exchange happens from the bottom to the top. The kelp has all the energy and passes it along to the next thing that eats it.
