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Any shark lover knows that not all sharks are fierce predators with a mouth full of teeth. The whale shark, the largest shark, feeds on millions of tiny plankton in massive gulps, and is a favorite species recognizable by most. But the elusive megamouth? In fact, shark scientists know very little about the basic biology of megamouth sharks.

How is it that we know so little about the third largest shark in the world? Megamouth sharks live far offshore and likely spend much of their time deep underwater. Just over megamouth shark sightings have been recorded since their discovery and many of these were the result of entanglement in fishing gear. A few specimens, like the one newly acquired by the Smithsonian National Museum of Natural History , are preserved in museums and institutions and are the basis for a lot of what we know about them.

It was only relatively recently that scientists became aware of this large shark. With a wide, gaping mouth, prominent eyes, and tadpole-like body shape, this goofy looking catch baffled the crew, since its appearance was very different from the typical shark. Due to its expansive mouth, the shark was named the megamouth. We now know that the goofy appearance is partly due to how the shark feeds. Instead of relying on teeth, megamouths are filter feeders, meaning they sift out small plankton like krill from the water.

Including the megamouth, there are three species of filter feeding sharks—the whale shark and the basking shark round out the bunch. But despite sharing a similar feeding strategy, the three are not closely related and it is likely that they each evolved filter feeding independently.

In both feeding strategies water continuously flows out the gills. And to feed like whale sharks—with a sharp inhale that sucks in water in the immediate area— requires stiff jaw cartilage to quickly open the mouth. They can, however, expand their mouth to an enormous size, even compared to the other filter feeding sharks. This allows them to consume close to gallons of water in one gulp—the amount of water held by two standard bath tubs.

While other sharks may not feed in a comparable way, that does not mean it is completely novel in the marine world. To understand megamouth feeding may require looking beyond sharks to another large finned creature—baleen whales. Species like blue and humpback whales engulf their prey in gigantic gulps and then slowly sift the water back out through their baleen. For now, the life of the megamouth remains a mystery.

In the absence of an observation of the megamouth feeding, scientists turn to the next best thing. In this case, that includes comparing the anatomy of the available specimens to the anatomy of other filter feeders.

Until that million-dollar shot, we can only imagine and revel in the knowledge that a massive shark still leaves us stumped. Skip to main content. When hauled up on deck in , this megamouth became the first specimen viewed by people.

US Navy. A large basking shark can filter , gallons of water through its mouth per hour. Flickr User jidanchaomian. Tags: Sharks. Search Smithsonian Ocean.


Fascinating Filter Feeders.The Whale Shark (Rhincodon typus)

Whale sharks Rhincodon typus and manta rays (Mobulidae) possess reticulated gill rakers in the shape of filtering pads covered by dermal denticles that may. Download Free PDF During surface ram filter feeding, sharks swam at an average velocity of m/s 3 demonstrated to feed on squid and cuttlefish.


3 filter feeder sharks free download. Please wait while your request is being verified…


They also face as the animal swam toward the observer. Video images were recorded with either a al. Software, Inc. Materials and methods 2. Habitat use 2. On only two of these days no whale sharks continental shelf near Isla Holbox and Isla Contoy, north of Cabo were seen.

Aerial surveys were conducted from a Cessna airplane or expressed as a percent count of total composition. A total of sharks of seawater was calculated. The total plankters measured. Random sampling was ensured number of sharks sighted per hour of observation for each hour by marking the sorting dish into subsections and using a random of the day from to was compiled for the combined number generator to pick which subsections, and subsequently boat and aerial observations.

The aerial observations most likely plankters, to sample. Length and width were taken for most of included pseudoreplicated sharks that were counted more than the plankters except for shrimp where depth replaced width.

All once on different days. Measuring criteria varied among species. For shrimp, were tagged with pop-up satellite archival transmitting tags PAT2, length was taken from the base of the eyes to the tip of the telson, PAT4 and MkPAT versions; Wildlife Computers, Redmond, WA, and depth was taken at the posterior region of the cephalothorax. USA in the study area, following procedures outlined by Wilson For copepods, amphipods and chaetognaths, length was taken from et al.

Each PAT tag was attached to a stainless steel dart the most anterior to the most posterior portion of the body. When a surface-swimming shark measured. Nutrient analysis ahead of the moving shark.

Total dry matter was measured using a forced air oven at mal for a user-determined duration. Total fat was determined using a hex- tether and came to the sea surface, it transmitted summaries of its ane extraction process AOAC, , protein was determined using archived data through the Argos satellite system. Gross energy was determined hour of the day. The 2. Open mouth width-to-height ratio samples in and , respectively.

Tows lasted s. The remaining measure. The two female specimens C and D were restrained sample was collected in a ml light-protected plastic Nalgene without anesthesia and measurements were taken. From the above bottle and placed on ice for later nutrient analysis. Samples for measurements various ratios of each measure to total length were the determination of nutrient content were frozen for transport calculated and means taken, as well as ratios of landmarks such as once returned to port.

Total plankton weight per tow was deter- open mouth width and height to internasal distance. The tissue was subsequently stored frozen area and thawed for the following measures. Of the 21 available of 40 total pads 10 from shark A, 11 from shark B , nine 1 cm2 sampling The mesh possesses an irregular geometry so the mesh diameter was measured at the shortest or All L4 measurements were averaged to estimate mean mesh diameter per pad and for all pads combined. Open area ratio When multiplied by the combined total area of all The height and spacing of the primary and Lower pads secondary vanes Fig.

The height of the channel was taken as the length of the under- 0. Digital images were analyzed with SigmaScan Pro software. The volume of water entering the mouth was calculated using a Thus, the pressure within the buccal cavity was esti- This illustration is, with permission, based upon a copyrighted illustration by Emily S.

The most posterior lower pad at the bottom is triangular in shape, and the lateral side of the pads is to the left. The lateral raphe between the lower and upper pads is visible toward the left. All other soft tissue has been removed.

White ruler is 15 cm. Because it is an upper pad, lateral is to the left and posterior toward the top. Upper pads are not as falcate on their medial margin as the lower pads. Note that the secondary vanes direct water laterally into the parabranchial chamber and over the gill tissue gt before it exits the pharyngeal slit not shown. White square is 1 cm. Note that the majority of the open mouth is underwater and a bow wave is formed by the lateral edges of the mouth.

Hourly percent time spent in surface waters 0—1 m by satellite tagged whale entrance region Ward-Smith, Lastly, it was assumed that sharks in the study area. The reported percentages are weighted averages of four sharks representing 67 days of archival depth data.

Overall, the four sharks spent an average of Mouth and mesh dimensions were taken as the average of the measured morphologies, mesh holes were assumed was 1. When visible, the laser calibration very unbalanced sample sizes. Plankton densities between the shark as measured by GPS.

Flow around the lateral edges of the feeding and non-feeding control sites were compared by a two- mouth formed by the labial cartilages formed a bow wave such tailed t test after ln transformation, and similarly, plankton biomass that water medial to each bow wave entered the mouth Fig.

Swimming speed of the feeding see also electronic supplements Shark 6 aerial view of surface animals was related to total length with a linear regression. All tests were conducted with an alpha level of 0.

Time between coughs ranged from 3. Vertical suction feeding The experiments and observations conducted during this was not observed. Animal Care Committee. Expressing these combined data as an hourly weighted average revealed a pattern of greater surface swimming in the morning 3. Results —, Field observations afternoon —, Overall, these sharks spent on In , and , a total of 33 whale sharks ranging in size average The average water temperature was the satellite-tagged sharks with the number of sharks per hour The few boat dry weight.

Likewise, plankton biomass was about 2. Plankton composition, size and nutrient analysis than at non-feeding sites 1. In the feeding areas, plankton was dominated by sergestid shrimp In non-feeding areas, plankton was domi- nated by calanoid copepods Internasal feeding areas ranged from 0.

In the non-feeding areas the length ranged width was 0. Based on open mouth internal heights, the from 0. The anterior upper valve was 3 cm and the poste- cent of total wet weight , mean lipid content was 0.

Mean calculated gross energy midline. The lower pads were larger in area than the cor- responding upper pads Table 1. The most posterior pads were the largest. A similar raphe also ran medially, joining the right and left pads dorsally and ventrally.

This tissue was connected to the pharyngeal wall anteriorly and to the entrance of the esophagus posteriorly, such that water must pass through the pads to exit to the parabranchial chamber and eventually out through the pha- ryngeal clefts. Standard errors are the funnel or the narrow aperture, without clearly explaining which measure they indicated.

Feeding behavior the most posterior hemibranch and into the parabranchial chamber before exiting through the pharyngeal clefts. Average mesh diameter was 0. During 1. For instance, white sharks Carcharodon carcharias , Linnaeus perform vertical and horizontal predatory lunges against surface prey Bromilow and Webb ; Martin et al. However, this behavior is quite rare for the whale shark and has been reported only in multi-species feeding frenzies.

In the second event, the only marine predators observed were whale sharks and a sea lion. The anchovies did not form a tighly packed bait ball formation at the surface as in the first event when we observed whale sharks lunging.

Instead, we observed whale sharks remaining stationary near the anchovy school. This behavior was different from the stationary feeding previously observed in this area, because whale sharks were not feeding in this case. Therefore, this is likely a behavior known as “sit-and-wait”. In this feeding strategy, the animal waits for the prey to cross the boundary of its strike by remaining immobile during long periods of time O’Brien et al.

Animals that cannot remain stationary, like the white shark, continue moving but in a restricted area Towner et al. This type of sit-and-wait was recorded before for whale sharks in the Belize Barrier Reef by remaining up to 10 h in an area less than m in diameter, waiting for cubera Lutjanus cyanopterus , Cuvier and dog snapper L. However, to our knowledge, no previous reports have shown whale sharks remaining stationary near their prey without feeding.

If the association with other predators allows whale sharks to access this type of prey, whale sharks could be waiting for other predators to encircle and compact the anchovies Fontes et al. For example, cetaceans Lagenorhynchus albirostris , Gray and Phocoena sp. Tunas Thunnus thynnus , Linnaeus and T. Whale sharks are not as fast as dolphins, tunas, pursuit-diving seabirds, barracudas, or sea lions. Therefore, the ability of these predators to encircle the anchovies and force them into a compact formation could facilitate the whale shark to access the anchovies.

Cape gannets Morus capensis , Lichtenstein have been reported to change their feeding technique on a school of fish Sardinops sagax , Jenyns when the frequency of attack by other predators increases Thiebault et al. When the frequency of predator attacks against a school of fish increases occurring every 2.

Our underwater videos showed that barracudas were constantly attacking anchovies from below the school, pushing them toward the surface; this is likely to benefit whale sharks and other predators by cutting off anchovies’ escape routes and keeping them surrounded.

This behavior has been observed in the Azores Portugal before Barreiros et al. Fishermen there and in Kuwait have reported seeing barracudas swimming near whale sharks Bishop and Abdul-Ghaffar It was not possible to record barracuda attacks in this study to know if they were related to whale shark lunges.

These records may support the hypothesis that the whale shark takes advantage of the disturbance caused by predatory fishes. Feeding events on schooling fish might represent important nutritional opportunities for whale sharks, because lunge-feeding is likely to consume more energy compared to zooplankton feeding techniques. Therefore, the frequency of simultaneous and sequential attacks should be high due to the competition among predators to access the temporarily available resource.

The low frequency of simultaneous lunging sessions suggests that whale sharks may be avoiding lunging at the same time or taking turns to feed. Considering their massive bodies, if they lunge at the same time, they may collide with each other.

It is known that other species of elasmobranchs, such as the white shark, establish temporary social ranks to feed Compagno ; Martin et al. This tendency could be to avoid collisions, or it could mean that lunging in the same direction increases feeding success.

When whale sharks performed horizontal lunges in the first event, they struck anchovies with their caudal fins. Their strong movements appeared to be a consequence of the whale shark’s acceleration across the water surface.

However, this can cause the anchovies to be stunned, affecting the number of anchovies caught by whale sharks and other predators. This may be similar to the way the thresher shark Alopias vulpinus , Bonnaterre uses its tail to stun its prey Bernal and Sepulveda ; Oliver et al.

Thiebault et al. If the frenetic entry of a whale shark into the school could disturb or stun the anchovies, this may explain the tendency to carry out consecutive attacks in the same direction, but more observations will be needed to test this hypothesis. We detail or documented several separate events of lunge-feeding in whale sharks, which has only been reported a handful of times in the scientific literature, including behaviors such as simultaneous lunges, sequential lunges, coordinated swimming, and sit-and-wait, which have never before been reported in whale sharks.

Although interactions between whale sharks and anchovies had not been reported before in Bahia de Los Angeles, we observed these events in 2 consecutive years, suggesting that whale sharks may commonly prey on baitfish in this area. These observations, along with previous reports, show that whale sharks change their feeding strategy to lunge-feeding when predatory fish round up baitfish.

This would explain why in other reports of whale sharks preying on fish, lunge-feeding was not reported.

Although further studies should be conducted on the whale shark’s feeding behavior on schooling fish, these preliminary observations, suggest that whale sharks exhibit flexible feeding behavior strategies to possibly maximize their energy gains. In this context, fish consumption could be more important than previously thought for this species. Mar Ecol Prog Ser — Article Google Scholar. Andrewartha B The whale sharks of Ningaloo Reef. Sportdiving Mag — Google Scholar.

Cybium 26 2 — Bernal D, Sepulveda CA The functional role of the caudal fin in the feeding ecology of the common thresher shark Alopias vulpinus.

J Fish Biol — Keep safe distance; Stay at least 3m away from the head and 4m away from the tail. Do NOT conduct free diving or duck diving on the top of the shark. Do NOT restrict their natural behavior and movement. Let the shark control the encounter. Avoid excessive flash photography. If necessary; avoid pointing the flash directly into their eyes, if you spot the pattern above the whale shark’s pectoral fin One or both sides we can identify the shark. Support ongoing research by submitting your Sighting Report.

Report any type of chasing, illegal fishing or disturbance to the authorities. Whilst little is known about natural threats to whale sharks, human activity is their biggest threat. Examples of this include: targeted fishing for their fins, meat and oil though in many places this is banned , accidental removal as bycatch in other fisheries, significant injury from vessel strikes, entanglement and pollution. Ecol Soc Am — Staddon J Adaptive behavior and learning.

Cambridge University Press. Effect of successive predator attacks on seabird feeding success. J Anim Ecol — Funct Ecol — Fish Bull — Proc Calif Acad Sci — Mar Biodivers Rec —5. Werth A Feeding in marine mammals.

In: Schwenk K ed Feeding: form, function and evolution in tetrapod vertebrates. Academic Press, New York, pp — Download references. Thanks to Ian J. Lynna Kiere reviewed the English. Finally, we are also grateful to the anonymous reviewers who provided very helpful comments.

Austin N. Montero-Quintana, Carlos F. You can also search for this author in PubMed Google Scholar. Revised the text: all the authors. Correspondence to Marcela Osorio-Beristain. This research was carried out in accordance with Mexican laws and guidelines for the ethical treatment of animals in general Animal Behavior Society Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

The original online version of this article was revised due to the fourth author’s last name published incorrectly and it has been corrected. The original online version of this article was revised due to a retrospective Open Access order. This article is published under an open access license. Please check the ‘Copyright Information’ section either on this page or in the PDF for details of this license and what re-use is permitted.

If your intended use exceeds what is permitted by the license or if you are unable to locate the licence and re-use information, please contact the Rights and Permissions team. Montero-Quintana, A. Whale shark Rhincodon typus predatory flexible feeding behaviors on schooling fish.

J Ethol 39 , — Download citation. Received : 07 November Accepted : 13 July Published : 26 July Issue Date : September Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Skip to main content. Search SpringerLink Search. Download PDF. Abstract Whale sharks are known to feed primarily on zooplankton all over the world; however, recent findings suggest that they also prey on fish using behaviors that have not been fully described.

Introduction The whale shark Rhincodon typus, Smith is the largest fish on earth Mcclain et al. Materials and methods Observations We recorded whale sharks interacting with schools of anchovies Anchoa sp.

Results A total of video clips were analyzed to describe the whale shark behavior during feeding events. Table 2 The number of observations of predators interacting with the school of anchovies during the first event, on November 29, Full size table. Full size image. Frame extracted from an underwater video showing a two whale sharks S. Jarman, S. Illustrations of the zoology of South Africa, vol.

In: Pisces. Smith, by whale sharks. Elder and Co. Johnson, W. Johns Hopkins University Press, Baltimore. LaBarbera, M. Feeding currents and particle capture mechanisms in suspen- Smith, J. Metabolic rate in relation to tempera- — Angus and Robertson, Brevoortia tyrannus. Bull 97, — Sydney, Australia. Meekan, M. DNA evidence of whale Taylor, J.

Seasonal occurrence, distribution, and movements of the whale sharks Rhincodon typus feeding on red crab Gecarcoidea natalis larvae at shark Rhincodon typus, at Ningaloo Reef, Western Australia. Res 47, Christmas Island.

Mehta, R. Design rules for small low speed wind tunnels. Taylor, J. Merino, M. Upwelling on the Yucatan shelf: hydrographic evidence. Ningaloo Reef currents: implications for coral spawn Sys. Part I. Fluid Mech. Taylor, L. Megamouth—a new species, , — Anatomy of the feeding apparatus of the nurse shark, dae from the Hawaiian Islands.

Ginglymostoma cirratum. Thurston, E. Inspection of Ceylon Pearl Banks. Madras Gov. The taking of a whale shark Rhiniodon typus in Southern 36— New York Zool. Tyminski, J. The vertical movements of whale sharks Nakaya, K. Feeding strategy of the megamouth shark tagged with pop-up archival satellite tags off Quintana Roo, Mexico.

In: Proceed- Megachasma pelagios Lamniformes: Megachasmidae. Res 84, 47— Cuban, Mexi- Uchida, S. On the morphology of the whale shark, Rhincodon typus Smith. EOS Trans. Collected Reprints — 5, — Videler, J. Fish Swimming. Chapman and Hall, London. Ripperger, S. Ward-Smith, A. Oxford University Press, New York. Rowat, D. Regional scale horizontal and local scale vertical move- Weihs, D. Effects of size on sustained swimming speeds of aquatic organisms.

In: Pedley, T. Academic Press, New Rowat, D. Aggregations York, pp. Weihs, D. Optimization of locomotion. In: Webb, P. Fishes 80, — Praeger Publishers, New York, pp. Aerial survey Weihs, D. Voluntary swimming speeds of two species as a tool to estimate whale shark abundance trends. Copeia , — Werth, A. Wetherbee, B. Food consumption and feeding habits. In: Carrier, Sanderson, S. Convergent and alternative designs for ver- J.

CRC tebrate suspension feeding. In: Hanken, J. Functional and Evolutionary Mechanisms. Three-dimensional kinematics and wake structure Chicago, pp. Sanderson, S.

Wilson, S. Schmid, T. Bioenergetics of the bull shark, Carcharhinus leucas, Nat. Zoo Biol. Two whale shark faecal samples from Ningaloo Schmidt, J.

Levine, M. Low genetic differentiation across three major ocean Wilson, S. The seasonal aggregation of whale populations of the whale shark, Rhincodon typus. Fishes 61, 1— Silas, E. On a recent capture of a whale shark Rhincodon Wilson, S. Movements of whale typus Smith at Tuticorin, with a note on information to be obtained on whale sharks Rhincodon typus tagged at Ningaloo reef, Western Australia. India 5, — Simon, M. Behaviour and kinematics of Zavala-Hidalgo, J.

Seasonal upwelling on the western and southern shelves of the Gulf of B , — Ocean Dyn. Threshold foraging behavior of basking sharks on zooplankton: life on an energetic knife-edge? B , — Marine Ecology Progress Series Seasonal movements and behaviour of basking sharks from archival tagging: no evidence of winter hibernation.

Journal of Fish Biology Inferred global connectivity of whale shark Rhincodon typus populations.


3 filter feeder sharks free download


Whale sharks , basking sharks , and megamouth sharks all grow to massive lengths, they all eat by filtering out plankton from the sea water. These sharks are found all over the globe and are incredibly fascinating examples of shark species. Though they are all gentle giants sharing the same diet, each species has a unique biology, habitat, and behavior. Whale sharks are the largest known fish on the planet, measuring an average of They have wide flat heads, with a rounded snout containing a massive, 4.

Inside their mouths are tiny teeth and 10 filter pads. On the sides of their heads, just behind their mouths they have two small eyes and two spiracles, small gill slits used to breath. Whale sharks are blue-grey or brown with light yellow and white spots and stripes on their backs and a smooth white underbelly containing five large gills slits.

They also have two large pectoral fins and two large dorsal fins. Whale sharks have a large habitat and tend to be long range swimmers. They prefer tropical and subtropical waters, with temperatures averaging 72 degrees fahrenheit.

Though often found in the open water, they tend to stay near the surface of the water. Sometimes they will congregate along the coasts where it is believed they mate.

The Whale Shark diet consists mainly of zooplankton. These magnificent creatures have a truly unique way of filter feeding. They are active filter feeders which means they either suction water into their mouths or they ram feed which means they swim forward forcing the water and food into their mouths. Once they have water and food in their mouths, the filter pads separate the water from the plankton. Whale Sharks tend to filter between pounds of food an hour.

Small fish are also part of the Whale Shark diet, but they will only feed on them when plankton is sparse. Shark Academy: The Whale Shark. Basking Sharks are the second largest fish in the world. Basking Sharks grow up to 26 feet in length and weigh up to 5 tons. There have been some estimates that basking sharks can reach up to 33 ft in length. On average a Basking Shark has a mouth that is 3 feet wide containing tiny hooked teeth. The basking shark is bluish-grey with a white underbelly.

They are often mistaken for Great White Sharks because of having a similar body shape and fins. Also, like Great White Sharks, they have gill slits that circle their neck. Basking Sharks have a larger range than Whale Sharks. They prefer cooler waters with temperatures around degrees fahrenheit, though they often migrate across warmer waters during seasonal changes. Their habitat is usually determined by the abundance of food in the water.

They are often found close to the surface but have been known to dive as deeply as 2, feet. Basking Sharks differ from Whale Sharks in their feeding behaviors as well. Basking Sharks are passive feeders, meaning they take in water as they swim. Basking Sharks swim at roughly 2. They tend to feed near the surface and often by the mouths of rivers, and will eat continuously around the clock. Shark Academy: The Basking Shark. The Megamouth Shark is the smallest of the three filter feeder sharks.

Megamouth Sharks can grow to 18 feet in length. Though female Megamouth Sharks tend to grow to an average of 16 feet, while males grow to an average of 13 feet. They megamouth has a stout, chubby body that is brown with a white belly. The megamouth has a long tail with a longer top caudal fin than the lower. Megamouth sharks have protruding mouths that grow to an average of 4. Their mouths are lined with hundred of small, nonfunctional teeth in 50 rows.

Megamouth sharks are incredibly rare. There have only been 55 confirmed sightings of Megamouth Shark in history. Megamouth Sharks prefer warm tropical waters and are found in the Pacific, Atlantic, and Indian Oceans. They are vertical migrants spending their days at a depth of feet and their nights near the surface between feet. Megamouth Sharks tend to follow the vertical migration patterns of plankton.

Megamouth sharks are very slow swimmers, moving around a mile an hour. Like Basking Sharks they are passive filter feeders. However, scientists believe that the Megamouth Shark may also feed by suction like the Whale Shark, but this has yet to be observed in the wild.

While they swim, Megamouth Sharks move water through their mouths and out their gills, trapping food with their gill rakers.

The mouth of the Megamouth Shark is uniquely designed to attract unsuspecting prey. As you can see there are some incredible differences between the three filter feeding sharks.

Though they are all large, docile creatures that feed on small plankton, they each have unique characteristics to their species. Whale Sharks are the largest and most active feeders, Basking Sharks look like deadly Great White Sharks but are really slow passive feeders, and Megamouths are vertical hunters that trap their prey with light.

Filter feeder sharks highlight the diversity of shark species, having wildly different behaviors and features than their counterparts.