CETACEA.

Presentation on theme: "CETACEA."— Presentation transcript:

1 CETACEA

2 “Cetartiodactyla” Whales are so highly specialized for an aquatic life, that until recently their phylogenetic relationship to other mammals was controversial. Whales are artiodactyls. The molecular evidence indicates whales and hippos are sister taxa.

3 Mesonychid condylarths
Anthracotheres Mesonychid condylarths

4

5 Modern Cetacean Traits, 1
exclusively aquatic (secondary adaptation) fusiform body with shortened neck and elongate tail [tail modified into horizontal flukes (supported only by connective tissue)]

6 Cetacean Traits, 2 pelvic girdle reduced to vestigial
paddle shaped, anterior limbs with hyperphalangy

7 Cetacean Traits, 3 highly modified, telescoped skull
external nares dorsally located nares connects directly to trachea. Fig. 19-7

8 TELESCOPING Migration of nasal openings (blowholes) to top
Position of external nares Modern Horse Fossil Archaeocete (Basilosaurus; with heterodont dentition) Migration of nasal openings (blowholes) to top Maxilla and premaxilla telescope backwards over frontals and parietals The premaxillary and maxillary bones form most of the roof of the skull in front, hardly any frontal bone. Modern odontocete (Delphinus, common dolphin) Modern Mystecete (Balaenoptera, fin whale)

9 Classification Mysticetes Odontocetes

10 Mysticeti – Baleen whales
no teeth, except embryologically baleen (=whalebone) plates ( ) composed of keratin Filter feeders Longevity is unknown. Estimates for blue whales: 30 to 90 years, fin whales: 90 to 100 years, and sei whales: as long as 60 years. The Oral History of Toothless Whales Baleen whales carry their medical records in their mouths. by Jennifer S. Holland

11 Bowhead Whales (Balaena mysticetus )
The average age of animals killed during whaling is estimated at 60 to 70 years, based on examination of changes in the eye nucleus. Several individuals have ancient ivory and stone harpoon heads in their flesh and examination of their eye nucleus has resulted in estimated lifespans up to 200 years (George et al. 1999), making bowhead whales the longest lived mammalian species.

12 Mysticeti Baleen whales
Two external nasal openings in symmetrical skull Produce sounds to identify sex, social status and location External nares

13 large whales utilize the SOFAR channel as a means of long-distance communication using low-frequency calls oceanexplorer.noaa.gov/.../acoustics/ media/sofar%20_100.jpg

14 Many Species of Baleen Whales Migrate
Migration Routes of Humpback & Gray Whales summer at high latitudes winter at low latitudes Gray whales undertake the longest annual migration of any mammal: Spend wintertime in birthing and breeding lagoons in Mexico Spend summertime feeding in highly productive Arctic waters

15 Large zooplankton is the main component for most baleen whales
Diet Of Great Whales Large zooplankton is the main component for most baleen whales

16 Balaenidae (2, 4) Bowhead and right whales
Large whales up to 18 m long and over 67,000 kg Head huge; 1/3 of total length Carcasses float; Were easiest whales to exploit Northern right whale population has declined from 200,000 to 300

17 Right whales Skimmers that feed largely on copepods
No longitudinal throat grooves Baleen plates long and narrow Fig a

18 How Right Whales Feed Slowly swim near surface with mouth open through concentrations of plankton. Filling its mouth with huge volumes of seawater, it uses its muscular tongue to expel the water sideways through the baleen curtains. users.ipfw.edu/haddock/434MarineRepsBirdsMammals.pp Water in

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20 Balaenopteridae Rorqual whales: the fin backed and humpback whales.
Minke Blue Fin Sei

21 Balaenopteridae (2, 7) Balaenoptera acutorostrata [minke]: 8-10 m, up to 9000 kg.  Minke whales are the most numerous of the baleen whales. Balaenoptera musculus [blue whale]: up to 30 m, 200,000 kg. Megaptera novaeangliae [humpback whale].

22 Half a million calories per gulp.
Oregon State scientists captured some rare blue whale feeding behavior from a research drone. Ravenous Blue Whale Swallows Nearly An Entire Shoal Of Krill In One Mouthful Half a million calories per gulp.

23 BBC The-Hunt-shots-Blue-Whale

24 Balaenopterids are gulpers
Numerous throat grooves (60-80) that expand Baleen plates short Lunge feeding on fish and crustaceans (krill) Engulf up to 70 tons of water

25

26 Lunge Feeding

27 Food chain of the blue whale
Upwelling, Productivity, short food chains Shrimp & other krill Up to 30,000 individuals/m3 Phytoplankton & zooplankton The Blue Whale is only one step in the food-chain away from some of the smallest “plants” on the planet. A simple food chain is the secret to the success of the baleen whales - keep the chain short and transfer as much energy as possible as efficiently as possible. Whales consume 50 – 200 million tons of plankton/year

28 Megaptera novaeangliae
Humpback whale 14-19 m. 40,000 kg Vocalizations

29 Feeding in Humpback Whales
Lunge feed Side feed Fluke feed (as they dive they flex tail to generate wave that concentrates krill)

30 4. Bubble net Individuals ascend spirally below school of prey
Blow bubbles which form a curtain, corralling the macroplankton to the center) Swim rapidly up through middle of bubble net Engulf prey at surface FIGURE 19-09A: A spiral shaped wall of bubbles is produced by a submerged whale, which traps a school of fish

31 Eschrichtiidae - Gray whale (1, 1)
Large whales, to over 14 m long and over 30,000 kg in weight Throat with 2-4 longitudinal throat grooves. Gulping: bottom feeder on amphipods, crustaceans, mollusks, annelids.

32 Gray whales swim on their sides just off the bottom, while sweeping their heads back and forth. This disturbs the amphipods and causes them to rise. The whale then sucks in the amphipods, where they are trapped inside the baleen. Using their tongues, they push the sediments through their baleen filters.

33 Grey whale countercurrent in tongue
Whales have countercurrent exchange in flippers and tail Thermoregulation in the mouth via countercurrent exchange Heat conservation in cold water with vascularized tongue.

34 Females stay in shallow lagoons to give birth
Family Echrichtiidae Migratory: summer in arctic; Winter and calve in gulf of California. Migrate along coast (10,000-20,000 km; Blue whales migrate similar distances). Females stay in shallow lagoons to give birth Numbers have increased greatly in recent years. Virtually extinct in the 1930's–12,000 today.

35 Blowhole and attached barnacles (can be used for identification) are visible on this California gray whale. Bahia Magdalena, Baja California Sur, Mexico

36 Odontoceti teeth present, simple, homodont, Monophyodont no baleen

37 skull generally asymmetrical around the single external nare (A)
mysticete A. odontocete

38 Sounds Audible whistles and squeaks for intraspecific communication. (Table 22-4) ECHOLOCATION: short, high-frequency clicks produced in nasal air sacs and associated valves ("monkey lips") opening on the passage to the blowhole.

39 Generation of Odontoceti echolocation clicks
A fatty "melon" behind the face (oil in the sperm whale) probably acts as an "acoustic lens. (Fig ) May be able to stun prey.

40 Odontoceti echolocation
Short, high-frequency sound pulses are bounced off objects to determine: Size ,Shape, Distance, Internal structure Sound returns via oil-filled lower jaw

41 Delphinidae--dolphins
Largest family [17 genera, 34 spp.] Includes bottlenose dolphins, pilot whales, spotted dolphins, spinner dolphins (tuna fish industry), orca whales Typically highly gregarious Tursiops truncatus

42 Tursiops truncatus Atlantic bottlenose dolphin, is the common dolphin of the Texas coast. They can grow to be 10 feet (3.0 m) long and weigh as much as 600 pounds (272 kg)

43 Differences between dolphins and porpoises that have many exceptions
Dolphins have: An elongated snout (rostrum) A sickle-shaped (falcate) dorsal fin In porpoises (Phocoenidae) The jaw is short and there is no beak The dorsal fin is low or absent Bottle-nosed dolphin Dall’s porpoise

44 The only consistent difference between dolphins and porpoises
Dolphins have: Teeth that end in points In porpoises (Phocoenidae) Teeth are blunt Killer whale jawbone

45 Physeteridae--sperm whales [2,3]
Snout large, broad, blunt, undifferentiated from rest of head. Top of head extends well beyond lower jaw. Squid predators Teeth present in lower jaw only. Physeter: 18 m long, 53,000 kg. 2,500,000 originally; 1,500,000 now. Dive to depths of > 3200 m Kogia: 4 m long, 320 kg.

46 Spermaceti waxy liquid in nose of sperm whale (Fig. 22-15)
Spermaceti organ involved in buoyancy regulation and/or echolocation uwacadweb.uwyo.edu/buskirk/Zoology4370/cetacea.web.ppt

47 Monodontidae--Narwhal and beluga [2,2]
Narwhal song

48 Narwhal In males, one of the two upper teeth (canine) extends anteriorly as a straight spirally grooved tusk. Tooth on opposite side is usually rudimentary, very rarely double. In females, tusks generally absent, but when present, often paired. feeding The first-ever footage of Narwhals using their tusks for feeding FisheriesCanada

49 The tusk is an innervated sensory organ with millions of nerve endings connecting seawater stimuli in the external ocean environment with the brain. Tusk sense minute changes in temperature, pressure and water composition

50 Monodontidae--Narwhal and beluga [2,2]
beluga--white whale important economically to Inuits, as a source of blubber, oil, and leather

51 Long Snouted river dolphins [4,5]
large rivers of India & Pakistan; Amazon and Orinoco; China A paraphyletic group of small dolphins (1-3 m.) small eyes, some are blind (muddy rivers) River dolphin Pontoporia blainvillei

52 https://bmcevolbiol. biomedcentral. com/articles/10

53 Ziphiidae – beaked whales (18 spp.)
Beaked whales are among the least known of all living whales. Most species eat only squid, are deep divers, and may be the longest duration divers of all (1-2 hr) uwacadweb.uwyo.edu/buskirk/Zoology4370/cetacea.web.ppt

54 Ziphidae Snout is generally long and narrow
Except for one species, dentition is 1-2 teeth/lower jaw uwacadweb.uwyo.edu/buskirk/Zoology4370/cetacea.web.ppt

55 Beaked Whales’ Tusks Evolved Through Sexual Selection Process
“The tusks help females identify males within their species, which could otherwise be difficult as these species are quite similar to each other in shape and coloration.”

56

57 SOURCE: Mar. Fish. Rev. 76, 37–48 (2014)
SOURCE: Mar. Fish. Rev. 76, 37–48 (2014)

58 Aftermath of whaling (Table from Carwardine, 1999)
Species Original Present Sperm whale 2,500,000 1,500,000 Blue whale , ,000 Fin whale , ,000 Sei whale , ,000 Bryde's whale , ,000 Minke whale , ,000 Humpback whale , ,000 Gray whale , ,000 Northern right whale , Southern right whale , ,000 Bowhead whale , ,000

59 Whale Populations – “Then” and Now

60 extinct? In 2007, the baiji river dolphin (Lipotes vexillifer), a victim of the pollution and boat traffic of China's Yangtze river, was added to the list of creatures on the verge of extinction. it went from a healthy population of some 6000 animals to extinct in a few decades

61 Vaquita Porpoise Faces Imminent Extinction—Can It Be Saved?
Scientists estimate there are just 30 remaining vaquitas, the world's smallest porpoise, a species found only in the waters of the Gulf of California.

62 The two species of minke are the world's most hunted whales
The two species of minke are the world's most hunted whales. Japan targets about 950 a year for its research programs. Commercially, Norway issues quotas to hunt about 1,000 per year, while Icelandic boats catch about 50 per year. Greenland's Inuit hunters can take up to 212 for subsistence purposes. Japan has recently added the fin to its list of science targets and plans to take 50 per year. Iceland has also caught small numbers commercially in recent years. No more than 140 eastern grays a year can be taken by US and Russian subsistence hunters. There are thought to be more than 17,000 in existence. The bowhead is a target for indigenous hunters in Alaska, Chukotka and Greenland who are allowed to catch no more than 69 individuals a year under IWC rules.

63 Conservation Genetics Frankham et al. 2002
Conservation Genetics Frankham et al Introduction to Conservation Genetics. Cambridge Univ. Press Conservation genetics is the application of genetics to preserve species as dynamic entities capable of coping with environmental change. It encompasses: Use of genetic information in wildlife forensics Genetic management of small populations Identifying and defining units of conservation within and between species biosci.ohio-state.edu/~eeob/eeobH400/H400_2004_Lecture_9.ppt

64 Wildlife Forensics Molecular genetic techniques can be used to identify products of illegal harvest of protected species Example: Detection of Illegal hunting and sale of meat from protected whales by Japan and Norway (Baker and Palumbi 1996) IWC instituted a global moratorium on commercial whaling in 1985 Japan and Norway continued to hunt few species (minke) for “scientific purposes” - meat sold commercially Issue: Were protected species also being illegally harvested and meat sold as from species that could be hunted? biosci.ohio-state.edu/~eeob/eeobH400/H400_2004_Lecture_9.ppt

65 Genetic Analysis of Whale Meat
“Undercover” purchase of fresh whale meat in Japanese markets Illegal to transport tissues from protected species PCR-amplification of whale mtDNA control region sequence in hotel room Sequenced in home labs biosci.ohio-state.edu/~eeob/eeobH400/H400_2004_Lecture_9.ppt

66 Analysis of 16 Whale Meat Samples
Samples 19b, 41, 3 11, WS4 from Protected species 19b - Humpback 41, 3, 11, WS4 - Fin whales 16, 13, 28 - Porpoise and dolphin

67 Molecular identification of baleen whale products
The result of over the last ten years has been a wide variety of different animals that we have detected in the whaling market. We have found all of the great whales of the world (with the exception of the right whales) in the whale meat markets of Japan and Korea. Even though a small number of species are suppose to be there according to scientific whaling, we have found virtually all of them. We have found northern and southern minke whales. These are the expected ones, and they in fact occur in the most numbers. We have also found brydes whales, whales of new species (pygmy brydes), sei whales, humpback whales, a lot of fin whales, blue whales, etc. Molecular identification of baleen whale products 339 369 10 2 9 7 49 N. minke S. minke Brydes Pygmy Brydes Sei Humpback The result of over the last ten years has been a wide variety of different animals that we have detected in the whaling market. We have found all of the great whales of the world (with the exception of the right whales) in the whale meat markets of Japan and Korea. Even though a small number of species are suppose to be there according to scientific whaling, we have found virtually all of them. We have found northern and southern minke whales. These are the expected ones, and they in fact occur in the most numbers. We have also found brydes whales, whales of new species (pygmy brydes), sei whales, humpback whales, a lot of fin whales, blue whales, etc. Fin Blue Grey Data from Palumbi, Baker labs

68 Meat harvested prior to harvest bans genotyped to monitor distribution
Conclusions Results of analysis: stricter controls over sale of “scientifically harvested” whale meat Meat harvested prior to harvest bans genotyped to monitor distribution Other applications: species identity of caviar and seal penises, population origin of poached chimps biosci.ohio-state.edu/~eeob/eeobH400/H400_2004_Lecture_9.ppt

69 2010 IWC meeting Wiki At the 2010 in Morocco, representatives of the 88 member nations discussed whether or not to lift the 24 year ban on commercial whaling. Japan, Norway and Iceland have urged the organization to lift the ban. A coalition of anti-whaling nations has offered a compromise plan that would allow these countries to continue whaling, but with smaller catches and under close supervision. Their plan would also completely ban whaling in the Southern Ocean More than 200 scientists and experts have opposed the compromise proposal for lifting the ban, and have also opposed allowing whaling in the Southern Ocean, which was declared a whale sanctuary in 1994. Opponents of the compromise plan want to see an end to all commercial whaling, but are willing to allow subsistence-level catches by indigenous peoples.

70 end

71 Pakicetidae Astragalus
’Phenacodus, a primitive ungulate had an unspecialized ankle bone that resembles that of Pachyaena, a mesonychian ungulate from 50 My ago. The double-pulleyed astragali of Pakicetus, Diacodexis (the oldest known even-toed ungulate) and Sus (pig) indicate a close relationship between these species. News and Views Nature to Thewissen 2001

72 Fossil Comparison: Ankle Bones
K. D. Rose, Science 293, (September 2001, 2001) p216.

73 New Fossils 2001: early Eocene
Pakicetus attocki (a) and Ichthyolestes pinfoldi (b) Thewissen et al, Nature 20 Sept 2001 fig 2

74 Fig. 3. Reconstitution de Pakicetus (par Carl Buell)
Fig. 3. Reconstitution de Pakicetus (par Carl Buell).Reconstruction of Pakicetus (painting by Carl Buell). L’origine et l’histoire évolutive des Cétacés In Press, Corrected Proof, Available online 10 September 2008 Christian de Muizon Partial skeleton of Pakicetus (Early Eocene, Pakistan) made of several individuals (scale bar = 20 cm) (courtesy of H.J.G. Thewissen).

75 L’origine et l’histoire évolutive des Cétacés In Press, Corrected Proof, Available online 10 September 2008 Christian de Muizon Fig. 6. Reconstitution d’Ambulocetus natans (par Carl Buell).Reconstruction of Ambulocetus natans (painting by Carl Buell). Skeleton (Holotype) of Ambulocetus natans from the Early Eocene of Pakistan (scale bar = 30 cm); reconstruction of the skeleton of Ambulocetus from the holotype and only specimen known so far. (Courtesy of H.J.G. Thewissen).

76 Rhodhocetus kasrani Protocetidae 47 My
Perspective, Science on Gingerich 2001 Ankle bones astragali above calcanei below Mesonychids differ

77 TELESCOPING = Position of External nares
Pa Modern Horse Pr M O N Fossil Archaeocete (Basilosaurus; with heterodont dentition) F Pa Pr Migration of nasal openings (blowholes) to top Maxilla and premaxilla telescope backwards over frontals and parietals The premaxillary and maxillary bones form most of the roof of the skull in front, hardly any frontal bone. M O N M Modern odontocete (Delphinus, common dolphin) Pa Pr F M O N Pa Pr F M Modern Mystecete (Balaenoptera, fin whale) O TELESCOPING From Slijper, 1979

78 Bradycardia Fig

79

80

81 An example of migration: Gray whales
Gray whales undertake the longest annual migration of any mammal: Spend wintertime in birthing and breeding lagoons in Mexico Spend summertime feeding in highly productive Arctic waters Figure 14-27