Kogiidae

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Kogiidae
Temporal range: Miocene – Recent
[1]
Kogia sima.jpg
Dwarf sperm whale, Kogia sima
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Superfamily: Physeteroidea
Family: Kogiidae
Gill, 1871
Genera

See text

Kogiidae is a family comprising at least two extant species of Cetacea, the pygmy and dwarf sperm whales. As their common names suggest, they somewhat resemble sperm whales, with squared heads and small lower jaws, but are much smaller in size, with much shorter skulls and more notable dorsal fins than sperm whales.[2] Kogiids are also characterized by a "false gill slit" behind their eyes.[3]

A number of genera are extinct.[4]

Taxonomy[edit]

There is some amount of uncertainty over if Kogiidae belong in the sperm whale family. Research still suggests a close relationship between Kogiidae and sperm whales using mitochondrial DNA, which supports Kogiidae as part of the sperm whale family.[5] Other phylogenetic research raises further questions over a potential relationship between kogiids and Ziphiidae.[5] Other questions exist regarding the high relatedness in mitochondrial DNA between Platanista and kogiids.[6] Fossil evidence is limited for this family, which potentially limits an understanding of their relationship to other extant cetaceans.[7]

Researchers have proposed that K. sima may represent at least two genetically unique species, and further genetic research is needed to determine the real number of extant species of Kogiidae.[8]

A comparison of an extinct monodont, Denebola brachycephala (top), and an extinct kogiid, Praekogia cedrosensis (bottom), both from the Late Miocene.

ORDER ARTIODACTYLA

Biology[edit]

Kogiid skulls are characterized by a very short rostrum, the smallest among extant cetaceans, as well as high levels of asymmetry, which is expected among odontocetes.[7][10] Kogiid skulls have the most blunt mandible among extant cetaceans as well. Extant kogiidae also show relatively high encephalization quotient, the ratio between observed brain size and expected brain size. The pygmy sperm whale has an EQ of 1.78, while the dwarf sperm whale's EQ is 1.63.[7] Kogiidae do possess spermaceti in their head like sperm whales.[11] However, kogiid spermaceti is unique as the whales are able to control its temperature.[12] Kogiidae are also homodonts, showing teeth all of the same size and shape.[13]

Kogiidae possess a unique system of organs to produce sound, including a bagpipe-like structure to produce sound and an amplifying horn.[12]

Kogiidae have a modified colon which works as an "ink sac", storing liquid red feces.[14] They are able to release over three gallons of this fecal "ink" to confuse or discourage predators.[15]

Ecology[edit]

Range[edit]

Kogiidae are believed to be cosmopolitan species, inhabiting all oceans except polar waters, remaining between the 50° latitude lines.[14]

Two fossilized species of Kogia sp. were shown to exhibit sympatry, similar to the two modern members of Kogia, which researchers suggested shows that this behavior has been part of Kogiidae for at least 3 million years.[16]

Behavior and feeding[edit]

Extant kogiids travel in small groups and rarely surface, potentially to avoid predators like orcas.[17]

Kogiidae are deep diving whales, believed to dive up to depths of 500m.[7] Kogiids feed using a technique known as suction feeding, and their diet primarily consists of squid.[18][19] Pygmy sperm whales are able to eat larger prey than dwarf sperm whales, although their diet as a whole is relatively similar.[19] They have also been observed using echolocation to find their prey.[20]

Human threats[edit]

Most observations of Kogia have come from individuals tangled in fishing line or stranded individuals.[7] There is a commercial fishery for K. breviceps in parts of southeast Asia and the Lesser Antilles.[21] Both species of extant kogiidae have also been observed stranded with plastics blocking their intestines.[15][21]

References[edit]

  1. ^ http://fossilworks.org/bridge.pl?a=taxonInfo&taxon_no=53256. Missing or empty |title= (help)
  2. ^ A., Jefferson, Thomas (1993). Marine mammals of the world. Leatherwood, Stephen., Webber, Marc A., United Nations Environment Programme., Food and Agriculture Organization of the United Nations. Rome: United Nations Environment Programme. p. 64. ISBN 9251032920. OCLC 30643250.
  3. ^ 1955-, Reid, Fiona, (2009). A field guide to the mammals of Central America & Southeast Mexico (2nd ed.). Oxford: Oxford University Press. p. 301. ISBN 0195343220. OCLC 237402526.
  4. ^ a b 1893-, Kellogg, Remington; 1871-1930., Matthew, William Diller (1929). "A new fossil toothed whale from Florida. American Museum novitates ; no. 389".
  5. ^ a b May-Collado, Laura; Agnarsson, Ingi. "Cytochrome b and Bayesian inference of whale phylogeny". Molecular Phylogenetics and Evolution. 38 (2): 344–354. doi:10.1016/j.ympev.2005.09.019.
  6. ^ Verma, Sunil Kumar; Sinha, Ravindra Kumar; Singh, Lalji. "Phylogenetic position of Platanista gangetica: insights from the mitochondrial cytochrome b and nuclear interphotoreceptor retinoid-binding protein gene sequences". Molecular Phylogenetics and Evolution. 33 (2): 280–288. doi:10.1016/j.ympev.2004.06.018.
  7. ^ a b c d e Perrin, William; Würsig, Bernd; Thewissen, J. G. M. (2008). Encyclopedia of Marine Mammals. Elsevier Science. ISBN 9780080919935.
  8. ^ Chivers, S. J.; Leduc, R. G.; Robertson, K. M.; Barros, N. B.; Dizon, A. E. (2005-10-01). "Genetic Variation of Kogia Spp. with Preliminary Evidence for Two Species of Kogia Sima". Marine Mammal Science. 21 (4): 619–634. doi:10.1111/j.1748-7692.2005.tb01255.x. ISSN 1748-7692.
  9. ^ a b c d e f Velez-Juarbe, Jorge; Wood, Aaron R.; Gracia, Carlos De; Hendy, Austin J. W. (2015-04-29). "Evolutionary Patterns among Living and Fossil Kogiid Sperm Whales: Evidence from the Neogene of Central America". PLOS ONE. 10 (4): e0123909. doi:10.1371/journal.pone.0123909. ISSN 1932-6203.
  10. ^ Huggenberger, S.; Leidenberger, S.; Oelschläger, H. H. A. (December 13, 2016). "Asymmetry of the nasofacial skull in toothed whales (Odontoceit)". Journal of Zoology. 302 (1): 15–23. doi:10.1111/jzo.12425.
  11. ^ Costa-Silva, Samira; Sacristán, Carlos; Groch, Kátia regina; Sánchez-Sarmiento, Angélica María; Reisfeld, Laura; Dutra, Gustavo; Lassálvia, Cristiane; Catão-Dias, José Luiz (2017-01-01). "Histological aspects of the mucosa of the spermaceti chamber of a dwarf sperm whale". Brazilian Journal of Veterinary Research and Animal Science. 53 (3). ISSN 1413-9596.
  12. ^ a b Clarke, M. R. (April 2003). "Production and control of sound by the small sperm whales, Kogia breviceps and K. sima and their implications for other Cetacea". Journal of the Marine Biological Association of the United Kingdom. 83 (2): 241–263. doi:10.1017/s0025315403007045h. ISSN 1469-7769.
  13. ^ "Cetacean Palaeobiology". palaeo.gly.bris.ac.uk. Retrieved 2017-12-05.
  14. ^ a b Bloodworth, Brian E.; Odell, Daniel K. (2008-10-09). "Kogia breviceps (Cetacea: Kogiidae)". Mammalian Species (819): 1–12. doi:10.1644/819.1. ISSN 0076-3519.
  15. ^ a b Fisheries, NOAA. "Dwarf Sperm Whale (Kogia sima) :: NOAA Fisheries". www.nmfs.noaa.gov. Retrieved 2017-11-22.
  16. ^ Vélez-Juarbe, Jorge; Wood, Aaron R.; Pimiento, Catalina (2016-07-03). "Pygmy sperm whales (Odontoceti, Kogiidae) from the Pliocene of Florida and North Carolina". Journal of Vertebrate Paleontology. 36 (4): e1135806. doi:10.1080/02724634.2016.1135806. ISSN 0272-4634.
  17. ^ Morisaka, T.; Connor, R. C. (2007-07-01). "Predation by killer whales (Orcinus orca) and the evolution of whistle loss and narrow-band high frequency clicks in odontocetes". Journal of Evolutionary Biology. 20 (4): 1439–1458. doi:10.1111/j.1420-9101.2007.01336.x. ISSN 1420-9101.
  18. ^ Bloodworth, Brian; Marshall, Christopher D. (2005-10-01). "Feeding kinematics of Kogia and Tursiops (Odontoceti: Cetacea): characterization of suction and ram feeding". Journal of Experimental Biology. 208 (19): 3721–3730. doi:10.1242/jeb.01807. ISSN 0022-0949. PMID 16169949.
  19. ^ a b Staudinger, Michelle D.; McAlarney, Ryan J.; McLellan, William A.; Ann Pabst, D. (2014-04-01). "Foraging ecology and niche overlap in pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales from waters of the U.S. mid-Atlantic coast". Marine Mammal Science. 30 (2): 626–655. doi:10.1111/mms.12064. ISSN 1748-7692.
  20. ^ Merkens, Karlina; Barkley, Yvonne; Hill, Marie; Oleson, Erin (2016-10-01). "Dwarf sperm whale (Kogia sima) echolocation clicks from Guam (Western North Pacific Ocean)". The Journal of the Acoustical Society of America. 140 (4): 3415–3415. doi:10.1121/1.4970977. ISSN 0001-4966.
  21. ^ a b Fisheries, NOAA. "Pygmy Sperm Whale (Kogia breviceps) :: NOAA Fisheries". www.nmfs.noaa.gov. Retrieved 2017-11-17.