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Phoca
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Clade:	Pinnipedia
Family:	Phocidae
Tribe:	Phocini
Genus:	Phoca Linnaeus, 1758
Type species
Phoca vitulina Linnaeus, 1758
Species
P. largha P. vitulina P. mutica?

Phoca (/ˈfoʊkə/ FOH-kə) is a genus of the earless seals, within the family Phocidae. It now contains just two species, the common seal (or harbour seal) and the spotted seal (or largha seal). Several species formerly listed under this genus have been split into the genera Pusa, Pagophilus, and Histriophoca. Until recently, Phoca largha has been considered a subspecies of Phoca vitulina but now is considered its own species. For this reason, the fossil history of the genus is unclear, and it has formerly been used as wastebasket taxon for a number of fossils of uncertain affinity.

Species

Currently there are two confirmed members:

Image	Scientific name	Common Name	Distribution
	Phoca largha	spotted seal	Beaufort, Chukchi, Bering and Okhotsk Seas
	Phoca vitulina	common seal	northern Atlantic and Pacific Oceans and the Baltic and North Seas

There is also a third unconfirmed member:

Image	Scientific name	Common Name	Distribution
	Phoca mutica	long-necked seal	unknown

Former members of Phoca:

• Histriophoca fasciata (ribbon seal)
• Pusa caspica (Caspian seal)
• Pusa hispida (ringed seal)
• Pusa sibirica (nerpa or Baikal seal)
• Pagophilus groenlandica (harp seal)

Mating ecology

Both harbour and spotted seals are aquatically mating pinnipeds. Mating occurs in the water around the time when pups are weaned. Females in estrus are typically more dispersed than land-breeding pinnipeds and the distinction between foraging and reproductive behavior is less apparent. For this reason, it is difficult to study the mating patterns of this genus.

Female harbour seals start making foraging trips shortly before weaning their pup and consequently are widely dispersed when in estrus. Males restrict their range around the time females start to make these foraging trips. Harbour seals follow a polygynous mating system. More specifically it has been shown that male harbour seals partake in lek polygyny. Male seals defend underwater territories with well-defined boundaries. The most valuable territories are near haulouts or along traffic corridors that provide maximum exposure to estrous females. One male will occupy an area throughout the breeding season, and they will return to the same display area in consecutive years. Female harbour seals receive direct benefits from being in a lek, as the congregation of males into an area makes mate selection easier because females do not have to travel as far and it also helps to reduce exposure to predators.

Harbour seal males use underwater vocalizations and display dives within their aquatic territories, for both female attraction and male-male competition. Male harbour seal vocalizations consist of low-frequency broadband growls that peak in occurrence during the mating season. Males vocalize and display in small, distinct territories covering around 40–135 m. Each display area is spatially discrete and can be separated by up to 250 meters. Male harbour seals have considerable individual and geographic variation in their underwater vocalizations. Territory holders use the acoustic displays of intruders to locate and challenge invaders and will respond aggressively to a male call. Males assess each other by their vocalizations before deciding whether to respond. These vocalizations are energetically expensive to produce and are honest signals of male quality and dominance. Male body condition will decline as the mating season progresses.

Aquatic hierarchies in harbour seals develop before the breeding season and dominance is determined by direct male contests. These contests involve repeated confrontations between two males using surface splashing, fighting, paired somersaulting, and chasing techniques. The hierarchies may aid in holding territories or to mate with females during the breeding season. The dominance relationships are determined by size and sex, with adult males dominant to sub-adult males, and sub-adult females submissive to all other social classes. Aquatic courtship is long in duration and involves rolling, bubble blowing, and splashing to attract females. Female choice appears to play a strong role in this mating system but it has yet to be formally studied.

The mating system of spotted seals is quite different from harbour seals as spotted seals are serially monogamous. During the breeding season, a male will join a female approximately ten days before the female gives birth to a pup from the previous years mating. The pairs are considered to be territorial as they keep widely spaced from other spotted seals. The social group consists of an isolated adult pair and the females pup. The female spotted seal receives direct benefits from the male as he provides protection for her and the pup until it is weaned. Immediately after weaning mating occurs.

References

1. "Phoca". The Chambers Dictionary (9th ed.). Chambers. 2003. ISBN 0-550-10105-5.
2. Berta, A. & Churchill, M. (2012). "Pinniped Taxonomy: evidence for species and subspecies". Mammal Review. 42 (3): 207–234. doi:10.1111/j.1365-2907.2011.00193.x.
3. ^ Burns, John J. (2009). "Harbor Seal and Spotted Seal". Encyclopedia of Marine Mammals. pp. 533–542. doi:10.1016/B978-0-12-373553-9.00126-7. ISBN 9780123735539.
4. ^ Sullivan, R. M. (1981). "Aquatic Displays and Interactions in Harbor Seals, Phoca vitulina, with Comments on Mating Systems". Journal of Mammalogy. 62 (4): 825–831. doi:10.2307/1380606. JSTOR 1380606.
5. Van Parijs, S. M.; Hastie, G. D.; Thompson, P. M. (1999). "Geographical variation in temporal and spatial vocalization patterns of male harbour seals in the mating season". Animal Behaviour. 58 (6): 1231–1239. doi:10.1006/anbe.1999.1258. PMID 10600144.
6. ^ Hayes, Sean A.; Costa, Daniel P.; Harvey, James T.; Boeuf, BURNEY J. (2004-07-01). "Aquatic Mating Strategies of the Male Pacific Harbor Seal (Phoca Vitulina Richardii): Are Males Defending the Hotspot?". Marine Mammal Science. 20 (3): 639–656. Bibcode:2004MMamS..20..639H. doi:10.1111/j.1748-7692.2004.tb01184.x. ISSN 1748-7692.
7. ^ van Parijs, S. M.; Thompson, P. M.; Tollit, D. J.; Mackay, A. (1997). "Distribution and activity of male harbor seals during the mating season". Animal Behaviour. 54 (1): 35–43. doi:10.1006/anbe.1996.0426. PMID 9268433.
8. ^ van Parijs, S. M.; Janik, V. M.; Thompson, P. M. (2000). "Display-area size, tenure length, and site fidelity in the aquatically mating male harbour seal, Phoca vitulina". Canadian Journal of Zoology. 78 (12): 2209–2217. doi:10.1139/cjz-78-12-2209.
9. Coltman, D. W.; Bowen, W. D.; Wright, J. M. (1998). "Male mating success in an aquatically mating pinniped, the harbour seal (Phocu vitulina), assessed by micro- satellite DNA markers". Molecular Ecology. 7 (5): 627–638. Bibcode:1998MolEc...7..627C. doi:10.1046/j.1365-294x.1998.00373.x. PMID 9633104.
10. Hanggi, E. B.; Schusterman, R. J. (1994). "Underwater acoustic displays and individual variation in male harbour seals, Phoca vitulina". Animal Behaviour. 48 (6): 1275–1283. doi:10.1006/anbe.1994.1363.
11. ^ Van Parijs, Sofie M; Kovacs, Kit M (2002-07-01). "In-air and underwater vocalizations of eastern Canadian harbour seals, Phoca vitulina". Canadian Journal of Zoology. 80 (7): 1173–1179. doi:10.1139/z02-088. ISSN 0008-4301.
12. ^ Hayes, Sean A.; Kumar, Anurag; Costa, Daniel P.; Mellinger, David K.; Harvey, James T.; Southall, Brandon L.; Boeuf, Burney J. Le (2004). "Evaluating the function of the male harbour seal, Phoca vitulina , roar through playback experiments". Animal Behaviour. 67 (6): 1133–1139. doi:10.1016/j.anbehav.2003.06.019.
13. ^ Nicholson, T. E. (2000). Social structure and underwater behavior of harbor seals in southern Monterey Bay, California. M.S. thesis, San Francisco State University.
14. Sullivan, R. M. (1982). "Agonistic behavior and dominance relationships in the harbor seal, Phoca vitulina". Journal of Mammalogy. 63 (4): 554–569. doi:10.2307/1380260. JSTOR 1380260.
15. Beier, J. C.; Wartzok, D. (1979). "Mating behavior of captive spotted seals (Phoca largha)". Animal Behaviour. 27: 772–781. doi:10.1016/0003-3472(79)90013-7.
16. Burns, J. J.; Ray, G. C.; Fay, F. H.; Shaughnessy, P. D. (1972). "Adoption of a strange pup by the ice-inhabiting harbour seal, Phoca vitulina largha". Journal of Mammalogy. 53 (3): 594–598. doi:10.2307/1379048. JSTOR 1379048.

v t e Genera of pinnipeds and their stem-allies
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Suborder: Caniformia Infraorder: Arctoidea
Pan-Pinnipedia †Amphicynodontidae Allocyon Amphicticeps Amphicynodon Drassonax Kolponomos Pachycynodon Parictis Wangictis †Semantoridae Necromites Potamotherium Puijila Semantor Pinnipedimorpha †Enaliarctos Pinnipediformes †Pacificotaria †Pinnarctidion †Pteronarctos Pinnipedia Phocidae †Devinophoca Monachinae †Magnotherium Monachini †Afrophoca †Auroraphoca †Messiphoca Monachus Neomonachus †Eomonachus †Noriphoca †Palmidophoca †Pliophoca †Pontophoca †Pristiphoca †Terranectes Miroungini †Callophoca Mirounga Lobodontini †Acrophoca †Australophoca †Hadrokirus †Homiphoca Hydrurga Leptonychotes Lobodon Ommatophoca †Piscophoca †Properiptychus †Virginiaphoca Phocinae †Cryptophoca †Frisiphoca †Kawas †Leptophoca †Monachopsis †Monotherium †Phocanella †Prophoca †Sarmatonectes Erignathini Erignathus †Platyphoca Cystophorini Cystophora †Miophoca †Pachyphoca Phocini †Batavipusa †Gryphoca Halichoerus Histriophoca †Nanophoca Pagophilus Phoca †Planopusa †Praepusa Pusa Otarioidea see below↓
Otarioidea †Desmatophocidae Allodesmus Atopotarus Desmatophoca Eodesmus Odobenidae †Archaeodobenus †Imagotaria †Kamtschatarctos †Nanodobenus †Neotherium †Osodobenus †Pelagiarctos †Pontolis †Proneotherium †Prototaria †Pseudotaria †Titanotaria Neodobenia †Dusignathinae Dusignathus Gomphotaria Odobeninae †Aivukus Odobenus †Ontocetus †Pliopedia †Protodobenus †Valenictus Panotariidae †Eotaria Otariidae Callorhinae Callorhinus †Pithanotaria Otariinae †Thalassoleon Zalophini Eumetopias †Oriensarctos †Proterozetes Zalophus Otariini Arctocephalus Arctophoca †Hydrarctos Neophoca Otaria Phocarctos
Lists List of pinnipeds List of fossil pinnipedimorphs

• Phocins
• Carnivoran genera
• Taxa named by Carl Linnaeus