Phoca largha, Pallas, 1811
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publication ID |
https://doi.org/ 10.5281/zenodo.6607185 |
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DOI |
https://doi.org/10.5281/zenodo.6606920 |
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persistent identifier |
https://treatment.plazi.org/id/464F694F-FFA4-A858-FACE-D4B49235FE27 |
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treatment provided by |
Diego |
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scientific name |
Phoca largha |
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Spotted Seal
French: Phoque tacheté / German: Largha-Seehund / Spanish: Foca manchada
Other common names: Largha Seal
Taxonomy. Phoca largha Pallas, 1811 View in CoL ,
quam quod observetur tantum ad orientale littus Camtschatcae” (= Eastern coast of Kamchatka, Russia).
This species is monotypic.
Distribution. N Pacific Ocean, from the Yellow and Bohai seas in N China N through Sea of Japan, Sea of Okhotsk, Bering Sea, and Chukchi Sea to W Beaufort Sea and Alaska. View Figure
Descriptive notes. Total length 161-176 cm (males) and 151-169 cm (females); weight 85-110 kg (males) and 65-115 kg (females). Newborns are 77-92 cm in length and weigh 7-12 kg. Spotted Seals are medium-sized, with a variable pelage that ranges dorsally from a dark gray to silver or tan background and slightly lighter ventrally, with dark splotches and spots scattered over the body. Newborns have a thick woolly creamy lanugo (fine, soft hair) that is molted near or just after weaning at c.3—4 weeks of age.
Habitat. Particularly in areas of seasonal pack ice, with a pelagic distribution in winter and spring and a different coastal and pelagic distribution during ice-free months. For example, south of Saint Lawrence Island, Alaska,in late winter, Spotted Seals avoided large ice floes (more than 48 m in diameter) and preferred small ice floes (less than 20 m in diameter) ice floes. In contrast, sympatric Ringed Seals ( Phoca hispida ) and Walruses ( Odobenus rosmarus ) preferred large ice floes, and Bearded Seals ( Erignathus barbatus ) preferred areas between large and small ice floes.
Food and Feeding. Spotted Seals have a diverse diet of crustaceans, cephalopods, and fish, including walleye pollock ( Theragra chalcogramma), Arctic cod (primarily Boreogadus saida), sand lance ( Ammodytidae ), capelin ( Mallotus villosus), saffron cod ( Eleginus gracilis), Pacific herring ( Clupea pallasii), flounders, and salmon, depending on area. Fatty acid composition of blubber of Spotted Seals from subsistence harvests near Little Diomede Island, Alaska (USA), differed from that of sympatric Ringed Seals, Ribbon Seals ( Histriophoca fasciata ), and Bearded Seals, suggesting dietary separation. Such comparisons offatty acids are not only useful as an index of diet but also as a benchmark to assess future climate change. High levels of isotopic nitrogen in lumbar muscles of Spotted Seals from subsistence harvest near Little Diomede and Shishmaref islands, Alaska, suggested a fish-dominated diet; stomachs contents corroborated that conclusion, and all of 50 stomach contents examined contained fish taxa, dominated by Pacific herring, Arctic cod, and saffron cod.
Breeding. Female Spotted Seals generally give birth to a single offspring in March— April, although a few twins have been reported. Females nurse their young for ¢.3—4 weeks. A single adult male associates with a female early in the breeding season and then remains with her until she weans her offspring and goes into estrus. Mating occurs in the water about the time a female weans her offspring.
Activity patterns. Spotted Seals occupy relatively isolated and inaccessible areas of pack ice from autumn through spring when they breed and molt, and then they are highly mobile and pelagic the rest of the year. Most Spotted Seals molt in May-June.
Movements, Home range and Social organization. Spotted Seals are mostly associated with seasonal pack ice in autumn, winter, and early spring. They are relatively dispersed then and rarely aggregate in large groups except in mouths of estuaries as new ice forms, where they feed on spawning fish, and near coasts when haul outs on sea ice become more limited. Even then, Spotted Seals are mostly asocial. Spotted Seals appear to be monogamous, and males are territorial while waiting for females to come into estrus. In sea-ice habitats in late winter and early spring, they are mostly solitary or form triads of an adult female, her offspring, and an adult male, standing by to mate with her after she weans her offspring and goes into estrus in spring. Spotted Seals appear to be mostly pelagic the rest of the year and dispersed widely over the Bering Sea, the Sea of Okhotsk, and the Sea ofJapan while feeding.
Status and Conservation. Classified as Data Deficient on The IUCN Red List. Abundance of Spotted Seals is poorly known, but some estimates are ¢.200,000 individuals in the Bering and Chukchi seas and at least 130,000 individuals in the Sea of Okhotsk. Populations are estimated at 4000-5000 individuals in the Yellow and Bohai seas and more than 8000 individuals in the Sea ofJapan. Conservation threats include loss of sea ice from climate change, occasional entanglement in salmon trap nets near the Nemuro Peninsula offJapan, and rare bycatch in fishing gear such as ground-fish trawlers. In 2010, the Southern Distinct Population Segment of the Spotted Seal in the Yellow Sea and Peter the Great Bay of China and Russia was listed as threatened under the US Endangered Species Act. Population segments of Spotted Seals in the Bering Sea and the Sea of Okhotsk were considered but were not listed.
Bibliography. Burns (1970, 2009), Cooper et al. (2009), Dehn et al. (2007), Lowry et al. (2000), Naito & Nishiwaki (1972), Quakenbush & Sheffield (2007), Rugh et al. (1997), Simpkins et al. (2003).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
