scholarly journals Oldest record of monk seals from the North Pacific and biogeographic implications

2019 ◽  
Vol 15 (5) ◽  
pp. 20190108 ◽  
Author(s):  
Jorge Velez-Juarbe ◽  
Ana M. Valenzuela-Toro
Keyword(s):  
North Pacific ◽  
Fossil Record ◽  
Marine Mammals ◽  
Pacific Region ◽  
The North ◽  
Biogeographic History ◽  
History Of ◽  
North Pacific Region ◽  
Monk Seals ◽  
The North Pacific

True seals (crown Phocidae) originated during the late Oligocene–early Miocene (approx. 27–20 Ma) in the North Atlantic/Mediterranean region, with later (middle Miocene, approx. 16–11 Ma) dispersal events to the South Atlantic and South Pacific. Contrasting with other pinnipeds, the fossil record of phocids from the North Pacific region is scarce and restricted to the Pleistocene. Here we present the oldest fossil record of crown phocids, monachines (monk seals), from the North Pacific region. The specimens were collected from the upper Monterey Formation in Southern California and are dated to 8.5–7.1 Ma, predating the previously oldest known record by at least 7 Ma. This record provides new insights into the early biogeographic history of phocids in the North Pacific and is consistent with a northward dispersal of monk seals (monachines), which has been recognized for other groups of marine mammals. Alternatively, this finding may correspond with a westward dispersal through the Central American Seaway of some ancestor of the Hawaiian monk seal. This record increases the taxonomic richness of the Monterey pinniped assemblage to five taxa, making it a fairly diverse fossil assemblage, but also constitutes the oldest record of sympatry among all three extant pinniped crown clades.

The Last Surviving Ammonoid at the end of the Cretaceous in the North Pacific Region

2016 ◽  
Vol 20 (2) ◽  
pp. 116-120 ◽  
Author(s):  
Ken'ichi Kurihara ◽  
Manabu Kano ◽  
Hiroshi Sawamura ◽  
Yoshio Sato
Keyword(s):  
North Pacific ◽  
Pacific Region ◽  
The North ◽  
North Pacific Region ◽  
The North Pacific

New Nanaimo Group ammonites (Cretaceous, Santonian–Campanian) from British Columbia and Washington State

1989 ◽  
Vol 63 (2) ◽  
pp. 218-227 ◽  
Author(s):  
James W. Haggart ◽  
Peter D. Ward
Keyword(s):  
United States ◽  
British Columbia ◽  
North Pacific ◽  
Washington State ◽  
Western Canada ◽  
Pacific Region ◽  
The North ◽  
North Pacific Region ◽  
The North Pacific

The ammonite species Puzosia (Mesopuzosia) densicostata Matsumoto, Kitchinites (Neopuzosia) japonicus Spath, Anapachydiscus cf. A. nelchinensis Jones, Menuites cf. M. menu (Forbes), Submortoniceras chicoense (Trask), and Baculites cf. B. boulei Collignon are described from Santonian–Campanian strata of western Canada and northwestern United States. Stratigraphic occurrences and ranges of the species are summarized and those taxa important for correlation with other areas in the north Pacific region are noted.

REVIEW OF THE TREMATODE GENERA BACCIGER AND PENTAGRAMMA (FELLODISTOMATIDAE) AND DESCRIPTION OF P. PETROWI (LAYMAN, 1930) N. COMB. FROM MARINE FISHES FROM THE PACIFIC COAST OF CANADA

1965 ◽  
Vol 43 (2) ◽  
pp. 381-405 ◽  
Author(s):  
L. Margolis ◽  
Hilda Lei Ching
Keyword(s):  
North Pacific ◽  
Pacific Coast ◽  
Marine Fishes ◽  
Pacific Region ◽  
British Isles ◽  
Type B ◽  
The North ◽  
The Pacific ◽  
North Pacific Region ◽  
The North Pacific

The generic diagnoses of Bacciger and Pentagramma are emended. Recognized as members of the genus Bacciger are the type, B. bacciger (Rudolphi, 1819), from the Mediterranean, Black, and Azov Seas; B. nicolli Palombi, 1934, from Atlantic waters near the British Isles; and B. opisthonemae Nahhas and Cable, 1964, from Jamaican waters. Pentagramma consist of P. symmetricum Chnlkova, 1939, the type, from the Black and Azov Seas and P. petrowi (Layman, 1930) n. comb, from the northern part of the North Pacific region. Synonyms of P. petrowi are Monorcheides(?) petrowi Layman, 1930: Orientophorus sayori Yamaguti, 1942; Faustula sayori (Yamaguti, 1942); Orientophorus petrowi (Layman, 1930); and Bacciger petrowi (Layman, 1930). Pentagramma petrowi is redescribed and additional details of morphology are included for P. symmetricum, B. bacciger, and B. nicolli. Measurements of the species discussed and extensive host and locality records are tabulated.

scholarly journals Intra-annual variations in atmospheric dust and tritium in the North Pacific region detected from an ice core from Mount Wrangell, Alaska

2007 ◽  
Vol 112 (D10) ◽  
Author(s):  
Teppei J. Yasunari ◽  
Takayuki Shiraiwa ◽  
Syosaku Kanamori ◽  
Yoshiyuki Fujii ◽  
Makoto Igarashi ◽  
...  
Keyword(s):  
North Pacific ◽  
Ice Core ◽  
Pacific Region ◽  
Atmospheric Dust ◽  
Annual Variations ◽  
The North ◽  
North Pacific Region ◽  
The North Pacific

scholarly journals La experiencia del cultivo comercial de camarones marinos en estanques de producción en Costa Rica

2013 ◽  
Vol 5 ◽  
pp. 87
Author(s):  
José A. Valverde-Moya ◽  
Jorge Alfaro-Montoya
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
Management Plan ◽  
Average Weight ◽  
Pacific Region ◽  
Long Cycle ◽  
The North ◽  
North Pacific Region ◽  
Gulf Of Nicoya ◽  
The North Pacific

El cultivo de camarones marinos en estanques de producción en Costa Rica ha estado restringido a una pequeña fracción del territorio (1 000 ha), siendo el sector del Pacífico Norte, a ambas márgenes del Golfo de Nicoya, uno de los más productivos. En los últimos 2 años se ha logrado implementar en estas fincas un Plan de Manejo, que ha permitido obtener de manera continua y predecible niveles adecuados de producción convencional de camarón. El presente estudio describe los resultados de un Plan de Manejo utilizando densidades de siembra de 10 camarones/m2 en tres ciclos cortos (90-120 días) y 15 camarones/m2 en un ciclo largo (180 días), durante los años 2011 y 2012, en 11 estanques de fincas ubicadas en Colorado de Abangares, Guanacaste. La sobrevivencia fue mejor en los ciclos del 2011 (75% y 80%) con respecto a los del 2012 (58% y 51%) y el peso promedio final fue inferior en los ciclos cortos (11-14 g) en relación con el peso promedio ponderado, tomando en cuenta las raleas, en el ciclo largo (cerca de 20 g). Debido a que no hubo compensación en el crecimiento y la biomasa en el último ciclo con la sobrevivencia más baja, la productividad decayó a 600 kg/ha después de haberse venido dando incrementos considerables (de 1 118 a  1 263 y 1 730 kg/ha) en los tres ciclos anteriores. Se discuten posibles factores causantes de la baja productividad en este ciclo realizado a finales del 2011 e inicios del 2012.AbstractThe culture of marine shrimp in earthen ponds in Costa Rica has been restricted to a small portion of theterritory (1 000 ha), being the North Pacific region, at both margins of the Gulf of Nicoya, one of the mostproductive areas. During 2011-2012 these farms implemented a Management Plan that has allowed forcontinuously and predictably obtaining adequate levels of conventional shrimp production. The presentstudy describes the results obtained with the Management Plan used at stocking densities of 10 shrimp/m2in three short cycles (90-120 days) and 15 shrimp/m2 in one long cycle (180 days) during 2011 and 2012in 11 ponds located in Colorado de Abangares, Guanacaste. Survival was better in the 2011 cycles (75%and 80%) as compared to the 2012 cycles (58% and 51%); the final average weight was lower for the shortcycles (11-14 g) in relation to the long cycle (approximately 20 g). Because there was no compensationon growth and biomass in the last cycle with the lowest survival, productivity decreased to 600 kg/ha afterhaving obtained remarkable increments (from 1 118 to 1 263 and 1 730 kg/ha) in the three previous cycles.The possible factors causing low productivity in this cycle at the end and at the beginning of the year arediscussed in this paper.

scholarly journals La experiencia del cultivo comercial de camarones marinos en estanques de producción en Costa Rica

2013 ◽  
Vol 5 ◽  
pp. 87 ◽  
Author(s):  
José A. Valverde-Moya ◽  
Jorge Alfaro-Montoya
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
Management Plan ◽  
Average Weight ◽  
Pacific Region ◽  
Long Cycle ◽  
The North ◽  
North Pacific Region ◽  
Gulf Of Nicoya ◽  
The North Pacific

El cultivo de camarones marinos en estanques de producción en Costa Rica ha estado restringido a una pequeña fracción del territorio (1 000 ha), siendo el sector del Pacífico Norte, a ambas márgenes del Golfo de Nicoya, uno de los más productivos. En los últimos 2 años se ha logrado implementar en estas fincas un Plan de Manejo, que ha permitido obtener de manera continua y predecible niveles adecuados de producción convencional de camarón. El presente estudio describe los resultados de un Plan de Manejo utilizando densidades de siembra de 10 camarones/m2 en tres ciclos cortos (90-120 días) y 15 camarones/m2 en un ciclo largo (180 días), durante los años 2011 y 2012, en 11 estanques de fincas ubicadas en Colorado de Abangares, Guanacaste. La sobrevivencia fue mejor en los ciclos del 2011 (75% y 80%) con respecto a los del 2012 (58% y 51%) y el peso promedio final fue inferior en los ciclos cortos (11-14 g) en relación con el peso promedio ponderado, tomando en cuenta las raleas, en el ciclo largo (cerca de 20 g). Debido a que no hubo compensación en el crecimiento y la biomasa en el último ciclo con la sobrevivencia más baja, la productividad decayó a 600 kg/ha después de haberse venido dando incrementos considerables (de 1 118 a  1 263 y 1 730 kg/ha) en los tres ciclos anteriores. Se discuten posibles factores causantes de la baja productividad en este ciclo realizado a finales del 2011 e inicios del 2012.AbstractThe culture of marine shrimp in earthen ponds in Costa Rica has been restricted to a small portion of theterritory (1 000 ha), being the North Pacific region, at both margins of the Gulf of Nicoya, one of the mostproductive areas. During 2011-2012 these farms implemented a Management Plan that has allowed forcontinuously and predictably obtaining adequate levels of conventional shrimp production. The presentstudy describes the results obtained with the Management Plan used at stocking densities of 10 shrimp/m2in three short cycles (90-120 days) and 15 shrimp/m2 in one long cycle (180 days) during 2011 and 2012in 11 ponds located in Colorado de Abangares, Guanacaste. Survival was better in the 2011 cycles (75%and 80%) as compared to the 2012 cycles (58% and 51%); the final average weight was lower for the shortcycles (11-14 g) in relation to the long cycle (approximately 20 g). Because there was no compensationon growth and biomass in the last cycle with the lowest survival, productivity decreased to 600 kg/ha afterhaving obtained remarkable increments (from 1 118 to 1 263 and 1 730 kg/ha) in the three previous cycles.The possible factors causing low productivity in this cycle at the end and at the beginning of the year arediscussed in this paper.

The genus Anonyx (Crustacea, Amphipoda) in the North Pacific and Arctic oceans: Anonyx compactus group

1989 ◽  
Vol 67 (8) ◽  
pp. 1945-1954 ◽  
Author(s):  
D. H. Steele
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Pacific Region ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
Normal Length ◽  
The North ◽  
North Pacific Region ◽  
The North Atlantic ◽  
The North Pacific

The Anonyx compactus group is characterized by the morphology of the inner ramus of the second uropod, which is of normal length and depth but is completely constricted distally and bears a long spine at the constriction. This group comprises eight species of which three, Anonyx attenuatus, Anonyx stappersi, and Anonyx stebbingi, are newly described. Anonyx stappersi was identified as Chironesimus debruyni by L. Stappers and A. stebbingi as A. ampulloides by T. R. R. Stebbing. Seven of these species are known from the North Pacific region, and three from the North Atlantic region, but none has a circumpolar distribution.

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