The “Cribrilina annulata" problem and new species of Juxtacribrilina (Bryozoa: Cheilostomata: Cribrilinidae) from the North Pacific

Zootaxa ◽  
2021 ◽  
Vol 5016 (3) ◽  
pp. 333-364
Author(s):  
MATTHEW H. DICK ◽  
ANDREI V. GRISCHENKO ◽  
DENNIS P. GORDON ◽  
ANDREW N. OSTROVSKY

Originally described from Greenland, Juxtacribrilina annulata (Fabricius, 1780) (previously known as Cribrilina annulata) has long been regarded as having a circumpolar, Arctic-boreal distribution. The genus Juxtacribrilina Yang, Seo, Min, Grischenko & Gordon, 2018 accommodated J. annulata and three related North Pacific species formerly in Cribrilina Gray, 1848 that lack avicularia, have a reduced (hood-like, cap-like, or vestigial) ooecium closely associated with modified latero-oral spines to form an ooecial complex, and produce frontally or marginally positioned dwarf ovicellate zooids. While the recently described NW Pacific species J. mutabilis and J. flavomaris, which have a vestigial ooecium like a short, flattened spine, clearly differ from J. annulata, the differences between J. annulata and other Pacific populations remained unclear. Here we provide descriptions for five species from the North Pacific region. We identified a specimen from the Sea of Okhotsk as J. annulata. Among the other four species, J. ezoensis n. sp. has a trans-Pacific distribution (abundant at Akkeshi, Hokkaido, Japan; also detected in the Commander Islands and at Ketchikan, Southeast Alaska); J. pushkini n. sp. was found only at Ketchikan; J. dobrovolskii n. sp. was found only at Shikotan Island in the Lesser Kuril Chain; and J. tumida n. sp. was found only at Kodiak, Gulf of Alaska. These four species all differ from J. annulata in having one or two frontal pore chambers on the proximal gymnocyst of most zooids; in budding frontal dwarf ovicellate zooids from these chambers rather than from basal pore chambers; in producing dwarf zooids more abundantly; and in having ooecia that are somewhat to markedly more reduced (cap-like rather than hood-like) and more closely integrated with the modified latero-oral spines. Furthermore, in the Pacific species, the ooecium in basal zooids arises from the roof of the distal pore chamber of the maternal zooid; ovicellate zooids can thus also bud a distal autozooid and are often arranged in columnar series with other zooids. In J. annulata, the hood-like kenozooidal ooecium budded from the maternal zooid replaces the distal autozooid, and ovicellate zooids are thus usually not embedded in a columnar series.  

1993 ◽  
Vol 50 (12) ◽  
pp. 2608-2625 ◽  
Author(s):  
William G. Pearcy ◽  
Joseph P. Fisher ◽  
Mary M. Yoklavich

Abundances of Pacific pomfret (Brama japonica), an epipelagic fish of the North Pacific Ocean, were estimated from gillnet catches during the summers of 1978–1989. Two size modes were common: small pomfret <1 yr old, and large fish ages 1–6. Large and small fish moved northward as temperatures increased, but large fish migrated farther north, often into the cool, low-salinity waters of the Central Subarctic Pacific. Lengths of small fish were positively correlated with latitude and negatively correlated with summer surface temperature. Interannual variations in the latitude of catches correlated with surface temperatures. Large catches were made in the eastern Gulf of Alaska (51–55°N) but modes of small pomfret were absent here, and large fish were rare at these latitudes farther to the west. Pomfret grow rapidly during their first two years of life. They are pectoral fin swimmers that swim continuously. They prey largely on gonatid squids in the region of the Subarctic Current in the Gulf of Alaska during summer. No evidence was found for aggregations on a scale ≤1 km. Differences in the incidence of tapeworm, spawning seasons, and size distributions suggest the possibility of discrete populations in the North Pacific Ocean.


1965 ◽  
Vol 43 (2) ◽  
pp. 381-405 ◽  
Author(s):  
L. Margolis ◽  
Hilda Lei Ching

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.


2021 ◽  
pp. 415-484
Author(s):  
Jason S. Link ◽  
Anthony R. Marshak

This chapter describes the North Pacific region and the major issues facing this marine fisheries ecosystem, and presents some summary statistics related to the 90 indicators of ecosystem-based fisheries management (EBFM) criteria. The North Pacific contains the fifth-highest number of managed taxa, including commercially and recreationally important groundfish (e.g., walleye pollock, Pacific cod, sablefish, lingcod, halibut, rockfishes, yellowfin sole), cephalopods, king-and Tanner crabs, salmon, and steelhead. The North Pacific ecosystem has biota and marine communities that are responding to the consequences of fishing pressure, climate oscillations, and other ocean uses. More recent stressors, including substantial regional warming, associated species shifts, increasing human population density, and proliferation of invasive species are affecting this system and altering its composition, dynamics, and LMR production. Overall, a moderate to high degree of EBFM progress has been made in the eastern Bering Sea, Aleutian Islands, and Gulf of Alaska in terms of implementation, advancing knowledge of ecosystem principles, examining trade-offs, assessing risks and vulnerabilities, and in beginning to establish and use ecosystem-level reference points for management. While much information has been obtained and applied toward ecosystem-level calculations, syntheses, and models, continued progress in applying these system-wide emergent properties into regional management frameworks remains necessary.


2009 ◽  
Vol 39 (6) ◽  
pp. 1317-1339 ◽  
Author(s):  
Robert S. Pickart ◽  
Alison M. Macdonald ◽  
G. W. K. Moore ◽  
Ian A. Renfrew ◽  
John E. Walsh ◽  
...  

Abstract The seasonal change in the development of Aleutian low pressure systems from early fall to early winter is analyzed using a combination of meteorological reanalysis fields, satellite sea surface temperature (SST) data, and satellite wind data. The time period of the study is September–December 2002, although results are shown to be representative of the long-term climatology. Characteristics of the storms were documented as they progressed across the North Pacific, including their path, central pressure, deepening rate, and speed of translation. Clear patterns emerged. Storms tended to deepen in two distinct geographical locations—the Gulf of Alaska in early fall and the western North Pacific in late fall. In the Gulf of Alaska, a quasi-permanent “notch” in the SST distribution is argued to be of significance. The signature of the notch is imprinted in the atmosphere, resulting in a region of enhanced cyclonic potential vorticity in the lower troposphere that is conducive for storm development. Later in the season, as winter approaches and the Sea of Okhotsk becomes partially ice covered and cold, the air emanating from the Asian continent leads to enhanced baroclinicity in the region south of Kamchatka. This corresponds to enhanced storm cyclogenesis in that region. Consequently, there is a seasonal westward migration of the dominant lobe of the Aleutian low. The impact of the wind stress curl pattern resulting from these two regions of storm development on the oceanic circulation is investigated using historical hydrography. It is argued that the seasonal bimodal input of cyclonic vorticity from the wind may be partly responsible for the two distinct North Pacific subarctic gyres.


Paleobiology ◽  
1989 ◽  
Vol 15 (4) ◽  
pp. 335-356 ◽  
Author(s):  
Geerat J. Vermeij

Geographical restriction to refuges implies the regional extinction of taxa in areas of the previous range falling outside the refuge. A comparison of the circumstances in the refuge with those in areas from which the taxa were eliminated is potentially informative for pinpointing the causes of extinction. A synthesis of data on the geographical and stratigraphical distributions of cool-water molluscs of the North Pacific and North Atlantic Oceans during the late Neogene reveals four patterns of geographical restriction, at least two of which imply that climatic cooling was not the only cause of extinction during the last several million years. These four patterns are (1) the northwestern Pacific restriction, involving 15 taxa whose amphi-Pacific distributions during the late Neogene became subsequently restricted to the Asian side of the Pacific; (2) the northwestern Atlantic restriction, involving six taxa whose early Pleistocene distribution is inferred to have been amphi-Atlantic, but whose present-day and late Pleistocene ranges are confined to the northwestern Atlantic; (3) a vicariant Pacific pattern, in which many ancestral amphi-Pacific taxa gave rise to separate eastern and western descendants; and (4) the circumboreal restriction, involving six taxa whose early Pleistocene distribution, encompassing both the Atlantic and Pacific Oceans, became subsequently limited to the North Pacific. Like the Pliocene extinctions in the Atlantic, previously studied by Stanley and others, the vicariant Pacific pattern is most reasonably interpreted as having resulted from regional extinction of northern populations in response to cooling. The northwestern Pacific and Atlantic restrictions, however, cannot be accounted for in this way. In contrast to the northeastern margins of the Pacific and Atlantic, the northwestern margins are today characterized by wide temperature fluctuations and by extensive development of shore ice in winter. Northeastern, rather than northwestern, restriction would be expected if cooling were the overriding cause of regional extinction. Among the other possible causes of extinction, only a decrease in primary productivity can account for the observed northwestern and circumboreal patterns of restriction. Geographical patterns of body size and the distribution of siliceous deposits provide supporting evidence that primary productivity declined after the Miocene in the northeastern Pacific, but remained high in the northwestern Pacific, and that productivity in the Pacific is generally higher than it is in the Atlantic. The patterns of geographical restriction in the northern oceans thus provide additional support to previous inferences that reductions in primary productivity have played a significant role in marine extinctions.


2006 ◽  
Vol 134 (12) ◽  
pp. 3567-3587 ◽  
Author(s):  
Linda M. Keller ◽  
Michael C. Morgan ◽  
David D. Houghton ◽  
Ross A. Lazear

Abstract A climatology of large-scale, persistent cyclonic flow anomalies over the North Pacific was constructed using the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) global reanalysis data for the cold season (November–March) for 1977–2003. These large-scale cyclone (LSC) events were identified as those periods for which the filtered geopotential height anomaly at a given analysis point was at least 100 m below its average for the date for at least 10 days. This study identifies a region of maximum frequency of LSC events at 45°N, 160°W [key point 1 (KP1)] for the entire period. This point is somewhat to the east of regions of maximum height variability noted in previous studies. A second key point (37.5°N, 162.5°W) was defined as the maximum in LSC frequency for the period after November 1988. The authors show that the difference in location of maximum LSC frequency is linked to a climate regime shift at about that time. LSC events occur with a maximum frequency in the period from November through January. A composite 500-hPa synoptic evolution, constructed relative to the event onset, suggests that the upper-tropospheric precursor for LSC events emerges from a quasi-stationary long-wave trough positioned off the east coast of Asia. In the middle and lower troposphere, the events are accompanied by cold thickness advection from a thermal trough over northeastern Asia. The composite mean sea level evolution reveals a cyclone that deepens while moving from the coast of Asia into the central Pacific. As the cyclone amplifies, it slows down in the central Pacific and becomes nearly stationary within a day of onset. Following onset, at 500 hPa, a stationary wave pattern, resembling the Pacific–North American teleconnection pattern, emerges with a ridge immediately downstream (over western North America) and a trough farther downstream (from the southeast coast of the United States into the western North Atlantic). The implications for the resulting sensible weather and predictability of the flow are discussed. An adjoint-derived sensitivity study was conducted for one of the KP1 cases identified in the climatology. The results provide dynamical confirmation of the LSC precursor identification for the events. The upper-tropospheric precursor is seen to play a key role not only in the onset of the lower-tropospheric height falls and concomitant circulation increases, but also in the eastward extension of the polar jet across the Pacific. The evolution of the forecast sensitivities suggest that LSC events are not a manifestation of a modal instability of the time mean flow, but rather the growth of a favorably configured perturbation on the flow.


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

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