LIFE HISTORY STUDIES OF THE PACIFIC COAST MARINE ALGA, COLLINSIELLA TUBERCULATA SETCHELL AND GARDNER

1960 ◽  
Vol 38 (6) ◽  
pp. 969-983 ◽  
Author(s):  
Robert F. Scagel
Keyword(s):  
Life History ◽  
Pacific Coast ◽  
Late Summer ◽  
Systematic Position ◽  
Early Summer ◽  
Morphological Data ◽  
Sexual Life ◽  
Enteromorpha Intestinalis ◽  
The Pacific ◽  
Successive Generations

Culture studies of a marine green alga, described from the Pacific Coast of North America as Collinsiella tuberculata Setchell and Gardner, have shown it to be a stage in the life history of a form of Enteromorpha intestinalis (L.) Link. The Collinsiella-stage is thought to be the sexual phase, or a basal remnant of the Enteromorpha-stage, and produces biflagellate gametes. The typical tubular thallus of Enteromorpha has been grown in culture from zygotes of the Collinsiella-stage and zoospores of the Enteromorpha-stage. Parthenogenetic development of gametes is also indicated. Some of the tubular plants produce biflagellate gametes which cannot be distinguished from those of the Collinsiella-stage. Others produce quadriflagellate zoospores, which may be meiospores or mitospores. An accessory method of reproduction by quadriflagellate mitospores (neutral spores) occurs and this asexual cycle has been carried through three successive generations in culture without an intervening sexual phase. Tubular thalli of Enteromorpha inteslinalis (L.) Link producing biflagellate gametes during the spring and early summer and quadriflagellate zoospores during the late summer are found in nature in the same area from which the Collinsiella-stage was obtained. These are believed to represent in nature the normal sexual life cycle of this plant, which has been reported to have an alternation of isomorphic generations. The possible relationships between the stages obtained in culture and those observed in nature are discussed. A number of hypothetical conclusions have been drawn with respect to the systematic position of the genus Enteromorpha and related genera. These studies are being continued to clarify several unknown aspects brought out by this preliminary study. A cytological study is being undertaken to substantiate the conclusions drawn from the morphological data.

BIOLOGY AND BEHAVIOR OF ZIMMERMAN PINE MOTH, DIORYCTRIA ZIMMERMANI, IN MICHIGAN

1967 ◽  
Vol 99 (5) ◽  
pp. 529-536 ◽  
Author(s):  
R. B. Carlson ◽  
J. W. Butcher
Keyword(s):  
Life History ◽  
Vertical Distribution ◽  
Uniform Distribution ◽  
Late Summer ◽  
Head Capsule ◽  
Early Summer ◽  
Main Stem ◽  
History Of ◽  
And Behavior ◽  
The Vertical Distribution

AbstractThis paper reports on studies of biology and life history of the Zimmerman pine moth, Dioryctria zimmermani (Grote), in southern Michigan.Adults emerged during the last 3 weeks of August and eggs hatched through mid-September. Eggs were laid almost entirely on the main stem and, upon hatching, the larvae entered recesses in the bark and spun hibernacula, ostensibly without feeding.Studies on the vertical distribution of larvae and pupae showed a fairly uniform distribution over the main stem in spring and early summer. In late summer, a larger percentage was found in middle whorls.Based on head capsule measurements, it is tentatively proposed that there are six larval stadia. Occurrence of parasitism in the last larval stadia is discussed, and a new egg parasite is reported.The presence of D. abietivorella Grote in the study areas is noted, and discussed briefly.

Life-history studies–a new approach to the taxonomy of ligulate species of Desmarestia (Phaeophyceae) from the Pacific coast of Canada

1986 ◽  
Vol 64 (10) ◽  
pp. 2192-2196 ◽  
Author(s):  
Akira F. Peters ◽  
Dieter G. Müller
Keyword(s):  
Life History ◽  
Sexual Dimorphism ◽  
North America ◽  
Life Histories ◽  
Pacific Coast ◽  
Culture Conditions ◽  
Growth Forms ◽  
Dioecious Species ◽  
New Approach ◽  
The Pacific

Life histories of two ligulate forms of Desmarestia with different phylloid width from one site on the Canadian Pacific coast were studied in culture. Meiospores from a form with narrow phylloids germinated into monoecious gametophytes. Meiospores from a form with broad phylloids developed into dioecious gametophytes, showing sexual dimorphism characteristic for dioecious species of Desmarestia. The two growth forms also differed in culture conditions required for gametogenesis. We conclude that at least two different species of ligulate Desmarestia occur on the Pacific coast of North America.

The Life History and Immature Stages of Synergus pacificus McCracken and Egbert (Hymenoptera: Cynipidae)

1965 ◽  
Vol 97 (2) ◽  
pp. 185-188 ◽  
Author(s):  
David Evans
Keyword(s):  
British Columbia ◽  
Life History ◽  
Pacific Coast ◽  
Immature Stages ◽  
Central California ◽  
Larval Stages ◽  
The Pacific

AbstractSynergus pacificus McCracken and Egbert (Hymenoptera: Cynipidae) is an inquiline of oak gall cynipids in the Pacific Coast area from southern British Columbia to central California. Approximately 1,000 specimens were examined during the course of this study. Descriptions of the egg and larval stages are given, and information on life history and ecology is presented.

scholarly journals SPATIAL ESTIMATION OF EUPHAUSIID BIOMASS ALONG THE PACIFIC COAST OF EASTERN HOKKAIDO, JAPAN IN EARLY SUMMER OF 2008

2011 ◽  
Vol 19 (3) ◽  
Author(s):  
Naoki Tojo ◽  
Kenji Minami ◽  
Ryuichi Matsukura ◽  
Yohei Kawauchi ◽  
Tetsuichiro Funamoto ◽  
...  
Keyword(s):  
Pacific Coast ◽  
Early Summer ◽  
Spatial Estimation ◽  
The Pacific

scholarly journals Two Configurations of the Western Arctic Shelfbreak Current in Summer

2012 ◽  
Vol 42 (3) ◽  
pp. 329-351 ◽  
Author(s):  
Wilken-Jon von Appen ◽  
Robert S. Pickart
Keyword(s):  
Late Summer ◽  
Beaufort Sea ◽  
Early Summer ◽  
Coastal Current ◽  
Mean Flow ◽  
Warm Core ◽  
The Pacific ◽  
Western Arctic ◽  
Alaskan Coastal Current ◽  
Pacific Summer Water

Abstract Data from a closely spaced array of moorings situated across the Beaufort Sea shelfbreak at 152°W are used to study the Western Arctic Shelfbreak Current, with emphasis on its configuration during the summer season. Two dynamically distinct states of the current are revealed in the absence of wind, with each lasting approximately one month. The first is a surface-intensified shelfbreak jet transporting warm and buoyant Alaskan Coastal Water in late summer. This is the eastward continuation of the Alaskan Coastal Current. It is both baroclinically and barotropically unstable and hence capable of forming the surface-intensified warm-core eddies observed in the southern Beaufort Sea. The second configuration, present during early summer, is a bottom-intensified shelfbreak current advecting weakly stratified Chukchi Summer Water. It is baroclinically unstable and likely forms the middepth warm-core eddies present in the interior basin. The mesoscale instabilities extract energy from the mean flow such that the surface-intensified jet should spin down over an e-folding distance of 300 km beyond the array site, whereas the bottom-intensified configuration should decay within 150 km. This implies that Pacific Summer Water does not extend far into the Canadian Beaufort Sea as a well-defined shelfbreak current. In contrast, the Pacific Winter Water configuration of the shelfbreak jet is estimated to decay over a much greater distance of approximately 1400 km, implying that it should reach the first entrance to the Canadian Arctic Archipelago.

On the Life History of the Douglas-fir Cone Moth, Barbara colfaxiana (Kft.) (Lepidoptera: Olethreutidae), and one of its Parasites, Glypta evetriae Cush. (Hymenoptera: Ichneumonidae)

1960 ◽  
Vol 92 (11) ◽  
pp. 826-834 ◽  
Author(s):  
A. F. Hedlin
Keyword(s):  
British Columbia ◽  
Life History ◽  
Rocky Mountains ◽  
Pacific Coast ◽  
Douglas Fir ◽  
Lake Area ◽  
Seed Loss ◽  
The Pacific ◽  
History Of ◽  
Loss Range

The Douglas-fir cone moth has been reported causing damage to cones and seeds of Douglas fir for a number of years; reports of seed loss range from light to almost 100 per cent. The insect occurs throughout the range of the host in British Columbia, the Pacific Coast States, and the Rocky Mountains.Observations recorded here were made during 1957 and 1958 in the Cowichan Lake area of Vancouver Island, and 1959 in the interior of British Columbia.

The Central American Midsummer Drought: Regional Aspects and Large-Scale Forcing*

2007 ◽  
Vol 20 (19) ◽  
pp. 4853-4873 ◽  
Author(s):  
Richard Justin O. Small ◽  
Simon P. de Szoeke ◽  
Shang-Ping Xie
Keyword(s):  
Gulf Of Mexico ◽  
Central America ◽  
Large Scale ◽  
Late Summer ◽  
Heavy Precipitation ◽  
Early Summer ◽  
Southern Mexico ◽  
Low Level ◽  
The North ◽  
The Pacific

Abstract The midsummer drought (MSD) is a diminution in rainfall experienced during the middle of the rainy season in southern Mexico and Central America, as well as in the adjacent Caribbean, Gulf of Mexico, and eastern Pacific seas. The aim of this paper is to describe the regional characteristics of the MSD and to propose some possible forcing mechanisms. Satellite and in situ data are used to form a composite of the evolution of a typical MSD, which highlights its coincidence with a low-level anticyclone centered over the Gulf of Mexico and associated easterly flow across Central America. The diurnal cycle of precipitation over the region is reduced in amplitude during midsummer. The MSD is also coincident with heavy precipitation over the Sierra Madre Occidental (part of the North American monsoon). Reanalysis data are used to show that the divergence of the anomalous low-level flow during the MSD is the main factor governing the variations in precipitation. A linear baroclinic model is used to show that the seasonal progression of the Pacific intertropical convergence zone (ITCZ), which moves northward following warm sea surface temperature (SST) during the early summer, and of the Atlantic subtropical high, which moves westward, are the most important remote factors that contribute toward the low-level easterly flow and divergence during the MSD. The circulation associated with the MSD precipitation deficit helps to maintain the deficit by reinforcing the low-level anticyclonic flow over the Gulf of Mexico. Surface heating over land also plays a role: a large thermal low over the northern United States in early summer is accompanied by enhanced subsidence over the North Atlantic. This thermal low is seen to decrease considerably in midsummer, allowing the high pressure anomalies in the Atlantic and Pacific Oceans to extend into the Gulf of Mexico. These anomalies are maintained until late summer, when an increase in rainfall from the surge in Atlantic tropical depressions induces anomalous surface cyclonic flow with westerlies fluxing moisture from the Pacific ITCZ toward Central America.

Phenology, Population Dynamics, and Flowering Dynamics of Case's Ladies'-tresses, Spiranthes casei var. casei (Orchidaceae), in Ottawa, Ontario

2009 ◽  
Vol 123 (1) ◽  
pp. 19 ◽  
Author(s):  
Joyce M. Reddoch ◽  
Allan H. Reddoch
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Seed Production ◽  
Late Summer ◽  
Early Summer ◽  
Population Trends ◽  
Life History Stages ◽  
Deer Herbivory ◽  
Cloudy Weather

We describe a seven-year study (2002–2008) of a population of Case’s Ladies’-tresses (Spiranthes casei var. casei) in the western Greenbelt in Ottawa, Ontario, that had been extant since at least 1972. We also record a temporary colonization in the eastern Greenbelt for 11 years (1998–2008). The seven life history stages identified were seed, juvenile, immature, flowering, vegetative, offshoot (ramet), and non-emergent. Mature plants present in the first two years of the study had mean half lives of 9.4 years. Flowering and seed production were limited by damp, cloudy weather when fall rosettes develop, by gastropod herbivory in early summer, by drought in mid-summer, and by deer herbivory in late summer. Given the resulting wide fluctuations in the fractions of plants flowering, as well as the lack of visibility of vegetative plants, this study demonstrates the limitations of annual censuses of flowering stems for determining the actual sizes of populations and for detecting long-term population trends.

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