Growth, Reproductive Output, and Energy Partitioning in Weathervane Scallops, Patinopecten caurinus, from British Columbia

1987 ◽  
Vol 44 (1) ◽  
pp. 152-160 ◽  
Author(s):  
B. A. MacDonald ◽  
N. F. Bourne
Keyword(s):  
Reproductive Output ◽  
Somatic Tissue ◽  
Energy Partitioning ◽  
Food Sources ◽  
Total Production ◽  
Annual Reproductive Cycle ◽  
The West ◽  
Spawning Period ◽  
Strait Of Georgia ◽  
Available Energy

Major differences in population growth and reproductive characteristics of Patinopecten caurinus were related to water temperatures and food sources associated with collection sites in the Strait of Georgia and off the west coast of Vancouver Island. Inshore populations were dominated by larger, faster growing scallops that apparently live longer than offshore scallops. Individuals from the inshore site exhibited enhanced reproductive output total production, and turnover ratios compared with offshore scallops. Histological and stereological techniques were used to assess the annual reproductive cycle. Results revealed a single but protracted spawning period for inshore scallops beginning in mid-April and ending in mid-June whereas offshore scallops spawned during July and August. As scallops grew older there was a gradual shift in emphasis from growth to reproduction in addition to periods when gametogenesis proceeded at the expense of somatic tissue. The quantity of available energy invested m reproduction may restrict growth periods and limit the amount of growth for bivalve species from various habitats.

Growth and Reproductive Energetics of three Scallop Species from British Columbia (Chlamys hastata, Chlamys rubida, and Crassadoma gigantea)

1991 ◽  
Vol 48 (2) ◽  
pp. 215-221 ◽  
Author(s):  
B. A. MacDonald ◽  
R. J. Thompson ◽  
N. F. Bourne
Keyword(s):  
British Columbia ◽  
Reproductive Output ◽  
Reproductive Effort ◽  
Shell Height ◽  
Somatic Growth ◽  
Somatic Tissue ◽  
Tissue Growth ◽  
Net Production ◽  
Available Energy ◽  
Gamete Production

Three scallop species from British Columbia display different strategies for partitioning available energy between somatic tissue growth and gamete production as they increase in age. The spiny scallop Chlamys hastata and the pink scallop Chlamys rubida only live about 6 yr and rarely exceed 80 mm in shell height whereas the rock scallop Crassadoma gigantea may reach 170 mm in height and live for 20 yr or more. Growth, reproductive output, and reproductive effort at any given age are higher in Chlamys hastata than in the smaller Chlamys rubida. Somatic growth in Crassadoma gigantea ceases completely in the final years, but in the short-lived species Chlamys hastata and Chlamys rubida, individuals continue to grow until they die. In long-lived pectinids the emphasis often shifts from somatic growth to gamete production before the midpoint of the life cycle, and our observations on Crassadoma gigantea are consistent with this trend. Short-lived species, however, invest relatively less in reproduction; in our study, reproductive output in Chlamys rubida did not exceed 40% of nonrespired assimilation (net production), and reproductive effort in Chlamys hastata did not reach 50% until the final year of life.

Factors influencing the distribution of Egregia menziesii (Phaeophyta, Laminariales) in British Columbia, Canada

1978 ◽  
Vol 56 (9) ◽  
pp. 1198-1205 ◽  
Author(s):  
D. K. Gordon ◽  
R. E. DE Wreede
Keyword(s):  
British Columbia ◽  
High Temperature ◽  
Laboratory Experiments ◽  
Algal Flora ◽  
The West ◽  
Common Component ◽  
Strait Of Georgia ◽  
Low Salinity ◽  
Factors Influencing ◽  
Juan De Fuca

Egregia menziesii (Turner) Areschoug is a common component of the algal flora along the west coast of Vancouver Island, Queen Charlotte Strait, and the Strait of Juan de Fuca but is absent from the Strait of Georgia in British Columbia, Canada. This distribution pattern was found to be correlated with temperature and salinity in that E. menziesii is not present in areas where there are seasonal periods of low salinity and high temperature. To test this correlation, field transplants of sporophytes and laboratory experiments with sporophytes and culture work were carried out. The results suggest that the distribution of E. menziesii is limited by specific combinations of salinity and temperature; it requires high salinities and temperatures less than 15 °C for its survival.

Timing and Magnitude of Energy Deposition and Loss in the Body, Liver, and Gonads of Northern Pike (Esox lucius)

1979 ◽  
Vol 36 (5) ◽  
pp. 481-487 ◽  
Author(s):  
James S. Diana ◽  
W. C. Mackay
Keyword(s):  
Somatic Growth ◽  
Northern Pike ◽  
Esox Lucius ◽  
The Body ◽  
Total Production ◽  
Spawning Period ◽  
Pike Esox Lucius ◽  
Testicular Growth ◽  
Gonad Growth ◽  
Somatic Energy

Northern pike (Esox lucius) were sampled periodically from Lac Ste. Anne, Alberta, between March 1976 and September 1978. The yearly cycle of production and depletion was determined for individual 3-yr-old fish. Body growth in length was similar for both sexes, and occurred during the summer. Somatic caloric growth was completed during the summer by females, while male somatic growth continued over winter. Gonad growth began in August; testicular growth was completed by September while ovarian growth occurred mainly during winter. There was no loss of somatic energy during ovary growth. Energy requirements for testicular growth appeared to come from liver stores. Both sexes lost considerable somatic energy between March and May, the spawning period; this loss appeared to be due to spawning activity and not late gonad growth. Young-of-year fish did not mature sexually and all of their energy accumulation went into somatic tissue. Total production in females from May to March was twice as high as production in males. Both sexes had similar yearly somatic production, while females had approximately 15 fold higher gonadal production than males. Key words: calories, growth, liver, gonad, somatic, Esox lucius, production, spawning depletion

The annual reproductive cycle of the black prickleback, Xiphister atropurpureus, a Pacific Coast blennioid fish

1974 ◽  
Vol 52 (7) ◽  
pp. 795-802 ◽  
Author(s):  
John P. Wourms ◽  
David Evans
Keyword(s):  
Reproductive Cycle ◽  
Egg Size ◽  
Gonad Index ◽  
Egg Mass ◽  
Base Line ◽  
Annual Reproductive Cycle ◽  
Intertidal Habitat ◽  
Spawning Period ◽  
Egg Number ◽  
Xiphister Atropurpureus

Semimonthly determinations of the gonad index made during the course of a year show that Xiphister atropurpureus has an annual reproductive cycle. The gonad index (ovary) increases during midwinter, attains a maximum value of 20 in late April–May, and declines to a base-line value of 0.5 from June to December. Spawning occurs during a 6-week period in late April–May. Spawning takes place in zone 4 of the intertidal habitat. Eggs deposited singly are fertilized and then shaped into a spherical mass by the parents. As egg envelopes harden, they adhere to one another to form a coherent mass. The egg mass is guarded by one or both parents. The annual reproductive cycle is considered to be a necessary consequence of the energetic demands of oogenesis combined with selection for a spawning period which is environmentally optimal. Alternative cycles based on modification of the present egg size (large)/egg number (few) relationship do not appear feasible, since the required modification of the egg size/egg number ratio would be selectively disadvantageous. The intertidal habitat of Xiphisier is subject to several potential environmental hazards: wave shock, reduced salinity due to rain and runoff, and excessively high or low temperatures. These are seasonal hazards which occur during winter or summer. Spawning is timed (April–May), so the probability that developing eggs will be exposed to environmental risks is minimized while the probability of exposure to environmental benefits is maximized. It is suggested that the reproductive cycle is under photoperiodic control.

Seismic investigation of the Coast Plutonic Complex – Insular Belt boundary beneath the Strait of Georgia

1984 ◽  
Vol 21 (9) ◽  
pp. 1033-1049 ◽  
Author(s):  
Donald J. White ◽  
Ron M. Clowes
Keyword(s):  
Crustal Structure ◽  
Seismic Refraction ◽  
Unconsolidated Sediments ◽  
The West ◽  
Strait Of Georgia ◽  
Seismic Properties ◽  
Air Gun ◽  
Plutonic Complex ◽  
Major Fault ◽  
Coast Plutonic Complex

The Strait of Georgia, a topographic depression between Vancouver Island and the mainland of British Columbia, is considered to be the boundary between two tectonic provinces: the Coast Plutonic Complex on the east and the Insular Belt to the west. The allochthonous nature of the Insular Belt has been established, mainly on the basis of paleomagnetic measurements. Various tectonic models to explain the geological differences between the two provinces have been proposed. One of these suggests that the boundary is an old transform fault zone and is represented currently by a thrust fault along the eastern side of the Strait of Georgia. Other models propose that the Coast Plutonic Complex is a feature superimposed by tectonic and metamorphic events after the accretion of the Insular Belt. Such models do not require a major crustal discontinuity along the Strait of Georgia.In May 1982, a seismic refraction survey using a 32 L air gun and a radio telemetering sonobuoy system was carried out in the Strait of Georgia with the objective of investigating the nature of this boundary and determining the upper crustal structure. Three reversed profiles across the strait were shot; these are supplemented by several high-resolution reflection profiles from previous experiments. Two-dimensional models of the crustal structure across the strait have been constructed using a forward modelling ray trace and synthetic seismogram algorithm to match the travel times and amplitude characteristics of the data.Three basic layers or strata form the models, for which the maximum depth of reliability is 3 km. The first layer consists of unconsolidated sediments and Pleistocene glacial deposits, and the second represents Late Cretaceous – early Tertiary basin fill sediments that form the Nanaimo Group, the Burrard–Kitsilano formations, and the Chuckanut Formation. The third layer is likely the extension of the Coast Plutonic Complex beneath the strait, but the westerly limit of this unit is undetermined because of seismic properties similar to those of the Insular Belt volcanics. A local fault is located ~15 km northeast of Galiano Island on the west side of the strait. However, our study shows no evidence for a major fault along the strait. Thus those aspects of tectonic models that require the existence of a major transform or transcurrent fault boundary along the Strait of Georgia. may have to be revised.

A Statistical Examination of Anisakis Larvae (Nematoda) in Herring (Clupea pallasi) of the British Columbia Coast

1955 ◽  
Vol 12 (4) ◽  
pp. 571-592 ◽  
Author(s):  
Yvonne M. M. Bishop ◽  
Leo Margolis
Keyword(s):  
British Columbia ◽  
West Coast ◽  
Maximum Level ◽  
Vancouver Island ◽  
First Year ◽  
Intensity Of Infection ◽  
The West ◽  
Strait Of Georgia ◽  
Clupea Pallasi ◽  
First Year Of Life

The presence of larval Anisakis in British Columbia herring was examined during the winter fisheries of 1950–51 and 1951–52. In the commercial catches in the Strait of Georgia the incidence was found to be between 80 and 90%. In Hecate Strait, on the west coast of Vancouver Island and in the mainland coastal area of Queen Charlotte Sound it was between 90 and 100%. The intensity of infection varied greatly in different fishing areas (i.e. in different herring populations). Generally, the maximum level of infection occurred in the Queen Charlotte Sound coastal regions, and decreased both north and south of this area. Fish on the west coast of Vancouver Island were more heavily infected than those on the east coast (Strait of Georgia). The level of infection increased with age, I-year fish (i.e. fish in their first year of life) being uninfected. The intensity of infection remained constant throughout the winter for any particular age and area and was the same for both sexes. In most areas the level of infection was a little lower in 1951–52 than in 1950–51.

Fecundity of the deep-sea fish in the north-east atlantic Alepocephalus bairdii (Pisces: Alepocephalidae)

1999 ◽  
Vol 79 (4) ◽  
pp. 765-767 ◽  
Author(s):  
V. Allain
Keyword(s):  
Standard Length ◽  
Deep Sea ◽  
Batch Fecundity ◽  
East Atlantic ◽  
The West ◽  
Spawning Period ◽  
North East ◽  
The North ◽  
First Maturity ◽  
Sea Fish

Alepocephalus bairdii is a deep sea fish caught but discarded by semi-industrial fisheries from the north-east Atlantic Ocean. Reproductive features were investigated on 448 females of 29–93 cm standard length (SL) captured over 2 y (December 1995–December 1997) at 800–1280 m off the west coast of the British Isles. The first maturity of females was determined at L50=55 cm SL. A well-defined spawning period could not be determined in this species; a batch spawner characterized by an indeterminate annual fecundity. Absolute batch fecundity was estimated between 458 and 7049 oocytes per female 63–88 cm SL.

Reproductive biology of the serpulid Ficopomatus (Mercierella) enigmaticus in the Thames Estuary, S.E. England

1981 ◽  
Vol 61 (3) ◽  
pp. 805-815 ◽  
Author(s):  
D. R. Dixon
Keyword(s):  
Sexual Maturity ◽  
Reproductive Output ◽  
Adult Population ◽  
High Water ◽  
Peak Activity ◽  
Annual Reproductive Cycle ◽  
Temporal Constraint ◽  
Cellular Changes ◽  
Male Phase ◽  
Sexually Mature

Details of the gross cellular changes taking place in the gonadial tissues and coelom of Ficopomatus during the annual reproductive cycle are presented. There is no true gonad in either sex; instead, germ cell precursors are produced by divisions of a germinal epithelium associated with the ring blood vessels in the intersegmental septa.Segments producing gametes do not all develop simultaneously; the posterior segments are generally at a more advanced stage of sexual maturity. The later stages in gamete development take place free in the coelom, where nourishment is supplied presumably by the mobilization of materials formerly stored in tissues surrounding the gut.Spawning commences in June and continues through to October, with peak activity coinciding with the period of high water temperature in August and early September. The adult population comprises males, females, and protandrous hermaphrodites which in the male phase become sexually mature in advance of the rest of the population, and as females later on. These transitional individuals are thought to contribute a negligible amount to the effective reproductive output in those populations living where there is marked temporal constraint on the period of reproduction.The different reproductive capacities of temperate and tropical Ficopomatus are considered.

The Life History and Post Embryonic Development of the Copepods, Calanus tonsus Brady and Euchaeta japonica Marukawa

1934 ◽  
Vol 1 (1) ◽  
pp. 1-65 ◽  
Author(s):  
Mildred H. Campbell
Keyword(s):  
Life History ◽  
Deep Water ◽  
Reproductive Period ◽  
Spawning Period ◽  
Strait Of Georgia ◽  
Deep Water Species ◽  
One Year ◽  
Development Proceeds ◽  
Water Species ◽  
Reserve Food

Calanus tonsus Brady is an abundant, deep water species in the strait of Georgia. Development is characterized by a distinct metamorphosis and the six nauplius and six copepodid stages are described. The life cycle extends over one year and breeding occurs in the spring at the surface. The nauplii and early copepodid stages are soon replaced by stage V which dominates the plankton from May to December. C. tonsus exists as an adult for approximately two months—January and February. Maturity is accompanied by marked degeneration of the mouth parts in both sexes, death following shortly. The retrograde development appears associated with a change in habits. Stage V stores up reserve food, and the mature females with the disappearance of feeding devices depend upon this accumulated food during the reproductive period. Euchaeta japonica Marukawa occurs in limited numbers in the deep water of the strait of Georgia. It undergoes a similar metamorphosis to C. tonsus and the twelve stages are described. There is no definite spawning period but reproduction occurs throughout the year in deep water where development proceeds. Several broods may be produced by one female but the males are believed to die shortly after copulation. The nauplii differ from those of C. tonsus due to larger size, slight increase in length from stage I to stage VI and retarded development of the appendages. The conspicuous feature of the copepodid development is the extreme degeneration of the male mouth parts.

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