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.

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.

Spawning Mode and Reproductive Output of the Tropical Cephalopod Idiosepius pygmaeus

1993 ◽  
Vol 50 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Andrew R. Lewis ◽  
J. Howard Choat
Keyword(s):  
Body Weight ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Potential ◽  
Adult Life ◽  
Somatic Growth ◽  
Egg Laying ◽  
Adult Life Span ◽  
Adult Weight ◽  
Food Stress

Reproductive biology of the tropical sepioid cephalopod Idiosepius pygmaeus was investigated in wild specimens and in individuals maintained in aquaria through the adult life span. This species produced multiple egg batches over 80% of the observable adult weight range, indicating a coordination of reproductive and somatic growth. Reproductive output was consistent within, but variable between, individuals. Oocyte synthesis and maturation occur continuously after sexual maturation has been reached. Senescence and death are not related to an exhaustion of reproductive potential. On average, captive female I. pygmaeus with access to unlimited food produced 640 eggs in 11 batches over 18 d. When reproductive output was expressed as a ratio of dry female body weight, on average, specimens had incorporated five times their body weight into eggs and egg coatings. Under food stress, captive specimens laid fewer eggs but maintained egg size and periodicity of egg laying. Food stress had no effect on either laying duration or weight at death. This study provides further evidence that terminal spawning modes are not ubiquitous amongst cephalopods.

scholarly journals The Maintenance of Sex and David Lack's Principle

2016 ◽  
Author(s):  
Joachim Dagg
Keyword(s):  
Reproductive Output ◽  
Reproductive Effort ◽  
Experimental Studies ◽  
Optimal Number ◽  
Evolutionary Constraints ◽  
Immune Functions ◽  
Maintenance Of Sex ◽  
Mutant Female ◽  
The Cost ◽  
David Lack

Combining George C. Williams' idea that evolutionary constraints prevent asexual mutants from arising more frequently in low fecundity organisms, like mammals and birds, with an earlier one by David Lack that the brood size of these organisms has an optimum, and producing larger broods reduces their fitness, leads to a novel hypothesis about the maintenance of sex in them. All else equal, the eggs of an asexual mutant female should simply start developing without fertilisation, and there is no reason to assume that they would stop doing so after the optimal number of offspring has been produced. Without a way to control their reproductive output, asexual mutants should over-reproduce and suffer a cost of doing so. Experimental studies suggest that the cost of enlarged broods could limit the advantage of asexual mutants considerably. Moreover, research discovered that increased reproductive effort reduces immune functions of low fecundity organisms. This offers a surprising synthesis between Williams' constraint and Hamilton's parasite hypothesis on maintaining sex in low fecundity organisms: Compromised immune functions of asexual hosts may render them susceptible rather than adaptation on the side of parasites to overcome host resistance.

Reproductive patterns and energy management strategies of females of the fiddler crab Leptuca uruguayensis with short reproductive seasons

2020 ◽  
Author(s):  
Agustina Marciano ◽  
Laura Susana López-Greco ◽  
Karine Delevati Colpo
Keyword(s):  
Reproductive Effort ◽  
Fiddler Crab ◽  
Management Strategies ◽  
Somatic Growth ◽  
Integrated Approach ◽  
Breeding Strategy ◽  
Reproductive Season ◽  
Female Size ◽  
Income Breeding ◽  
Size Number

Reproduction is a costly process that depends on the management of available resources. Here, we aimed to understand the energetic strategies of females of the fiddler crab Leptuca uruguayensis (Nobili 1901), in a population with short reproductive seasons. For this, we developed an integrated approach to recognize the brooding time, spawning pattern modulated by female size, number of spawns per female, and content of reserves in the ovary and hepatopancreas. Based on the condition of the ovary and hepatopancreas, the reproductive season was divided into three periods. In each of these periods, it was possible to record a spawning event, which was mainly represented by large females. Most of the females had one spawn during the breeding season, and only large females had two spawns, with an interval of approximately two months. We propose that L. uruguayensis presents a mixed capital-income breeding strategy associated with the female size and period of the reproductive season. We conclude that large females make the greatest reproductive effort for the population, because they can have two spawns, whereas medium and small females make a low contribution because they are still investing energy in somatic growth to increase fecundity in the next reproductive season.

scholarly journals Regulation of reproduction and longevity by nutrient-sensing pathways

2017 ◽  
Vol 217 (1) ◽  
pp. 93-106 ◽  
Author(s):  
Nicole M. Templeman ◽  
Coleen T. Murphy
Keyword(s):  
Molecular Mechanisms ◽  
Energy Levels ◽  
Somatic Growth ◽  
Reproductive Function ◽  
Adenosine Monophosphate ◽  
Somatic Tissue ◽  
Nutrient Sensing ◽  
Reproductive Capacity ◽  
Biological Processes ◽  
Signaling Systems

Nutrients are necessary for life, as they are a crucial requirement for biological processes including reproduction, somatic growth, and tissue maintenance. Therefore, signaling systems involved in detecting and interpreting nutrient or energy levels—most notably, the insulin/insulin-like growth factor 1 (IGF-1) signaling pathway, mechanistic target of rapamycin (mTOR), and adenosine monophosphate-activated protein kinase (AMPK)—play important roles in regulating physiological decisions to reproduce, grow, and age. In this review, we discuss the connections between reproductive senescence and somatic aging and give an overview of the involvement of nutrient-sensing pathways in controlling both reproductive function and lifespan. Although the molecular mechanisms that affect these processes can be influenced by distinct tissue-, temporal-, and pathway-specific signaling events, the progression of reproductive aging and somatic aging is systemically coordinated by integrated nutrient-sensing signaling pathways regulating somatic tissue maintenance in conjunction with reproductive capacity.

In vivo assessment of changes in air and tissue volumes after pneumonectomy

1997 ◽  
Vol 82 (4) ◽  
pp. 1340-1348 ◽  
Author(s):  
S. Takeda ◽  
E. Y. Wu ◽  
R. H. Epstein ◽  
A. S. Estrera ◽  
C. C. W. Hsia
Keyword(s):  
Ct Scan ◽  
Left Lung ◽  
Early Period ◽  
Somatic Growth ◽  
Transpulmonary Pressure ◽  
Tissue Growth ◽  
Volume Changes ◽  
Topographical Distribution ◽  
In Vivo Assessment

Takeda, S., E. Y. Wu, R. H. Epstein, A. S. Estrera, and C. C. W. Hsia. In vivo assessment of changes in air and tissue volumes after pneumonectomy. J. Appl. Physiol. 82(4): 1340–1348, 1997.—We examined the progression and topographical distribution of postpneumonectomy volume changes in immature foxhounds undergoing right pneumonectomy (R-Pnx, n = 5) or sham pneumonectomy (Sham, n = 6) at 2 mo of age and subsequently raised to maturity. Volumes of lung air (Vair) and tissue (Vti) were estimated by computerized tomography (CT) scan at 7, 22, and 52 wk after surgery at a transpulmonary pressure of 20 cmH2O. Estimates of Vti by CT scan included both septal tissue as well as nonseptal tissue (small- and medium-sized airways and blood vessels); these were compared with estimates of septal Vti by an acetylene rebreathing (Rb) method. We found significant correlations between these techniques (VairCT = 0.83 VairRb + 275, R = 0.97; VtiCT = 1.62 VtiRb − 30, R = 0.81). Extravascular septal Vti returned to normal 7 wk after R-Pnx and remained normal up to maturity. Nonseptal Vti remained significantly below normal. The greatest increase in Vti occurred in the midlung region just cephalad and caudal to the heart. After an early period of accelerated tissue growth after R-Pnx, the rate of septal tissue growth matched that of somatic growth, whereas nonseptal tissue growth lagged behind. Compensatory growth of the remaining left lung was not associated with selective alterations in thoracic development.

Reproductive effort of an endemic major reef builder along an inshore–offshore gradient in south-western Atlantic

2010 ◽  
Vol 91 (8) ◽  
pp. 1613-1616 ◽  
Author(s):  
Débora O. Pires ◽  
Bárbara Segal ◽  
Alice C. Caparelli
Keyword(s):  
Particulate Matter ◽  
Nutrient Limitation ◽  
Reproductive Effort ◽  
Energy Allocation ◽  
Tissue Growth ◽  
Carbonate Sediments ◽  
Western Atlantic ◽  
Reef Complex ◽  
Uptake Rates ◽  
Wide Range

Mussismilia braziliensisis endemic to the south-western Atlantic, where it plays an important role as a major reef builder. It occurs in a wide range of sediment conditions between coastal and offshore environments. Here, we investigated its reproductive effort along an inshore–offshore gradient. Three sites were sampled with varying distances (15 to 60 km) from the mainland in the Abrolhos Reef Complex (18° S). Reproductive effort was estimated as fecundity (number of eggs per: polyp, cm2, mm3, and mesenteries). Mean fecundity per polyp was 338.7 (±73.5 SD) and the highest number of eggs per polyp was 987. Percentages of fertile mesenteries per polyp were similar among sites. However, the fecundity per mesentery varied among colonies and among sites. Fecundity per polyp increased as its area, volume, height and number of fertile mesenteries increases. The area closest to the coast (‘Pedra de Leste’) presented the highest mean fecundity per polyp (410 eggs ± 159.2 SD), cm2(233.47 eggs ± 219.44 SD), mm3(4.95 eggs ± 2.34 SD) and mesentery (10.6 eggs ± 4.3 SD). Corals closest to the coast had 55% higher fecundity per polyp and 64% higher fecundity per cm2than corals offshore. This area presented the highest contribution of non-carbonate sediments deposited on the reefs. Therefore, we suggest that colonies ofM. braziliensismay present higher uptake rates of particulate matter at inshore reefs, which allow for higher rates of tissue growth (less nutrient limitation) and energy allocation to reproduction.

Managing confined populations: the influence of density on the home range and habitat use of reintroduced burrowing bettongs (Bettongia lesueur)

2004 ◽  
Vol 31 (4) ◽  
pp. 457 ◽  
Author(s):  
Graeme R. Finlayson ◽  
Katherine E. Moseby
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Food Availability ◽  
Reproductive Output ◽  
Reproductive Effort ◽  
High Density ◽  
Home Ranges ◽  
Low Density ◽  
Reproductive Condition ◽  
Behavioural Changes

The home range, reproductive condition and warren and habitat use of reintroduced female burrowing bettongs was compared within two enclosures in the Arid Recovery Reserve at estimated densities of 2.75 and 7.5 bettongs km–2. Bettongs at both densities exhibited similar behaviour, with females using an average of 2.7 warrens over six months and home ranges averaging 29 and 35 ha in the low- and high-density enclosure respectively. All five female bettongs studied in the low-density enclosure were carrying pouch young at the beginning and end of the six-month study but only one of the five females in the high-density enclosure was carrying pouch young after six months. Higher food availability may have accounted for the higher reproductive effort and slightly smaller home ranges observed in the low-density enclosure. Female bettongs at both densities favoured dune habitat over chenopod swales and all burrows were in dune habitat. Although some differences in reproductive output were observed, it is likely that densities are not yet high enough to cause significant behavioural changes.

Growth and reproduction of Macoma balthica (L.) on a mud flat in the Fraser River estuary, British Columbia

1983 ◽  
Vol 61 (4) ◽  
pp. 887-894 ◽  
Author(s):  
E. R. McGreer
Keyword(s):  
Growth Rate ◽  
British Columbia ◽  
Shell Height ◽  
Macoma Balthica ◽  
River Estuary ◽  
Dry Weight ◽  
Maximum Growth ◽  
Fraser River ◽  
Mud Flat ◽  
Growth And Reproduction

Growth and reproduction of the bivalve, Macoma balthica (Linnaeus, 1758) was studied for one year (April 1977 – March 1978) on an intertidal mud flat in the Fraser River estuary, British Columbia. The maximum number of individuals (1830/m2) occurred in April, then steadily declined throughout the year. Spawning occurred between mid-June and late July but recruitment was slow and prolonged. Peak spatfall (age 0+ individuals) did not occur until the following March when a maximum density of only 410/m2 for newly settled spat was observed. The oldest animals found were 5+ years of age. Maximum growth took place from April through July. The growth rate measured was one of the highest recorded for any M. balthica population. A direct relationship between high water temperatures, a fast growth rate, and reduced longevity was apparent. A regression of body weight on shell height was used to calculate a condition factor (CF), which reached its highest value during growth and its lowest value immediately after spawning. The mean annual biomass measured was 2.96 g dry weight per square metre.

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