Respiratory Adaptations of the Fingernail Clams Sphaerium occidentale and Musculium securis to Ephemeral Habitats

1983 ◽  
Vol 40 (6) ◽  
pp. 783-791 ◽  
Author(s):  
Paul M. McKee ◽  
Gerald L. Mackie
Keyword(s):  
Oxygen Uptake ◽  
Life Histories ◽  
Natural Habitat ◽  
Pond Water ◽  
Temperature Acclimation ◽  
Early Summer ◽  
Temporary Pond ◽  
Obligate Aerobe ◽  
Fingernail Clams ◽  
Growth And Reproduction

Experiments performed on seasonal collections of the pisidiids Sphaerium occidentale and Musculium securis from a temporary pond suggest that respiratory adaptations are related to the specific life histories of the two species. Sphaerium occidentale lives up to 3 yr and all age classes aestivate during dry periods, while M. securis lives for about 1 yr and only newborn aestivate. Both species are iteroparous and reproduce primarily in late spring and early summer. Oxygen uptake rates at field temperature and Q10 values are low in both species during hibernation and aestivation, indicating respiratory stability and energy conservation. These rates and respiratory coefficients peak in spring during maximal growth and reproduction. Respiration in M. securis is more independent of temperature than in S. occidentale, reflecting the requirement of the former to complete growth and reproduction more quickly. Both animals show temperature acclimation patterns permitting early activity in spring and, thus, a more efficient exploitation of the short aquatic season. This pattern is more pronounced in the shorter lived M. securis. During aestivation, M. securis is a facultative anaerobe, while S. occidentale is an obligate aerobe. Neither species displays an oxygen debt following aestivation when immersed in water. Arousal from aestivation, as indicated by oxygen uptake, is delayed when clams are introduced to pond water. This apparently inhibits a premature resumption of activity and decreases the likelihood of desiccation in the natural habitat.

Life history adaptations of the fingernail clams Sphaerium occidentale and Musculium securis to ephemeral habitats

1981 ◽  
Vol 59 (12) ◽  
pp. 2219-2229 ◽  
Author(s):  
P. M. McKee ◽  
G. L. Mackie
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Life Histories ◽  
Stochastic Theory ◽  
Environmental Stresses ◽  
Temporary Pond ◽  
Continue Development ◽  
Large Numbers ◽  
Fingernail Clams ◽  
Ephemeral Habitats

Life histories of the fingernail clams Sphaerium occidentale and Musculium securis from a temporary pond are examined to show adaptations to ephemeral habitats. Musculium securis ceases growth upon birth and only newborn occur in the dry pond, whereas all length classes of S. occidentale are omnipresent. Aestivation is not obligatory in the life cycle of either species. Both grow and reproduce regardless of aestivation experience.Life history strategies of both clams counteract environmentally imposed, density-independent mortality pressures. Sphaerium occidentale has slower growth and greater longevity than M. securis which must complete its life cycle before the pond dries. During aestivation, broods continue development in S. occidentale but not in M. securis. If water is present in fall, both opportunistically use this period for development. Both produce large numbers of small newborn and exhibit multivoltine and iteroparous strategies, although M. securis releases consecutive broods only during a single spring birth period and only if the aquatic season is extended, whereas S. occidentale releases consecutive broods during a spring birth period, in autumn if water is present, and during a 2nd year. A mixed tactic, according to the stochastic theory, has been adopted by both for survival under highly variable environmental stresses.

Individual Growth and Reproduction

2019 ◽  
pp. 38-56
Author(s):  
Ken H. Andersen
Keyword(s):  
Life History ◽  
Growth Model ◽  
Life Histories ◽  
Maximum Size ◽  
Individual Growth ◽  
Energy Budgets ◽  
Asymptotic Size ◽  
The Individual ◽  
Growth And Reproduction

This chapter develops descriptions of how individuals grow and reproduce. More specifically, the chapter seeks to determine the growth and reproduction rates from the consumption rate, by developing an energy budget of the individual as a function of size. To that end, the chapter addresses the question of how an individual makes use of the energy acquired from consumption. It sets up the energy budgets of individuals by formulating the growth model using so-called life-history invariants, which are parameters that do not vary systematically between species. While the formulation of the growth model in terms of life-history invariants is largely successful, there is in particular one parameter that is not invariant between life histories: the asymptotic size (maximum size) of individuals in the population. This parameter plays the role of a master trait that characterizes most of the variation between life histories.

Effects of simulated herbivory on growth and reproduction of two beach annuals, Cakile edentula and Corispermum hyssopifolium

1992 ◽  
Vol 70 (12) ◽  
pp. 2467-2475 ◽  
Author(s):  
Kevin E. Gedge ◽  
M. A. Maun
Keyword(s):  
Reproductive Output ◽  
Natural Habitat ◽  
Critical Time ◽  
Insect Herbivores ◽  
Compensatory Response ◽  
Large Numbers ◽  
Cakile Edentula ◽  
Specialist Insect ◽  
Heavy Damage ◽  
Growth And Reproduction

Cakile edentula var. lucustris (sea rocket) and Corispermum hyssopifolium (bugseed) are two annual flowering plants that grow on the sandy shores of the Great Lakes. This habitat is extremely unpredictable and plants are subject to grazing by a number of insect herbivores as well as browsing by white-tailed deer. The objectives of these studies were to estimate the extent of herbivore damage under natural conditions, to determine the most vulnerable stage of damage, and to examine the compensatory ability of each species to tolerate herbivory. Greenhouse experiments showed that both species were able to compensate for low to moderate levels of artificial defoliation. However, high levels near the time of anthesis reduced the growth and reproductive output of both species. Similar experiments in the field revealed that although the critical time of damage was still the same, the plants were less able to tolerate herbivory. Cakile edentula plants exposed to natural herbivory in an unsprayed cabbage field were quickly attacked by large numbers of specialist insect herbivores and completely defoliated in 11 days. The fact that such damage does not occur in its natural habitat suggests that Cakile edentula escapes heavy damage because insects are unable to locate these populations along the shoreline. Key words: white-tailed deer, defoliation intensity, defoliation stage, compensatory response, indeterminate growth.

Effects of extreme pH on the physiology of the Australian 'yabby' Cherax destructor: acute and chronic changes in haemolymph oxygen levels, oxygen consumption and metabolic levels

1995 ◽  
Vol 198 (2) ◽  
pp. 409-418 ◽  
Author(s):  
B Ellis ◽  
S Morris
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Oxygen Transport ◽  
Consumption Rate ◽  
Lactate Concentration ◽  
Acid Water ◽  
Freshwater Crayfish ◽  
Glucose Levels ◽  
Cherax Destructor ◽  
Growth And Reproduction

Respiration and metabolism of the freshwater crayfish Cherax destructor were investigated with respect to the acidification and alkalization of its environment. Crayfish were exposed for up to 504 h (21 days) to pH 4.5, pH 7.1 (control) or pH 8.0 water and oxygen consumption rate, haemolymph oxygen transport and haemolymph glucose and lactate concentrations were determined. The effect of reducing environmental [Ca2+] in acid water from 500 to 50 µmol l-1 was also examined. In acid water (500 µmol l-1 Ca2+), oxygen uptake by Cherax was reduced by 79 % after 504 h (21 days) compared with 'control' animals (pH 7.1, 500 µmol l-1 Ca2+). Haemolymph lactate concentration (mean 0.6 mmol l-1) remained constant, indicating that anaerobiosis was not important, while glucose concentrations were regulated within the range of control values (0.32±0.01 mmol l-1). The arterial-venous CO2 difference of Cherax haemolymph decreased after 288 h and PaO2 increased from 11.1±0.5 mmHg to 42.4±1.0 mmHg between 96 h and 288 h. Decreased oxygen uptake and delivery without compensatory increases in anaerobiosis or glucose levels describe a hypometabolic response to low pH. The hypometabolic response of Cherax was greater in alkaline water as shown by a 53 % reduction in O2 uptake rate compared with a 44 % reduction in acid-exposed (500 µmol l-1 Ca2+) animals after 96 h. This decrease in M(dot)O2 of alkaline-exposed animals was correlated with decreased haemolymph glucose levels (from 0.32±0.01 at 0 h to 0.06±0.01 mmol l-1 at 96 h). Lowering the [Ca2+] of the water both increased the magnitude of the effects of acid exposure and elicited further changes in haemolymph oxygen transport. The maintenance of high haemolymph PO2 during pH stress appears to reduce the involvement of haemocyanin, since this promotes decreased a­v CO2. Hypometabolism probably permits Cherax to conserve resources that might otherwise be used, however, for growth and reproduction. The implications for the fitness of the animal are discussed.

Reproductive strategies in Akodon azarae (Rodentia, Muridae)

2004 ◽  
Vol 82 (10) ◽  
pp. 1572-1577 ◽  
Author(s):  
Olga V Suárez ◽  
María Busch ◽  
Fernando O Kravetz
Keyword(s):  
Litter Size ◽  
Reproductive Strategies ◽  
Life Histories ◽  
Reproductive Period ◽  
Early Summer ◽  
Reproductive Value ◽  
Central Feature ◽  
Birth Season ◽  
Akodon Azarae

The balance between litter size and the quality of offspring is a central feature to many optimal litter-size theories. We analyzed the reproductive strategies of Akodon azarae (Fischer, 1829) females, according to maternal life histories and the time of birth. Litter size decreased significantly from spring to autumn. A significant birth–season effect on mass at birth was observed. A compensatory effect of growth rate was evident during lactation. During spring and early summer, over-wintered females produced an average of 5 young, with maximum survival at weaning (100%). Females born during the current reproductive season showed a smaller litter size, probably because they favor residual reproductive value with respect to current reproduction since they have a higher life expectancy and future chances of mating than over-wintered females. Mortality reached 50% at weaning for summer litters from young mothers, whereas it declined to 22.2% in autumn. Differences in both parental investment and offspring survival suggest that litter size in A. azarae varies along the reproductive period and is dependent both on females' life history and on environmental conditions.

Growth and reproduction of some Diaptomus spp. in Saskatchewan ponds

1968 ◽  
Vol 46 (3) ◽  
pp. 511-520 ◽  
Author(s):  
William W. Sawchyn ◽  
U. Theodore Hammer
Keyword(s):  
Water Temperature ◽  
Clutch Size ◽  
Field Studies ◽  
Early Summer ◽  
Life Cycles ◽  
Three Generations ◽  
Chemical Conditions ◽  
Growth And Reproduction

Field studies on the life cycles of seven species of Diaptomus were undertaken in some ponds in southern and central Saskatchewan. D. sanguineus, D. arcticus, D. stagnalis, and D. kiseri have one generation per year, beginning early in the spring and disappearing by early summer. D. leptopus, D. forbesi, and D. nudus appear somewhat later, have two or three generations per year, and persist throughout the rest of the ice-free period. Correlations were found between water temperature and egg clutch size of Diaptomus females. Variations in size of individuals of different generations were related to temperature. Attempts to associate changes in chemical conditions of the ponds with growth and reproduction of Diaptomus spp. were unsuccessful.

Distributional, morphological and genetic consequences of dispersal for temporary pond water mites

2004 ◽  
Vol 49 (2) ◽  
pp. 170-180 ◽  
Author(s):  
Andrew J. Bohonak ◽  
Bruce P. Smith ◽  
Melissa Thornton
Keyword(s):  
Pond Water ◽  
Temporary Pond ◽  
Water Mites

Population dynamics of three species of dasyurid marsupials in arid central Australia: a 10-year study

2001 ◽  
Vol 28 (5) ◽  
pp. 493 ◽  
Author(s):  
Christopher R. Dickman ◽  
Adele S. Haythornthwaite ◽  
Gayle H. McNaught ◽  
Paul S. Mahon ◽  
Bobby Tamayo ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Life Histories ◽  
Arid Zone ◽  
Early Spring ◽  
Early Summer ◽  
Late Winter ◽  
Sand Ridge ◽  
Red Foxes ◽  
Central Australia ◽  
Simpson Desert

This study investigated the population dynamics of three species of dasyurid marsupials in sand ridge habitat of the Simpson Desert, western Queensland, over a 10-year period between March 1990 and December 1999. The lesser hairy-footed dunnart (Sminthopsis youngsoni), was captured most consistently over the period of study, followed by the wongai ningaui (Ningaui ridei), and the mulgara (Dasycercus cristicauda). Rates of recapture were low (4.5–22.2%), probably because individuals of each species are very mobile. All species bred in late winter or early spring when animals were aged at least 8–10 months, and independent juveniles first appeared usually in summer. S. youngsoni reared a second litter in late spring or early summer in 3 of the 10 years studied, when the availability of food was likely to have been high; neither N. ridei nor D. cristicauda were known to attempt a second litter within a season. To explore factors that might influence population dynamics, we compared capture rates of each species with measures of rainfall, temperature, vegetation cover, abundance of predators [feral cats (Felis catus), red foxes (Vulpes vulpes), and goannas (Varanus spp.)], dragons, other dasyurids and indices of food abundance. The abundance of S. youngsoni appeared to depend primarily on the cover of spinifex 7–9 months earlier, that of D. cristicauda was related most strongly to rainfall 7–9 months earlier, while that of N. ridei was related to minimum temperature lagged by 1–3 months. While the dynamics of other arid-zone mammals are driven demonstrably by interactions between rainfall, resource availability and predation, our findings suggest that dasyurids have limited flexibility in their life histories and are influenced more subtly and by factors such as facilitation that are just beginning to become apparent.

Invasive traits of veronicellid slugs in the Hawaiian Islands and temperature response suggesting possible range shifts under a changing climate

2020 ◽  
Vol 86 (2) ◽  
pp. 147-155
Author(s):  
Rachel M Sommer ◽  
Robert H Cowie
Keyword(s):  
Invasive Species ◽  
Life Histories ◽  
Temperature Response ◽  
Egg Mass ◽  
Warming Climate ◽  
Self Fertilization ◽  
Single Mating ◽  
The Mean ◽  
Mass Mating ◽  
Growth And Reproduction

Abstract Understanding life history traits is important for assessing potential invasiveness, particularly in the context of the future spread of invasive species under climate change. A number of species of Veronicellidae have been introduced beyond their native ranges and have become invasive. Two of these species, Veronicella cubensis and Laevicaulis alte, are widespread in Hawaii, yet little is known of their life histories. This study of growth and reproduction and their relation to temperature in these two species was undertaken using laboratory stocks derived from individuals collected in Hawaii. More data were collected for V. cubensis than for L. alte because of difficulty maintaining the latter in the lab. Veronicella cubensis grew faster at 22 °C than at 27 °C. At 22 °C, the mean age at which V. cubensis first mated was 203 d, and the mean age when eggs were first laid was 226 d. Mating in V. cubensis lasted more than a day, and it took up to 4 d to lay an egg mass. Mating took less than a day in L. alte. No self-fertilization was recorded in V. cubensis, but a single L. alte individual maintained alone from hatching laid fertilized eggs. Sperm storage after a single mating in V. cubensis was estimated to last up to 6 months. In both species the time for eggs to hatch was shorter at 27 °C than at 22 °C. Hatchability was between 74 and 93%. Veronicella cubensis lived for at least 2 years and was estimated to produce at least 400 eggs over its life. Climate warming will probably lead to expansion of the ranges of V. cubensis and L. alte to higher elevations in Hawaii and elsewhere. Growth and reproduction will also be affected by a warming climate and therefore impact the success of these invasive species.

Juvenile salmon and steelhead occupancy of stream pools treated and not treated with restoration structures, Entiat River, Washington

2015 ◽  
Vol 72 (2) ◽  
pp. 166-174 ◽  
Author(s):  
Karl M. Polivka ◽  
E. Ashley Steel ◽  
Jenni L. Novak
Keyword(s):  
Current Velocity ◽  
Habitat Restoration ◽  
Natural Habitat ◽  
Early Summer ◽  
Fish Abundance ◽  
Steelhead Trout ◽  
Habitat Occupancy ◽  
Interaction Terms ◽  
Physical Attributes ◽  
Fish Response

We observed habitat occupancy by juvenile Chinook salmon (Oncorhynchus tschawytscha) and steelhead trout (Oncorhynchus mykiss) at in-stream habitat restoration structures constructed in the Entiat River, Washington, USA. In 2009–2013, fish abundance measurements during rearing (July–October) showed high temporal variability in pools with restoration structures. Both species were more abundant at restored pools than at natural pools in early summer (July), but this difference was typically absent by September. Fish response to restoration structures also varied across years. When looking only at restored pools, there were strong seasonal fluxes in parameters describing the effects of temperature, water depth, and current velocity on fish abundance. Significant interaction terms such as current velocity × depth and temperature × current velocity were present for both species, suggesting that these may be important physical attributes improved by restoration. Through extensive sampling in untreated habitat, both within the treated segment and in nearby control segments, we found that when higher Chinook abundance was observed at restored pools, it was apparently attributable to an increase in habitat capacity and not due to depletion of fish from natural habitat in the same segment. Steelhead habitat selection was too inconsistent for conclusions about capacity, but we did not observe evidence that structures depleted untreated habitat.

Sign in / Sign up

Export Citation Format

Share Document