Hydrological manipulation to assist spawning of a threatened galaxiid fish in a highland lake system

2013 ◽  
Vol 64 (9) ◽  
pp. 887 ◽  
Author(s):  
Scott A. Hardie
Keyword(s):  
Life Histories ◽  
Adult Life ◽  
Fold Increase ◽  
Water Release ◽  
Inland Waterways ◽  
Water Diversions ◽  
Lake System ◽  
Yoy Fish ◽  
Delayed Spawning ◽  
Hydrologic Conditions

Hydrological alterations threaten freshwater fishes globally, with infrastructure-related modification of inland waterways (e.g. dams, water diversions) having profound impacts on many species. Adapting existing water-management systems can provide opportunities for undertaking hydrological manipulations to assist management of threatened fishes. The present study conducted two hydrological manipulations in an impounded highland lake system in Tasmania, Australia, under differing hydrological conditions in 2007 and 2009, to assist recovery of an endemic species, Galaxias auratus, following a prolonged drought. Monitoring at egg, larvae, juvenile and adult life stages revealed a positive response by G. auratus in Lake Crescent (recipient of water release), with no adverse impact on the species in Lake Sorell (source of water release). In both years, reproductive constraints imposed by water level-related availability of sediment-free rocky substrata delayed spawning (~1 month) of G. auratus in Lake Crescent. Despite this, spawning and recruitment occurred in 2007 (drought year) and 2009 (drought-breaking year), and the 2007 manipulation resulted in a two-fold increase in the seasonal density of larvae in Lake Crescent and an abundant cohort of YOY fish. Given knowledge of life histories and eco-hydrological relationships, manipulating (or re-instating) hydrologic conditions is a powerful tool for assisting recovery of threatened lacustrine fishes.

scholarly journals Maternal investment, life histories and the evolution of brain structure in primates

2019 ◽  
Vol 286 (1911) ◽  
pp. 20191608 ◽  
Author(s):  
Lauren E. Powell ◽  
Robert A. Barton ◽  
Sally E. Street
Keyword(s):  
Life History ◽  
Life Histories ◽  
Brain Size ◽  
Developmental Trajectories ◽  
Adult Life ◽  
Maternal Investment ◽  
Brain Evolution ◽  
Brain Structures ◽  
Juvenile Period ◽  
Adult Lifespan

Life history is a robust correlate of relative brain size: larger-brained mammals and birds have slower life histories and longer lifespans than smaller-brained species. The cognitive buffer hypothesis (CBH) proposes an adaptive explanation for this relationship: large brains may permit greater behavioural flexibility and thereby buffer the animal from unpredictable environmental challenges, allowing for reduced mortality and increased lifespan. By contrast, the developmental costs hypothesis (DCH) suggests that life-history correlates of brain size reflect the extension of maturational processes needed to accommodate the evolution of large brains, predicting correlations with pre-adult life-history phases. Here, we test novel predictions of the hypotheses in primates applied to the neocortex and cerebellum, two major brain structures with distinct developmental trajectories. While neocortical growth is allocated primarily to pre-natal development, the cerebellum exhibits relatively substantial post-natal growth. Consistent with the DCH, neocortical expansion is related primarily to extended gestation while cerebellar expansion to extended post-natal development, particularly the juvenile period. Contrary to the CBH, adult lifespan explains relatively little variance in the whole brain or neocortex volume once pre-adult life-history phases are accounted for. Only the cerebellum shows a relationship with lifespan after accounting for developmental periods. Our results substantiate and elaborate on the role of maternal investment and offspring development in brain evolution, suggest that brain components can evolve partly independently through modifications of distinct developmental phases, and imply that environmental input during post-natal maturation may be particularly crucial for the development of cerebellar function. They also suggest that relatively extended post-natal maturation times provide a developmental mechanism for the marked expansion of the cerebellum in the apes.

scholarly journals Arrested B Lymphopoiesis and Persistence of Activated B Cells in Adult Interleukin 7−/− Mice

2001 ◽  
Vol 194 (8) ◽  
pp. 1141-1150 ◽  
Author(s):  
Thiago L. Carvalho ◽  
Tomaz Mota-Santos ◽  
Ana Cumano ◽  
Jocelyne Demengeot ◽  
Paulo Vieira
Keyword(s):  
T Cell ◽  
B Lymphocytes ◽  
Early Life ◽  
B Lymphocyte ◽  
Marginal Zone ◽  
Adult Life ◽  
Fold Increase ◽  
B Lymphopoiesis ◽  
Interleukin 7 ◽  
B1 Cells

Interleukin 7 is a crucial factor for the development of murine T and B lymphocytes. We now report that, in the absence of interleukin 7, B lymphocyte production takes place exclusively during fetal and perinatal life, ceasing after 7 wk of age. In peripheral organs, however, the pool of B lymphocytes is stable throughout adult life and consists only of cells that belong to the B1 and marginal zone (MZ) compartments. This is accompanied by a 50-fold increase in the frequency of immunoglobulin (Ig)M- and IgG-secreting cells, and the concentration of serum immunoglobulins is increased three- to fivefold. Both the MZ phenotype and the increase in serum IgM are T cell independent. These findings reveal a previously undescribed pathway of B lymphopoiesis that is active in early life and is interleukin 7 independent. This pathway generates B1 cells and a normal sized MZ B lymphocyte compartment.

scholarly journals The influence of juvenile and adult environments on life-history trajectories

2005 ◽  
Vol 273 (1587) ◽  
pp. 741-750 ◽  
Author(s):  
Barbara Taborsky
Keyword(s):  
Life History ◽  
Life Histories ◽  
Adult Life ◽  
Growth Conditions ◽  
Offspring Size ◽  
Juvenile Growth ◽  
Life History Variation ◽  
Major Life ◽  
Adult Growth ◽  
Trade Offs

There is increasing evidence that the environment experienced early in life can strongly influence adult life histories. It is largely unknown, however, how past and present conditions influence suites of life-history traits regarding major life-history trade-offs. Especially in animals with indeterminate growth, we may expect that environmental conditions of juveniles and adults independently or interactively influence the life-history trade-off between growth and reproduction after maturation. Juvenile growth conditions may initiate a feedback loop determining adult allocation patterns, triggered by size-dependent mortality risk. I tested this possibility in a long-term growth experiment with mouthbrooding cichlids. Females were raised either on a high-food or low-food diet. After maturation half of them were switched to the opposite treatment, while the other half remained unchanged. Adult growth was determined by current resource availability, but key reproductive traits like reproductive rate and offspring size were only influenced by juvenile growth conditions, irrespective of the ration received as adults. Moreover, the allocation of resources to growth versus reproduction and to offspring number versus size were shaped by juvenile rather than adult ecology. These results indicate that early individual history must be considered when analysing causes of life-history variation in natural populations.

SPILL PREVENTION AT INLAND MARINAS: A SHASTA LAKE, CALIFORNIA, CASE STUDY

1997 ◽  
Vol 1997 (1) ◽  
pp. 365-371
Author(s):  
Michelle Rogow ◽  
Scott Sellwood
Keyword(s):  
Oil Spills ◽  
Oil Pollution ◽  
Environmental Issues ◽  
Prevention Measures ◽  
Inland Waterways ◽  
Underground Storage Tanks ◽  
Shasta Lake ◽  
Available Technology ◽  
Hydrologic Conditions

ABSTRACT Since the enactment of the Oil Pollution Act of 1990 (OPA 90), there has been a greater focus on spill prevention and response preparedness at large marine transfer facilities. Little attention, however, has been paid to facilities that fall short of 42,000 gallons. Many of these smaller facilities, which are located on the nation's inland waterways, are marinas that fuel recreational boats. Spill prevention at facilities on inland waterways is complicated by factors such as location, hydrologic conditions, regulation under multiple jurisdictions, and lack of available technology. This paper discusses the various types of petroleum product storage, transfer, and delivery systems, as well as spill prevention measures employed by marinas on Shasta Lake, California. Shasta Lake is a mecca of recreational boating, having almost a dozen marinas along its shores. Like many inland waterways, Shasta Lake is affected by precipitation and dam control, which drastically change the surface area of the lake. To stay afloat and operational, marinas, including their fuel transfer capabilities, must be mobile. This presents complex technical and environmental issues for the marinas, which use different combinations of equipment for storing and transferring fuel. Storage systems include fixed or mobile, aboveground or underground storage tanks and floating fuel systems. The piping used to deliver fuel to dispensers located on the marina dock is usually a combination of rigid and flexible lines. Each system is subject to a variety of laws and regulations, with every facility varying in compliance levels. By evaluating the precarious situations and spill events at Shasta Lake and other marinas, we can better assist in compliance efforts and more effectively protect our nation's waterways from oil spills.

Laboratory adaptation ofBactrocera tryoni(Diptera: Tephritidae) decreases mating age and increases protein consumption and number of eggs produced per milligram of protein

2004 ◽  
Vol 94 (6) ◽  
pp. 517-524 ◽  
Author(s):  
A. Meats ◽  
H.M. Holmes ◽  
G.L. Kelly
Keyword(s):  
Dietary Protein ◽  
Egg Size ◽  
Adult Life ◽  
Fold Increase ◽  
Dry Weight ◽  
Egg Load ◽  
Fresh Weight ◽  
Bactrocera Tryoni ◽  
Laboratory Adaptation

AbstractA significant reduction in age of mating occurred during the first four generations (G1–G4) of laboratory adaptation of wildBactrocera tryoni(Froggatt) and this was associated with the earlier attainment of peak egg load although no significant differences were detected in the peak egg load itself. A long term laboratory (LTL) strain had a significantly earlier mating age and higher peak egg load than flies of wild origin or those from the first four laboratory generations. The amount of protein consumed by females in the first week of adult life was significantly higher in the LTL strain than in flies of wild origin or G1–G4 but there were no significant changes (or only slight changes) with laboratory adaptation in the amounts of protein consumed up to the ages of mating and peak egg load. Laboratory adaptation resulted in no significant changes in egg size, egg dry weight, puparial fresh weight and the dry weight of newly emerged females. The large increase in fecundity with laboratory adaptation is associated with a 4- to 5-fold increase in the rate of conversion of dietary protein to eggs (i.e. eggs produced per mg of protein consumed).

XXI.—The Life-history and Development of Agriolimax agrestis L., the Gray Field Slug.

1939 ◽  
Vol 59 (3) ◽  
pp. 563-597 ◽  
Author(s):  
Robert Carrick
Keyword(s):  
Life History ◽  
Life Histories ◽  
Adult Life ◽  
Single Species ◽  
Functional Changes ◽  
Breeding Habit ◽  
Early Stages ◽  
History Of ◽  
Highly Evolved

Among Gasteropod Molluscs the life-histories and development of the most highly evolved members, the terrestrial Pulmonates, have been less intensively studied than those of more primitive aquatic forms. This has been due in part to the technical difficulties involved in the permanent preparation of material for study, and in part to the fact that the investigator seeking for primitive features of phyletic interest is more likely to find these among more generalised species of Gasteropods than among those which are obviously adapted, both during the early stages of their development and in adult life, to a habitat far removed from the ancestral one.It is the purpose of this paper to present data bearing upon the life-history of a single species of land Pulmonate, Agriolimax agrestis L., to enlarge upon certain aspects of the embryology of this species, and to demonstrate the structural and functional changes of the larva which have accompanied the transition from an aquatic to a terrestrial breeding habit.

scholarly journals Ecdysteroid Hormones Link the Juvenile Environment to Alternative Adult Life Histories in a Seasonal Insect

2014 ◽  
Vol 184 (3) ◽  
pp. E79-E92 ◽  
Author(s):  
Vicencio Oostra ◽  
Ana Rita A. Mateus ◽  
Karin R. L. van der Burg ◽  
Thomas Piessens ◽  
Marleen van Eijk ◽  
...  
Keyword(s):  
Life Histories ◽  
Adult Life

Divergent life histories among smallmouth bassMicropterus dolomieuinhabiting a connected river-lake system

2008 ◽  
Vol 73 (4) ◽  
pp. 829-852 ◽  
Author(s):  
B. L. Barthel ◽  
S. J. Cooke ◽  
J. H. Svec ◽  
C. D. Suski ◽  
C. M. Bunt ◽  
...  
Keyword(s):  
Life Histories ◽  
Lake System

Phenotypic effects of leptin in an ectotherm: a new tool to study the evolution of life histories and endothermy?

2000 ◽  
Vol 203 (2) ◽  
pp. 295-300 ◽  
Author(s):  
P.H. Niewiarowski ◽  
M.L. Balk ◽  
R.L. Londraville
Keyword(s):  
Life Histories ◽  
Evolutionary Biology ◽  
Fold Increase ◽  
Human Obesity ◽  
Sceloporus Undulatus ◽  
Research Activity ◽  
Age At First Reproduction ◽  
Evolution Of Life ◽  
Phosphate Buffered Saline

Leptin is a hormone that regulates energy expenditure and body mass in mammals, and it has attracted considerable attention because of its potential in treating human obesity. Comprehensive data from both pathological and non-pathological systems strongly support a role for leptin in regulating energy metabolism, in thermoregulation and in regulating the onset of puberty. We report here that daily injections of recombinant murine leptin in fence lizards (Sceloporus undulatus) produce phenotypic effects similar to those observed when leptin injections are given to mice. Lizards injected with leptin had body temperatures 0.6 degrees C higher, ate 30 % less food and showed a 14 % reduction in activity rates, and females showed a 2. 5-fold increase in resting metabolic rates, compared with lizards injected with vehicle only (phosphate-buffered saline). We also detected native lizard leptin using an immunoassay. Our results indicate that leptin is expressed in ectotherms and may be conserved both functionally and structurally. In the wake of unprecedented research activity on the role of leptin as a cause of, and potential treatment for, human obesity, we believe that other applications of leptin research have been ignored. For example, the response of lizards to leptin injection in our study has important implications for two broad areas of research in evolutionary biology: the evolution of age at first reproduction and of endothermy. We argue that research in these areas, previously limited to comparative approaches, may now benefit from experimental manipulations using leptin.

Frequency of honeydew excretion in the lac insect, Kerria lacca (Kerr) (Homoptera: Tachardiidae)

1968 ◽  
Vol 46 (3) ◽  
pp. 600-601 ◽  
Author(s):  
P. N. Srivastava ◽  
R. K. Varshney
Keyword(s):  
Adult Female ◽  
Adult Stage ◽  
Physiological Activity ◽  
Adult Life ◽  
Fold Increase ◽  
Kerria Lacca ◽  
Honeydew Excretion ◽  
Lac Insect

The frequency of honeydew excretion in the larva of the lac insect, Kerria lacca (Kerr), varies from 2.08 to 3.30 droplets, and that in the fertilized adult female from 8.04 to 10.10 droplets per insect per hour. Approximately three- to- five-fold increase in the frequency of excretion from the larval to the adult stage is an indication of the vigorous physiological activity during the adult life of the insect.

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