scholarly journals Early developmental stages of native populations of Ciona intestinalis under increased temperature are affected by local habitat history

2021 ◽  
pp. jeb.233403
Author(s):  
E. A. Clutton ◽  
G. Alurralde ◽  
T. Repolho
Keyword(s):  
Native Species ◽  
Developmental Stages ◽  
Ciona Intestinalis ◽  
Heart Beat ◽  
Environmental Drivers ◽  
Temperature Conditions ◽  
Increased Temperature ◽  
Fertilisation Rate ◽  
Habitat History ◽  
Larvae Development

Temperature modulates marine ectotherm physiology, influencing survival, abundance and species distribution. While native species could be susceptible to ocean warming, thermal tolerance might favour the spread of non-native species. Determining the success of invasive species in response to climate change is confounded by the cumulative, synergistic or antagonistic effects of environmental drivers, which vary at a geographical and temporal scale. Thus, an organism's acclimation or adaptive potential could play an important evolutionary role by enabling or conditioning species tolerance to stressful environmental conditions. We investigated developmental performance of early life stages of the ascidian Ciona intestinalis (derived from populations of anthropogenically-impacted and control sites) to an extreme weather event (i.e. marine heat wave). Fertilisation rate, embryo and larval development, settlement, metamorphosis success and juvenile heart beat rate were assessed as experimental endpoints. With the exception of fertilization and heart beat rates, temperature influenced all analysed endpoints. C. intestinalis derived from control sites were the most negatively affected by increased temperature conditions. Opposingly, C. intestinalis from anthropogenically impacted sites showed a positive response to thermal stress, with a higher proportion of larvae development, settlement and metamorphosis success being observed under increased temperature conditions. No differences were observed for heart beat rates between sampled populations and experimental temperature conditions. Moreover, interaction between temperature and populations was statistically significant for embryo and larvae development, and metamorphosis. We hypothesize that selection resulting from anthropogenic forcing could shape stress resilience of species in their native range and subsequently confer advantageous traits underlying their invasive potential.

scholarly journals Predicting the potential distribution of the vase tunicate Ciona intestinalis in Canadian waters: informing a risk assessment

2008 ◽  
Vol 65 (5) ◽  
pp. 788-794 ◽  
Author(s):  
Thomas W. Therriault ◽  
Leif-Matthias Herborg
Keyword(s):  
Risk Assessment ◽  
Native Species ◽  
Potential Distribution ◽  
Negative Impact ◽  
Ciona Intestinalis ◽  
Environmental Niche ◽  
Environmental Models ◽  
Introduced Range ◽  
Negative Impacts ◽  
Almost All

Abstract Therriault, T. W., and Herborg, L-M. 2008. Predicting the potential distribution of the vase tunicate Ciona intestinalis in Canadian waters: informing a risk assessment. – ICES Journal of Marine Science, 65: 788–794. A crucial step in characterizing the potential risk posed by non-native species is determining whether a potential invader can establish in the introduced range and what its potential distribution could be. To this end, various environmental models ranging from simple to complex have been applied to predict the potential distribution of an invader, with varying levels of success. Recently, in marine waters, tunicates have received much attention, largely because of their negative impacts on shellfish aquaculture. One of these species is the vase tunicate Ciona intestinalis, which recently has had a negative impact on aquaculture operations in Atlantic Canada and could pose a risk in Pacific Canada. To inform the risk assessment of this species, we evaluated two different types of environmental model. Simple models based on reported temperature or salinity tolerances were relatively uninformative, because almost all waters were deemed suitable. In contrast, a more complex genetic algorithm for rule-set prediction (GARP) environmental niche model, based on documented Canadian occurrence points, provided informative projections of the potential distribution in Canadian waters. In addition to informing risk assessments, these predictions can be used to focus monitoring activities, particularly towards vectors that could transport C. intestinalis to these favourable environments.

Rehabilitating Downy Brome (Bromus tectorum)–Invaded Shrublands Using Imazapic and Seeding with Native Shrubs

2011 ◽  
Vol 4 (2) ◽  
pp. 223-233 ◽  
Author(s):  
Suzanne M. Owen ◽  
Carolyn Hull Sieg ◽  
Catherine A. Gehring
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Native Species ◽  
Developmental Stages ◽  
Growth Stages ◽  
Plant Community Composition ◽  
Downy Brome ◽  
Invasive Grass ◽  
Shrub Species ◽  
Native Shrubs

AbstractRehabilitation of downy brome–infested shrublands is challenging once this invasive grass dominates native communities. The effectiveness of imazapic herbicide in reducing downy brome cover has been variable, and there is uncertainty about the impacts of imazapic on native species. We used a before-after-control-impact (BACI) field experiment and greenhouse studies to (1) determine if imazapic herbicide applied at 132 g ai ha−1 (8 oz/ac−1) and seeding with two native shrub species (Wyoming big sagebrush [Artemisia tridentata] and Mexican cliffrose [Purshia mexicana]) reduced downy brome cover and promoted shrub establishment, (2) assess potential effects of imazapic on nontarget plant species and plant community composition, and (3) determine if imazapic affected downy brome or seeded shrub species when applied at different developmental stages. Seeding shrubs, alone, or in combination with imazapic application, did not significantly increase shrub density, possibly because of droughty conditions. In the field, imazapic reduced downy brome cover by 20% and nontarget forb cover by 25% and altered plant community composition the first year after treatment. Imazapic was lethal to downy brome at all growth stages in the greenhouse and reduced shrub germination by 50 to 80%, but older shrub seedlings were more tolerant of the herbicide. We conclude that a one-time application of imazapic combined with seeding shrubs was only slightly effective in rehabilitating areas with high downy brome and thatch cover and resulted in short-term impacts to nontarget species. These results highlight the need to treat downy brome infestations before they become too large. Also, removing thatch prior to treating with imazapic, although likely lethal to the native shrubs we studied, could increase the effectiveness of imazapic.

Extreme Ionic and Temperature Effects on Germination of Weeping Alkaligrass (Puccinellia distans), Nuttall's Alkaligrass (Puccinellia nuttalliana) and Kentucky Bluegrass (Poa pratensis)

Weed Science ◽  
2007 ◽  
Vol 55 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Catherine S. Tarasoff ◽  
Daniel A. Ball ◽  
Carol A. Mallory-Smith
Keyword(s):  
Native Species ◽  
Poa Pratensis ◽  
Seed Viability ◽  
Kentucky Bluegrass ◽  
Salt Tolerant ◽  
Puccinellia Distans ◽  
Semiarid Environments ◽  
Temperature Conditions ◽  
Soil Temperatures ◽  
Germination Experiments

The introduced species weeping alkaligrass, and the native species Nuttall's alkaligrass, two of the most salt-tolerant C3 grasses found in arid and semiarid environments of western North America, occur within the Grande Ronde valley of eastern Oregon. Both species occur as weeds within Kentucky bluegrass seed fields and subsequently as grass seed contaminants. Two separate germination experiments were conducted to understand better the seed germination biology of these two species compared to Kentucky bluegrass under negative water potentials or high temperature conditions. Results of these studies indicate that although all three species benefited from an ionic enhancement associated with NaCl, weeping alkaligrass was the most drought and salt tolerant of the three species. Dry seeds of weeping alkaligrass were also particularly tolerant to high temperatures with no differences in germination at temperatures below 50 C, indicating that seed viability under nonirrigated field conditions should be unaffected by high soil temperatures. Under soil temperature conditions as high as 40 C, moist Kentucky bluegrass seeds had the greatest germination rates, indicating that this species should benefit from irrigation more than the other two species.

scholarly journals Pilferer, murderer of innocents or prey? The potential impact of killer shrimp (Dikerogammarus villosus) on crayfish

2020 ◽  
Vol 83 (1) ◽  
Author(s):  
Sara Roje ◽  
Kateřina Švagrová ◽  
Lukáš Veselý ◽  
Arnaud Sentis ◽  
Antonín Kouba ◽  
...  
Keyword(s):  
Native Species ◽  
Developmental Stages ◽  
Aquatic Organisms ◽  
Freshwater Ecosystems ◽  
Signal Crayfish ◽  
Dikerogammarus Villosus ◽  
Native Communities ◽  
Marbled Crayfish ◽  
Invasive Amphipod ◽  
The Impact

Abstract Freshwater ecosystems worldwide are facing the establishment of non-native species, which, in certain cases, exhibit invasive characteristics. The impacts of invaders on native communities are often detrimental, yet, the number and spread of non-native invasive species is increasing. This is resulting in novel and often unexpected combinations of non-native and native species in natural communities. While the impact of invaders on native species is increasingly well-documented, the interactions of non-native invaders with other non-native invaders are less studied. We assessed the potential of an invasive amphipod, the killer shrimp Dikerogammarus villosus (Sowinsky, 1894), to cope with other established invaders in European waters: North American crayfish of the Astacidae family—represented by signal crayfish Pacifastacus leniusculus (Dana, 1852), and the Cambaridae family—represented by marbled crayfish Procambarus virginalis Lyko, 2017. The main goal of this study was to investigate if killer shrimp, besides their role as prey of crayfish, can significantly influence their stocks by predating upon their eggs, hatchlings and free-moving early juveniles. Our results confirmed that killer shrimp can predate on crayfish eggs and hatchlings even directly from females abdomens where they are incubated and protected. As marbled crayfish have smaller and thinner egg shells as well as smaller juveniles than signal crayfish, they were more predated upon by killer shrimp than were signal crayfish. These results confirmed that the invasive killer shrimp can feed on different developmental stages of larger freshwater crustaceans and possibly other aquatic organisms.

401. In vivo development of embryos derived from sex-sorted and non-sorted ram sperm

2008 ◽  
Vol 20 (9) ◽  
pp. 81
Author(s):  
K. H. Beilby ◽  
C. C. Grupen ◽  
W. M. C. Maxwell ◽  
G. Evans
Keyword(s):  
Y Chromosome ◽  
Embryo Development ◽  
X Chromosome ◽  
Developmental Stages ◽  
Domestic Animals ◽  
Embryo Production ◽  
Fertilisation Rate ◽  
Ram Sperm ◽  
In Pregnancy

The use of sex-sorted ram sperm results in pregnancy rates similar or superior to that of non-sorted sperm after laparoscopic insemination of synchronised ewes under defined conditions [1, 2]. To further assess the fertility of sex-sorted ram sperm, embryo production and development rates were examined after the insemination of superovulated ewes with either sex-sorted or non-sorted sperm. Merino ewes (n = 30) were synchronised in oestrus using progestagen sponges inserted for 14 days and hormonally stimulated with PMSG (600 IU) on sponge removal (SR), FSH (133 mg) at decreasing doses every 12 h for 4 days before insemination, and GnRH 24 h before insemination. Each ewe was inseminated in the uterus by laparoscopy 42–44 h after SR with 15 × 106 motile X- or Y-chromosome bearing or non-sorted spermatozoa. On day 6 after insemination, antegrade flushing of both uterine horns was performed. Overall, the fertilisation rate was higher using X-chromosome bearing sperm (70%) compared with both Y-chromosome enriched (59%) and non-sorted treatments (64%). Embryo development was more advanced after the insemination of non-sorted sperm with more hatching (hg) and expanded blastocysts (exb) recovered per animal (hg: 3.37 ± 1.19; exb: 5.00 ± 1.68) compared with sorted groups (X hg: 1.71 ± 0.92; exb: 3.28 ± 1.80; Y hg: 1.67 ± 1.67; exb: 1.50 ± 1.02). Moreover, embryos were recovered at earlier developmental stages after insemination with Y- compared with X-chromosome bearing sperm. In conclusion, the use of sex-sorted sperm did not affect the efficiency of embryo production. However, the development of embryos derived from sex-sorted sperm was delayed compared with those from non-sorted sperm. (1) de Graaf et al. 2007. Reproduction in Domestic Animals 42, 648–653 (2) Beilby et al. 2008. Theriogenology [IN PRESS]

scholarly journals Stepwise Embryonic Toxicity of Silver Nanoparticles onOryzias latipes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jae-Gu Cho ◽  
Kyung-Tae Kim ◽  
Tae-Kwon Ryu ◽  
Jae-woo Lee ◽  
Ji-Eun Kim ◽  
...  
Keyword(s):  
Heart Rate ◽  
Silver Nanoparticles ◽  
Embryonic Development ◽  
Developmental Stages ◽  
Developmental Toxicity ◽  
Heart Beat ◽  
Hatching Rate ◽  
Dose Dependent Decrease ◽  
Embryonic Toxicity ◽  
Dose Dependent

The developmental toxicity of silver nanoparticles (AgNPs) was investigated following exposure ofOryzias latipes(medaka) embryos to 0.1−1 mg/L of homogeneously dispersed AgNPs for 14 days. During this period, developmental endpoints, including lethality, heart rate, and hatching rate, were evaluated by microscopy for different stages of medaka embryonic development. To compare toxic sensitivity, acute adult toxicity was assessed. There was no difference in acute lethal toxicity between embryo and adult medaka. Interestingly, we found that the increase in stepwise toxicity was dependent on the developmental stage of the embryo. Lethal embryonic toxicity increased from exposure days 1 to 3 and exposure days 5 to 8, whereas there was no change from exposure days 3 to 5. In addition, 7 d exposure to 0.8 mg/L AgNPs resulted in significant heart beat retardation in medaka embryos. AgNPs also caused a dose-dependent decrease in the hatching rate and body length of larvae. These results indicate that AgNP exposure causes severe developmental toxicity to medaka embryos and that toxicity levels are enhanced at certain developmental stages, which should be taken into consideration in assessments of metallic NPs toxicity to embryos.

Environmental drivers of fish functional diversity and composition in the Lower Colorado River Basin

2010 ◽  
Vol 67 (11) ◽  
pp. 1791-1807 ◽  
Author(s):  
Thomas K. Pool ◽  
Julian D. Olden ◽  
Joanna B. Whittier ◽  
Craig P. Paukert
Keyword(s):  
Life History ◽  
River Basin ◽  
Functional Diversity ◽  
Native Species ◽  
Fish Community ◽  
Colorado River ◽  
Colorado River Basin ◽  
Environmental Drivers ◽  
Lower Colorado River Basin ◽  
Lower Colorado River

Freshwater conservation efforts require an understanding of how natural and anthropogenic factors shape the present-day biogeography of native and non-native species. This knowledge need is especially acute for imperiled native fishes in the highly modified Lower Colorado River Basin (LCRB), USA. In the present study we employed both a taxonomic and functional approach to explore how natural and human-related environmental drivers shape landscape-scale patterns of fish community composition in the LCRB. Our results showed that hydrologic alteration, watershed land use, and regional climate explained 30.3% and 44.7% of the total variation in fish community taxonomic and functional composition, respectively. Watersheds with greater dam densities and upstream storage capacity supported higher non-native functional diversity, suggesting that dams have provided additional “niche opportunities” for non-native equilibrium life-history strategists by introducing new reservoir habitat and modifying downstream flow and thermal regimes. By contrast, watersheds characterized by greater upstream land protection, lower dam densities, and higher variation in spring and summer precipitation supported fish communities with a strong complement of native species (opportunistic–periodic strategists). In conclusion, our study highlights the utility of a life-history approach to better understand the patterns and processes by which fish communities vary along environmental gradients.

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