scholarly journals Survive or swim: different relationships between migration potential and larval size in three sympatric Mediterranean octocorals

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Katell Guizien ◽  
N. Viladrich ◽  
Á. Martínez-Quintana ◽  
L. Bramanti
Keyword(s):  
Life History Strategy ◽  
Free Fall ◽  
Swimming Activity ◽  
The Other ◽  
Distribution Models ◽  
Larval Size ◽  
Activity Frequency ◽  
Migration Potential ◽  
Gorgonian Species ◽  
Marine Benthic Invertebrates

Abstract Knowledge about migration potential is key to forecasting species distributions in changing environments. For many marine benthic invertebrates, migration happens during reproduction because of larval dispersal. The present study aims to test whether larval size can be used as a surrogate for migration potential arising from larval longevity, competence, sinking, or swimming behavior. The hypothesis was tested using larvae of three sympatric gorgonian species that release brooded lecithotrophic larvae in the same season: Paramuricea clavata, Corallium rubrum and Eunicella singularis. Despite different fecundities and larval sizes, the median larval longevity was similar among the three species. Free-fall speed increased with larval size. Nevertheless, the only net sinkers were the P. clavata larvae, as swimming was more common than free fall in the other two species with larger larvae. For the other two species, swimming activity frequency decreased as larval size increased. Interestingly, maximum larval longevity was lowest for the most active but intermediately sized larvae. Larval size did not covary consistently with any larval traits of the three species when considered individually. We thus advise not using larval size as a surrogate for migration potential in distribution models. The three species exemplified that different mechanisms, i.e., swimming activity or larval longevity, resulting from a trade-off in the use of energy reserves can facilitate migration, regardless of life history strategy.

Capture of conspecific planktonic larvae by the suspension-feeding gastropod Crepipatella peruviana: association between adult and larval size

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
G A Rivera-Figueroa ◽  
J A Büchner-Miranda ◽  
L P Salas-Yanquin ◽  
J A Montory ◽  
V M Cubillos ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Larval Mortality ◽  
Feeding Preference ◽  
The Other ◽  
Suspension Feeding ◽  
Adult Size ◽  
Free Living ◽  
Larval Size ◽  
Suspension Feeders ◽  
Planktonic Larvae

ABSTRACT Free-living, planktonic larvae can be vulnerable to capture and ingestion by adult suspension-feeders. This is particularly the case for larvae that settle gregariously in benthic environments where suspension-feeders occur at high densities. Larvae of gregarious suspension-feeding species are at particularly high risk, as adults of their own species often serve as cues for metamorphosis. We conducted laboratory experiments to assess the extent to which adults of the suspension-feeding caenogastropod Crepipatella peruviana would capture and ingest their own larvae. Experiments were conducted with adults of different sizes, with larvae of different ages and sizes, and in the presence or absence of phytoplankton. Adults captured larvae in all experiments. The presence of microalgae in the water did not influence the extent of larval capture. On average, 39% of larvae were captured during the 3-h feeding periods, regardless of adult size. However, up to 34% of the larvae that were captured on the gill were later discarded as pseudofaeces; the other 64% were ingested. The extent of capture by adults was not related to adult size, or to larval size and, thus, to larval age. Our results suggest that the filtration of congeneric larvae by adult C. peruviana is a result of accidental capture rather than a deliberate feeding preference. Such ingestion could, however, still be an important source of larval mortality, especially when the advanced larvae of this species are searching for a suitable substrate for metamorphosis.

Liquid Behavior in Containers with a Liquid-Packing Bag for Liquid Products Subjected to Drop Impact

2006 ◽  
Vol 321-323 ◽  
pp. 1280-1283 ◽  
Author(s):  
Eisaku Umezaki ◽  
Yuuma Shinoda ◽  
Katsunori Futase
Keyword(s):  
High Speed ◽  
Free Fall ◽  
The Other ◽  
Impact Loads ◽  
Visualization Technique ◽  
Transparent Plastic ◽  
Plastic Films ◽  
Liquid Behavior ◽  
Liquid Products ◽  
Polyethylene Particles

The behavior of liquid in containers subjected to impact loads due to free fall was investigated using a visualization technique. Two types of containers were used. One consisted of a case made of transparent plastic plates and a liquid-packing bag made of transparent plastic films. The bag contained about 1,000 ml of liquid. The other was a case made only of transparent plastic plates. The case contained about 1,000 ml of water. The liquid consisted of water and ethanol. Polyethylene particles of about 3 mm in diameter were included in the liquid to visualize the movement of liquid in the containers. The containers were subjected to impact due to free fall, and photographs of the containers were taken using a high-speed camera. Results indicated that the behavior of liquid in the container with a liquid-packing bag is different from that of the container without a liquid-packing bag.

scholarly journals State-dependent behavior and alternative behavioral strategies in brown trout (Salmo trutta L.) fry

2015 ◽  
Author(s):  
Joacim Näslund ◽  
Jörgen I Johnsson
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Population Based ◽  
Swimming Activity ◽  
The Other ◽  
Behavioral Strategies ◽  
Food Ration ◽  
State Dependent ◽  
Behavioral Trials ◽  
Bodily State

Animals generally adjust their behavior in response to bodily state (e.g. size and energy reserves) to optimize energy intake in relation to mortality risk, weighing predation probability against starvation. Here we investigated whether brown trout adjust their behavior in relation to feeding history (energetic status) and body size during a major early-life selection bottleneck, when fast growth also appear to be important. We manipulated growth using different food ration schemes over two consecutive time periods (P1 = 12 days, P2 = 23 days), excluding social effects through individual isolation. During these experimental periods the fish were fed either high or low food rations in a crossed design. In behavioral trials following the treatment, where acute hunger levels were standardized among all treatments, fish that were initially fed high rations (P1) and thereafter low rations (P2) had on average 15-21% higher swimming activity than the other groups, but large within-treatment variation rendered only weak statistical support for the effect. Furthermore, fish on low ration during P2 tended to be more aggressive than fish on high ration. Size was related to behavioral expression, with larger fish being more active and aggressive. Swimming activity and active aggression were positively correlated, forming a behavioral syndrome in the studied population. Based on these behavioral traits we could also distinguish two behavioral clusters, one consisting of more active and aggressive individuals, and the other consisting of less active and aggressive individuals. This indicates that two behavioral strategies may exist in young brown trout.

The necessity for testing germination of fresh seeds in studies on diaspore heteromorphism as a life-history strategy

2013 ◽  
Vol 23 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Jerry M. Baskin ◽  
Juan J. Lu ◽  
Carol C. Baskin ◽  
Dun Y. Tan
Keyword(s):  
Life History ◽  
High Risk ◽  
Life History Strategy ◽  
The Other ◽  
Dispersal Ability ◽  
Correct Interpretation ◽  
Bet Hedging ◽  
High Dispersal ◽  
Dimorphic Species ◽  
Dispersal Characteristics

AbstractMany studies have compared diaspore dispersal ability and degree of dormancy in the two diaspores of dimorphic plant species. A primary goal of these studies was to determine if germination and dispersal characteristics of the two morphs fit within a high risk–low risk (bet-hedging) life-history strategy, i.e. high dispersal/low dormancy in one morph versus low dispersal/high dormancy in the other one. In a survey of 26 papers on 28 diaspore dimorphic species, we found that in 12 of the studies, which were published between 1978 and 2008, seeds were stored, and thus possibly afterripened, before they were tested for germination. The 14 papers that tested fresh seeds were published between 1963 and 2010. Failure to test fresh seeds likely resulted in misinterpretation of the diaspore dispersal/dormancy strategy in some of the species investigated. We conclude that it is imperative that fresh seeds be tested for germination in order to be certain that the correct relationship between dispersal and dormancy is elucidated, and thus that the correct interpretation is made concerning life-history strategy and bet-hedging, in dimorphic species.

scholarly journals Evaluation of species distribution models for estimating animal dark diversity

2021 ◽  
Author(s):  
Camilo Matus-Olivares ◽  
Jaime Carrasco ◽  
José Luis Yela ◽  
Paula Meli ◽  
Andres Weintraub ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Species Distribution ◽  
Species Distribution Model ◽  
Predictive Performance ◽  
The Other ◽  
Distribution Model ◽  
Distribution Data ◽  
Ensemble Model ◽  
Distribution Models ◽  
Software Environment

Abstract Aim Applying wide and effective sampling of animal communities is rarely possible due to the associated costs and the use of techniques that are not always efficient. Thus, many areas have a faunistic hidden diversity we denote Animal Dark Diversity (ADD), defined as the diversity that is present but not yet detected plus the diversity defined by Pärtel et al. (2011) that is not (yet) present despite the area’s favourable habitat conditions. We evaluated different species distribution model types (SDM techniques) on the basis of three requirements for ADD estimate reliability: 1) estimated spatial patterns of ADD do not differ significantly from other SDM techniques; 2) good predictive performances; and 3) low overfitting. Location Iberian Peninsula. Taxon Chiroptera and Noctuoidea (Lepidoptera) Methods We used distribution data for 25 species of bats and 352 species of moths. We evaluated eleven SDM techniques using biomod2 package implemented in the R software environment. We fitted the various SDM techniques to the data for each species and compared the resulting ADD estimates for the two animal groups under three threshold types. Results The results demonstrated that estimated ADD spatial patterns vary significantly between SDM techniques and depend on the threshold type. They also showed that SDM techniques with overfitting tend to generate smaller ADD sizes, thus reducing the possible species presence estimates. Among the SDMs studied, the ensemble models delivered ADD geographic patterns more like the other techniques while also presenting a high predictive performance for both faunal groups. However, the Ensemble Model Committee Average (ECA) performed much better on the sensitivity metric than all other techniques under any of the thresholds tested. In addition, ECA stood out clearly from the other ensemble model techniques in displaying low-medium overfitting. Main conclusions SDM techniques should no differ among each other in their ADD estimations, have good predictive performances and exhibit low overfitting. Furthermore, to reduce estimate uncertainty it is suggested that the threshold type be one that transforms high values of presences probabilities into binary information and furthermore that the SDM technique have a sensitivity bias, as otherwise the estimates will perform better for species absence in cases where it is not in fact known whether a species is truly absent.

scholarly journals Cynicism and the Collapse of Multilateralism

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Mahbi Maulaya
Keyword(s):  
International Relations ◽  
Qualitative Method ◽  
General Pattern ◽  
Free Fall ◽  
International Order ◽  
The Other ◽  
International Treaties ◽  
Theoretical Frameworks ◽  
Preliminary Attempt ◽  
Fundamental Reason

<p><em>International order is now witnessing the declining efficacy and extremely fragile condition of multilateralism. Several states start to doubt and leave international treaties, agreements, organizations, and institutions. This circumstance led into the speculation of “Multilateralism Collapse". Yet, there is only a small number of International Relations scholars who attempt to detect the general pattern that indicate the fundamental reason of relevant states to withdraw from multilateralism manifestation. Hence, this study is a preliminary attempt to fill the gap by providing a concrete explanation on the reason why the multilateralism is failing. This paper argues that the growing cynicism among the relation of international actors is served to be the reason of multilateralism free fall. There are two types of cynicism which this paper has discovered, the cynicism as a trigger and cynicism as a statement. Cynicism as a trigger tracked whereby the relevant state’s withdrawal from the multilateralism manifestation is merely caused by a sense of distrust. On the other hand, cynicism as a statement is the expression of relevant states to justify its withdrawal action and distract world’s attention from its hidden interest. Since this study requires a specific and deep interpretation on sets of event and data, the utilization of qualitative method was considered effective. This study applied two theoretical frameworks, namely cynicism and multilateralism.</em></p>

The other angle of Maslow's pyramid: How scarce environments trigger low-opportunity-cost innovations

2019 ◽  
Vol 42 ◽  
Author(s):  
Jordane Boudesseul ◽  
Cathy Rubiños
Keyword(s):  
Life History ◽  
Opportunity Cost ◽  
Cognitive Process ◽  
Industrial Revolution ◽  
Life History Strategy ◽  
The Other ◽  
Necessary Condition ◽  
Standards Of Living

Abstract Is it true that innovation occurs only in abundant environments? Baumard defends that increased standards of living are a necessary condition for a change in life history strategy to help understand the Industrial Revolution. Here, we argue that many examples of innovations occur in scarce environments when there is near-zero opportunity cost. We suggest potential psychological pathways to explain this dual-cognitive process.

Effect of Preservation on the Weight of Marine Benthic Invertebrates

1982 ◽  
Vol 39 (1) ◽  
pp. 221-224 ◽  
Author(s):  
Eric L. Mills ◽  
Karin Pittman ◽  
Brent Munroe
Keyword(s):  
Benthic Invertebrates ◽  
Dry Weight ◽  
The Other ◽  
Tissue Composition ◽  
Fresh Weight ◽  
Short Term ◽  
Long Term Changes ◽  
Biomass Determination ◽  
Marine Benthic Invertebrates

It would be convenient if preserved animals could be used to determine fresh-weight biomass. However, marine annelids, nematodes, bivalves, amphipods, and isopods all lost weight when preserved and stored in 70% isopropanol. In 10% formalin only bivalves lost weight significantly; the other groups showed evidence of small increases or decreases. Many animals preserved in alcohol decreased sharply in weight within a few minutes, probably due to dehydration. In formalin most increased at first, then slowly decreased. The response to preservatives is complex, involving short-term changes of water content and long-term changes of tissue composition. Precision, though not accuracy, of preserved wet weights can only be achieved after specimens have been in preservatives for a month or more, especially in the case of isopropanol. For these reasons, wet and dry weight biomass figures should be determined from fresh, unpreserved animals.Key words: fixation, preservation (organisms), biomass determination, benthos

scholarly journals Molar Buccal Tubes Front and Back Openings Dimensions and Torsional Play

2018 ◽  
Vol 30 (3) ◽  
pp. 32-39
Author(s):  
Hiyam J Al-Zubaidi ◽  
Akram F Alhuwaizi
Keyword(s):  
Orthodontic Treatment ◽  
In Vitro Study ◽  
Free Fall ◽  
Optical Microscope ◽  
The Other ◽  
Posterior Teeth ◽  
Adobe Photoshop ◽  
The Wire ◽  
Metal Block

Background/: Buccal tubes are orthodontic attachments used on the posterior teeth instead of bands, so it is important to focus on the effect of their properties on orthodontic treatment. The aims of the present in vitro study are to evaluate and compare the buccal tube front and back openings dimensions and the torsional play angle of six different brands. Materials and Methods: The samples consisted of Single bondable, non-convertible first molar buccal tubes from six brands supplied from six companies (Dentaurum, Forestadent, Ormco, 3M, American Orthodontic, A-Star). Regarding tube opening dimension, ten buccal tubes of each brand were examined by an optical microscope. Each tube was fixed during examination using synthetic mud and oriented for observation of the front and back slot openings. A picture was taken for both tube openings and the result appeared on the computer's screen where width and height measurements were made. While regarding torsional play angle, ten buccal tubes of each brand were used. Each tube was fixed on a metal block attached to a surveyor base. Then an L-shaped wire was inserted inside the front opening of the tube. Two photographs were taken, one with the wire in free fall position and the other with the wire elevated by a 10g weight with the same angle of shooting as the first photograph. Later, the two images were superimposed in Adobe Photoshop program, and an electronic MB-ruler Software was used to calculate the angle which represents the torsional play within each tube. The data were then statistically analyzed using ANOVA and LSD tests. Results: There are marked differences between measured tube dimensions and the manufacturer stated dimensions with the front tube openings being generally larger than the back opening dimensions. Furthermore, the torsional play angle was highest in A-Star and smallest in Ormco's tubes. This angle was significantly correlated to the height of the tube front opening. Conclusion: It can be concluded that tube dimension varies among different companies and effect greatly torsional play angle.

scholarly journals Applying Fuzzy Logic to Comparative Distribution Modelling: A Case Study with Two Sympatric Amphibians

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
A. Márcia Barbosa ◽  
Raimundo Real
Keyword(s):  
Fuzzy Logic ◽  
Bufo Bufo ◽  
The Other ◽  
Distribution Models ◽  
Distribution Modelling ◽  
Multiple Species ◽  
Logic Operations ◽  
Epidalea Calamita ◽  
Favourability Function

We modelled the distributions of two toads (Bufo bufoandEpidalea calamita) in the Iberian Peninsula using the favourability function, which makes predictions directly comparable for different species and allows fuzzy logic operations to relate different models. The fuzzy intersection between individual models, representing favourability for the presence of both species simultaneously, was compared with another favourability model built on the presences shared by both species. The fuzzy union between individual models, representing favourability for the presence of any of the two species, was compared with another favourability model based on the presences of either or both of them. The fuzzy intersections between favourability for each species and the complementary of favourability for the other (corresponding to the logical operation “A and not B”) were compared with models of exclusive presence of one species versus the exclusive presence of the other. The results of modelling combined species data were highly similar to those of fuzzy logic operations between individual models, proving fuzzy logic and the favourability function valuable for comparative distribution modelling. We highlight several advantages of fuzzy logic over other forms of combining distribution models, including the possibility to combine multiple species models for management and conservation planning.

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