Matriphagy in five species of the genus Anelosimus (Araneae: Theridiidae)

Behaviour ◽  
2021 ◽  
pp. 1-8
Author(s):  
M. de Fatima Rocha Dias ◽  
V.P. Rios ◽  
J. Vasconcellos-Neto ◽  
C. Viera
Keyword(s):  
Parental Care ◽  
Laboratory Conditions ◽  
Social Species ◽  
Evolution Of Sociality ◽  
Taxonomic Groups ◽  
Different Levels ◽  
Social Level

Abstract Parental care has evolved numerous times in many taxonomic groups of animals. Matriphagy, as an extreme example of parental care, is present in many social species, subsocial species, and even in solitary spiders. Here, we describe matriphagy in five species of Anelosimus of different levels of sociality: social (A. dubiosus), intermediate social (A. jabaquara), subsocial (A. vierae, A. baeza), and solitary (A. nigrescens). Each group contained a female and its brood, maintained under standardized laboratory conditions. All species showed matriphagy, regardless of their social level. Further studies are necessary to clarify whether matriphagy is a necessary precondition for the evolution of sociality in spiders, or if it is phylogenetically conserved in some families.

Female, but not male, agonistic behaviour is associated with male reproductive success in stable bluebanded goby (Lythrypnus dalli) hierarchies

Behaviour ◽  
2014 ◽  
Vol 151 (10) ◽  
pp. 1367-1387 ◽  
Author(s):  
Tessa K. Solomon-Lane ◽  
Madelyne C. Willis ◽  
Devaleena S. Pradhan ◽  
Matthew S. Grober
Keyword(s):  
Reproductive Success ◽  
Egg Laying ◽  
Dominant Male ◽  
Male Reproductive Success ◽  
Agonistic Behaviour ◽  
Social Species ◽  
Evolution Of Sociality ◽  
Lythrypnus Dalli ◽  
Linear Hierarchies ◽  
Substantial Control

In many social species, there are important connections between social behaviour and reproduction that provide critical insights into the evolution of sociality. In this study, we describe associations between agonistic behaviour and male reproductive success in stable social groups of bluebanded gobies (Lythrypnus dalli). This highly social, sex-changing species forms linear hierarchies of a dominant male and multiple subordinate females. Males reproduce with each female in the harem and care for the eggs. Since aggression tends to be associated with reduced reproduction in social hierarchies, we hypothesized that males in groups with high rates of aggression would fertilise fewer eggs. We also hypothesized that a male’s agonistic behaviour would be associated with his reproductive success. Dominants often exert substantial control over their harem, including control over subordinate reproduction. To address these hypotheses, we quantified egg laying/fertilisation over 13 days and observed agonistic behaviour. We show that there was a significant, negative association between male reproductive success and the total rate agonistic interactions by a group. While no male behaviours were associated with the quantity of eggs fertilised, female agonistic behaviour may be central to male reproductive success. We identified a set of models approximating male reproductive success that included three female behaviours: aggression by the highest-ranking female and approaches by the lowest-ranking female were negatively associated with the quantity of eggs fertilised by males in their groups, but the efficiency with which the middle-ranking female displaced others was positively associated with this measure. These data provide a first step in elucidating the behavioural mechanisms that are associated with L. dalli reproductive success.

scholarly journals Experience, but not age, is associated with volumetric mushroom body expansion in solitary alkali bees

2021 ◽  
pp. jeb.238899
Author(s):  
Mallory A. Hagadorn ◽  
Makenna M. Johnson ◽  
Adam R. Smith ◽  
Marc A. Seid ◽  
Karen M. Kapheim
Keyword(s):  
Structural Changes ◽  
Evolutionary Relationship ◽  
Brain Regions ◽  
Mushroom Bodies ◽  
Order Processing ◽  
Social Species ◽  
Evolution Of Sociality ◽  
Foraging Experience ◽  
Brain Changes ◽  
The Brain

In social insects, changes in behavior are often accompanied by structural changes in the brain. This neuroplasticity may come with experience (experience-dependent) or age (experience-expectant). Yet, the evolutionary relationship between neuroplasticity and sociality is unclear, because we know little about neuroplasticity in the solitary relatives of social species. We used confocal microscopy to measure brain changes in response to age and experience in a solitary halictid bee (Nomia melanderi). First, we compared the volume of individual brain regions among newly-emerged females, laboratory females deprived of reproductive and foraging experience, and free-flying, nesting females. Experience, but not age, led to significant expansion of the mushroom bodies—higher-order processing centers associated with learning and memory. Next, we investigated how social experience influences neuroplasticity by comparing the brains of females kept in the laboratory either alone or paired with another female. Paired females had significantly larger olfactory regions of the mushroom bodies. Together, these experimental results indicate that experience-dependent neuroplasticity is common to both solitary and social taxa, whereas experience-expectant neuroplasticity may be an adaptation to life in a social colony. Further, neuroplasticity in response to social chemical signals may have facilitated the evolution of sociality.

scholarly journals Determination of mechanical properties of soil under laboratory conditions

2014 ◽  
Vol 60 (Special Issue) ◽  
pp. S66-S69 ◽  
Author(s):  
V. Malý ◽  
M. Kučera
Keyword(s):  
Mechanical Properties ◽  
Penetration Depth ◽  
Measuring Device ◽  
Laboratory Conditions ◽  
Measuring Network ◽  
Set Up ◽  
Different Diameters ◽  
Different Levels ◽  
Properties Of Soil

This paper presents the mechanical properties of soil. In order to determine the properties of soil under laboratory conditions, a special measuring device was constructed, viz. a bevameter. Two types of soil with different levels of moisture were examined and their mechanical properties were determined. Measurements were taken of non-compressed soil. A measuring network was set up, consisting of measuring and recording devices. In the course of measuring, the force and penetration depth of the pressing plate were recorded simultaneously. Three different diameters of pressing plate were used, namely 38, 50 and 70 mm. The pressure on the contact area was calculated after completion of the measurements, and the relationships between pressure and penetration depth were presented graphically.

scholarly journals Antimicrobial defences increase with sociality in bees

2007 ◽  
Vol 3 (4) ◽  
pp. 422-424 ◽  
Author(s):  
Adam Stow ◽  
David Briscoe ◽  
Michael Gillings ◽  
Marita Holley ◽  
Shannon Smith ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Genetic Relatedness ◽  
Microbial Pathogens ◽  
Strongly Correlated ◽  
Social Species ◽  
Evolution Of Sociality ◽  
Selective Agents ◽  
Order Of Magnitude ◽  
Risk Of Disease ◽  
Solitary Species

Evidence for the antiquity and importance of microbial pathogens as selective agents is found in the proliferation of antimicrobial defences throughout the animal kingdom. Social insects, typified by crowding and often by low genetic variation, have high probabilities of disease transmission and eusocial Hymenoptera may be particularly vulnerable because of haplodiploidy. Mechanisms they employ to reduce the risk of disease include antimicrobial secretions which are particularly important primary barriers to infection. However, until now, whether or not there is selection for stronger antimicrobial secretions when the risk of disease increases because of sociality has not been tested. Here, we present evidence that the production of progressively stronger antimicrobial compounds was critical to the evolution of sociality in bees. We found that increases in group size and genetic relatedness were strongly correlated with increasing antimicrobial strength. The antimicrobials of even the most primitive semi-social species were an order of magnitude stronger that those of solitary species, suggesting a point of no return, beyond which disease control was essential. Our results suggest that selection by microbial pathogens was critical to the evolution of sociality and required the production of strong, front-line antimicrobial defences.

scholarly journals Adversity magnifies the importance of social information in decision-making

2016 ◽  
Author(s):  
Alfonso Perez-Escudero ◽  
Gonzalo G de Polavieja
Keyword(s):  
Decision Making ◽  
Mathematical Analysis ◽  
Social Information ◽  
The Other ◽  
Adverse Conditions ◽  
Social Species ◽  
Life Threatening ◽  
Low Levels ◽  
The Impact ◽  
Different Levels

In adverse conditions, individuals follow the majority more strongly. This phenomenon is very general across social species, but explanations have been particular to the species and context, including antipredatory responses, deflection of responsibility, or increase in uncertainty. Here we show that the impact of social information in realistic decision-making typically increases with adversity, giving more weight to the choices of the majority. The conditions for this social magnification are very natural, but were absent in previous decision-making models due to extra assumptionsthat simplified mathematical analysis, like very low levels of stochasticity or the assumption that when one option is good the other one must be bad. We show that decision-making in collectives can quantitatively explain the different impact of social influence with different levels of adversity for different species and contexts, including life-threatening situations in fish and simple experiments in humans.

The Evolution of Sociality, Helping, and Morality

2017 ◽  
Author(s):  
Dennis Krebs ◽  
Kaleda Denton
Keyword(s):  
Evolutionary Theory ◽  
Helping Behavior ◽  
Moral Judgments ◽  
Social Species ◽  
Evolution Of Sociality ◽  
Early Humans ◽  
Changes Over Time ◽  
Personal Interests ◽  
General Explanation ◽  
Over Time

Evolutionary theory offers an explanation for the emergence of, and variations in, sociality, helping behavior, and morality in both animals and humans. These traits evolved in some species to help them adapt to their environments. Humans possess them in abundance not because God created humans in his own image but rather because these traits were especially beneficial to early humans. To flesh out this general explanation, this chapter considers the ways in which social and moral adaptations helped humans and members of other social species (but not members of nonsocial species) propagate their genes. Humans are among the most social of all animals, and the structure of human groups has undergone several significant changes over time, adding stresses on moral motives. People can make impartial moral judgments, even when they do not foster personal interests, thanks to evolved processes enhancing motivations to make fair moral judgments.

Mate choice copying in two species of darters (Percidae: Etheostoma)

Behaviour ◽  
2013 ◽  
Vol 150 (11) ◽  
pp. 1255-1274 ◽  
Author(s):  
Rachel L. Moran ◽  
Carl N. von Ende ◽  
Bethia H. King
Keyword(s):  
Social Learning ◽  
Mate Choice ◽  
Parental Care ◽  
Nest Site ◽  
Etheostoma Flabellare ◽  
Mate Choice Copying ◽  
Filamentous Green Algae ◽  
The One ◽  
Taxonomic Groups ◽  
The Relationship

Mate choice copying is a form of social learning that is defined as the increased likelihood of an individual choosing a particular mate after observing another individual choosing that mate. Mate choice copying has been demonstrated in a range of taxonomic groups, but not usually for both sexes. Mate choice copying experiments were performed here using two congeneric sympatric darters, Etheostoma flabellare and E. zonale. In E. flabellare, males guard a nest site under a rock and care for developing eggs. In E. zonale, eggs are attached to filamentous green algae and neither sex provides parental care. Our results provide the first evidence that mate choice copying occurs in darters. Previously it was hypothesised that copying might be more common in species and sexes that provide parental care, the reasoning being that the costs of choosing poorly may be higher. However, mate choice copying was found in both sexes of E. zonale (no parental care) and in male but not female E. flabellare (male only parental care). Thus, the only group that did not mate choice copy was the one whose mate would be providing care, and even E. flabellare females copy the mate choice of other females by some definitions. The relationship, if any, between which sex provides parental care and whether copying occurs remains unclear, and the number of species for which such data are available is limited.

Natal dispersal and demography of a subsocial Anelosimus species and its implications for the evolution of sociality in spiders

1998 ◽  
Vol 76 (12) ◽  
pp. 2137-2147 ◽  
Author(s):  
L Avilés ◽  
G Gelsey
Keyword(s):  
Transition Probabilities ◽  
Local Area ◽  
Natal Nest ◽  
Life History Stages ◽  
Social Species ◽  
Evolution Of Sociality ◽  
The Social ◽  
Local Areas ◽  
Dispersal Distances ◽  
Close Inbreeding

The transition to permanent-sociality in spiders is thought to have involved the suppression of the dispersal phase characteristic of hypothetical subsocial or periodic-social ancestral species. Extant periodic-social species may provide insights into this transition. The periodic-social Anelosimus jucundus in southern Arizona was found to form mother-offspring and sibling associations that disintegrate prior to the mating season. Following the breakdown of the social phase, more than twice as many females as males became established within a few metres of the natal nest. Given that the predispersal sex ratio was 1:1, a fraction of the males may have dispersed beyond the local area. The short dispersal distances of at least a fraction of individuals of both sexes, the clustering of nests in local areas, and at least two possible cases of sibling mating suggest, however, that dispersal may not eliminate the possibility of close inbreeding in this species. Estimated transition probabilities between life-history stages show that the heaviest loss of individuals occurs during dispersal. Once established, 41% of the females that reached maturity succeeded in producing grown progeny. We discuss the implications of these findings in terms of the transition from periodic to permanent sociality in spiders and of current models that consider the interplay between competition and inbreeding avoidance in the evolution of dispersal.

scholarly journals Selfish mothers indeed! Resource-dependent conflict over extended parental care in free-ranging dogs

2015 ◽  
Vol 2 (12) ◽  
pp. 150580 ◽  
Author(s):  
Manabi Paul ◽  
Sreejani Sen Majumder ◽  
Anjan K. Nandi ◽  
Anindita Bhadra
Keyword(s):  
Parental Care ◽  
Social Dynamics ◽  
Lifetime Reproductive Success ◽  
Resource Quality ◽  
Social Species ◽  
Rich Food ◽  
The Social ◽  
Protein Rich ◽  
Free Ranging ◽  
Extended Parental Care

Parent–offspring conflict (POC) theory provides an interesting premise for understanding social dynamics in facultatively social species. In free-ranging dogs, mothers increase conflict over extended parental care with their pups beyond the weaning stage. In this study, we investigated whether resource quality affects POC in the dogs that typically live in a highly competitive environment as scavengers. We built a theoretical model to predict the alternative options available to the mother in the context of food sharing with her pups when protein-rich food (meat) is provided, as compared to carbohydrate-rich food (biscuits). We fit the mothers’ response from experimental data to the model and show that the mothers choose a selfish strategy, which can in turn ensure higher lifetime reproductive success, while depriving the current litter access to better resources. These results have interesting implications for understanding the social dynamics of the dogs, and the emergence of facultative sociality in a species that evolved from strongly social ancestors. We speculate that the tendency of increased conflict in resource-rich conditions might have driven the process of domestication in the ancestors of dogs which defected from their groups in favour of richer resources around human settlements.

scholarly journals DETOXICATION OF LEAD IN MERETRIX LYRATA UNDER ARTIFICIAL BREEDING IN VIETNAM

2019 ◽  
pp. 122-128
Author(s):  
Truong Van Tuan
Keyword(s):  
Heavy Metals ◽  
Social Economic ◽  
Sea Water ◽  
Lead Content ◽  
Economic Activities ◽  
Lead Accumulation ◽  
Laboratory Conditions ◽  
Artificial Breeding ◽  
Series Of Experiments ◽  
Different Levels

Polluting of the environment by wastes of social-economic activities, industrial, agricultural and household sources is considerably dangerous for artificial breeding of clam Meretrix lyrata in the mouth of the Bach Dang (Vietnam) because of heavy metals in clam organisms accumulated in dangerous concentrations. Accumulation and excretion of lead in Meretrix lyrata was studied under laboratory conditions. There were conducted a series of experiments on breeding of Meretrix lyrata and its exposure to water with different levels of lead (C = 0.003; 0.05; 0.1; 0.3; 0.4; 0.6 mg/l). Lead content in Meretrix lyrata was analyzed after 10, 15, 20, 25, 30 days. In 10 days after the exposure of Meretrix lyrata to clear sea water it was marked that concentrations of lead were not excreted, about 30% of it remained in clam bodies regardless of initially accumulated amount of Pb. It has been stated that concentration of Pb in Meretrix lyrata in all tanks (except C = 0,6 mg/l) gradually increased with the duration of exposure. In 25 days of exposure of individuals in water with concentration of C = 0.6 mg/l, about 20% of Meretrix lyrata individuals died, after 30 days died 100% individuals. The results obtained can be assumed as the basis for investigating lead accumulation and its excretion by clam Meretrix lyrata organisms grown in artificial conditions.

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