scholarly journals The non-additive effects of body size on nest architecture in a polymorphic ant

2018 ◽  
Vol 373 (1753) ◽  
pp. 20170235 ◽  
Author(s):  
Christina L. Kwapich ◽  
Gabriele Valentini ◽  
Bert Hölldobler
Keyword(s):  
Body Size ◽  
Synergistic Effects ◽  
Mating Frequency ◽  
Nest Architecture ◽  
Harvester Ant ◽  
Insect Societies ◽  
Interdisciplinary Approaches ◽  
Size Groups ◽  
Veromessor Pergandei ◽  
Colony Level

Like traditional organisms, eusocial insect societies express traits that are the target of natural selection. Variation at the colony level emerges from the combined attributes of thousands of workers and may yield characteristics not predicted from individual phenotypes. By manipulating the ratios of worker types, the basis of complex, colony-level traits can be reduced to the additive and non-additive interactions of their component parts. In this study, we investigated the independent and synergistic effects of body size on nest architecture in a seasonally polymorphic harvester ant, Veromessor pergandei . Using network analysis, we compared wax casts of nests, and found that mixed-size groups built longer nests, excavated more sand and produced greater architectural complexity than single-sized worker groups. The nests built by polymorphic groups were not only larger in absolute terms, but larger than expected based on the combined contributions of both size classes in isolation. In effect, the interactions of different worker types yielded a colony-level trait that was not predicted from the sum of its parts. In nature, V. pergandei colonies with fewer fathers produce smaller workers each summer, and produce more workers annually. Because body size is linked to multiple colony-level traits, our findings demonstrate how selection acting on one characteristic, like mating frequency, could also shape unrelated characteristics, like nest architecture. This article is part of the theme issue ‘Interdisciplinary approaches for uncovering the impacts of architecture on collective behaviour'.

scholarly journals The developmental variations of the sagitta otolith in the young and mature male of a hermaphrodite polynemidae fish, Eleutheronema tetradactylum (Shaw, 1804)

2021 ◽  
Vol 61 ◽  
pp. e20216178
Author(s):  
Soumen Roy ◽  
Itika Bardhan
Keyword(s):  
Body Size ◽  
Fork Length ◽  
The Body ◽  
Size Groups ◽  
Protandrous Hermaphrodite ◽  
Ultrastructural Characteristics ◽  
Developmental Variations ◽  
The One ◽  
First Time ◽  
One Way Anova

The Eleutheronema tetradactylum is a protandrous, hermaphrodite, marine perciformes fish. The body length of this fish acts as an important diagnostic marker for male and female discrimination. The present study describes for the first time the ultrastructural characteristics on the medial surface of the sagitta otolith in different body size groups of males of E. tetradactylum (Polynemidae: Perciformes) using scanning electron microscopy. The sagitta is a spindle-shaped structure that includes a well-developed rostrum and a poorly developed antirostrum. The sulcus is ostio-pseudocaudal type, almost straight and devoid of the collum. The ostium is a well-developed, vase-shaped structure. The cauda includes the colliculum and a well-developed caudal bulb with several distinct growth stripes. The length of the caudal bulb is significantly correlated to the growth of the body size of the fish. The excisura major is indistinct and the excisura minor is absent. The cristae are distinct on both sides of the sulcus. The one-way ANOVA test revealed that the development of several sagitta features shows significant differences in various body size groups of E. tetradactylum. The growth of the sagitta length is more closely related to the fork length than the sagitta width. Therefore, the sagitta length and the caudal bulb length can be used as important predictors to evaluate the fish size. The cauda region of the sagitta in E. tetradactylum is unique as well as more decorative than those of another Polynemidae fish and other hermaphrodite, marine perciformes fishes. The sagitta characteristics of E. tetradactylum might be advantageous in the identification of the sex and the taxonomy of the hermaphrodite fish species.

scholarly journals Towards a general life-history model of the superorganism: predicting the survival, growth and reproduction of ant societies

2012 ◽  
Vol 8 (6) ◽  
pp. 1059-1062 ◽  
Author(s):  
Jonathan Z. Shik ◽  
Chen Hou ◽  
Adam Kay ◽  
Michael Kaspari ◽  
James F. Gillooly
Keyword(s):  
Life History ◽  
Terrestrial Ecosystems ◽  
The Body ◽  
Ant Colonies ◽  
Insect Societies ◽  
Model Predictions ◽  
Body Sizes ◽  
Survival And Reproduction ◽  
Growth And Reproduction ◽  
Colony Level

Social insect societies dominate many terrestrial ecosystems across the planet. Colony members cooperate to capture and use resources to maximize survival and reproduction. Yet, when compared with solitary organisms, we understand relatively little about the factors responsible for differences in the rates of survival, growth and reproduction among colonies. To explain these differences, we present a mathematical model that predicts these three rates for ant colonies based on the body sizes and metabolic rates of colony members. Specifically, the model predicts that smaller colonies tend to use more energy per gram of biomass, live faster and die younger. Model predictions are supported with data from whole colonies for a diversity of species, with much of the variation in colony-level life history explained based on physiological traits of individual ants. The theory and data presented here provide a first step towards a more general theory of colony life history that applies across species and environments.

scholarly journals Entomopathogenic Rickia wasmannii fungal infection generated colony-level stress effects cause size decline in Myrmica ants

2021 ◽  
Author(s):  
Sándor Csősz ◽  
Zoltán Rádai ◽  
András Tartally ◽  
Lilla Erika Ballai ◽  
Ferenc Báthori
Keyword(s):  
Body Size ◽  
Negative Effects ◽  
Infection Level ◽  
Stress Effects ◽  
Myrmica Ants ◽  
Body Sizes ◽  
Myrmica Scabrinodis ◽  
Rickia Wasmannii ◽  
Colony Level

Abstract Parasitism-generated negative effects on ant societies are multifaceted, implying individual and colony-level responses. Though laboratory based evidence shows that the sublethal fungus Rickia wasmannii is responsible for physiological and behavioral responses that may negatively affect individual workers’ resilience and life expectancy in Myrmica ant workers, colony-level stress response to this parasite is largely unknown. Here, we focus on understanding of a long-term, colony-level effect of Rickia infection on Myrmica scabrinodis ant populations by tracking trait size-based changes. We collected worker specimens from infected and uninfected colonies from the same population in order to: (i) compare body size in response to parasitism, (ii) assess the extent to which possible changes in size are associated with the severity of infection, and (iii) investigate shifts in body size in response to infection over time by testing correlation of workers’ ages and sizes. We found that workers from infected colonies were significantly smaller than their healthy congeners, but neither infection level nor the age of the workers showed significant correlation with the size in infected colonies. Decreasing body sizes in infected colonies can be ascribed to workers’ mediated stress toward developing larvae, which are unable to attain the average body size before they pupate.

scholarly journals Is diversity in worker body size important for the performance of bumble bee colonies?

2020 ◽  
Author(s):  
Jacob G. Holland ◽  
Shinnosuke Nakayama ◽  
Maurizio Porfiri ◽  
Oded Nov ◽  
Guy Bloch
Keyword(s):  
Body Size ◽  
Bombus Terrestris ◽  
Bumble Bee ◽  
Insect Societies ◽  
Physiological Adaptations ◽  
Comparable Performance ◽  
Colony Performance ◽  
Size Diversity ◽  
Individual Effort ◽  
Bee Colonies

ABSTRACTSpecialization and plasticity are important for many forms of collective behavior, but the interplay between these factors is little understood. In insect societies, workers are often predisposed to specialize in different tasks, sometimes with morphological or physiological adaptations, facilitating a division of labor. Workers may also plastically switch between tasks or vary their effort. The degree to which predisposed specialization limits plasticity is not clear and has not been systematically tested in ecologically relevant contexts. We addressed this question in 20 freely-foraging bumble bee (Bombus terrestris) colonies by continually manipulating colonies to contain either a typically diverse or reduced (“homogeneous”) worker body size distribution, over two trials. Pooling both trials, diverse colonies did better in several indices of colony performance. The importance of body size was further demonstrated by the finding that foragers were larger than nurses even in homogeneous colonies with a very narrow body size range. However, the overall effect of size diversity stemmed mostly from one trial. In the other trial, homogeneous and diverse colonies showed comparable performance. By comparing behavioral profiles based on several thousand observations, we found evidence that workers in homogeneous colonies in this trial rescued colony performance by plastically increasing behavioral specialization and/or individual effort, compared to same-sized individuals in diverse colonies. Our results are consistent with a benefit to colonies of predisposed (size-diverse) specialists under certain conditions, but also suggest that plasticity or effort, can compensate for reduced (size-related) specialization. Thus, we suggest that an intricate interplay between specialization and plasticity is functionally adaptive in bumble bee colonies.

scholarly journals Body Size and Behaviour Traits of Dogs in Czech Households

2009 ◽  
Vol 78 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Eva Baranyiová ◽  
Antonín Holub ◽  
Mojmír Tyrlík
Keyword(s):  
Body Size ◽  
Body Mass ◽  
The Body ◽  
Medium Size ◽  
Rural Environments ◽  
Size Groups ◽  
Working Dogs ◽  
Average Body Mass ◽  
Household Members ◽  
Giant Size

The objective of this study was to analyse the effect of body size of dogs on their coexistence with humans in Czech households. For this purpose we used questionnaire data on 246 dogs indicating the breed. The dogs were divided into five body size groups, i.e. toy (T, up to 5 kg body mass, n = 32), small (S, 5 - 10 kg body mass, n = 52), medium size (M, 10 - 17 kg body mass, n = 39), large (L, 17 - 33 kg body mass, n = 70), giant (G, over 33 kg body mass, n = 53). The largest dogs surpassed the body mass of the smallest dogs at least seven times, and giant dogs weighed at least one half and toy dogs less than one tenth of the average body mass of people in the Czech human population. Despite this the majority of the studied traits regardless of body mass of the dogs showed no significant differences. In the vast majority of Czech households all dogs were considered household members, taken on travels or vacations, photographed and their birthdays were celebrated. Aggressiveness of the dogs did not correlate with their body size. Among the 84 traits of the behaviour of dogs and their owners, which were analysed, only 23, i.e. 27.4% traits were significantly related to their body mass. Larger and heavier dogs were more frequently kept in houses with yards and gardens, in rural environments. Toy and small dogs prevailed in urbanised environments, in apartments. They were allowed to use furniture, sleep in beds of household members. Moreover, toy dogs predominated in one-person households. Large dogs were more often trained, sometimes by professional trainers, obeyed commands better and were more often described as obedient. They were considered not only as companions but also as working dogs. Giant size dogs were also more often trained to be protective. These data show that the differences in the body size of dogs modified their co-existence with humans only to a limited extent.

scholarly journals Strength surpasses relatedness–queen larva selection in honeybees

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255151
Author(s):  
Saad Naser AL-Kahtani ◽  
Kaspar Bienefeld
Keyword(s):  
Apis Mellifera ◽  
Reproductive Success ◽  
Eusocial Insect ◽  
Preoviposition Period ◽  
Queen Rearing ◽  
Insect Societies ◽  
Selection Of ◽  
Colony Level

Nepotism was initially theoretically predicted and sometimes found to trigger the selection of specific larvae to be reared as queens in the honeybee Apis mellifera. Although the importance of selecting the next queen for a colony indicates that it should not occur at random, nepotism is increasingly considered unlikely in eusocial insect societies. Different prenatal maternal supplies of embryos have been found to impact fitness in many other species and therefore could be a possible trigger underlying the likelihood of being raised as a queen. We offered related or unrelated larvae from six colonies originating from eggs of different weights for emergency queen rearing in queenless units with worker bees from these six colonies. We showed that nurses did not significantly prefer related larvae during queen rearing, which confirms the theory that different relatedness-driven kin preferences within a colony cannot be converted into a colony-level decision. However, we found that larvae originating from heavier eggs were significantly preferred for queen breeding. Studies on other species have shown that superior maternal supply is important for later reproductive success. However, we did observe tendencies in the expected direction (e.g., queens that hatched from heavier eggs had both more ovarioles and a shorter preoviposition period). Nevertheless, our data do not allow for a significant conclusion that the selection of larvae from heavy eggs truly offers fitness advantages.

The influence of size on the trophic interactions between juveniles of two syntopic Trachinotus species

2020 ◽  
Vol 100 (4) ◽  
pp. 595-605
Author(s):  
Joice Silva de Souza ◽  
Luciano Neves dos Santos
Keyword(s):  
Body Size ◽  
Trophic Interactions ◽  
Null Model ◽  
Sandy Beaches ◽  
Medium Size ◽  
Size Difference ◽  
Trophic Resources ◽  
Eastern Brazil ◽  
Size Groups ◽  
Food Partitioning

AbstractSyntopic species with similar anatomic configuration may face strong competition for trophic resources, thus relying on developed mechanisms to ensure coexistence. The present study investigated the influence of body size on trophic interactions between juveniles of two closely related fish species at three sandy beaches in south-eastern Brazil. A total of 150 fish were sampled, where 103 were identified as Trachinotus carolinus (mean ± SE: weight = 9 g ± 1.13) and 47 as Trachinotus goodei (weight = 46.7 g ± 3.34). A significant size-difference between juvenile Trachinotus was detected by a null-model analysis (P = 0.04), with T. carolinus (TL = 79.6 mm ± 2.4) presenting a smaller body size than T. goodei (TL = 147.7 mm ± 4.2). The main prey items consumed by T. carolinus were Perna perna (IAi = 0.76) and Emerita brasiliensis (IAi = 0.18), whereas the latter was the major T. goodei dietary prey (IAi = 0.71). Both prey were correlated with larger-sized juveniles of each pompano species, whereas smaller fish shared non-preferred trophic items. Such opportunistic behaviour of smaller juveniles may account for the dietary overlap detected between the Trachinotus species (P = 0.09). Size-related dietary partitioning was observed for the largest T. goodei juveniles, which displayed only a slight overlap with T. carolinus, and between juveniles belonging to the small and medium size groups of each pompano species. Therefore, food partitioning related to pompano body size seems to be especially important for the smallest juveniles, as they present the highest vacuity (particularly T. carolinus) in the sampled beaches, suggesting that these individuals are under intra- and interspecific competitive pressure, which may affect local coexistence.

scholarly journals Nest architecture shapes the collective behaviour of harvester ants

2015 ◽  
Vol 11 (10) ◽  
pp. 20150695 ◽  
Author(s):  
Noa Pinter-Wollman
Keyword(s):  
Network Analysis ◽  
Social Interactions ◽  
Spatial Organization ◽  
Collective Behaviour ◽  
Nest Architecture ◽  
Harvester Ants ◽  
Spatial Constraints ◽  
Ant Colonies ◽  
Harvester Ant

Structures influence how individuals interact and, therefore, shape the collective behaviours that emerge from these interactions. Here I show that the structure of a nest influences the collective behaviour of harvester ant colonies. Using network analysis, I quantify nest architecture and find that as chamber connectivity and redundancy of connections among chambers increase, so does a colony's speed of recruitment to food. Interestingly, the volume of the chambers did not influence speed of recruitment, suggesting that the spatial organization of a nest has a greater impact on collective behaviour than the number of workers it can hold. Thus, by changing spatial constraints on social interactions organisms can modify their behaviour and impact their fitness.

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