Differences in proportional claw size among left- and right-handed Atlantic sand fiddler crabs Leptuca pugilator (Bosc, 1801) (Decapoda: Brachyura: Ocypodidae)

2019 ◽  
Vol 39 (6) ◽  
pp. 720-723
Author(s):  
Benjamin E Martin
Keyword(s):  
Body Size ◽  
The Body ◽  
Sexually Dimorphic ◽  
Evolutionary Perspective ◽  
Prominent Feature ◽  
Body Proportions ◽  
Fiddler Crabs ◽  
Sexual Signal ◽  
Right Hand ◽  
Left And Right

Abstract The sexually dimorphic, enlarged major claw is a prominent feature among fiddler crabs and acts as both a sexual signal and weapon. Most often the enlarged claw occurs on the left and right sides of fiddler crabs in relatively even proportions (40–60%), but populations exhibit an extreme right handedness bias (> 90%) in a few cases. The mechanisms maintaining relatively even handedness proportions among fiddler crabs remains debatable, but from an evolutionary perspective it should be maintained through an evenness in fitness (reproduction and survival) between left- and right-handed crabs. I investigated handedness ratios and claw to body size in a Leptuca pugilator (Bosc, 1801) population on Sapelo Island, Georgia, USA. In collecting 417 adult male crabs, there was a slight right-hand bias (54%, χ 2= 2.9376, P = 0.087), which was similar to the previous study of this population 17 years prior. I nevertheless found right-handed crabs had significantly smaller claw size relative to their carapace size (P = 0.018). Overall, this study documents inequality in the body proportions between left- and right-handed L. pugilator within a population operating at a slight right hand-bias. I discuss how my study contributes to previous discussions on handedness bias in fiddler crabs as well as potential mechanisms that control its widespread handedness evenness.

scholarly journals Description of the male of fossil <i>Calomicrus eocenicus</i> Bukejs et Bezděk (Coleoptera: Chrysomelidae: Galerucinae) from Eocene Baltic amber using X-ray microtomography

Fossil Record ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Andris Bukejs ◽  
Jan Bezděk ◽  
Vitalii I. Alekseev ◽  
Kristaps Kairišs ◽  
Ryan C. McKellar
Keyword(s):  
Body Size ◽  
Body Cavity ◽  
The Body ◽  
Baltic Amber ◽  
Sexually Dimorphic ◽  
Apical Margin ◽  
Fossil Species ◽  
X Ray ◽  
Total Body ◽  
First Time

Abstract. A male representative of the extinct species Calomicrus eocenicus Bukejs et Bezděk, 2014 (Chrysomelidae: Galerucinae) is found and described for the first time from Eocene Baltic amber using X-ray microtomography. The aedeagus is well preserved within the body cavity of the specimen, and it is illustrated in detail. This fossil species exhibits distinct sexual dimorphism: the male has a smaller total body size, as well as a copula-adapted modification in abdominal ventrite 5 (apical margin deeply trilobed, with round medial fovea present); meanwhile the female is larger in body size and has a simple abdominal ventrite 5 (without fovea, non-incised and widely rounded apically). Similar sexually dimorphic characters are typical for extant members of the tribe Luperini, and this report is the first time that they are described in an Eocene species. The known sexually dimorphic characters present in Coleoptera within Eocene Baltic amber are briefly discussed.

scholarly journals Allometry and morphological trait relationship in the sexually dimorphic Chinese dobsonfly, Acanthacorydalis asiatica (Wood-Mason, 1884) (Megaloptera, Corydalidae)

ZooKeys ◽  
2019 ◽  
Vol 854 ◽  
pp. 119-129
Author(s):  
Chengquan Cao ◽  
Pei Yu ◽  
Fumio Hayashi
Keyword(s):  
Body Size ◽  
Male Genitalia ◽  
Wing Length ◽  
The Body ◽  
Sexually Dimorphic ◽  
Male Body ◽  
Male Body Size ◽  
Intermediate Size ◽  
Mandible Length ◽  
Dimorphic Species

Male insects with large weapons such as horns and elongate mandibles would be expected to invest more on such structures than other parts of the body for advantages in male to male competition for mating. In male genitalia, however, intermediate size provides a better fit for more females than small or large sizes, and such a male would leave more offspring regardless of their body size. These predictions were tested using a static allometry analysis between body size and other trait sizes. Acanthacorydalisasiatica is a large dobsonfly (Megalotera) and males have conspicuously large mandibles used as weapons. We examined the hypothesis that the male mandibles of this sexually dimorphic species are sexually selected to enlarge, whereas the male genitalia are stable to be intermediate regardless of a great variation in body size. The results, as predicted, showed positive allometry between male body size and mandible length but negative allometry between male body size and ectoproct length (a male grasping structure). Sperm are transferred through a small spermatophore attached externally to the female genital opening, so it may be evolutionarily unnecessary to develop an enlarged male genital size. In contrast, there may be a trade-off between male mandible size and wing length, because of negative allometry between body size and wing length in males but isometry between them in females.

scholarly journals The physique of Oxford undergraduates: Relationship With Weight Variation, Schooling and Habits

1954 ◽  
Vol 52 (3) ◽  
pp. 369-378 ◽  
Author(s):  
R. W. Parnell
Keyword(s):  
Body Size ◽  
Body Shape ◽  
Bone Development ◽  
The Body ◽  
Student Health ◽  
Body Proportions ◽  
American Universities ◽  
Weight Variation ◽  
American Students ◽  
University Performance

In earlier reports on the physique of Oxford undergraduates attending the pilot student health service from 1947 to 1950 emphasis was laid on body shape. Parnell (1952) pointed out the tendency for centrally placed Sheldonian somato-types, that is those with more balanced mid-range body proportions, to occur more frequently in the Oxford sample than in American universities, a tendency incidentally which advances further according to the level of university performance attained. Tanner (1952) emphasized the tendency for Oxford students to show less mesomorphy, that is muscle and bone development, than American students but he reports a comment from Sheldon himself that the distribution at Harvard resembled the Oxford distribution more closely. This approach, by the analysis of body shape, to the problem of physical characteristics accompanying academic selection is of particular interest, but in calculating the somatotype, height is deliberately ignored by being placed as the denominator of all the body proportions employed. Height, however, is an index of body size, as opposed to body shape, and has an importance of its own. This report concerns observations on Oxford undergraduates in which more attention is paid to body size, and particular attention also to variation of weight during university residence.

scholarly journals RESEARCH OF PHYSIOMETRIC INDICATORS OF FEMALE STUDENTS FROM TRAKIA UNIVERSITY

2020 ◽  
Vol 18 (Suppl.1) ◽  
pp. 695-698
Author(s):  
P. Angelova ◽  
P. Petkov
Keyword(s):  
Motor Skills ◽  
Vital Capacity ◽  
Female Students ◽  
The Body ◽  
Average Value ◽  
Right Hand ◽  
Hand Dynamometer ◽  
Left And Right ◽  
Objective Determination

Reliable data on physical fitness and determination of the functional state of the body reflect the level of physical capabilities and the level of development of motor skills. Objective: Determination of individual physiometric indicators in students. Contingent: 130 female students of Trakia University. The average value of the vital capacity in the studied students is 3, 60, and vital indicator 61,61. With the left and right hand dynamometer, mean right hand values ​​of 15,46 kg were found, and left - 12,76 kg. Force strength is set at 63,42kg. Conclusion: The relative share of students with low values ​​of the vital capacity is high, the values ​​for dynamometry force are also low; there is a disproportion between good physical development due to acceleration factors and recorded retention or deterioration of physical capacity.

Visual context differentially mediates left- and right-hand reaching movements

2009 ◽  
Author(s):  
Jos J. Adam ◽  
Susan Hoonhorst ◽  
Rick Muskens ◽  
Jay Pratt ◽  
Martin H. Fischer
Keyword(s):  
Reaching Movements ◽  
Visual Context ◽  
Right Hand ◽  
Left And Right

The Body Size of Headstarted and Wild Juvenile European Pond Turtles (Emys orbicularis)

2017 ◽  
Vol 25 (2) ◽  
pp. 161
Author(s):  
Sławomir Mitrus ◽  
Bartłomiej Najbar ◽  
Adam Kotowicz ◽  
Anna Najbar
Keyword(s):  
Body Size ◽  
The Body ◽  
Emys Orbicularis

scholarly journals First record of Pachycrocuta brevirostris (Gervais, 1850) from Ukraine on the background of the European occurrence of the species

2021 ◽  
Author(s):  
Adrian Marciszak ◽  
Yuriy Semenov ◽  
Piotr Portnicki ◽  
Tamara Derkach
Keyword(s):  
Body Size ◽  
First Record ◽  
The Body ◽  
Crocuta Crocuta ◽  
Early Pleistocene ◽  
Eastern Asia ◽  
South Eastern

AbstractCranial material ofPachycrocuta brevirostrisfrom the late Early Pleistocene site of Nogaisk is the first record of this species in Ukraine. This large hyena was a representative of the Tamanian faunal complex and a single specialised scavenger in these faunas. The revisited European records list ofP.brevirostrisdocumented the presence of this species in 101 sites, dated in the range of 3.5–0.4 Ma. This species first disappeared in Africa, survived in Europe until ca. 0.8–0.7 Ma, and its last, relict occurrence was known from south-eastern Asia. The main reason of extinction ofP.brevirostrisprobably was the competition withCrocuta crocuta. The cave hyena was smaller, but its teeth were proportionally larger to the body size, better adapted to crushing bones and slicing meat, and could also hunt united in larger groups.

scholarly journals Insect body size changes under future warming projections: a case study of Chironomidae (Insecta: Diptera)

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Rungtip Wonglersak ◽  
Phillip B. Fenberg ◽  
Peter G. Langdon ◽  
Stephen J. Brooks ◽  
Benjamin W. Price
Keyword(s):  
Body Size ◽  
Ambient Temperature ◽  
Wing Length ◽  
The Body ◽  
Mesocosm Experiments ◽  
Future Warming ◽  
Increasing Temperature ◽  
Emergence Date ◽  
Average Body

AbstractChironomids are a useful group for investigating body size responses to warming due to their high local abundance and sensitivity to environmental change. We collected specimens of six species of chironomids every 2 weeks over a 2-year period (2017–2018) from mesocosm experiments using five ponds at ambient temperature and five ponds at 4°C higher than ambient temperature. We investigated (1) wing length responses to temperature within species and between sexes using a regression analysis, (2) interspecific body size responses to test whether the body size of species influences sensitivity to warming, and (3) the correlation between emergence date and wing length. We found a significantly shorter wing length with increasing temperature in both sexes of Procladius crassinervis and Tanytarsus nemorosus, in males of Polypedilum sordens, but no significant relationship in the other three species studied. The average body size of a species affects the magnitude of the temperature-size responses in both sexes, with larger species shrinking disproportionately more with increasing temperature. There was a significant decline in wing length with emergence date across most species studied (excluding Polypedilum nubeculosum and P. sordens), indicating that individuals emerging later in the season tend to be smaller.

scholarly journals Potential host ranges of three Asian larval parasitoids of Drosophila suzukii

2021 ◽  
Author(s):  
Kent M. Daane ◽  
Xingeng Wang ◽  
Brian N. Hogg ◽  
Antonio Biondi
Keyword(s):  
Body Size ◽  
Host Species ◽  
Classical Biological Control ◽  
Developmental Time ◽  
The Body ◽  
Phylogenetic Position ◽  
Egg Load ◽  
Drosophila Suzukii ◽  
Larval Parasitoids ◽  
Female Body Size

AbstractAsobara japonica (Hymenoptera: Braconidae), Ganaspis brasiliensis and Leptopilina japonica (Hymenoptera: Figitidae) are Asian larval parasitoids of spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae). This study evaluated these parasitoids’ capacity to attack and develop from 24 non-target drosophilid species. Results showed that all three parasitoids were able to parasitize host larvae of multiple non-target species in artificial diet; A. japonica developed from 19 tested host species, regardless of the phylogenetic position of the host species, L. japonica developed from 11 tested species; and G. brasiliensis developed from only four of the exposed species. Success rate of parasitism (i.e., the probability that an adult wasp successfully emerged from a parasitized host) by the two figitid parasitoids was low in hosts other than the three species in the melanogaster group (D. melanogaster, D. simulans, and D. suzukii). The failure of the figitids to develop in most of the tested host species appears to correspond with more frequent encapsulation of the parasitoids by the hosts. The results indicate that G. brasiliensis is the most host specific to D. suzukii, L. japonica attacks mainly species in the melanogaster group and A. japonica is a generalist, at least physiologically. Overall, the developmental time of the parasitoids increased with the host’s developmental time. The body size of female A. japonica (as a model species) was positively related to host size, and mature egg load of female wasps increased with female body size. We discuss the use of these parasitoids for classical biological control of D. suzukii.

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