scholarly journals A bilateral gynandromorph of Discoelius dufourii (Hymenoptera, Vespidae, Zethinae): morphology and mating behaviour

2021 ◽  
Vol 81 ◽  
pp. 23-41
Author(s):  
Anna Budrienė ◽  
Eduardas Budrys ◽  
Svetlana Orlovskytė

A gynandromorph is an organism combining both female- and male-type tissues. While the vast majority of studies have described the morphology of gynandromorphs, their sexual behaviours remain under-explored. We studied a predominantly bilateral gynandromorph specimen of the predatory wasp Discoelius dufourii (Hymenoptera: Vespidae: Zethinae) reared from a trap-nest. In addition to describing the morphology, we explored the gynandromorph’s response to a conspecific female, comparing it with the behavioural interactions between normal males and females of D. dufourii and the phylogenetically related D. zonalis. For most specific behavioural elements, males of both Discoelius species exhibited a greater frequency and a higher probability of occurrences of the behaviour than did females. However, aggression and plopping behaviours were prevalent in females. The gynandromorphic specimen demonstrated behavioural activities similar to those of a male, including a relatively frequent mate body antennation and an attempt to mount a female. However, it approached the female less frequently in comparison to conspecific normal males, and it did not demonstrate substrate antennation and jumping, typical of Discoelius male mating behaviour. Based on the parameters of the nest cell, the probability of the development of the gynandromorphic specimen from an unfertilized (male) egg was higher than the probability of development from a fertilized (female) egg.

2020 ◽  
Vol 22 ◽  
Author(s):  
Shannon L Summers ◽  
Akito Y Kawahara ◽  
Ana P. S. Carvalho

Male mating plugs have been used in many species to prevent female re-mating and sperm competition. One of the most extreme examples of a mating plug is the sphragis, which is a large, complex and externalized plug found only in butterflies. This structure is found in many species in the genus Acraea (Nymphalidae) and provides an opportunity for investigation of the effects of the sphragis on the morphology of the genitalia, which is poorly understood. This study aims to understand morphological interspecific variation in the genitalia of Acraea butterflies. Using specimens from museum collections, abdomen dissections were conducted on 19 species of Acraea: 9 sphragis bearing and 10 non-sphragis bearing species. Genitalia imaging was performed for easier comparison and analysis and measurements of genitalia structures was done using ImageJ software. Some distinguishing morphological features in the females were found. The most obvious difference is the larger and more externalized copulatory opening in sphragis bearing species, with varying degrees of external projections. Females of the sphragis bearing species also tend to have a shorter ductus (the structure that connects the copulatory opening with the sperm storage organ) than those without the sphragis. These differences may be due to a sexually antagonistic coevolution between the males and females, where the females evolve larger and more difficult to plug copulatory openings and the males attempt to prevent re-mating with the sphragis.


1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.


2019 ◽  
Vol 70 (4) ◽  
pp. 211-216
Author(s):  
Jim Pateman ◽  
Peter Russell

Two Euphydryas aurinea beckeri females from Sierra Blanca, Malaga, Spain were captured and returned to the U.K.; each laid a single egg batch on Succisa pratensis. Both batches hatched and the resulting larvae were reared through to adulthood. One group of larvae produced butterflies with three different mutations: pupae with spines, legs lacking distal tarsals and claws, and with appendages attached to the genitalia which protruded though the rear of the abdomens in both males and females. The other group of larvae produced normal males and females.


2013 ◽  
Vol 61 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Yukie Sato ◽  
Maurice W. Sabelis ◽  
Martijn Egas ◽  
Farid Faraji

2020 ◽  
Author(s):  
Noritaka Hirohashi ◽  
Noriyosi Sato ◽  
Yoko Iwata ◽  
Satoshi Tomano ◽  
Md Nur E Alam ◽  
...  

Male animals are not given equal mating opportunities under competitive circumstances. Small males often exhibit alternative mating behaviours and produce spermatozoa of higher quality to compensate for their lower chances of winning physical contests against larger competitors [1]. Because the reproductive benefits of these phenotypes depend on social status/agonistic ranks that can change during growth or aging [2], sperm traits should be developed/switched into fitness optima according to their prospects. However, reproductive success largely relies upon social contexts arising instantaneously from intra- and inter-sexual interactions, which deter males from developing extreme traits and instead favour behavioural plasticity. Nevertheless, the extent to which such plasticity influences developmentally regulated alternative sperm traits remains unexplored. Squids of the family Loliginidae are excellent models to investigate this, because they show sophisticated alternative reproductive tactics (ARTs) by which small males, known as “sneakers”, produce longer spermatozoa and perform extra-pair copulation to attach their sperm packages near the female seminal receptacle (SR). In contrast, large “consort” males have shorter spermatozoa and copulate via pair-bonding to insert their sperm packages near the internal female oviduct [3]. In addition, plasticity in male mating behaviour is common in some species while it is either rare or absent in others. Thus, squid ARTs display a broad spectrum of adaptive traits with a complex repertoire in behaviour, morphology and physiology [3].


2021 ◽  
Vol 288 (1942) ◽  
pp. 20202679
Author(s):  
Rachna B. Reddy ◽  
Kevin E. Langergraber ◽  
Aaron A. Sandel ◽  
Linda Vigilant ◽  
John C. Mitani

Like many animals, adult male chimpanzees often compete for a limited number of mates. They fight other males as they strive for status that confers reproductive benefits and use aggression to coerce females to mate with them. Nevertheless, small-bodied, socially immature adolescent male chimpanzees, who cannot compete with older males for status nor intimidate females, father offspring. We investigated how they do so through a study of adolescent and young adult males at Ngogo in Kibale National Park, Uganda. Adolescent males mated with nulliparous females and reproduced primarily with these first-time mothers, who are not preferred as mating partners by older males. Two other factors, affiliation and aggression, also influenced mating success. Specifically, the strength of affiliative bonds that males formed with females and the amount of aggression males directed toward females predicted male mating success. The effect of male aggression toward females on mating success increased as males aged, especially when they directed it toward females with whom they shared affiliative bonds. These results mirror sexual coercion in humans, which occurs most often between males and females involved in close, affiliative relationships.


Behaviour ◽  
2015 ◽  
Vol 152 (14) ◽  
pp. 1883-1910 ◽  
Author(s):  
Peter Morse ◽  
Kyall R. Zenger ◽  
Mark I. McCormick ◽  
Mark G. Meekan ◽  
Christine L. Huffard

The southern blue-ringed octopus,Hapalochlaena maculosaHoyle (1883), is a nocturnal species that exhibits a mating system in which females hold sperm from multiple males over a one to two month breeding window before laying a single egg clutch. Contrary to most studied animal mating systems where anisogamy exists, gamete package production is limited for both males and females of this species (approx. 50 spermatophores/eggs). This presents an animal model for studying aspects of sperm competition and dynamic mate choice behaviours. The present study reports on the mating behaviour ofH. maculosaobserved under laboratory conditions using infrared closed-circuit television video footage. Rates of male copulation attempts increased with male size, while female receptivity to mating attempts increased with female size, resulting in larger animals of both sexes gaining more copulations and spending more time per day in copulation. There was some evidence of female preference of larger males, but no male preference of females based on measured morphological traits. Both sexes terminated copulations in equal frequencies but male-terminated copulations were significantly shorter in duration. Males were more likely to terminate copulation early with females they had previously mated with, however were less likely to do so if the female had recently mated with a different male. Among male-terminated copulations, males mated for longer with females that had previously mated with other males in the trial. Male–male mounts were as common as male–female mounts, suggesting that maleH. maculosaare not able to discriminate the sex of conspecifics. These findings suggest male strategic allocation of spermatophores based female mating history is an important factor influencing mating behaviours of this species.


Sign in / Sign up

Export Citation Format

Share Document