scholarly journals Extreme fertilization bias towards freshly inseminated sperm in a species exhibiting prolonged female sperm storage

2018 ◽  
Vol 5 (3) ◽  
pp. 172195 ◽  
Author(s):  
Clelia Gasparini ◽  
Emma Daymond ◽  
Jonathan P. Evans
Keyword(s):  
Artificial Insemination ◽  
Poecilia Reticulata ◽  
Sperm Storage ◽  
Sperm Precedence ◽  
Control Potential ◽  
Complete Dominance ◽  
Poeciliid Fish ◽  
Behavioural Interactions ◽  
Males And Females ◽  
Reproductive Cycles

The storage of sperm by females across successive reproductive cycles is well documented in internal fertilizers, yet the fate of stored sperm when they compete with ‘new’ sperm to fertilize a female's eggs has rarely been considered. This gap in our understanding is likely due to the logistical difficulties of controlling behavioural interactions during or after mating, which in turn may influence how many sperm are inseminated and how stored sperm are ultimately used during successive bouts of sperm competition with freshly inseminated sperm. Here, we use artificial insemination (AI) in guppies ( Poecilia reticulata ), a polyandrous live-bearing poeciliid fish exhibiting prolonged sperm storage by females, to overcome these challenges. The use of AI enables us to control potential differential maternal effects (e.g. behaviourally mediated cryptic female choice) and specifically test for post-copulatory paternity biases that favour either stored or fresh sperm when they compete to fertilize eggs. Our paternity analyses revealed the almost complete dominance of freshly inseminated sperm over stored sperm, supporting previous studies reporting similar patterns following natural matings across successive brood cycles. However, our use of AI, which excluded behavioural interactions between males and females, most likely generated a far stronger pattern of fresh sperm precedence compared with those reported in previous studies, possibly implicating ‘cryptic' forms of selection by females that may sometimes bolster the success of stored sperm.

The Effects of the sphragis on male and female genitalia in Acraea (Nymphalidae) butterflies

2020 ◽  
Vol 22 ◽  
Author(s):  
Shannon L Summers ◽  
Akito Y Kawahara ◽  
Ana P. S. Carvalho
Keyword(s):  
Interspecific Variation ◽  
Sperm Storage ◽  
Male Mating ◽  
Museum Collections ◽  
Storage Organ ◽  
Mating Plug ◽  
Males And Females ◽  
Comparison And Analysis ◽  
Imagej Software ◽  
Sexually Antagonistic Coevolution

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.

scholarly journals Implications of multiple mating for offspring relatedness and shoaling behaviour in juvenile guppies

2008 ◽  
Vol 4 (6) ◽  
pp. 623-626 ◽  
Author(s):  
Jonathan P Evans ◽  
Jennifer L Kelley
Keyword(s):  
Social Interactions ◽  
Artificial Insemination ◽  
Social Behaviour ◽  
Poecilia Reticulata ◽  
Multiple Mating ◽  
Potential Cost ◽  
Close Proximity ◽  
Shoaling Behaviour

Polyandry (female multiple mating) can confer important benefits to females, but few studies have considered its potential costs. One such cost may arise through differences in the relatedness of offspring born to females with different mating histories; offspring born to monandrous females are always full siblings, while those produced by polyandrous females may be full or half siblings. These differences may have important consequences for social interactions among offspring. We used artificial insemination in the guppy ( Poecilia reticulata ), a promiscuous live-bearing fish, to evaluate shoaling behaviour in polyandrous and monandrous broods. We combined this information with known parentage data for the polyandrous broods to determine whether sibling relatedness influenced offspring shoaling behaviour. While we detected no effect of mating treatment (polyandry/monandry) on shoaling behaviour, we found that pairs of full siblings spent significantly more time shoaling (and in close proximity) than pairs of half siblings. This latter finding confirms the ability of newborn guppies to distinguish brood mates on the basis of kinship, but also suggests an important and hitherto unrealized potential cost of polyandry: a reduction in within-brood relatedness with potentially important implications for offspring social behaviour.

scholarly journals Intraspecific ecomorphological variations in Poecilia reticulata (Actinopterygii, Cyprinodontiformes): comparing populations of distinct environments

2015 ◽  
Vol 105 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Fábio T. Mise ◽  
Fagner de Souza ◽  
João P. A. Pagotto ◽  
Erivelto Goulart
Keyword(s):  
Poecilia Reticulata ◽  
Principal Component ◽  
Water Current ◽  
Way Of Life ◽  
Morphological Variations ◽  
Current Availability ◽  
Environment Type ◽  
Morphological Variables ◽  
Males And Females ◽  
Morphological Differences

ABSTRACT Morphological variations, according to the principles of ecomorphology, can be related to different aspects of the organism way of life, such as occupation of habitats and feeding behavior. The present study sought to examine the intraspecific variation in two populations of Poecilia reticulata Peters, 1859, that occur in two types of environments, a lotic (Maringá Stream) and a lentic (Jaboti Lake). Due to a marked sexual dimorphism, males and females were analyzed separately. Thus, the proposed hypotheses were that the populations that occur in distinct environments present morphological differences. The morphological variables were obtained using morphometric measurements and the ecomorphological indexes. The data were summarized in a Principal Component Analysis (PCA). A Multivariate Analysis of Variance (Manova) was made to verify significant differences in morphology between the populations. Males and females showed similar ecomorphological patterns according to the environment they occur. In general the population from Maringá Stream had fins with major areas, and the Jaboti Lake population eyes located more dorsally. Additionally, others morphological differences such as wider mouth of the males from Maringá Stream, wider heads on Jaboti Lake females and more protractible mouths on males from Jaboti Lake suggest a set of environmental variables that can possibly influence the ecomorphological patterns of the populations, as the water current, availability of food resources and predation. In summary, the initial hypotheses could be confirmed, evidencing the occurrence of distinct ecomorphotypes in the same species according to the environment type.

Reproductive biology of the false coral snake Oxyrhopus guibei (Colubridae) from southeastern Brazil

2002 ◽  
Vol 23 (4) ◽  
pp. 495-504 ◽  
Author(s):  
Otavio Marques ◽  
Lígia Pizzatto
Keyword(s):  
Body Size ◽  
Reproductive Biology ◽  
Rainy Season ◽  
Reproductive Activity ◽  
Climatic Conditions ◽  
Southeastern Brazil ◽  
Coral Snake ◽  
Males And Females ◽  
Reproductive Cycles ◽  
Number Of Individuals

AbstractThe reproductive biology of the false coral snake, Oxyrhopus guibei, was studied through dissection of 496 specimens, combined with observations on captive individuals. Males mature with smaller body size than females, females attain much larger body size, and male-male combat is not expected. Clutch size ranged from 3 to 20, and was correlated with female length. Reproductive cycles in both males and females seem to be continuous, with vitellogenesis and spermatogenesis occurring throughout the year. Reproductive activity in both sexes decreased at the end of the rainy season possibly due to previous intense reproductive activity in more favorable climatic conditions. The smaller number of individuals collected at the end of the rainy season apparently occurs due to the decrease of reproductive activity of this snake.

The reproductive cycles of the sunflower beetle, Zygogramma exclamationis (Coleoptera: Chrysomelidae), in Manitoba

1979 ◽  
Vol 57 (10) ◽  
pp. 1934-1943 ◽  
Author(s):  
G. H. Gerber ◽  
G. B. Neill ◽  
P. H. Westdal
Keyword(s):  
Average Length ◽  
Oocyte Development ◽  
Oviposition Period ◽  
Laboratory Studies ◽  
Total Length ◽  
Males And Females ◽  
Reproductive Cycles ◽  
New Generation

Field and laboratory studies showed that Zygogramma exclamationis (F.) has only one generation per year in Manitoba. New generation adults emerge in August, but do not copulate or develop any eggs before entering the soil to hibernate. They reemerge the following May. Vitellogenesis is initiated either before or shortly after emergence. The first mature oocytes appear 2–4 days after emergence. Oviposition is initiated soon after the first eggs are developed, usually within 1 week of emergence. Copulation is initiated by both males and females within 2 days of emergence and both mate many times during their life. Females lay almost every day during the oviposition period. In the laboratory in 1974, the average number of eggs per female was 1968 (range, 260–3587). In experiments out-of-doors in 1976 and 1977, the females laid 968 (range, 657–1400) and 636 (range, 132–1554) eggs per female, respectively. In these three studies, the average length of the oviposition period ranged between 42.5 days in 1977 and 60.7 days in 1974. In the field in 1975–1977, eggs were found from mid-May to mid-July and the total length of the oviposition period was estimated to be 6–7 weeks. The females normally die a few days after oviposition is completed. A system for classifying the stages of oocyte development is described.

Patterns of sperm use in two populations of Red-sided Garter Snake (Thamnophis sirtalis parietalis) with long-term female sperm storage

2014 ◽  
Vol 92 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Christopher R. Friesen ◽  
Robert T. Mason ◽  
Stevan J. Arnold ◽  
Suzanne Estes
Keyword(s):  
Multiple Paternity ◽  
Sperm Storage ◽  
Female Reproductive Tract ◽  
High Rate ◽  
Order Effects ◽  
Thamnophis Sirtalis ◽  
Sperm Precedence ◽  
Experimental Population ◽  
Thamnophis Sirtalis Parietalis

Long-term sperm storage may contribute to postcopulatory sexual selection because it enhances the commingling of sperm from different males within the female reproductive tract, which is the prerequisite for sperm competition. Long-term sperm storage and multiple paternity has been documented in snakes, but the identity of the last potential father is usually unknown in studies demonstrating multiple paternity. Here we present the first study in Red-sided Garter Snakes (Thamnophis sirtalis parietalis (Say in James, 1832)) to use experimental population crosses to assess stored sperm usage, mate-order effects, and the potential for interpopulational gametic isolation. We found a high rate of multiple paternity indicative of ubiquitous long-term sperm storage in this system, and observed last-male sperm precedence in all families (n = 66). Postzygotic isolation was absent, and we observed only a weak asymmetry in pattern of sperm precedence in our population crosses.

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