Female preference for multiple partners: sperm competition in the hide beetle, Dermestes maculatus (DeGeer)

1999 ◽  
Vol 58 (3) ◽  
pp. 669-675 ◽  
Author(s):  
Melanie S. Archer ◽  
Mark A. Elgar
Keyword(s):  
Sperm Competition ◽  
Female Preference ◽  
Dermestes Maculatus ◽  
Multiple Partners

scholarly journals Selection on sperm morphology under relaxed sperm competition in a wild passerine bird

2008 ◽  
Vol 5 (1) ◽  
pp. 58-61 ◽  
Author(s):  
Sara Calhim ◽  
Helene M Lampe ◽  
Tore Slagsvold ◽  
Tim R Birkhead
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Sperm Morphology ◽  
Reproductive Traits ◽  
Female Preference ◽  
Passerine Bird ◽  
High Heritability ◽  
Individual Consistency ◽  
Sperm Size

Theories regarding the role of sexual selection on the evolution of sperm traits are based on an association between pre-copulatory (e.g. female preference) and post-copulatory (e.g. ejaculate quality) male reproductive traits. In tests of these hypotheses, sperm morphology has rarely been used, despite its high heritability and intra-individual consistency. We found evidence of selection for longer sperm through positive phenotypic associations between sperm size and the two major female preference traits in the pied flycatcher, Ficedula hypoleuca . Our results support the sexually selected sperm hypothesis in a species under low sperm competition and demonstrate that natural and pre-copulatory sexual selection forces should not be overlooked in studies of intraspecific sperm morphology evolution.

Multiple mating by females is not dependent on body size in the salamander Desmognathus ochrophaeus

1996 ◽  
Vol 17 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Cara Shillington ◽  
Paul Verrell
Keyword(s):  
Mate Choice ◽  
Sperm Competition ◽  
Multiple Mating ◽  
Natural Populations ◽  
Mating Frequency ◽  
Published Data ◽  
Multiple Partners ◽  
Plethodontid Salamander ◽  
The Face ◽  
Desmognathus Ochrophaeus

AbstractMale mate choice for particular "classes" of females may be devalued if chosen females are more likely to mate with multiple partners (thus precipitating sperm competition). Larger females carry greater numbers of eggs available for fertilization in the plethodontid salamander Desmognathus ochrophaeus, and are chosen by males in simultaneous mate-choice tests. We found no difference in mating frequency between 12 large females and 12 smaller females across 576 male-female encounters. Given limited published data on patterns of sperm utilization in this salamander, we conclude that male choice of more fecund partners may be advantageous even in the face of multiple mating by females and resultant sperm competition. Studies of natural populations of salamanders are required to confirm this conclusion.

PHYTOCHEMICAL SCREENING AND LARVICIDAL EFFECT EVALUATION OF AZADIRACHTA INDICA (L) LEAF EXTRACT ON DERMESTES MACULATUS (DE GEER, 1774) INFESTATION OF SMOKED CLARIAS GARIEPINUS (BURCHELL, 1822)

2020 ◽  
Vol 4 (2) ◽  
pp. 41-45
Author(s):  
Sadam Sulaiman Indabo ◽  
Rufai Zakari
Keyword(s):  
Azadirachta Indica ◽  
Leaf Extract ◽  
Standard Procedure ◽  
Clarias Gariepinus ◽  
Phytochemical Screening ◽  
Range Finding ◽  
Dermestes Maculatus ◽  
Randomized Design ◽  
Fish Samples ◽  
Initial Source

Dermestes maculatus is a major pest of stored fish in Nigeria, fish is preserved with highly persistent synthetic chemicals. There have been an increasing effort at developing plant-based toxicants that are environmentally friendly. Therefore, this study was conducted to screen the leaf extract of Azadirachta indica for phytochemical constituents. The efficacy of the methanolic leaf extract of the plant against D. maculatus was also evaluated. The leaves of A. indica were obtained, processed and taken to laboratory for methanolic extraction. Phytochemical screening was carried out to identify saponins, flavonoids, alkaloids, tannins, steroids, cardiac glycosides, glycosides, triterpenes and carbohydrates using standard procedure.  Both clean and infested samples of smoke-dried Clarias gariepinus were purchased from Sabon Gari Market, Zaria. The infested samples were used as initial source of D. maculatus larvae. Range finding test was carried out prior to the bioassay. During the bioassay, clean un-infested fish samples were weighed and introduced into kilner jars and respective dosages of 0.2g, 0.4g, 0.6g and 0.8g of extract were added. Another set of fish samples without the extract were maintained as control. The experiment was arranged in Completely Randomized Design with three replicates. Fifteen larvae of D. maculatus were introduced into both treated and control containers and covered. Mortality was recorded after 24, 48, 72 and 96 hours. Data obtained revealed an increase in mortality with increasing dose and time. Mortality ranged from 1.67 to 11.00. Therefore, leaf extract of A. indica should be incorporated in the development of larvicide against D. maculatus.   

Development and validity evidence of the Spanish-speaking scale of sexual sensation seeking.

2019 ◽  
Author(s):  
Patricio Mena-Chamorro ◽  
Rodrigo Ferrer
Keyword(s):  
Sexual Activity ◽  
Undergraduate Students ◽  
Sensation Seeking ◽  
Two Dimensions ◽  
Personality Factor ◽  
Validity Evidence ◽  
Measurement Instruments ◽  
Multiple Partners ◽  
Time Space ◽  
Sexual Sensation Seeking

Background: STIs, principally HIV/AIDS, are public health problems that are transmitted by sexual risk behaviours, which have been associated with the sexual sensation seeking (an specific personality factor). In South American context, there are no measurement instruments with psychometric evidence for their use and, in other contexts, only the Sexual sensation seeking scale (Kalichman et al., 1994) is available, which is outdated in content and validity evidence. The purpose of this work is development a scale, in accordance with contemporary psychometric standards, to assess sexual sensation seeking for South Americans young people and adults. Method: instrumental study, with time-space sampling (n=813) of undergraduate students from the two Chilean cities with the highest rates of HIV. Results: Final scale have 8 items to assess two dimensions: 1) sexual emotions seeking; and 2) tendency to sexual boredom. The identified structure provides adequate levels of reliability (ω> .8; α> .7), presents validity evidence, based on the internal structure of the test, using CFA and ESEM (CFI> .95, TLI> .95, RMSEA <. 06), and based on the convergence with other measures (sexual activity with multiple partners, inadequate or insufficient use of protective barriers and sexual activity under the influence of alcohol or drugs). Conclusions: The Multidimensional Scale of Sexual Sensation Seeking evidence adequate psychometric properties to evaluate the search for sexual sensations in equivalents samples.

Female Preference and Variability Among t-Haplotypes in Wild House Mice

1994 ◽  
Vol 143 (5) ◽  
pp. 766-784 ◽  
Author(s):  
Sarah Lenington ◽  
Carol B. Coopersmith ◽  
Mark Erhart
Keyword(s):  
Female Preference ◽  
House Mice ◽  
Wild House Mice

scholarly journals Rats show direct reciprocity when interacting with multiple partners

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nina Kettler ◽  
Manon K. Schweinfurth ◽  
Michael Taborsky
Keyword(s):  
Time Delay ◽  
Decision Rule ◽  
Prisoner's Dilemma ◽  
Decision Rules ◽  
Prisoner’S Dilemma ◽  
Cognitive Demands ◽  
Multiple Partners ◽  
Norway Rats

AbstractDirect reciprocity, where individuals apply the decision rule ‘help someone who has helped you’, is believed to be rare in non-human animals due to its high cognitive demands. Especially if previous encounters with several partners need to be correctly remembered, animals might either stop reciprocating favours previously received from an individual, or switch to the simpler generalized reciprocity mechanism. Here we tested the decision rules Norway rats apply when interacting with multiple partners before being able to return received help. In a sequential prisoner’s dilemma situation, focal subjects encountered four different partners that were either helpful or not, on four consecutive days. On the fifth day, the focal subject was paired with one of the previous four partners and given the opportunity to provide it with food. The focal rats returned received help by closely matching the quantity of help their partner had previously provided, independently of the time delay between received and given help, and independently of the ultimate interaction preceding the test. This shows that direct reciprocity is not limited to dyadic situations in Norway rats, suggesting that cognitive demands involved in applying the required decision rules can be met by non-human animals even when they interact with multiple partners differing in helping propensity.

scholarly journals Sperm Competition in the Absence of Fertilization in Caenorhabditis elegans

Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Andrew Singson ◽  
Katherine L Hill ◽  
Steven W L’Hernault
Keyword(s):  
Caenorhabditis Elegans ◽  
Sperm Competition ◽  
Sperm Function ◽  
Sperm Precedence ◽  
Wild Type ◽  
Nematode Caenorhabditis Elegans ◽  
C Elegans ◽  
Normal Sperm ◽  
Self Fertilization ◽  
Competition Assays

Abstract Hermaphrodite self-fertilization is the primary mode of reproduction in the nematode Caenorhabditis elegans. However, when a hermaphrodite is crossed with a male, nearly all of the oocytes are fertilized by male-derived sperm. This sperm precedence during reproduction is due to the competitive superiority of male-derived sperm and results in a functional suppression of hermaphrodite self-fertility. In this study, mutant males that inseminate fertilization-defective sperm were used to reveal that sperm competition within a hermaphrodite does not require successful fertilization. However, sperm competition does require normal sperm motility. Additionally, sperm competition is not an absolute process because oocytes not fertilized by male-derived sperm can sometimes be fertilized by hermaphrodite-derived sperm. These results indicate that outcrossed progeny result from a wild-type cross because male-derived sperm are competitively superior and hermaphrodite-derived sperm become unavailable to oocytes. The sperm competition assays described in this study will be useful in further classifying the large number of currently identified mutations that alter sperm function and development in C. elegans.

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