Article
Behavioral Sciences
Charel Reuland, Brett M. Culbert, Erika Fernlund Isaksson, Ariel F. Kahrl, Alessandro Devigili, John L. Fitzpatrick
Summary: The study reveals a positive relationship between social status and ejaculate quality in the pygmy halfbeak fish, with dominant males producing higher quality ejaculates under conditions of frequent male-male interactions. Additionally, dominant males are in better physical condition, growing faster and possessing larger livers, suggesting a possible condition dependence of competitive traits. Female presence or absence did not affect sperm swimming speed or testes mass, highlighting the importance of male-male behavioral interactions in driving social-status-dependent differences in ejaculate traits.
BEHAVIORAL ECOLOGY
(2021)
Article
Biology
Xin Tong, Peng-Yang Wang, Mei-Zhuo Jia, Randy Thornhill, Bao-Zhen Hua
Summary: The study found that traumatic mating in scorpionflies can negatively impact female fecundity, but helps males gain an advantage in mating, potentially for increased success in sperm competition.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2021)
Article
Multidisciplinary Sciences
Sanne van Gammeren, Michael Lang, Martin Rucklin, Menno Schilthuizen
Summary: This study investigated the association between asymmetric male genital morphology and sperm allocation in the fruit fly Drosophila pachea. The results showed no evidence of asymmetric sperm deposition related to genital asymmetry. It suggests that the asymmetry may have evolved to optimize low sperm transfer rates during copulation.
Article
Ecology
Lauri Myllymaa, Jussi Lehtonen
Summary: Kin selection and gamete interactions are two major research themes in evolutionary biology. There is a natural connection between the two as gametes often originate from the same parent. This article discusses the relation between kin selection and gamete competition, limitation, local competition, and sex allocation.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Physiology
Takahiro Sato, Toshie Sugiyama, Tsuneo Sekijima
Summary: Hibernating bats with delayed fertilization have extended time-window for sperm competition, and males show adaptations for sperm competition by storing motile spermatozoa during hibernation and attempting to mate with torpid females. Forced copulations increase male's chances of obtaining a mate while avoiding pre-copulatory female choice, but it is maladaptive for females because they cannot choose higher-quality males while in torpor.
FRONTIERS IN PHYSIOLOGY
(2023)
Article
Ecology
Clarissa M. House, Zenobia Lewis, Manmohan D. Sharma, David J. Hodgson, John Hunt, Nina Wedell, David J. Hosken
Summary: Research on Drosophila simulans found that male genitalia are subject to multivariate selection during both noncompetitive mating and sperm competition, with the strongest selection observed during noncompetitive mating and the weakest during sperm offense. However, the direction of selection remains consistent across different scenarios, with no evidence of antagonistic selection. Overall, despite rapid evolution, sexual selection on genital traits in this species is not particularly strong.
Article
Ecology
Sara E. E. Lipshutz, Samuel J. J. Torneo, Kimberly A. A. Rosvall
Summary: Sexual selection drives trait variation, and male competition for mating opportunities is linked to sperm size. The influence of female-female competition and male-male competition on sperm morphology is not well understood. We examined two species with socially polyandrous mating systems, finding that the species with greater polyandry had longer midpieces and tails in their sperm, as well as lower intraejaculate variation in tail length. These results suggest that female-female competition may shape male-male competition by selecting for longer and less variable sperm traits.
AMERICAN NATURALIST
(2023)
Article
Cell Biology
Melissah Rowe, Annabel Van Oort, Lyanne Brouwer, Jan T. Lifjeld, Michael S. Webster, Joseph F. Welklin, Daniel T. Baldassarre
Summary: This study found that sperm quantity (indicated by cloacal protuberance volume) was associated with reproductive success in male red-backed fairy-wrens, while sperm morphology was not. This suggests that males use a large number of sperm as a defensive strategy to protect within-pair paternity success in a system with high risk of sperm competition and female control of copulation.
Article
Cell Biology
Geoff A. Parker
Summary: These two papers discuss sperm competition, sexual selection, and the origin and evolution of gamete dimorphism, revealing the importance of sexual selection in biological evolution and influencing our understanding of sexual strategy differences between the sexes and gametic cells.
Article
Multidisciplinary Sciences
M. A. Izquierdo, T. M. Dederichs, F. Cargnelutti, P. Michalik
Summary: Through behavioral and morphological studies, we found that the male reproductive organ (procursus) of Gertschiola neuquena, a species belonging to an early branched and understudied spider subfamily, interacts with the female reproductive organ during copulation. Micro-CT analysis of mating pairs revealed that the long and filiform procursus is inserted deeply into the female spermatheca, while the intromittent sclerite (embolus) only reaches the most distal part of the female sperm storage organ. Histological data showed that sperm are present in the proximal part of the spermatheca. This is the first case in spiders where the sperm allocation function of the intromittent sclerite is replaced by another structure.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Genetics & Heredity
Dawn S. Chen, Andrew G. Clark, Mariana F. Wolfner
Summary: In a study on Drosophila, researchers found that inhibiting the activity of Tdc2 neurons in females resulted in a higher proportion of offspring from the first male. This suggests that octopaminergic/tyraminergic signaling plays a role in biased sperm usage in multiply-mated females, and highlights a new role for the female nervous system in postcopulatory sexual selection.
Article
Behavioral Sciences
Marco Demont, Paul Ward, Wolf U. Blanckenhorn, Stefan Luepold, Oliver Y. Martin, Luc F. Bussiere
Summary: The study revealed a skew in sperm storage across female spermathecae, with the quantity of second-male sperm stored generally decreasing with increasing spermathecal size. Factors such as copula duration and timing of oviposition also influenced the proportion of sperm stored by the second male. Interestingly, there was a strong correlation between the proportion of second-male stored sperm and paternity success, highlighting the significance of sperm competition in postcopulatory sexual selection.
BEHAVIORAL ECOLOGY
(2021)
Article
Engineering, Environmental
Ilef Romdhani, Alessandra Gallo, Massimo Venditti, Mohamed Rida Abelouah, Rita Varchetta, Hana Najahi, Khouloud Boukadida, Raffaele Boni, Aicha Ait Alla, Sergio Minucci, Mohamed Banni
Summary: This study aimed to investigate the effects of environmental microplastics (EMP) on the quality and reproductive capacity of Mytilus galloprovincialis mussels. The results showed that exposure to EMP altered the oxidative status and mitochondrial membrane potential of mussel spermatozoa, reduced their motility, DNA integrity, and increased apoptosis, leading to a decline in overall viability. The presence of the prothymosin-alpha (PTMA) protein in the spermatozoa further supported its susceptibility to the effects of microplastics. These findings raise concerns about the reproductive capacity of mussels under environmental microplastic pollution and highlight potential long-term threats to population sustainability.
JOURNAL OF HAZARDOUS MATERIALS
(2024)
Article
Fisheries
Haoyu Guo, Dongxue Zhang, Liang Wang, Wentao Li, Pingguo He, Joacim Naslund, Xiumei Zhang
Summary: Sperm competition in golden cuttlefish shows a consistent pattern of last-male sperm precedence, with no detected effect of male size on offspring paternity.This study contributes to the understanding of mating systems in cephalopods and highlights the importance of proper mating schemes for resource use efficiency and genetic diversity in offspring production.
Article
Behavioral Sciences
Yuki Kondo, Masanori Kohda, Yasunori Koya, Satoshi Awata
Summary: Sperm allocation strategies in the externally fertilizing fish medaka were investigated. The study found that male medaka adjust the number of sperm released per mating according to their premating experience and cues from rival males.
Article
Zoology
Ara Monadjem, Leigh R. Richards, Jan Decher, Rainer Hutterer, Mnqobi L. Mamba, Jen Guyton, Piotr Naskrecki, Wanda Markotter, Benjamin Wipfler, Anna S. Kropff, Desire L. Dalton
Summary: Pipistrelloid bats in Africa are poorly understood due to their small size and morphological similarity. Recent molecular studies have led to the discovery of new species, complicating the taxonomy. A new Pipistrellus species has been described from West Africa, with implications for the classification of the genus. The Upper Guinea rainforest zone may be a hotspot for pipistrelloid bats and should be prioritized for conservation efforts.
ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
(2021)
Article
Zoology
Ara Monadjem, Terrence C. Demos, Desire L. Dalton, Paul W. Webala, Simon Musila, Julian C. Kerbis Peterhans, Bruce D. Patterson
Summary: Vespertilionidae is the largest family of bats, with approximately 500 described species. Uncertainties in systematic relationships among pipistrelle-like bats in Africa are highlighted due to their drab pelage and lack of obvious morphological characters. Through extensive genetic and morphological sampling, three African genera in Pipistrellini were identified and the paraphyletic nature of the genus Neoromicia was resolved by assigning species to four genera.
ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
(2021)
Article
Zoology
Mnqobi L. Mamba, Desire L. Dalton, Themb'alilahlwa A. M. Mahlaba, Anna S. Kropff, Ara Monadjem
Summary: This study surveyed 52 small mammal species in a cross-border conservation area between Liberia and Guinea, uncovering the importance of the region for small mammals and supporting the establishment of a transboundary protected area.
Article
Ecology
Machawe I. Maphalala, Ara Monadjem, Keith L. Bildstein, Ben Hoffman, Colleen Downs
Summary: This study analyzed admission records from 2015 to 2016 at a raptor rehabilitation centre in Pietermaritzburg, South Africa, and found that the reason for admission is a significant predictor of the outcome of rehabilitation. Raptors with no severe injuries had a higher success rate in rehabilitation compared to those suffering from collision injuries.
AFRICAN JOURNAL OF ECOLOGY
(2021)
Article
Ecology
Ara Monadjem, Felicity Simelane, Julie Teresa Shapiro, Bonginkosi C. Gumbi, Mnqobi L. Mamba, Muzi D. Sibiya, Sifiso M. Lukhele, Themb'alilahlwa A. M. Mahlaba
Summary: National species checklists are important for biodiversity conservation, but are often incomplete. Using species distribution models, it is possible to predict overlooked species and assess the completeness of national checklists. In Eswatini, a small African country, new bat species have continued to be recorded, suggesting that further species may still be overlooked.
EUROPEAN JOURNAL OF WILDLIFE RESEARCH
(2021)
Article
Parasitology
Sandor Hornok, Tamara Szentivanyi, Nora Takacs, Aron Botond Kovacs, Olivier Glaizot, Philippe Christe, Nicolas Fasel, Miklos Gyuranecz, Jeno Kontschan
Summary: The study reveals the close phylogenetic relationship between Latrocimicinae and Haematosiphoninae, which share important morphologic characters but not hosts. By analyzing Latrocimicinae with molecular and phylogenetic methods, the resolution of the phylogeny of Cimicidae was significantly improved. However, the phylogenetic relationships within different subfamilies infesting bats show complexity and inconsistency with the hosts' phylogeny.
PARASITES & VECTORS
(2021)
Article
Multidisciplinary Sciences
Ewa Komar, Nicolas J. Fasel, Paulina A. Szafranska, D. K. N. Dechmann, Marcin Zegarek, Ireneusz Ruczynski
Summary: The ability of animals to produce endogenous heat helps them cope with environmental changes, but comes with high energetic costs. Small endothermic mammals in temperate zones often use torpor to compensate for these energy demands, resulting in delayed reproduction. This study found that prolonged exposure to low ambient temperatures shifted energy allocation away from sexual maturation towards self-maintenance in male bats, leading to a one-month delay in sperm maturation. However, heavier bats were able to invest more in thermoregulation and mature faster. Interestingly, bats in constant high temperatures avoided deep torpor and matured faster, but had slower sperm production compared to natural conditions.
SCIENTIFIC REPORTS
(2022)
Article
Biology
Nicolas J. Fasel, Colin Vullioud, Michel Genoud
Summary: This study proposes a novel method for distinguishing torpor from euthermy in endotherms, which has been successfully applied to metabolic data of mammals. The method allows estimation of the lower critical temperature of the thermoneutral zone and assignment of measurements to different states.
Article
Ecology
Iroro Tanshi, Benneth C. Obitte, Ara Monadjem, Stephen J. Rossiter, Marina Fisher-Phelps, Tigga Kingston
Summary: This study compares bat species diversity in Nigeria, Indonesia, and Malaysia, finding comparable diversity between Nigeria and Indonesia, but greater diversity in Malaysia. The study also highlights the higher nestedness of bat assemblages in the Malay Peninsula compared to the Lower Guinean Forest.
Article
Zoology
G. Malan, E. Harris, T. Harris, A. Monadjem
Summary: This study analyzed the diet of Bat Hawks and their foraging groups based on regurgitated pellets. The results showed that the hawks primarily foraged near vegetation and preyed on clutter-edge foragers, including both birds and bats.
Article
Zoology
Alexandra Howard, Ara Monadjem, Duncan MacFadyen, Christian T. Chimimba
Summary: This study utilized a multi-method comparative approach to survey bat species in the foothills of the Drakensberg Mountain range in South Africa. By combining historical museum records and species distribution modeling, the researchers predicted species occurrence in the study area. The study compared physical capture with acoustic surveys to assess bat species assemblages. The results highlight the importance of using complementary sampling methods for a more comprehensive assessment of bat species richness in a targeted landscape.
Article
Ecology
Ara Monadjem, Kevin Healy, Thomas Guillerme, Adam Kane
Summary: This study investigates the effects of spatial processes and environmental filtering on the beta diversity of small mammals in Sub-Saharan Africa. The results show that spatial processes are primarily influenced by dispersal ability, and there are variations in beta diversity among different small mammal taxa.
JOURNAL OF BIOGEOGRAPHY
(2023)
Review
Biodiversity Conservation
Amanda L. Grunwald, Terrence C. Demos, Yvette Ngueagni, Martin N. Tchamba, Ara Monadjem, Paul W. Webala, Julian C. Kerbis Peterhans, Bruce D. Patterson, Luis A. Ruedas
Summary: The Cameroon Volcanic Line is an important area for the study of small mammals. A new species of bat was discovered in the central region of Cameroon, but its conservation status is a concern due to the threats to its habitat.
SYSTEMATICS AND BIODIVERSITY
(2023)
Letter
Ecology
Luke L. Powell, Pedro Vaz Pinto, Michael S. L. Mills, Ninda L. Baptista, Kerllen Costa, Klaas-Douwe B. Dijkstra, Amandio Luis Gomes, Patricia Guedes, Timoteo Julio, Ara Monadjem, Ana Filipa Palmeirim, Vladimir Russo, Martim Melo
NATURE ECOLOGY & EVOLUTION
(2023)
Article
Microbiology
Colette Cordonin, Yann Gomard, Ara Monadjem, M. Corrie Schoeman, Gildas Le Minter, Erwan Lagadec, Eduardo S. Gudo, Steven M. Goodman, Koussay Dellagi, Patrick Mavingui, Pablo Tortosa
Summary: Madagascar is a hotspot for endemic mammals and zoonotic pathogens. This study focused on bats and Leptospira infections to investigate whether these pathogens were acquired on the island or brought from continental Africa. The researchers found a wide diversity of Leptospira lineages in bats from Mozambique and concluded that bat colonists likely crossed the Mozambique Channel while infected with pathogenic Leptospira.