Sperm and alternative reproductive tactics: a review of existing theory and empirical data

Philosophical Transactions of the Royal Society B Biological Sciences, Год журнала: 2020, Номер 375(1813), С. 20200075 - 20200075

Опубликована: Окт. 18, 2020

Males that exhibit alternative reproductive tactics (ARTs) often differ in the risk of sperm competition and energetic trade-offs they experience. The resulting patterns selection could lead to between-tactic differences ejaculate traits. Despite extensive research on male ARTs, there is no comprehensive review whether what traits exist between ARTs. We existing theory evolution relevant ARTs then conduct a vote-counting empirical data comparing males adopting general expectation sneaker should produce are more competitive (e.g. higher quality or performance), we find does not predict explicitly how majority studies significant difference performance dominant males. However, when difference, tend have trait values than propose ways future theoretical can improve our understanding highlight studying species with will broader knowledge evolution. This article part theme issue ‘Fifty years competition’.

Язык: Английский

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Squid male alternative reproductive tactics are determined by birth date

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2024, Номер 291(2021)

Опубликована: Апрель 24, 2024

Alternative reproductive tactics (ARTs) are discontinuous phenotypes associated with reproduction, observed in males of many species. Typically, large adopt a tactic competing rivals for mating, while small stealing fertilization opportunities from the males. The ‘birth date hypothesis', proposing that birth influences determination each male's tactic, has been tested only teleost fish to date. Here, hypothesis was ARTs Japanese spear squid Heterololigo bleekeri (consort/sneaker) by analysing statolith growth increments. significantly differed between consorts (early-hatched) and sneakers (late-hatched). However, no differences were detected history up 100 days hatching. Most immature caught during season larger than sneakers, their hatch similar consorts, suggesting these had already following life-history pathway as consort. These results indicate H. determined based on early life. This study firstly suggests applies aquatic invertebrates, mechanism which determines individual phenotype is phenomenon more common previously believed.

Язык: Английский

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Tactical Tentacles: New Insights on the Processes of Sexual Selection Among the Cephalopoda

Frontiers in Physiology, Год журнала: 2019, Номер 10

Опубликована: Авг. 21, 2019

The cephalopods (Mollusca: Cephalopoda) are an exceptional class among the invertebrates, characterised by advanced development of their conditional learning abilities, long-term memories, capacity for rapid colour change and extremely adaptable hydrostatic skeletons. These traits enable to occupy diverse marine ecological niches, become successful predators, employ sophisticated predator avoidance behaviours have complex intraspecific interactions. Where studied, observations cephalopod mating systems revealed detailed insights life histories behavioural ecologies these animals. reproductive biology is typified high levels both male female promiscuity, alternative tactics, sperm storage prior spawning, intricate visual displays and/or use a distinct sensory ecology. This review summarises current understanding biology, where investigated, how pre-copulatory post-copulatory fertilisation patterns can influence processes sexual selection. Overall, it concluded that competition possibly cryptic choice likely be critical determinants which individuals' alleles get transferred subsequent generations in systems. Additionally, emphasised optimisation offspring quality bias genetically compatible males necessary drivers proliferation polyandry observed cephalopods, potential methods testing hypotheses proposed within conclusion this review. Further gaps knowledge selection operates group also highlighted, hopes prompting new directions research distinctive unique lineage.

Язык: Английский

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Dimorphic male squid show differential gonadal and ejaculate expenditure

Hydrobiologia, Год журнала: 2017, Номер 808(1), С. 5 - 22

Опубликована: Март 21, 2017

Язык: Английский

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Metformin improves boar sperm quality via 5′-AMP-activated protein kinase-mediated energy metabolism <i>in vitro</i>

动物学研究, Год журнала: 2020, Номер 41(5), С. 527 - 538

Опубликована: Янв. 1, 2020

Sperm are specialized cells that require adenosine triphosphate (ATP) to support their function. Maintaining sperm energy homeostasis in vitro is vitally important improve the efficacy of boar preservation. Metformin can activate 5′-AMP-activated protein kinase (AMPK) metabolic flexibility and maintain homeostasis. Thus, aim present study was investigate whether metformin quality through AMPK mediation metabolism. motility parameters, membrane integrity, acrosome mitochondrial potential (ΔΨ_m), ATP content, glucose uptake, lactate efflux were analyzed. Localization expression levels phospho-Thr¹⁷²-AMPK (p-AMPK) also detected by immunofluorescence western blotting. We found treatment significantly increased ΔΨ_m, content during storage at 17 °C. Moreover, results showed localized acrosomal region, connecting piece, midpiece p-AMPK distributed post-acrosomal midpiece. When incubated with for 4 h 37 °C, p-AMPK, all increased, whereas addition Compound C treatment, an inhibitor AMPK, counteracted these positive effects. Together, our suggest promotes activation, which contributes maintenance hemostasis activity, thereby maintaining functionality improving semen

Язык: Английский

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Strategic adjustment of ejaculate quality in response to variation of the socio-sexual environment

Behavioral Ecology and Sociobiology, Год журнала: 2021, Номер 75(6)

Опубликована: Май 14, 2021

Язык: Английский

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Male Alternative Reproductive Tactics and Associated Evolution of Anatomical Characteristics in Loliginid Squid

Frontiers in Physiology, Год журнала: 2019, Номер 10

Опубликована: Окт. 15, 2019

Loliginid squids provide a unique model system to explore male alternative reproductive tactics (ARTs) and their linkage size, behavioral decision making, possibly age. Large individuals fight one another the winners form temporary consortships with females, while smaller do not engage in male-male agonistic bouts but use various sneaker obtain matings, each varying mating fertilization success. There is substantial flexibility most species, as males can facultatively switch consort behaviors context changes. These forms of ARTs involve different: posture; site spermatophore deposition; success; sperm traits. Most traits dimorphism (both anatomical behavioral) are consistent traditional sexual selection theory, others have features that may evolved response environment faced by or permanent morph.

Язык: Английский

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Dimorphic ejaculates and sperm release strategies associated with alternative mating behaviors in the squid

Journal of Morphology, Год журнала: 2017, Номер 278(11), С. 1490 - 1505

Опубликована: Июль 18, 2017

Abstract Sperm competition is a powerful postcopulatory selective force influencing male adaptations associated with increasing fertilization success, and it usually related to the evolution of different strategies ejaculate expenditure between individuals. Ejaculates may also be influenced by additional pressures sperm competition, such as timing insemination fertilization, female reproductive tract morphology, environment. Also, males that adopt alternative mating tactics face distinct pressures, which lead intraspecific diversity in ejaculates. In loliginid squids, (sneakers consorts) differ not only behavior, but transfer spermatophores into two sites within female. Here, we compared structure functioning sneakers consorts squid Doryteuthis plei applying microscopy techniques vitro experiments. Sneakers exhibit differences spermatophore spermatophoric reactions spermatangium morphologies. Moreover, sneakers, release lasts longer their show an aggregative behavior detected consorts. Slow strategy guarantee provision, given wide interval sneaker egg release. For consorts, turn, intense quick discharge advantageous, egg‐laying relatively short. Within complex system, factors (i) (ii) influence ultimately shape divergent ejaculates dimorphic males.

Язык: Английский

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Spermatophore dimorphism in the chokka squid Loligo reynaudii associated with alternative mating tactics

Journal of Molluscan Studies, Год журнала: 2018, Номер 84(2), С. 157 - 162

Опубликована: Янв. 15, 2018

Chokka squid (Loligo reynaudii) have characteristic alternative mating tactics: 'consort' males temporarily pair with and guard a female transfer spermatophores onto her oviduct opening inside the mantle cavity, whereas 'sneaker' rush towards female's buccal membrane near sperm storage organ. Differences in behaviours their related sperm-storage sites clearly constrain fertilization process can drive dimorphism between consort sneaker males. The presence character of male has not yet been fully examined this species, but are commonly much larger than We observed clear spermatangia (the mass ejaculated from spermatophore), consistently associated two on body. Observations stored Needham's sac mature confirmed that small produce 'sneaker-type' 'consort-type' spermatangia, no individuals possessed both types. Therefore, by association, tactic adopted (including deposition site used) individual be determined observation spermatangial type, without requiring direct behavioural mating. This ability to infer information about will improve our understanding reproductive system dynamics species.

Язык: Английский

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A coordinated sequence of distinct flagellar waveforms enables a sharp flagellar turn mediated by squid sperm pH-taxis

Scientific Reports, Год журнала: 2017, Номер 7(1)

Опубликована: Окт. 5, 2017

Animal spermatozoa navigate by sensing ambient chemicals to reach the site of fertilization. Generally, such derive from female reproductive organs or cells. Exceptionally, squid mutually release and perceive carbon dioxide form clusters after ejaculation. We previously identified pH-taxis which each spermatozoon can execute a sharp turn, but how flagellar dynamics enable this movement remains unknown. Here, we show that initiation turn motion requires swim down steep proton gradient (a theoretical estimation ≥0.025 pH/s), crossing threshold pH value ~5.5. Time-resolved kinematic analysis revealed sequence results rhythmic exercise two motions: stereotypical 'bent-cane' shape followed asymmetric wave propagation, enables in realm low Reynolds numbers. This turning episode is terminated an 'overshoot' trajectory differs either straight-line motility turning. As with bidirectional pH-taxes some bacteria, also showed repulsion strong acid conditions similar kinematics as positive pH-taxis. These findings indicate might have unique reorientation mechanism, could be dissimilar classical egg-guided sperm chemotaxis other marine invertebrates.

Язык: Английский

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