Disposable penis and its replenishment in a simultaneous hermaphrodite

Sekizawa, Ayami; Seki, Satoko; Tokuzato, Masakazu; Shiga, Sakiko; Nakashima, Yasuhiro

doi:10.1098/rsbl.2012.1150

Cited by 12 publications

(16 citation statements)

References 11 publications

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“…Relevant traits include the number (e.g., Velando et al 2008) and morphology (e.g., Schärer et al 2011) of sperm transferred; mechanisms for the efficient transfer of sperm (e.g., Janicke and Schärer 2009a), or for physical displacement of previously deposited sperm (a proposed function of the "disposable" penis of the sea slug Chromodoris reticulata, Sekizawa et al 2013); suppression of remating by sperm recipients (see below); and…”

Section: Postmating Conflicts: Interests Of the Sperm Donormentioning

confidence: 99%

Sexual Conflict in Hermaphrodites

Schärer¹,

Janicke²,

Ramm³

2014

Cold Spring Harb Perspect Biol

100

137

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Hermaphrodites combine the male and female sex functions into a single individual, either sequentially or simultaneously. This simple fact means that they exhibit both similarities and differences in the way in which they experience, and respond to, sexual conflict compared to separate-sexed organisms. Here, we focus on clarifying how sexual conflict concepts can be adapted to apply to all anisogamous sexual systems and review unique (or especially important) aspects of sexual conflict in hermaphroditic animals. These include conflicts over the timing of sex change in sequential hermaphrodites, and in simultaneous hermaphrodites, over both sex roles and the postmating manipulation of the sperm recipient by the sperm donor. Extending and applying sexual conflict thinking to hermaphrodites can identify general evolutionary principles and help explain some of the unique reproductive diversity found among animals exhibiting this widespread but to date understudied sexual system.

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Section: Postmating Conflicts: Interests Of the Sperm Donormentioning

confidence: 99%

Sexual Conflict in Hermaphrodites

Schärer¹,

Janicke²,

Ramm³

2014

Cold Spring Harb Perspect Biol

100

137

View full text Add to dashboard Cite

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“…These findings indicate that sexual selection functions in simultaneous hermaphrodites as strongly as in gonochorists, if not more strongly. Furthermore, mating behaviours, such as penis fencing in flatworms (Michiels and Newman 1998), cephalo-traumatic secretion transfer in head-shielded slugs (Lange et al 2013(Lange et al , 2014, and disposable penises in nudibranchs (Sekizawa et al 2013), show that some simultaneous hermaphrodites undergo severe competition to acquire the chance to inseminate, and suggest that they expose themselves to sperm competition. Additionally, some simultaneously hermaphroditic invertebrates have an organ(s) to digest and absorb sperm received from mating partners (Baur 1998;Michiels 1998).…”

Section: Introductionmentioning

confidence: 99%

“…Chromodoris reticulata is reported to autotomize its penis after every copulation and replenish it within about 24 h in order to perform another copulation (Sekizawa et al 2013). The fact that this nudibranch has a mechanism to repeat copulation within a short period of time with disposable penises indicates their high mating frequency.…”

Section: Introductionmentioning

confidence: 99%

“…However, the exact function of these projections on the penis has not been understood. Since a sperm mass was often entangled in the spines on the surface of an autotomized penis after copulation in C. reticulata (Sekizawa et al 2013), this nudibranch has been proposed to scrape out allo-sperm already stored in the allo-sperm storage organ(s) of the mating partner with its thorny penis.…”

Section: Introductionmentioning

confidence: 99%

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A nudibranch removes rival sperm with a disposable spiny penis

Sekizawa

Goto

Nakashima

2018

J Ethol

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Simultaneous hermaphroditism is, at least initially, favoured by selection under low density-and therefore it can be assumed that sperm competition has little importance in this sexual system. However, many simultaneously hermaphroditic nudibranchs have both an allo-sperm storage organ (the seminal receptacle) and an allo-sperm digesting organ (the copulatory bursa), suggesting the possibility of the occurrence of sperm competition. A nudibranch, Chromodoris reticulata, autotomizes its penis after every copulation and replenishes it within about 24 h to perform another copulation. We observed that the surface of the autotomized penis was covered with many backward-pointing spines and that a sperm mass was often entangled on the spines. This suggests that the nudibranch removes sperm that is already stored in a mating partner's sperm storage organ(s) with its thorny penis. Using six microsatellite markers, we determined that the sperm mass attached to the penis were allo-sperm originating from individual(s) that had participated in prior copulations. We revealed that C. reticulata performed sperm removal using the thorny penis. These results suggest that competition in fertilization is quite intense and mating frequency in the wild is relatively high in this species.

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“…In contrast to self-infliction caused by partner resistance, in several species, the intromittent organs routinely break and the whole or parts thereof remain in the female (nudibranchs: Sekizawa et al 2013;spiders: Uhl et al 2010;Izquierdio and Rubio 2011;earwigs: Kamimura 2003;bees: Franck et al 2002). This self-inflicted CW can acquire adaptive function (such as preventing remating of the partner: Nessler et al 2007;Uhl et al 2010), in which case the term "wound inflictor" would,again, beambiguous,evenmoreso if specific break-off points evolved (e.g., Uhl et al 2010;Sekizawa et al 2013) that no longer result in wounding. In other species, injuries to the intromittent organs happen occasionally rather than routinely (moths: Cordero and Miller 2012; humans: the section Case Studies) and their adaptive function, if any, is unknown (but, see Cordero and Miller 2012).…”

Section: Which Sex Causes Cw?mentioning

confidence: 99%

Copulatory Wounding and Traumatic Insemination

Reinhardt

Anthes

Lange

2015

Cold Spring Harb Perspect Biol

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Copulatory wounding (CW) is widespread in the animal kingdom, but likely underreported because of its cryptic nature. We use four case studies (Drosophila flies, Siphopteron slugs, Cimex bugs, and Callosobruchus beetles) to show that CW entails physiological and lifehistory costs, but can evolve into a routine mating strategy that, in some species, involves insemination through the wound. Although interspecific variation in CW is documented, few data exist on intraspecific and none on individual differences. Although defensive mechanisms evolve in the wound recipient, our review also indicates that mating costs in species with CW are slightly higher than in other species. Whether such costs are dose-or frequencydependent, and whether defense occurs as resistance or tolerance, decisively affects the evolutionary outcome. In addition to sexual conflict, CW may also become a model system for reproductive isolation. In this context, we put forward a number of predictions, including (1) occasional CW is more costly than routine CW, (2) CW is more costly in between-than within-population matings, and (3) in the presence of CW, selection may favor the transmission of sexually transmitted diseases if they induce resource allocation. Finally, we outline, and briefly discuss, several medical implications of CW in humans.

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Disposable penis and its replenishment in a simultaneous hermaphrodite

Cited by 12 publications

References 11 publications

Sexual Conflict in Hermaphrodites

Sexual Conflict in Hermaphrodites

A nudibranch removes rival sperm with a disposable spiny penis

Copulatory Wounding and Traumatic Insemination

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