View source for Sexual cannibalism

{{Short description|Practice of animals eating their own mating partners}}
{{distinguish|Vorarephilia|text=[[Vorarephilia]] (sexual cannibalism on vertebrate animals)}}
[[File:Black widow ventral 1370.jpg|right|thumb|The prevalence of sexual cannibalism gives several species of ''[[Latrodectus]]'' the [[common name]] "black widow spider".]]
'''Sexual cannibalism''' is when an animal, usually the female, [[Cannibalism|cannibalizes]] its mate prior to, during, or after [[Copulation (zoology)|copulation]].<ref>{{Cite journal |last1=Polis |first1=Gary A. |last2=Farley |first2=Roger D. |date=1979 |title=Behavior and Ecology of Mating in the Cannibalistic Scorpion, Paruroctonus mesaensis Stahnke (Scorpionida: Vaejovidae) |url=https://www.jstor.org/stable/3704952 |journal=The Journal of Arachnology |volume=7 |issue=1 |pages=33–46 |jstor=3704952 |issn=0161-8202}}</ref> This trait is observed in many [[arachnid]] orders, several [[insect]] and [[crustacean]] clades,<ref>{{Cite journal |last1=Buskirk |first1=Ruth E. |last2=Frohlich |first2=Cliff |last3=Ross |first3=Kenneth G. |date=1984 |title=The Natural Selection of Sexual Cannibalism |url=https://www.jstor.org/stable/2461241 |journal=The American Naturalist |volume=123 |issue=5 |pages=612–625 |doi=10.1086/284227 |jstor=2461241 |bibcode=1984ANat..123..612B |issn=0003-0147}}</ref> [[Gastropoda|gastropod]]s, and some [[snake]] species. Several hypotheses to explain this seemingly paradoxical behavior have been proposed, including the adaptive foraging hypothesis,<ref name="Blamires-2011">{{Cite journal |last=Blamires |first=Sean J. |date=2011 |title=Nutritional implications for sexual cannibalism in a sexually dimorphic orb web spider |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1442-9993.2010.02161.x |journal=Austral Ecology |language=en |volume=36 |issue=4 |pages=389–394 |doi=10.1111/j.1442-9993.2010.02161.x |bibcode=2011AusEc..36..389B |issn=1442-9985}}</ref> aggressive spillover hypothesis<ref name="Arnqvist-1992">{{Cite journal |last=Arnqvist |first=Göran |date=1992 |title=Courtship Behavior and Sexual Cannibalism in the Semi-Aquatic Fishing Spider, Dolomedes fimbriatus (Clerck) (Araneae: Pisauridae) |url=https://www.jstor.org/stable/3705884 |journal=The Journal of Arachnology |volume=20 |issue=3 |pages=222–226 |jstor=3705884 |issn=0161-8202}}</ref> and mistaken identity hypothesis.<ref name="Gould-1984">{{Cite journal |last=Gould |first=S. |year=1984 |title=Only his wings remained |journal=Natural History |volume=93 |pages=10–18}}</ref> This behavior is believed to have evolved as a manifestation of [[sexual conflict]], occurring when the reproductive interests of males and females differ.<ref>{{Cite journal |last1=Chapman |first1=Tracey |last2=Arnqvist |first2=Göran |last3=Bangham |first3=Jenny |last4=Rowe |first4=Locke |date=2003 |title=Sexual conflict |url=https://linkinghub.elsevier.com/retrieve/pii/S0169534702000046 |journal=Trends in Ecology & Evolution |language=en |volume=18 |issue=1 |pages=41–47 |doi=10.1016/S0169-5347(02)00004-6}}</ref> In many species that exhibit sexual cannibalism, the female consumes the male upon detection. Females of cannibalistic species are generally hostile and unwilling to mate; thus many males of these species have developed adaptive behaviors to counteract female aggression.<ref name="Zhang, S., Kuntner, M. & Li, D.">{{Cite journal |last1=Zhang |first1=Shichang |last2=Kuntner |first2=Matjaž |last3=Li |first3=Daiqin |date=2011 |title=Mate binding: male adaptation to sexual conflict in the golden orb-web spider (Nephilidae: Nephila pilipes) |url=http://ezlab.zrc-sazu.si/uploads/2011/11/Zhangal2011_MateBinding-Nephila.pdf |journal=Animal Behaviour |language=en |volume=82 |issue=6 |pages=1299–1304 |doi=10.1016/j.anbehav.2011.09.010}}</ref><ref name="Fromhage, L. & Schneider, J. M.">{{Cite journal |last1=Fromhage |first1=Lutz |last2=Schneider |first2=Jutta M. |date=2005-03-01 |title=Safer sex with feeding females: sexual conflict in a cannibalistic spider |url=http://academic.oup.com/beheco/article/16/2/377/297882/Safer-sex-with-feeding-females-sexual-conflict-in |journal=Behavioral Ecology |language=en |volume=16 |issue=2 |pages=377–382 |doi=10.1093/beheco/ari011 |issn=1465-7279}}</ref>

==Prevalence==
Sexual cannibalism occurs among insects, arachnids and [[Amphipoda|amphipods]].<ref name="Polis-1981">{{Cite journal |last=Polis |first=G A |date=1981 |title=The Evolution and Dynamics of Intraspecific Predation |url=https://www.annualreviews.org/doi/10.1146/annurev.es.12.110181.001301 |journal=Annual Review of Ecology and Systematics |language=en |volume=12 |issue=1 |pages=225–251 |doi=10.1146/annurev.es.12.110181.001301 |bibcode=1981AnRES..12..225P |issn=0066-4162}}</ref> Sexual cannibalism occurs more often among species with prominent [[sexual size dimorphism]] (SSD); extreme SSD likely drives this trait of sexual cannibalism in [[spider]]s.<ref>{{Cite journal |last1=Wilder |first1=Shawn M. |last2=Rypstra |first2=Ann L. |date=2008 |title=Sexual Size Dimorphism Predicts the Frequency of Sexual Cannibalism Within and Among Species of Spiders |url=https://www.journals.uchicago.edu/doi/10.1086/589518 |journal=The American Naturalist |language=en |volume=172 |issue=3 |pages=431–440 |doi=10.1086/589518 |pmid=18616388 |bibcode=2008ANat..172..431W |issn=0003-0147}}</ref> It also sometimes occurs in some [[anaconda]]s, especially the [[green anaconda]] (''Eunectes murinus''), where females are larger than the males.<ref>{{cite journal | last1 = De la Quintana | first1 = Paola | last2 = Pacheco | first2 = Luis | last3 = Rivas | first3 = Jesús | title = ''Eunectes beniensis'' (Beni Anaconda). Diet: Cannibalism |date=January 2011 | access-date=7 April 2024| url = https://www.researchgate.net/publication/274698904 | journal = Herpetological Review | volume = 42 | issue = 4| page = 614 }}</ref>

==Proposed explanations==
[[File:Mantis Tenodera aridifolia01.jpg|thumb|A female [[Chinese mantis]] eats a male copulating with her.]]

Different hypotheses have been proposed to explain sexual cannibalism, namely adaptive foraging, aggressive spillover, [[mate choice]], and mistaken identity.

===Adaptive foraging===

The adaptive foraging hypothesis is a proposed pre-copulatory explanation in which females assess the nutritional value of a male compared to the male's value as a mate.<ref name="Barry-2008">{{Cite journal |last1=Barry |first1=Katherine L. |last2=Holwell |first2=Gregory I. |last3=Herberstein |first3=Marie E. |date=2008-07-01 |title=Female praying mantids use sexual cannibalism as a foraging strategy to increase fecundity |url=https://academic.oup.com/beheco/article-abstract/19/4/710/201821?redirectedFrom=fulltext |journal=Behavioral Ecology |volume=19 |issue=4 |pages=710–715 |doi=10.1093/beheco/arm156 |issn=1045-2249}}</ref> Starving females are usually in poor physical condition and are therefore more likely to cannibalize a male than to mate with him.<ref>{{Cite journal |last=Andrade |first=Maydianne C. B. |date=1998-01-01 |title=Female hunger can explain variation in cannibalistic behavior despite male sacrifice in redback spiders |url=https://academic.oup.com/beheco/article-abstract/9/1/33/239370?redirectedFrom=fulltext |journal=Behavioral Ecology |volume=9 |issue=1 |pages=33–42 |doi=10.1093/beheco/9.1.33 |issn=1045-2249}}</ref> Among mantises, cannibalism by female ''[[False garden mantis|Pseudomantis albofimbriata]]'' improves [[fecundity]], overall growth, and body condition.<ref name="Barry-2008" /> A study on the [[Chinese mantis]] found that cannibalism occurred in up to 50% of matings.<ref>{{cite journal |last1=Brown |first1=William D. |last2=Barry |first2=Katherine L. |title=Sexual cannibalism increases male material investment in offspring: quantifying terminal reproductive effort in a praying mantis |journal=Proceedings of the Royal Society B: Biological Sciences |volume=283 |issue=1833 |year=2016 |pages=20160656 |issn=0962-8452 |doi=10.1098/rspb.2016.0656|pmid=27358366 |pmc=4936037 |doi-access=free }}</ref> Among spiders, ''[[Six-spotted fishing spider|Dolomedes triton]]'' females in need of additional energy and nutrients for egg development choose to consume the closest nutritional source, even if this means cannibalizing a potential mate.<ref name="Johnson-2001">{{Cite journal |last=Johnson |first=J. Chadwick |date=2001-05-01 |title=Sexual cannibalism in fishing spiders (Dolomedes triton): an evaluation of two explanations for female aggression towards potential mates |url=https://www.sciencedirect.com/science/article/abs/pii/S0003347200916798 |journal=Animal Behaviour |volume=61 |issue=5 |pages=905–914 |doi=10.1006/anbe.2000.1679 |issn=0003-3472}}</ref> In ''[[Agelenopsis pennsylvanica]]'' and ''[[Lycosa tarantula]]'', a significant increase in fecundity, [[Ootheca|egg case]] size, hatching success, and survivorship of offspring has been observed when hungry females choose to cannibalize smaller males before copulating with larger, genetically superior males.<ref name="Berning-2012">{{Cite journal |last1=Berning |first1=Aric W. |last2=Gadd |first2=Ryan D. H. |last3=Sweeney |first3=Kayla |last4=MacDonald |first4=Leigh |last5=Eng |first5=Robin Y. Y. |last6=Hess |first6=Zachary L. |last7=Pruitt |first7=Jonathan N. |date=2012-09-01 |title=Sexual cannibalism is associated with female behavioural type, hunger state and increased hatching success |url=https://www.sciencedirect.com/science/article/abs/pii/S0003347212002916 |journal=Animal Behaviour |volume=84 |issue=3 |pages=715–721 |doi=10.1016/j.anbehav.2012.06.030 |issn=0003-3472}}</ref><ref name="Rabaneda-Bueno-2008">{{Cite journal |last1=Rabaneda-Bueno |first1=Rubén |last2=Rodríguez-Gironés |first2=Miguel Á |last3=Aguado-de-la-Paz |first3=Sara |last4=Fernández-Montraveta |first4=Carmen |last5=Mas |first5=Eva De |last6=Wise |first6=David H. |last7=Moya-Laraño |first7=Jordi |date=2008-10-22 |title=Sexual Cannibalism: High Incidence in a Natural Population with Benefits to Females |journal=PLOS ONE |language=en |volume=3 |issue=10 |pages=e3484 |doi=10.1371/journal.pone.0003484 |doi-access=free |issn=1932-6203 |pmc=2565799 |pmid=18941517|bibcode=2008PLoSO...3.3484R }}</ref> This reproductive success was largely due to the increased energy uptake by cannibalizing males and investing that additional energy in the development of larger, higher-quality egg cases.<ref name="Berning-2012" /><ref name="Wilder-2010">{{Cite journal |last1=Wilder |first1=Shawn M. |last2=Rypstra |first2=Ann L. |date=2010-03-01 |title=Males make poor meals: a comparison of nutrient extraction during sexual cannibalism and predation |journal=Oecologia |language=en |volume=162 |issue=3 |pages=617–625 |doi=10.1007/s00442-009-1518-3 |pmid=19960354 |bibcode=2010Oecol.162..617W |issn=1432-1939}}</ref> In ''D. triton'', post-copulatory sexual cannibalism was observed in the females that had a limited food source; these females copulated with the males and then cannibalized them.<ref name="Johnson-2001" />

The adaptive foraging hypothesis has been criticized because males are considered poor meals when compared to crickets; however, recent findings discovered ''[[Hogna#Hogna helluo|Hogna helluo]]'' males have nutrients crickets lack, including various [[protein]]s and [[lipid]]s.<ref name="Wilder-2010" /><ref name="Kralj-Fišer-2012">{{Cite journal |last1=Kralj-Fišer |first1=Simona |last2=Schneider |first2=Jutta M. |last3=Justinek |first3=Živa |last4=Kalin |first4=Sabina |last5=Gregorič |first5=Matjaž |last6=Pekár |first6=Stano |last7=Kuntner |first7=Matjaž |date=2012-01-01 |title=Mate quality, not aggressive spillover, explains sexual cannibalism in a size-dimorphic spider |url=https://link.springer.com/article/10.1007/s00265-011-1262-7 |journal=Behavioral Ecology and Sociobiology |language=en |volume=66 |issue=1 |pages=145–151 |doi=10.1007/s00265-011-1262-7 |bibcode=2012BEcoS..66..145K |issn=1432-0762}}</ref> In ''H. helluo'', females have a higher protein diet when cannibalizing males than when consuming only house crickets.<ref name="Wilder-2010" /> Further studies show that ''[[Argiope keyserlingi]]'' females with high-protein/low-lipid diets resulting from sexual cannibalism may produce eggs of greater egg energy density (yolk investment).<ref name="Blamires-2011" />

===Aggressive spillover===
The aggressive spillover hypothesis suggests that the more aggressive a female is concerning prey, the more likely the female is to cannibalize a potential mate.<ref name="Johnson-2001" /> The decision of a female to cannibalize a male is not defined by the nutritional value or genetic advantage ([[courtship dance]]s, male aggressiveness, & large body size) of males but instead depends strictly on her aggressive state.<ref name="Polis-1981"/><ref name="Johnson-2001" /> Aggression of the female is measured by latency (speed) of attack on prey. The faster the speed of attack and consumption of prey, the higher the aggressiveness level.<ref name="Barry, K. L., Holwell, G. I. & Herberstein, M. E." /> Females displaying aggressive characteristics tend to grow larger than other females and display continuous cannibalistic behavior. Such behavior may drive away potential mates, reducing chances of mating.<ref>{{Cite journal |last1=Riechert |first1=Susan E. |last2=Singer |first2=Frederick D. |last3=Jones |first3=Thomas C. |date=2001 |title=High gene flow levels lead to gamete wastage in a desert spider system |url=http://link.springer.com/10.1023/A:1013356325881 |journal=Genetica |volume=112/113 |pages=297–319 |doi=10.1023/A:1013356325881|pmid=11838772 }}</ref> Aggressive behavior is less common in an environment that is female-biased, because there is more competition to mate with a male. In these female dominated environments, such aggressive behavior comes with the risk of scaring away potential mates.<ref name="Rabaneda-Bueno-2008" /><ref>{{Cite journal |last=Morse |first=Douglass H. |date=2004-03-10 |title=A test of sexual cannibalism models, using a sit-and-wait predator |url=https://academic.oup.com/biolinnean/article-lookup/doi/10.1111/j.1095-8312.2003.00294.x |journal=Biological Journal of the Linnean Society |language=en |volume=81 |issue=3 |pages=427–437 |doi=10.1111/j.1095-8312.2003.00294.x}}</ref>

Males of the ''[[Pisaura mirabilis]]'' species [[Apparent death|feign death]] to avoid being cannibalized by a female prior to copulation.<ref name="Bilde-2006">{{Cite journal |last1=Bilde |first1=Trine |last2=Tuni |first2=Cristina |last3=Elsayed |first3=Rehab |last4=Pekár |first4=Stano |last5=Toft |first5=Søren |date=2006-03-22 |title=Death feigning in the face of sexual cannibalism |journal=Biology Letters |language=en |volume=2 |issue=1 |pages=23–25 |doi=10.1098/rsbl.2005.0392 |issn=1744-9561 |pmc=1617195 |pmid=17148316}}</ref> When males feign death, their success in reproduction depends on the level of aggressiveness the female displays.<ref name="Bilde-2006" /><ref>{{Cite journal |last1=Dougherty |first1=Liam R. |last2=Burdfield-Steel |first2=Emily R. |last3=Shuker |first3=David M. |date=2013-02-01 |title=Sexual stereotypes: the case of sexual cannibalism |url=https://www.researchgate.net/publication/249011141 |journal=Animal Behaviour |volume=85 |issue=2 |pages=313–322 |doi=10.1016/j.anbehav.2012.12.008 |issn=0003-3472}}</ref> Research has shown that in the ''[[Nephilingis livida|Nephilengys livida]]'' species, female aggressiveness had no effect on the likelihood of her cannibalizing a potential mate; male aggressiveness and male-male competition determined which male the female cannibalized. Males with aggressive characteristics were favored and had a higher chance of mating with a female.<ref name="Kralj-Fišer-2012" />

===Mate choice===
[[Image:Cannibalization(silk spider).jpg|thumb|right|300px|''[[Nephila]] sp.'' eating a conspecific]]

Females exercise mate choice, rejecting unwanted and unfit males by cannibalizing them.<ref name="Persons-2005">{{Cite journal |last1=Persons |first1=Matthew H. |last2=Uetz |first2=George W. |date=2005 |title=Sexual cannibalism and mate choice decisions in wolf spiders: influence of male size and secondary sexual characters |url=https://linkinghub.elsevier.com/retrieve/pii/S0003347204003495 |journal=Animal Behaviour |language=en |volume=69 |issue=1 |pages=83–94 |doi=10.1016/j.anbehav.2003.12.030}}</ref> Mate choice often correlates size with fitness level; smaller males tend to display a low level of fitness; smaller males are therefore eaten more often because of their undesirable traits.<ref name="Persons-2005" /> Males perform elaborate [[courtship dance]]s to display fitness and genetic advantage.<ref>{{Cite journal |last1=Maklakov |first1=Alexei A. |last2=Bilde |first2=Trine |last3=Lubin |first3=Yael |date=2003-10-01 |title=Vibratory courtship in a web-building spider: signalling quality or stimulating the female? |url=https://www.sciencedirect.com/science/article/pii/S0003347203922457 |journal=Animal Behaviour |volume=66 |issue=4 |pages=623–630 |doi=10.1006/anbe.2003.2245 |issn=0003-3472}}</ref> Female [[Orb-weaver spider|orb-web spiders]] (''Nephilengys livida'') tend to cannibalize males displaying less aggressive behavior and mate with males displaying more aggressive behavior, showing a preference for this trait,<ref name="Kralj-Fišer-2012" /> which, along with large body size that indicates a strong foraging ability, displays high male quality and genetic advantage.<ref name="Kralj-Fišer-2012" /><ref name="Prenter-2006">{{Cite journal |last1=Prenter |first1=John |last2=MacNeil |first2=Calum |last3=Elwood |first3=Robert W. |date=2006-03-01 |title=Sexual cannibalism and mate choice |url=https://www.sciencedirect.com/science/article/abs/pii/S0003347205004069 |journal=Animal Behaviour |volume=71 |issue=3 |pages=481–490 |doi=10.1016/j.anbehav.2005.05.011 |issn=0003-3472}}</ref>

Indirect mate choice can be witnessed in [[Dolomedes|fishing spiders]], ''Dolomedes fimbriatus'', where females do not discriminate against smaller body size, attacking males of all sizes. Females had lower success rates cannibalizing large males, which managed to escape where smaller males could not.<ref name="Arnqvist-1992" /> It was shown that males with desirable traits (large body size, high aggression, and long [[courtship dance]]s) had longer copulation duration than males with undesirable traits.<ref name="Kralj-Fišer-2012" /><ref name="Prenter-2006" /> In ''A. keyserlingi'' and ''Nephila edulis'' females allow longer copulation duration and a second copulation for smaller males.<ref>{{Cite journal |last1=Elgar |first1=M. A. |last2=Schneider |first2=J. M. |last3=Herberstein |first3=M. E. |date=2000-12-07 |title=Female control of paternity in the sexually cannibalistic spider Argiope keyserlingi |journal=Proceedings. Biological Sciences |volume=267 |issue=1460 |pages=2439–2443 |doi=10.1098/rspb.2000.1303 |issn=0962-8452 |pmc=1690835 |pmid=11133035}}</ref> The gravity hypothesis suggests that some species of spiders may favor smaller body sizes because they enable them to climb up plants more efficiently and find a mate faster.<ref>{{Cite journal |last1=Moya-Laraño |first1=Jordi |last2=Halaj |first2=Juraj |last3=Wise |first3=David H. |date=February 2002 |title=Climbing to Reach Females: Romeo Should be Small |url=https://academic.oup.com/evolut/article/56/2/420/6755389 |journal=Evolution |language=en |volume=56 |issue=2 |pages=420–425 |doi=10.1111/j.0014-3820.2002.tb01351.x |pmid=11926508 |issn=0014-3820}}</ref> Also smaller males may be favored because they hatch and mature faster, giving them a direct advantage in finding and mating with a female.<ref>{{Cite journal |last1=Vollrath |first1=Fritz |last2=Parker |first2=Geoff A. |date=November 1992 |title=Sexual dimorphism and distorted sex ratios in spiders |url=https://www.nature.com/articles/360156a0 |journal=Nature |language=en |volume=360 |issue=6400 |pages=156–159 |doi=10.1038/360156a0 |bibcode=1992Natur.360..156V |issn=1476-4687}}</ref> In ''[[Leucauge mariana]]'' females will cannibalize males if their sexual performance was poor. They use [[Palpal bulb|palpal]] inflations to determine sperm count and if the female deems sperm count too low she will consume the male.<ref>{{Cite journal|last1=Hernández|first1=Linda|last2=Aisenberg|first2=Anita|last3=Molina|first3=Jorge|date=2018|editor-last=Hebets|editor-first=E.|title=Mating plugs and sexual cannibalism in the Colombian orb-web spider Leucauge mariana|url=http://doi.wiley.com/10.1111/eth.12697|journal=Ethology|language=en|volume=124|issue=1|pages=1–13|doi=10.1111/eth.12697|bibcode=2018Ethol.124....1H }}</ref> In ''Latrodectus revivensis'' females tend to limit copulation duration for small males and deny them a second copulation, showing preference for larger body size.<ref name="Prenter-2006" /> Another form of mate choice is the genetic [[Bet hedging (biology)|bet-hedging]] hypothesis in which a female consumes males to prevent them from exploiting her.<ref>{{Cite journal |last=Watson |first=Paul J |date=1998 |title=Multi-male mating and female choice increase offspring growth in the spider ''Neriene litigiosa'' (Linyphiidae) |url=https://linkinghub.elsevier.com/retrieve/pii/S0003347297905935 |journal=Animal Behaviour |language=en |volume=55 |issue=2 |pages=387–403 |doi=10.1006/anbe.1997.0593|pmid=9480706 }}</ref> It is not beneficial for a female exploited by multiple males because it may result in prey theft, reduction in web, and reduced time of foraging.<ref>{{Cite journal |last1=Schneider |first1=Jutta M. |last2=Lubin |first2=Yael |date=1998 |title=Intersexual Conflict in Spiders |url=https://www.jstor.org/stable/3546677 |journal=Oikos |volume=83 |issue=3 |pages=496–506 |doi=10.2307/3546677 |jstor=3546677 |bibcode=1998Oikos..83..496S |issn=0030-1299}}</ref> Sexual cannibalism might have promoted the evolution of some [[behavior]]al and [[morphology (biology)|morphological]] traits exhibited by spiders today.<ref name="Prenter-2006" />

===Mistaken identity===
The mistaken identity hypothesis suggests that sexual cannibalism occurs when females fail to identify males that try to court.<ref name="Gould-1984" /> This hypothesis suggests that a cannibalistic female attacks and consumes the male without the knowledge of mate quality. In pre-copulatory sexual cannibalism, mistaken identity can be seen when a female does not allow the male to perform the [[courtship dance]] and engages in attack.<ref name="Johnson-2001" /> There is no conclusive evidence for this hypothesis because scientists struggle to distinguish between mistaken identity and the other hypotheses (aggressive spillover, adaptive foraging, and mate choice).<ref>{{Cite journal |last1=AISENBERG |first1=ANITA |last2=COSTA |first2=FERNANDO G. |last3=GONZÁLEZ |first3=MACARENA |date=2011-05-01 |title=Male sexual cannibalism in a sand-dwelling wolf spider with sex role reversal |url=https://academic.oup.com/biolinnean/article-abstract/103/1/68/2452429 |journal=Biological Journal of the Linnean Society |volume=103 |issue=1 |pages=68–75 |doi=10.1111/j.1095-8312.2011.01631.x |issn=0024-4066}}</ref>

==Male adaptive behaviours==
In some cases, sexual cannibalism may characterize an extreme form of male [[Monogamy in animals|monogamy]], in which the male sacrifices itself to the female. Males may gain reproductive success from being cannibalized by either providing nutrients to the female (indirectly to the offspring), or through enhancing the probability that their sperm is used to fertilize the female's eggs.<ref>{{Cite journal |last=Segoli |first=Michal |last2=Arieli |first2=Ruthie |last3=Sierwald |first3=Petra |last4=Harari |first4=Ally R. |last5=Lubin |first5=Yael |date=March 2008 |title=Sexual cannibalism in the brown widow spider (''Latrodectus geometricus'') |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1439-0310.2007.01462.x |journal=[[Ethology (journal)|Ethology]] |language=en |volume=114 |issue=3 |pages=279–286 |bibcode=2008Ethol.114..279S |doi=10.1111/j.1439-0310.2007.01462.x |issn=0179-1613}}</ref> Although sexual cannibalism is fairly common in spiders, male self-sacrifice has only been reported in six genera of [[Araneoidea|araneoid spiders]]. However, much of the evidence for male complicity in such cannibalistic behavior may be anecdotal, and has not been replicated in experimental and behavioural studies.<ref>{{Cite web |last=Suttle |first=Kenwyn Blake |year=1999 |title=The Evolution of Sexual Cannibalism |url=http://ib.berkeley.edu/courses/ib160/past_papers/suttle.html |access-date=2013-12-14}}</ref>

Male members of cannibalistic species have adapted different mating tactics as a mechanism for escaping the cannibalistic tendencies of their female counterparts. Current theory suggests antagonistic co-evolution has occurred, where adaptations seen in one sex produce adaptations in the other.<ref name="Fromhage, L. & Schneider, J. M."/> Adaptations consist of courtship displays, opportunistic mating tactics, and mate binding.

===Opportunistic mating===
The risk of cannibalism becomes greatly reduced when opportunistic mating is practiced.<ref name="Fromhage, L. & Schneider, J. M."/> Opportunistic mating has been characterized in numerous orb-weaving spider species, such as ''Nephila fenestrata'', where the male spider waits until the female is feeding or distracted, and then proceeds with copulation; this greatly reduces the chances of cannibalization. This distraction can be facilitated by the male's presentation of nuptial gifts, where they provide a distracting meal for the female in order to prolong copulation and increase paternity.<ref name="Fromhage, L. & Schneider, J. M."/>

===Altered sexual approach===
Multiple methods of sexual approaches have appeared in cannibalistic species as a result of sexual cannibalism.<ref name="Barry, K. L., Holwell, G. I. & Herberstein, M. E.">{{Cite journal |last1=Barry |first1=Katherine L. |last2=Holwell |first2=Gregory I. |last3=Herberstein |first3=Marie E. |date=2009 |title=Male mating behaviour reduces the risk of sexual cannibalism in an Australian praying mantid |url=http://link.springer.com/10.1007/s10164-008-0130-z |journal=Journal of Ethology |language=en |volume=27 |issue=3 |pages=377–383 |doi=10.1007/s10164-008-0130-z |issn=0289-0771}}</ref> The mechanism by which the male approaches the female is imperative for his survival. If the female is unable to detect his presence, the male is less likely to face cannibalization. This is evident in the mantid species, ''Tenodera aridifolia'', where the male alters his approach utilizing the surrounding windy conditions. The male attempts to avoid detection by approaching the female when the wind impairs her ability to hear him.<ref>{{Cite journal |last1=Watanabe |first1=Hiroshi |last2=Yano |first2=Eizi |date=2012 |title=Behavioral response of male mantid ''Tenodera aridifolia'' (Mantodea: Mantidae) to windy conditions as a female approach strategy |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1479-8298.2012.00535.x |journal=Entomological Science |language=en |volume=15 |issue=4 |pages=384–391 |doi=10.1111/j.1479-8298.2012.00535.x |issn=1343-8786}}</ref> In the praying mantid species ''Pseudomantis albofimbrata'', the males approach the female either from a "slow mounting from the rear" or a "slow approach from the front" position to remain undetected.<ref name="Barry, K. L., Holwell, G. I. & Herberstein, M. E."/>

===Mate guarding===
Sexual cannibalism has impaired the ability of the orb-weaving spider, ''N. fenestrata'', to perform mate guarding. If a male successfully mates with a female, he then exhibits mate guarding, inhibiting the female from re-mating, thus ensuring his paternity and eliminating sperm competition.<ref name="Schneider, J. M. & Elgar, M. A.">{{Cite journal |last=Schneider |first=J. M. |date=2001-09-01 |title=Sexual cannibalism and sperm competition in the golden orb-web spider Nephila plumipes (Araneoidea): female and male perspectives |url=https://academic.oup.com/beheco/article-lookup/doi/10.1093/beheco/12.5.547 |journal=Behavioral Ecology |volume=12 |issue=5 |pages=547–552 |doi=10.1093/beheco/12.5.547}}</ref> Guarding can refer to the blockage of female genital openings to prevent further insertion of a competing male's [[pedipalp]]s, or physical guarding from potential mates. Guarding can decrease female re-mating by fifty percent.<ref name="Fromhage, L. & Schneider, J. M."/> Males who experience genital mutilation can sometimes exhibit the "gloves off" hypothesis which states that a male's body weight and his endurance are inversely proportional. Thus when a male's body weight decreases substantially, his endurance increases as a result, allowing him to guard his female mate with increased efficiency.<ref name="Lee, Q. Q., Oh, J., Kralj-Fiser, S., Kuntner, M. & Li, D.">{{Cite journal |last1=Lee |first1=Qi Qi |last2=Oh |first2=Joelyn |last3=Kralj-Fišer |first3=Simona |last4=Kuntner |first4=Matjaž |last5=Li |first5=Daiqin |date=2012-10-23 |title=Emasculation: gloves-off strategy enhances eunuch spider endurance |journal=Biology Letters |language=en |volume=8 |issue=5 |pages=733–735 |doi=10.1098/rsbl.2012.0285 |pmid=22696287 |issn=1744-9561|pmc=3440970 }}</ref>

===Mate binding===
Mate binding refers to a pre-copulatory courtship behavior where the male deposits silk onto the abdomen of the female while simultaneously massaging her in order to reduce her aggressive behavior. This action allows for initial and subsequent copulatory bouts.<ref name="Zhang, S., Kuntner, M. & Li, D."/> While both chemical and tactile cues are important factors for reducing cannibalistic behaviors, the latter functions as a resource to calm the female, exhibited in the orb-weaver spider species, ''[[Nephila pilipes]]''.<ref name="Zhang, S., Kuntner, M. & Li, D."/> Additional hypotheses suggest that male silk contains [[pheromone]]s which seduce the female into submission. However, silk deposits are not necessary for successful copulation.<ref name="Zhang, S., Kuntner, M. & Li, D."/> The primary factor in successful subsequent copulation lies in the tactile communication between the male and female spider that results in female acceptance of the male.<ref name="Robinson, M. H. & Robinson, B.">{{cite book |last1=Robinson |first1=M. H. |first2=B. |last2=Robinson |year=1980 |title=Comparative studies of the courtship and mating behavior of tropical araneid spiders |series=Pacific Insects Monograph |volume=36 |url=http://hbs.bishopmuseum.org/pim/pdf/pim36.pdf |publisher=Department of Entomology, Bishop Museum}}</ref> The male mounts the posterior portion of the female's abdomen, while rubbing his spinnerets on her abdomen during his attempt at copulation.<ref name="Zhang, S., Kuntner, M. & Li, D."/> Mate binding was not necessary for the initiation of copulation in the golden orb-weaving spider, except when the female was resistant to mating. Subsequent copulatory bouts are imperative for the male's ability to copulate due to prolonged sperm transfer, therefore increasing his probability of paternity.<ref name="Zhang, S., Kuntner, M. & Li, D."/>

===Courtship displays===
Courtship displays in sexually cannibalistic spiders are imperative in order to ensure the female is less aggressive. Additional courtship displays include pre-copulatory dances such as those observed in the [[redback spider]], and vibrant male coloration morphologies which function as female attraction mechanisms, as seen in the peacock spider, ''[[Maratus volans]],'' or in ''[[Habronattus pyrrithrix]]''.<ref name="Robinson, M. H. & Robinson, B."/> [[Nuptial gift]]s play a vital role in safe copulation for males in some species. Males present meals to the female to facilitate opportunistic mating while the female is distracted.<ref name="Fromhage, L. & Schneider, J. M."/> 
Subsequent improvements in male adaptive mating success include web reduction, as seen in the Western black widow, ''Latrodectus hesperus''.<ref>{{Cite journal |last1=Scott |first1=Catherine |last2=Vibert |first2=Samantha |last3=Gries |first3=Gerhard |date=2012 |title=Evidence that web reduction by western black widow males functions in sexual communication |url=https://www.cambridge.org/core/product/identifier/S0008347X12000569/type/journal_article |journal=The Canadian Entomologist |language=en |volume=144 |issue=5 |pages=672–678 |doi=10.4039/tce.2012.56 |issn=0008-347X}}</ref> Once mating occurs, the males destroy a large portion of the female's web to discourage the female from future mating, thus reducing [[polyandry]], which has been observed in the Australian redback spider, ''Latrodectus hasselti''.<ref>{{Cite journal |last1=Stoltz |first1=Jeffrey A. |last2=McNeil |first2=Jeremy N. |last3=Andrade |first3=Maydianne C.B. |date=2007 |title=Males assess chemical signals to discriminate just-mated females from virgins in redback spiders |url=https://linkinghub.elsevier.com/retrieve/pii/S0003347207003132 |journal=Animal Behaviour |language=en |volume=74 |issue=6 |pages=1669–1674 |doi=10.1016/j.anbehav.2007.03.011}}</ref>

===Male-induced cataleptic state===
In some species of spiders, such as ''[[Agelenopsis aperta]]'', the male induces a passive state in the female prior to copulation.<ref name="Becker, E., Riechert, S. & Singer, F.">{{Cite journal |last1=Becker |first1=Elizabeth |last2=Riechert |first2=Susan |last3=Singer |first3=Fred |date=2005 |title=Male Induction of Female Quiescence/Catalepsis during Courtship in the Spider, Agelenopsis aperta |url=https://www.jstor.org/stable/4536229 |journal=Behaviour |volume=142 |issue=1 |pages=57–70 |doi=10.1163/1568539053627767 |jstor=4536229 |issn=0005-7959}}</ref> It has been hypothesized that the cause of this "quiescent" state is the male's massaging of the female's abdomen, following male vibratory signals on the web. The female enters a passive state, and the male's risk of facing cannibalism is reduced. This state is most likely induced as a result of a male volatile pheromone.<ref name="Becker, E., Riechert, S. & Singer, F."/> The chemical structure of the pheromone utilized by the male ''A. aperta'' is currently unknown; however, physical contact is not necessary for the induced passive state. Eunuch males, or males with partially or fully removed palps, are unable to induce the passive state on females from a distance, but can induce quiescence upon physical contact with the female; this suggests that the pheromone produced is potentially related to sperm production, since the male inserts sperm from his pedipalps, structures which are removed in eunuchs.<ref name="Becker, E., Riechert, S. & Singer, F."/> This adaptation has most likely evolved in response to the overly aggressive nature of female spiders.

=== Copulatory silk wrapping ===
In order to avoid being consumed by the female, some male spiders may utilize their silk to physically bind the female spider. For example, in ''[[Pisaurina mira]]'', also known as the nursery web spider, the male wraps the legs of the female in silk prior to and during copulation. While he holds legs III and IV of the female, he uses the silk to bind legs I and II.<ref>{{Cite journal|last1=Bruce|first1=John A.|last2=Carico|first2=James E.|date=1988|title=Silk Use during Mating in Pisaurina Mira (Walckenaer) (Araneae, Pisauridae)|url=https://www.jstor.org/stable/3705799|journal=The Journal of Arachnology|volume=16|issue=1|pages=1–4|jstor=3705799 |issn=0161-8202}}</ref> Because the male spider legs play a significant role in copulation, longer leg length ''P. mira'' are generally favored over shorter lengths. In the ''[[Paratrechalea]]'' genus, males silk wrap nutritive or worthless gifts to avoid being cannibalized by the female spider.

==Costs and benefits for males==
The physiological impacts of cannibalism on male fitness include his inability to father any offspring if he is unable to mate with a female. There are males in species of arachnids, such as ''N. plumipes'', that sire more offspring if the male is cannibalized after or during mating; copulation is prolonged and sperm transfer is increased.<ref name="Schneider, J. M. & Elgar, M. A."/> In the species of orb-weaving spider, ''Argiope arantia'', males prefer short copulation duration upon the first palp insertion in order to avoid cannibalism. Upon the second insertion, however, the male remains inserted in the female. The male exhibits a "programmed death" to function as a full-body genital plug. This causes it to become increasingly difficult for the female to remove him from her genital openings, discouraging her from mating with other males.<ref name="Foellmer, M. W. & Fairbairn, D. J.">{{Cite journal |last1=Foellmer |first1=Matthias W. |last2=Fairbairn |first2=Daphne J. |date=2003-11-07 |title=Spontaneous male death during copulation in an orb-weaving spider |journal=Proceedings of the Royal Society of London. Series B: Biological Sciences |language=en |volume=270 |issue=suppl_2 |pages=S183-5 |doi=10.1098/rsbl.2003.0042 |issn=0962-8452 |pmc=1809950 |pmid=14667377}}</ref> An additional benefit to cannibalization is the idea that a well-fed female is less likely to mate again.<ref>{{Cite journal |last=Andrade |first=Maydianne C. B. |date=1998 |title=Female hunger can explain variation in cannibalistic behavior despite male sacrifice in redback spiders |url=https://academic.oup.com/beheco/article-lookup/doi/10.1093/beheco/9.1.33 |journal=Behavioral Ecology |language=en |volume=9 |issue=1 |pages=33–42 |doi=10.1093/beheco/9.1.33 |issn=1045-2249}}</ref> If the female has no desire to mate again, the male who has already mated with her has his paternity ensured.

===Genital mutilation===
Before or after copulating with females, certain males of spider species in the superfamily Araneoidea become half or full eunuchs with one or both of their pedipalps (male genitals) severed. This behavior is often seen in sexually cannibalistic spiders, causing them to exhibit the "eunuch phenomenon".<ref name="Lee, Q. Q., Oh, J., Kralj-Fiser, S., Kuntner, M. & Li, D."/> Due to the chance that they may be eaten during or after copulation, male spiders use genital mutilation to increase their chances of successful mating. The male can increase his chances of paternity if the female's copulatory organs are blocked, which decreases sperm competition and her chances of mating with other males. In one study, females with mating plugs had a 75% lower chance of re-mating.<ref name="Kralj-Fišer, S., Gregorič, M., Zhang, S., Li, D. & Kuntner, M.">{{Cite journal |last1=Kralj-Fišer |first1=Simona |last2=Gregorič |first2=Matjaž |last3=Zhang |first3=Shichang |last4=Li |first4=Daiqin |last5=Kuntner |first5=Matjaž |date=2011 |title=Eunuchs are better fighters |url=https://linkinghub.elsevier.com/retrieve/pii/S0003347211000637 |journal=Animal Behaviour |language=en |volume=81 |issue=5 |pages=933–939 |doi=10.1016/j.anbehav.2011.02.010}}</ref>  Additionally, if a male successfully severs his pedipalp within the female copulatory duct the pedipalp can not only serve as a plug but can continue to release sperm to the female spermathacae, again increasing the male's chances of paternity. This is referred to as "remote copulation".<ref name="S. Kralj-Fiser 2012">{{Cite journal |last1=Li |first1=Daiqin |last2=Oh |first2=Joelyn |last3=Kralj-Fišer |first3=Simona |last4=Kuntner |first4=Matjaž |date=February 2012 |title=Remote copulation: male adaptation to female cannibalism |journal=Biology Letters |volume=8 |issue=4 |pages=512–515 |doi=10.1098/rsbl.2011.1202 |pmc=3391442 |pmid=22298805}}</ref> Occasionally (in 12% of cases in a 2012 study on Nephilidae spiders) palp severance is only partial due to copulation interruption by sexual cannibalism. Partial palp severance can result in a successful mating plug but not to the extent of full palp severance.<ref name="S. Kralj-Fiser 2012" />
Some males, as in the orb-weaving spider, ''Argiope arantia'', have been found to spontaneously die within fifteen minutes of their second copulation with a female.<ref name="Foellmer, M. W. & Fairbairn, D. J."/> The male dies while his pedipalps are still intact within the female, as well as still swollen from copulation. In this "programmed death", the male is able to utilize his entire body as a genital plug for the female, causing it to be much more difficult for her to remove him from her copulatory ducts.<ref name="Foellmer, M. W. & Fairbairn, D. J."/>
In other species males voluntarily self-amputate a pedipalp prior to mating and thus the mutilation is not driven by sexual cannibalism. This has been hypothesized to be due to an increased fitness advantage of half or full eunuchs. Upon losing a pedipalp, males experience a significant decrease in body weight that provides them with enhanced locomotor abilities and endurance, enabling them to better search for a mate and mate-guard after mating. This is referred to as the "gloves-off" theory.<ref name="Lee, Q. Q., Oh, J., Kralj-Fiser, S., Kuntner, M. & Li, D." /> Males and females have also been seen with the roles reversed in terms of genital mutilation. In ''[[Cyclosa argenteoalba]],'' males mutilate female spider's genitals by detaching the female's scape, making it impossible for another male to mate with them.

==Male self-sacrifice==
Male reproductive success can be determined by their number of fathered offspring, and monogyny is seen quite often in sexually cannibalistic species. Males are willing to sacrifice themselves, or lose their reproductive organs in order to ensure their paternity from one mating instance.<ref name="Foellmer, M. W. & Fairbairn, D. J."/><ref name="Kralj-Fišer, S., Gregorič, M., Zhang, S., Li, D. & Kuntner, M."/> Whether it is by spontaneous programmed death, or the male catapulting into the mouth of the female, these self-sacrificing males die in order for prolonged copulation to occur. Males of many of these species cannot replenish sperm stores, therefore they must exhibit these extreme behaviors in order to ensure sperm transfer and fathered offspring during their one and only mating instance. An example of such behavior can be seen in the [[redback spider]]. The males of this species "somersault" into the mouths of the female after copulation has occurred, which has been shown to increase paternity by sixty-five percent when compared to males that are not cannibalized. A majority of males in this species are likely to die on the search for a mate, so the male must sacrifice himself as an offering if it means prolonged copulation and doubled paternity. In many species, cannibalized males can mate longer, thus having longer sperm transfers.<ref>{{Cite journal |last=Andrade |first=M. C. B. |date=2003-07-01 |title=Risky mate search and male self-sacrifice in redback spiders |url=https://academic.oup.com/beheco/article-lookup/doi/10.1093/beheco/arg015 |journal=Behavioral Ecology |language=en |volume=14 |issue=4 |pages=531–538 |doi=10.1093/beheco/arg015 |issn=1465-7279|hdl=1807/1012 |hdl-access=free }}</ref>

==Male sexual cannibalism==
Although females often instigate sexual cannibalism, reversed sexual cannibalism has been observed in the spiders ''[[Micaria]] sociabilis''<ref>{{cite journal |last1=Sentenská |first1=Lenka |last2=Pekár |first2=Stano |title=Eat or not to eat: Reversed sexual cannibalism as a male foraging strategy in the spider Micaria sociabilis (Araneae: Gnaphosidae) |journal=Ethology |date=May 2014 |volume=120 |issue=5 |pages=511–518 |doi= 10.1111/eth.12225|bibcode=2014Ethol.120..511S }}</ref><ref name="Sentenská-2013">{{cite journal |last1=Sentenská |first1=Lenka |last2=Pekár |first2=Stano |title=Mate with the young, kill the old: Reversed sexual cannibalism and male mate choice in the spider Micaria sociabilis (Araneae: Gnaphosidae) |journal=Behavioral Ecology and Sociobiology |date=July 2013 |volume=67 |issue=7 |pages=1131–1139 |doi=10.1007/s00265-013-1538-1 |bibcode=2013BEcoS..67.1131S |s2cid=16789679}}</ref> and ''[[Allocosa brasiliensis]]''.<ref>{{cite journal |last1=Aisenberg |first1=Anita |last2=Costa |first2=Fernando |last3=Gonzalez |first3=Macarena |title=Male sexual cannibalism in a sand-dwelling wolf spider with sex role reversal |journal=Biological Journal of the Linnean Society |date=May 2011 |volume=103 |issue=1 |pages=68–75 |doi=10.1111/j.1095-8312.2011.01631.x |doi-access=free}}</ref><ref name="Aisenberg-2009">{{cite journal |last1=Aisenberg |first1=Anita |last2=Gonzalez |first2=Alvaro |last3=Postiglioni |first3=Rodrigo |last4=Simo |first4=Miguel |title=Reversed cannibalism, foraging, and surface activities of ''Allocosa alticeps'' and ''Allocosa brasiliensis'': Two wolf spiders from coastal sand dunes |journal=Journal of Arachnology |date=August 2009 |volume=37 |issue=2 |pages=135–138 |doi=10.1636/T08-52.1 |s2cid=51688375|url=https://www.biodiversitylibrary.org/part/229145 }}</ref> In a laboratory experiment on ''M. sociabilis'', males preferred to eat older females. This behavior may be interpreted as adaptive foraging, because older females have low reproductive potential and food may be limited. Reversed cannibalism in ''M. sociabilis'' may also be influenced by size dimorphism. Males and females are similar in size, and bigger males were more likely to be cannibalistic.<ref name="Sentenská-2013"/> In ''A. brasiliensis'' males tend to be cannibalistic in between mating seasons, after they have mated, gone out of their burrows to search for food, and left their mates in their burrows. Any females they cross during this period likely have little reproductive value, so this may also be interpreted as adaptive foraging.<ref name="Aisenberg-2009"/> It has also been observed in the crab ''[[Ovalipes catharus]].'' Reversed sexual cannibalism is also observed in a snake species called ''[[Malpolon monspessulanus]]'', commonly known as Montpellier snakes. This behavior may occur due to their opportunistic feeding habits, lack of availability of prey, or competition for resources among the individuals of the species. As this species exhibits male-biased sexual dimorphism, it is easier for male Montpellier snakes to attack and cannibalize the females. Male cannibalism might also be triggered by the refusal to mate by female ''M. monspessulanus.''<ref>{{Cite journal |last1=Glaudas |first1=Xavier |last2=Fuento |first2=Nicolas |date=January 2022 |title=The strange occurrence of male cannibalism on adult females in snakes |url=https://onlinelibrary.wiley.com/doi/10.1111/eth.13239 |journal=Ethology |language=en |volume=128 |issue=1 |pages=94–97 |doi=10.1111/eth.13239 |bibcode=2022Ethol.128...94G |s2cid=239153518 |issn=0179-1613}}</ref>

==Monogamy==
Males in these mating systems are generally [[Monogamy in animals|monogamous]], if not [[bigynous]].<ref name="Lee, Q. Q., Oh, J., Kralj-Fiser, S., Kuntner, M. & Li, D."/> Since males of these cannibalistic species have adapted to the extreme mating system, and usually mate only once with a polyandrous female, they are considered monogynous.<ref>{{Cite journal |last1=Michalik |first1=Peter |last2=Knoflach |first2=Barbara |last3=Thaler |first3=Konrad |last4=Alberti |first4=Gerd |date=2010-02-01 |title=Live for the moment—Adaptations in the male genital system of a sexually cannibalistic spider (Theridiidae, Araneae) |url=https://www.sciencedirect.com/science/article/abs/pii/S0040816609000548 |journal=Tissue and Cell |volume=42 |issue=1 |pages=32–36 |doi=10.1016/j.tice.2009.06.004 |pmid=19643451 |issn=0040-8166}}</ref>

== Other factors ==

===Sexual dimorphism===
[[Sexual dimorphism]] in size has been proposed as an explanation for the widespread nature of sexual cannibalism across distantly related arthropods. Typically, male birds and mammals are larger as they participate in male-male competition.<ref>{{Cite journal |last1=Wilder |first1=Shawn M. |last2=Rypstra |first2=Ann L. |last3=Elgar |first3=Mark A. |date=2009-12-01 |title=The Importance of Ecological and Phylogenetic Conditions for the Occurrence and Frequency of Sexual Cannibalism |url=https://www.annualreviews.org/doi/10.1146/annurev.ecolsys.110308.120238 |journal=Annual Review of Ecology, Evolution, and Systematics |language=en |volume=40 |issue=1 |pages=21–39 |doi=10.1146/annurev.ecolsys.110308.120238 |issn=1543-592X}}</ref> However, in arthropods this size dimorphism ratio is reversed, with females commonly larger than males. Sexual cannibalism may have led to selection for larger, stronger females in invertebrates.<ref name="Persons-2005" /> Further research is needed to evaluate the explanation. To date, studies have been done on wolf spiders such as ''[[Zyuzicosa]]'' (Lycosidae), where the female is much larger than the male.<ref>{{Cite journal |last=Logunov |first=D.V. |date=2011-09-23 |title=Sexual size dimorphism in burrowing wolf spiders (Araneae: Lycosidae) |url=http://www.zin.ru/journals/trudyzin/doc/vol_315_3/tz_315_3_logunov.pdf |journal=Proceedings of the Zoological Institute RAS |language=ru |volume=315 |issue=3 |pages=274–288 |doi=10.31610/trudyzin/2011.315.3.274 |issn=0206-0477}}</ref>

==See also==
{{Portal|Arthropods}}
* [[Evolutionary arms race]]
* [[Femme fatale]]
* [[Interlocus sexual conflict]]
* [[Sexual conflict]]
* [[Spider cannibalism]]
* [[Traumatic insemination]]

==References==
{{Reflist|30em}}

==External links==
*{{YouTube|id=O6WIab1Ns14|title=''Argiope aurantia'' male sacrifice}}
*{{YouTube|id=-sZY-OAVPyk|title=''Argiope aurantia'' sexual cannibalism}}
*[[Argiope argentata#Sexual cannibalism]] 
{{Feeding}}

{{Cannibalism}}

{{DEFAULTSORT:Sexual Cannibalism}}
[[Category:Animal cannibalism]]
[[Category:Mating]]
[[Category:Natural selection]]