Editing Amplexus (section)

==Horseshoe crabs==
[[File:Limulus polyphemus1.jpg|thumb|right|Amplectant pair of ''[[Limulus polyphemus]]''. The male is the smaller individual.]]
Amplexus occurs in all  four species of [[horseshoe crab]]. Horseshoe crabs typically go ashore for amplexus in high tide, and end up on beaches where the eggs are more protected.<ref>{{Cite journal|last1=Leschen|first1=Alison S.|last2=Grady|first2=Sara P.|last3=Valiela|first3=Ivan|date=2006|title=Fecundity and spawning of the Atlantic horseshoe crab, Limulus polyphemus, in Pleasant Bay, Cape Cod, Massachusetts, USA|journal=Marine Ecology|volume=27|issue=1|pages=54–65|doi=10.1111/j.1439-0485.2005.00053.x|issn=0173-9565|bibcode=2006MarEc..27...54L|hdl=1912/906|hdl-access=free}}</ref> The first pair of walking legs is used to tightly clasp the female in all species, and the second pair is also employed in all but ''[[Limulus polyphemus]]''.<ref name=Bottonetal1996>{{cite journal|last=Botton|first=Mark L.|author2=Shuster, Carl N.|author3= Sekiguchi, Koichi|author4= Sugita, Hiroaki|title=Amplexus and Mating Behavior in the Japanese Horseshoe Crab,'' Tachypleus tridentatus''|journal=Zoological Science|date=February 1996|volume=13|issue=1|pages=151–159|doi=10.2108/zsj.13.151|s2cid=85269977|doi-access=free}}</ref> A male horseshoe crab develops modified [[clasper]]s during sexual maturity when the male moults; these modified claspers can then help during the process of amplexus.<ref name=":6">{{Cite journal|last1=Botton|first1=Mark L.|last2=Shuster|first2=Carl N.|last3=Sekiguchi|first3=Koichi|last4=Sugita|first4=Hiroaki|date=1996|title=Amplexus and Mating Behavior in the Japanese Horseshoe Crab, Tachypleus tridentatus|journal=Zoological Science|volume=13|issue=1|pages=151–159|doi=10.2108/zsj.13.151|s2cid=85269977|issn=0289-0003|doi-access=free}}</ref> The male's pair of posterior claspers are known for having the ability to maintain long-term amplexus which have been found to always attach to the female's [[opisthosoma]] during amplexus.<ref name=":6" /> In contrast, the male's anterior claspers have been found to attach to the female's opisthosoma as well, but on the lateral edges of the opisthosoma and function to resist displacement from environmental factors.<ref name=":6" /> Uniquely, amplexus is most likely to occur between horseshoe crabs when the female horseshoe crab has a hard shell.<ref name=":6" /> Additionally, males who inhabit a clean shell are more likely to enter amplexus, compared to males who contain a dirty shell, as it seems that females have a preference for clean shells on males.<ref name=":6" /> A male horseshoe crab's claspers may also be an important factor of consideration for the initiation of amplexus. Since claspers are used for the attachment to the female, claspers that are in good condition are more successful for the initiation of amplexus.<ref name=":10">{{Cite journal|last1=Duffy|first1=Erin E.|last2=Penn|first2=Dustin J.|last3=Botton|first3=Mark L.|last4=Brockmann|first4=H. Jane|last5=Loveland|first5=Robert E.|date=2005-08-11|title=Eye and clasper damage influence male mating tactics in the horseshoe crab, Limulus polyphemus|journal=Journal of Ethology|volume=24|issue=1|pages=67–74|doi=10.1007/s10164-005-0163-5|s2cid=1398829|issn=0289-0771}}</ref> If a male horseshoe crab has a damaged or missing clasper, then that puts the male at a disadvantage and increases the probability of being displaced by other competing male crabs.<ref name=":10" />