Paratrechalea

Paratrechalea azul and Paratrechalea ornata are nocturnal and found on boulders at the edge of streams in Brazil, Uruguay, and Argentina.{{Cite journal |last1=Costa-Schmidt |first1=L.E. |last2=Machado |first2=G. |date=November 2012 |title=Reproductive interference between two sibling species of gift-giving spiders |url=http://dx.doi.org/10.1016/j.anbehav.2012.08.026 |journal=Animal Behaviour |volume=84 |issue=5 |pages=1201–1211 |doi=10.1016/j.anbehav.2012.08.026 |issn=0003-3472|url-access=subscription }} In Minas, Uruguay, the climate is stable.{{Cite web |author1=Ethan Freedman |date=2023-08-28 |title=When stressed, these male spiders woo mates with empty 'take-out containers' instead of dinner |url=https://www.livescience.com/animals/spiders/when-stressed-these-male-spiders-woo-mates-with-empty-take-out-containers-instead-of-dinner |access-date=2024-03-05 |website=livescience.com |language=en}}{{Cite journal |last1=Albo |first1=Maria J. |last2=Pavón-Peláez |first2=Camila |last3=Villar |first3=Mauro Martínez |last4=Buzatto |first4=Bruno A. |last5=Tomasco |first5=Ivanna |date=2023-07-27 |title=Stressful environments favor deceptive alternative mating tactics to become dominant |journal=BMC Biology |volume=21 |issue=1 |pages=162 |doi=10.1186/s12915-023-01664-5 |issn=1741-7007 |pmc=10375696 |pmid=37501205 |doi-access=free}} However, in Queguay, Uruguay, El Niño-Southern Oscillations impacts the rainfall, which creates variations in climate. There are unpredictable environmental conditions.

Paratrechalea comprises the following species:

• Paratrechalea azul Carico, 2005
• Paratrechalea galianoae Carico, 2005
• Paratrechalea julyae Silva & Lise, 2006
• Paratrechalea longigaster Carico, 2005
• Paratrechalea ornata (Mello-Leitão, 1943)
• Paratrechalea saopaulo Carico, 2005
• Paratrechalea wygodzinskyi (Soares & Camargo, 1948)

P. azul and P. ornata are phenotypically similar{{Cite journal |last1=Costa-Schmidt |first1=L. E. |last2=Machado |first2=G. |date=2012-11-01 |title=Reproductive interference between two sibling species of gift-giving spiders |url=https://www.sciencedirect.com/science/article/pii/S0003347212003776 |journal=Animal Behaviour |volume=84 |issue=5 |pages=1201–1211 |doi=10.1016/j.anbehav.2012.08.026 |issn=0003-3472|url-access=subscription }} and one of the ways to distinguish between species is their genitalia.{{Cite journal |last1=Costa-Schmidt |first1=Luiz Ernesto |last2=Araújo |first2=Aldo Mellender de |date=August 2010 |title=Genitalic variation and taxonomic discrimination in the semi-aquatic spider genus Paratrechalea (Araneae: Trechaleidae) |url=https://bioone.org/journals/the-journal-of-arachnology/volume-38/issue-2/JOA_A09-75.1/Genitalic-variation-and-taxonomic-discrimination-in-the-semi-aquatic-spider/10.1636/JOA_A09-75.1.full |journal=The Journal of Arachnology |volume=38 |issue=2 |pages=242–249 |doi=10.1636/JOA_A09-75.1 |issn=0161-8202}} Sexual selection is the driver of genitalia diversity. Also, there can be intraspecific and interspecific divergence that influences genitalia diversity. Intraspecific divergences deals with variation within the same species. Interspecific divergences is the variation between different species. In P. ornata species, there is a clear intraspecific divergence in genitalia shape morphology between the Uruguayan and Brazilian populations; there is a morphological interspecific divergence in P. azul, P. ornata, and P. galianoae.

There are reproductive conflicts within and between P. azul and P. ornata. P. azul males mistakenly mate with heterospecific (from a different species) females at a higher rate than P. ornata males. However, P. ornata males tend to be preyed upon and lose their nuptial gift more often when encountering a heterospecific female.

The P. ornata have two reproductive periods: March to June and September to December, males offer a nuptial gift and court on the stream edge.{{Cite journal |last1=Albo |first1=Maria J. |last2=Pavón-Peláez |first2=Camila |last3=Villar |first3=Mauro Martínez |last4=Buzatto |first4=Bruno A. |last5=Tomasco |first5=Ivanna |date=2023-07-27 |title=Stressful environments favor deceptive alternative mating tactics to become dominant |journal=BMC Biology |volume=21 |issue=1 |pages=162 |doi=10.1186/s12915-023-01664-5 |issn=1741-7007 |pmc=10375696 |pmid=37501205 |doi-access=free}} In Brazil, P. azul and P. ornata, their reproductive season overlaps from October to February.{{Cite journal |last1=Costa-Schmidt |first1=L.E. |last2=Machado |first2=G. |date=November 2012 |title=Reproductive interference between two sibling species of gift-giving spiders |url=http://dx.doi.org/10.1016/j.anbehav.2012.08.026 |journal=Animal Behaviour |volume=84 |issue=5 |pages=1201–1211 |doi=10.1016/j.anbehav.2012.08.026 |issn=0003-3472|url-access=subscription }} These two species tend to mate with each other because they phenotypically look similar to each other. Females provide silk for males, the females pheromones attract males,{{Cite journal |last1=Macedo-Rego |first1=Renato C. |last2=Costa-Schmidt |first2=Luiz Ernesto |last3=Machado |first3=Glauco |date=August 2021 |title=Males of a Neotropical spider adjust prey-gift construction but not mate search in response to sperm competition |url=https://onlinelibrary.wiley.com/doi/10.1111/eth.13202 |journal=Ethology |language=en |volume=127 |issue=8 |pages=661–668 |bibcode=2021Ethol.127..661M |doi=10.1111/eth.13202 |issn=0179-1613|url-access=subscription }} the males use the silk to wrap a nutritious nuptial gift.{{Cite web |first=Hannah |last=Krakauer |title=Zoologger: The spiders hit by fatal courtship muddles |url=https://www.newscientist.com/article/dn22344-zoologger-the-spiders-hit-by-fatal-courtship-muddles |access-date=2024-03-05 |website=New Scientist |language=en-US}}

The chelicerae of female and male in Paratrechalea spiders are shown to have a size and color dimorphism, which can be due to male courtship signaling.{{Cite journal |last1=Costa-Schmidt |first1=L. E. |last2=De Araújo |first2=A. M. |date=2008 |title=Sexual dimorphism in chelicerae size in three species of nuptial-gift spiders: a discussion of possible functions and driving selective forces |journal=Journal of Zoology |volume=275 |issue=3 |pages=307–313 |doi=10.1111/j.1469-7998.2008.00442.x}} The chelicerae trait is shown to be a male-biased sexual trait when compared to the female chelicerae size.  

Paratrechalea are in the Trechaleidae family. The males in the Trechaleidae and Pisauridae families provide nuptial gifts during mating.{{Cite journal |last1=Martínez-Villar |first1=Mauro |last2=Germil |first2=Mariana |last3=Pavón-Peláez |first3=Camila |last4=Costa-Schmidt |first4=Luiz Ernesto |last5=Albo |first5=Maria J. |date=September 2020 |title=Empty nuptial gifts: a further step in the evolution of deception in spiders? |url=https://bioone.org/journals/the-journal-of-arachnology/volume-48/issue-2/0161-8202-48.2.214/Empty-nuptial-gifts--a-further-step-in-the-evolution/10.1636/0161-8202-48.2.214.full |journal=The Journal of Arachnology |volume=48 |issue=2 |pages=214–217 |doi=10.1636/0161-8202-48.2.214 |issn=0161-8202|url-access=subscription }} Sexual selection favors nuptial gifts as it provides females direct benefits. P. azul, P. ornata, and P. galianoae have all shown to provide a nuptial gift. Female silk is used by males to create nuptial gift, the silk has pheromones that attract males.{{Cite journal |last1=Macedo-Rego |first1=Renato C. |last2=Costa-Schmidt |first2=Luiz Ernesto |last3=Machado |first3=Glauco |date=August 2021 |title=Males of a Neotropical spider adjust prey-gift construction but not mate search in response to sperm competition |url=https://onlinelibrary.wiley.com/doi/10.1111/eth.13202 |journal=Ethology |language=en |volume=127 |issue=8 |pages=661–668 |bibcode=2021Ethol.127..661M |doi=10.1111/eth.13202 |issn=0179-1613|url-access=subscription }} Chemical cues are important to distinguish the sex in order to increase their chances of mating. Female attraction to nuptial gifts with elaborate silk wrapping could have led the for worthless gift-giving.{{Cite journal |last1=Pavón-Peláez |first1=Camila |last2=Franco-Trecu |first2=Valentina |last3=Pandulli-Alonso |first3=Irene |last4=Jones |first4=Therésa M. |last5=Albo |first5=Maria J. |date=2022-01-05 |title=Beyond the prey: male spiders highly invest in silk when producing worthless gifts |journal=PeerJ |language=en |volume=10 |pages=e12757 |doi=10.7717/peerj.12757 |issn=2167-8359 |pmc=8742539 |pmid=35036108 |doi-access=free}} Recently the genus Paradossenus, the species P. longpies have demonstrated to wrap a nuptial gift both in the lab and field. There are males that spend more time wrapping worthless gifts, even when there are nutritious prey that could be wrapped. The evolution of worthless gift wrapping might be condition or resource dependent.

Although the chelicerae serves as an intersexual signaler, it is a functional trait for prey capture.{{Cite journal |last1=Costa-Schmidt |first1=L. E. |last2=De Araújo |first2=A. M. |date=2008 |title=Sexual dimorphism in chelicerae size in three species of nuptial-gift spiders: a discussion of possible functions and driving selective forces |journal=Journal of Zoology |volume=275 |issue=3 |pages=307–313 |doi=10.1111/j.1469-7998.2008.00442.x}} Females gain direct benefits when mating with males that provide nuptial gifts. Direct benefits consist of a male providing food, territory, or resources for the female in order to increase their chances to mate. However, in P. ornata species, males provide a nuptial gift that can be either be nutritive or worthless.{{Cite journal |last1=Pandulli-Alonso |first1=Irene |last2=Tomasco |first2=Ivanna H. |last3=Albo |first3=Maria J. |date=March 2022 |title=The handsome liar: Male spiders offering worthless gifts can benefit increasing mating duration |url=https://onlinelibrary.wiley.com/doi/10.1111/eth.13258 |journal=Ethology |language=en |volume=128 |issue=3 |pages=215–222 |bibcode=2022Ethol.128..215P |doi=10.1111/eth.13258 |issn=0179-1613|url-access=subscription }} Males that provide worthless gifts enhance their mating success by transferring more sperm. Males adjust their gift type when there is sperm competition risk. Moreover, male size and gift type impact mating duration, which increases female spiderlings. Female receptivity varies with age. Young females invest more time foraging and maturing, while older females are more receptive to mate.{{Cite journal |last1=Klein |first1=André L. |last2=Trillo |first2=Mariana C. |last3=Albo |first3=Maria J. |date=April 2012 |title=Sexual receptivity varies according to female age in a Neotropical nuptial gift-giving spider |url=https://bioone.org/journals/the-journal-of-arachnology/volume-40/issue-1/H11-31.1/Sexual-receptivity-varies-according-to-female-age-in-a-Neotropical/10.1636/H11-31.1.full |journal=The Journal of Arachnology |volume=40 |issue=1 |pages=138–140 |doi=10.1636/H11-31.1 |issn=0161-8202}} Older females tend to accept more gifts, however, there was no difference between young and older females in the latency to accept a gift. Although females are regarded as the choosier sex, P. ornata males have shown to be selective with whom they mate; males tend to mate with good condition females.{{Cite journal |last1=Solano-Brenes |first1=Diego |last2=Costa-Schmidt |first2=Luiz Ernesto |last3=Albo |first3=Maria Jose |last4=Machado |first4=Glauco |date=2021-07-08 |title=Differential allocation in a gift-giving spider: males adjust their reproductive investment in response to female condition |journal=BMC Ecology and Evolution |volume=21 |issue=1 |pages=140 |doi=10.1186/s12862-021-01870-1 |issn=2730-7182 |pmc=8268551 |pmid=34238218 |doi-access=free}} The quality of the gift varies depending on the condition of the female.

There are many hypotheses that try to explain why nuptial gifting spiders even provide a gift to females, such as mating effort hypothesis, sexual cannibalism, and parental investment. In P. ornata, there is a strong support for the male effort hypothesis, which highlights that males are more in control over mating duration and females ability to remate, higher mating success, and ability to transfer more sperm.{{Cite journal |last1=Albo |first1=María J. |last2=Costa |first2=Fernando G. |date=2010-05-01 |title=Nuptial gift-giving behaviour and male mating effort in the Neotropical spider Paratrechalea ornata (Trechaleidae) |url=https://www.sciencedirect.com/science/article/pii/S0003347210000400 |journal=Animal Behaviour |volume=79 |issue=5 |pages=1031–1036 |doi=10.1016/j.anbehav.2010.01.018 |issn=0003-3472|url-access=subscription }}

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Category:Trechaleidae

Category:Araneomorphae genera

Category:Spiders of South America

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