“`html
Satyrex ferox is among four freshly identified tarantula species whose males display remarkably elongated genitalia.(Image credit: Zamani et al. 2025 (Redistributed under the terms of Creative Commons licence CC BY 4.0))ShareShare by:
- Duplicate link
- X
Share this article 0Participate in the discussionFollow usInclude us as a favored source on GoogleNewsletterRegister for our newsletter
Researchers needed to devise an entirely new spider family, as four new species of tarantulas exhibited genitalia so lengthy that they defied categorization within any existing group.
The research group infers that the males have cultivated this extraordinary appendage to maintain a significant separation from combative females, renowned for consuming their mates during copulation.
The typical genital length of male tarantulas measures approximately 1.5 to 2 times the cumulative length of their head and thorax. However, as highlighted in a recent study, the newfound spiders’ palpi — specialized limbs employed for sperm transfer during mating — are quadruple the length of their torsos and nearly half the length of their longest legs.
You may like
-
Minuscule spiders constructing sizable ‘puppet’ lures out of disassembled prey were observed in Peru and the Philippines
-
The world’s most expansive spiderweb was discovered inside a ‘Sulfur Cave,’ harboring 111,000 arachnids dwelling in total darkness
-
Scientists have completed the sequencing of the vampire squid’s substantial genome, revealing the secrets of the ‘living fossil’
“The males belonging to these spiders possess the most extended palpi observed among all recognized tarantulas,” articulated Alireza Zamani, the leading author of the investigation and an arachnologist based at the University of Turku in Finland, in a formal declaration. “Based on both morphological and molecular insights, their divergence from their closest relatives necessitated the establishment of an entirely new genus for their categorization, which we have designated as Satyrex.”
The designation Satyrex is derived from a blend of the terms “satyr” and “rex.” In classical Greek lore, a satyr embodies a male spirit of nature, characterized by a human upper torso coupled with the lower anatomy of a goat or horse, while “rex” represents the Latin descriptor for a king. As per the declaration, satyrs are frequently portrayed with markedly oversized genitalia.
These newly discovered tarantulas reside within ground-level lairs and frigid crevices amongst rocks situated on the Arabian Peninsula and along the Horn of Africa. Zamani, along with his fellow researchers, initially encountered Satyrex arabicus in Saudi Arabia, captured visual documentation of Satyrex ferox across Yemen and Oman, and provided comprehensive descriptions of Satyrex somalicus and Satyrex speciosus within Somaliland. Their conclusions were disclosed on July 22 within the pages of the journal ZooKeys.
Within the assemblage of four newly identified species, S. ferox stands out as the most substantial and aggressive, therefore justifying its nomenclature. Both male and female specimens showcase leg spans reaching approximately 5.5 inches (14 centimeters), while the males’ palpi extend to an extraordinary length of 2 inches (5 cm), potentially offering a protective safeguard against cannibalistic tendencies exhibited by females during mating encounters.
“We have tentatively posited that the elongated palpi may enable the male to sustain a safer separation throughout copulation, thereby mitigating the prospect of being assailed and consumed by the profoundly aggressive female,” Zamani elucidated.
A figure representing the palpi of the newfound tarantula types S. ferox (C), S. arabicus (D), S. speciosus (E), and S. somalicus (F). The palpi labeled A and B are associated with the tarantula species Monocentropus balfouri and Monocentropus lambertoni, respectively. The depicted scale bars are 2 millimeters in length.
The species also exhibits a high degree of defensiveness. “Upon encountering even the most trivial disturbance, it elevates its forelegs in a menacing stance and emits a strident hissing sound by abrading specialized bristles situated on the foundational segments of its forelegs against one another,” Zamani detailed.
RELATED STORIES
—Shaggy colossal tarantula: The titan amongst miniature tarantulas boasting ‘feather duster’ legs
—Tarantulas established their dominance on Earth via expansion across a supercontinent, followed by dispersal across its fragmented segments throughout the ocean
—Parasitic nematode compels tarantulas to perform a tiptoeing gait, culminating in starvation-induced demise
Molecular alongside phylogenetic evaluations, through which scientists retrace a species’ evolutionary lineage via genetics, unveiled that a tarantula previously cataloged under the genus Monocentropus bears a more intimate kinship with Satyrex spiders. Researchers initially categorized Monocentropus longimanus stemming from Yemen back in 1903, though the spider has since undergone reclassification as Satyrex longimanus.
“The conspicuously elongated palpi observed in S. longimanus, in conjunction with the four recently characterized species, served among the pivotal traits steering us toward the construction of a novel genus for these spiders, rather than incorporating them within Monocentropus,” Zamani elucidated. “Within the realm of tarantula taxonomy, at the least, it appears that magnitude genuinely carries significance.”
Spider quiz: Test your web of knowledgeTOPICSnewfound species
Sascha PareSocial Links NavigationStaff writer
Sascha serves as a U.K.-based staff scribe for Live Science. She possesses a bachelor’s academic degree in biology obtained from the University of Southampton nestled in England and a master’s degree in the discipline of science communication earned from Imperial College London. Her literary works have graced the pages of The Guardian alongside the health-focused website Zoe. Beyond the domain of writing, she is passionate about tennis, the craft of bread-making, and the exploration of thrift repositories in pursuit of undiscovered treasures.
Show More Comments
It is compulsory to verify your displayed public designation prior to participation in commentary
Kindly sign out, then subsequently sign back in; this sequence will prompt you to input your designation.
LogoutRead more
Minuscule spiders constructing sizable ‘puppet’ lures out of disassembled prey were observed in Peru and the Philippines
The world’s most expansive spiderweb was discovered inside a ‘Sulfur Cave,’ harboring 111,000 arachnids dwelling in total darkness
Scientists have completed the sequencing of the vampire squid’s substantial genome, revealing the secrets of the ‘living fossil’
‘A forest with bonobos has never been so quiet’: Most extreme case of violence in ‘hippie’ species recorded, with females ganging up on male in unprecedented attack
Newly discovered toads bypass the tadpole phase, yielding the birth of live ‘toadlets’
In South Africa, a ‘butt drag fossil’ — a unique find — was identified, left behind by a fuzzy elephant kin 126,000 years prior
Latest in Spiders
Minuscule spiders constructing sizable ‘puppet’ lures out of disassembled prey were observed in Peru and the Philippines
The world’s most expansive spiderweb was discovered inside a ‘Sulfur Cave,’ harboring 111,000 arachnids dwelling in total darkness
Spiders are observed to keep fireflies captive as luminous detainees, luring additional prey to their webs