The Ander’s organ: A mechanism for Anti-predator Ultrasound in a Relict Orthopteran

Woodrow, Charlie, Judge, Kevin, Pulver, Christian Adlai , Jonsson, Thorin and Montealegre-Z, Fernando (2021) The Ander’s organ: A mechanism for Anti-predator Ultrasound in a Relict Orthopteran. Journal of Experimental Biology . ISSN 0022-0949

Full content URL: https://doi.org/10.1242/jeb.237289

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The Ander’s organ: A mechanism for Anti-predator Ultrasound in a Relict Orthopteran
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Abstract

The use of acoustics in predator evasion is a widely reported phenomenon amongst invertebrate taxa, but the study of ultrasonic anti-predator acoustics is often limited to the prey of bats. Here, we describe the acoustic function and morphology of a unique stridulatory structure in the relict orthopteran Cyphoderris monstrosa (Ensifera, Hagloidea): the Ander’s organ. This species is one of just eight remaining members of the family Prophalangopsidae, a group with a fossil record of over 90 extinct species widespread during the Jurassic. We reveal that the sound produced by this organ has the characteristics of a broadband ultrasonic anti-predator defence, with a peak frequency of 58 ± 15.5 kHz and a bandwidth of 50 kHz (at 10 dB below peak). Evidence from sexual dimorphism, knowledge on hearing capabilities and assessment of local predators, suggest the signal likely targets ground-dwelling predators. Additionally, we reveal a previously undescribed series of cavities underneath the organ that likely function as a mechanism for ultrasound amplification. Morphological structures homologous in both appearance and anatomical location to the Ander’s organ are observed to varying degrees in 4 of the 7 other extant members of this family, with the remaining 3 yet to be assessed. Therefore, we suggest that such structures may either be more widely present in this ancient family than previously assumed, or have evolved to serve a key function in the long-term survival of these few species, allowing them to outlive their extinct counterparts.

Keywords:Grig, insect, bioacoustics, predation, secondary defences, ancient
Subjects:C Biological Sciences > C180 Ecology
C Biological Sciences > C770 Biophysical Science
C Biological Sciences > C300 Zoology
C Biological Sciences > C340 Entomology
Divisions:College of Science > School of Life Sciences
ID Code:43197
Deposited On:11 Dec 2020 12:13

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