 |
| Ameronothrus retweet Pfingstl & Shimano, in Pfingstl, Hiruta, ... et Shimano, 2022. |
ABSTRACT
The recent discovery of the oribatid mite Ameronothrus twitter via a social media platform resulted in a considerable media response and raised the awareness of the public for these tiny organisms. As a direct consequence, another new marine associated ameronothroid species was now discovered via the same social media service. Moreover, the record of this new species, Ameronothrus retweet sp. n., represents the first report of an ameronothroid taxon from the Sea of Japan coast, indicating that this coastline was successfully colonized by these organisms and that further species could be present there. Ameronothrus retweet sp. n. shows an extraordinary sexual dimorphism with females having relatively shorter legs and a strongly folded notogastral integument. Based on morphological characteristics, it is suggested that the new species is closest related to Ameronothrus lineatus and Ameronothrus nigrofemoratus. A molecular genetic investigation of selected ameronothroid taxa, using the 18S rRNA gene, shows that all Ameronothrus species are closely related and represent a distinct monophyletic genus. In a larger phylogenetic context, the Fortuyniidae and Selenoribatidae are given as sister taxa with a monophyletic origin, whereas certain members of Ameronothridae are placed in paraphyletic positions, supporting theories of an independent origin of the marine associated lifestyle in ameronothroid mites.
KEYWORDS: Littoral, Honshu island, cool temperate zone, Ameronothridae, Twitter
 |
| Photographs of male (upper row) and female (lower row) Ameronothrus retweet sp. n. specimens in dorsal (left side) and ventral view (right side). |
Family Ameronothridae Vitzthum, 1942
Genus Ameronothrus Berlese, 1896
Type species – Eremaeus lineatus Thorell, 1871
Ameronothrus retweet Pfingstl and Shimano sp. nov.
[New Japanese name: Iwado-hamabe-dani]
Differential diagnosis: The colour is dark brown, nearly black. Body length is 641–859 µm. In centrodorsal notogastral cuticle with dense granulation, lateral parts are covered with larger granules. Prodorsal lamellar keels are converging. Short clavate sensilli are present. Interlamellar and exobothridial setae are absent. Labiogenal articulation is complete. One pair of adanal setae located posteriorly of anal orifice. Remarkable sexual dimorphism is present, females with strongly folded gastronotic integument and considerably shorter epimeral, genital, and aggenital setae. Male spermatopositor conspicuously elongated, female ovipositor very short. Primilateral setae pl on tarsus I are present. Dorsal companion seta d on genu I, II, and III and all tibiae are present. Tarsal distal setae end with a small nodule. Juveniles is unknown.
Etymology: The specific name ‘retweet’ is given as noun in apposition. “Retweet” is used as both a verb and noun on the social media application Twitter (twitter Inc.) and means repost or forward a message. The present work does not represent a direct act of retweeting in a strict sense, but the species was discovered by a post as a response to the message about the discovery of A. twitter.
Tobias Pfingstl, Shimpei F. Hiruta, Iris Bardel-Kahr, Yuito Obae and Satoshi Shimano. 2022. Another Mite Species discovered via Social Media - Ameronothrus retweet sp. nov. (Acari, Oribatida) from Japanese Coasts, exhibiting An Interesting Sexual Dimorphism. International Journal of Acarology. 48(4-5); 348-358. DOI: 10.1080/01647954.2022.2074538
