Draft:Patagonian dragon (Andiperla willinki)

Patagonian dragon (Andiperla willinki), Andes pearl or glacier stonefly is a metazoan organism belonging to the Plecoptera order, first described by the French entomologist Aubert Willink in 1956 (1).  It is a extremophile organism (extreme adaptation) able to thrive in the challenging environments present in South American glaciers.    

The Patagonian dragon may have relevance for global biogeochemical cycles affecting melting rates of snow and ice in glacier environments (2, 3) such as in the Upsala glacier (Santa Cruz, Argentina) where it was first discovered.

This metazoan organism is the largest insect completing its entire life cycle on glaciers from the Northern and Southern Patagonian Icefields in the countries of Argentina and Chile.  Adult A. willinki may reach up to 2.5 cm in length.

The Patagonian dragon can be found on the surface of glaciers near moulins, crevasses, ice pools and in the water.  Its hemolymph has a natural, glycerol-based antifreeze which keeps its body from freezing on the glacier subzero temperatures.  A. willinki nymphs submerge in meltwater pools on the glacier surface and feed on the bacteria/algae-rich sediment, called cryoconites.  This sediment is composed of algae, cyanobacteria and heterotrophic microorganisms.  A. willinki can also feed on smaller animals inhabiting the cryoconite sediment, such as springtails (4).

The adult Patagonian dragons are wingless and wander on the glacier surface, searching for prey and/or mating partners (5).  In 2018 Japanese researchers conducted analyses of the 16S rRNA gene amplicon and metagenomic sequencing in gut microbiome collected from A. willinki aquatic nymphs.  Their results indicated that Polaromonas and Dysgonomonadaceae bacterial phylotypes are the dominant bacterial taxa present in the gastrointestinal tract of the Patagonian dragon.  Besides being a source of nourishment, Dysgonomonadaceae bacteria has a role in assisting with the breakdown of polysaccharides derived from A. willinki-ingested food, such as algae, and that other dominant bacterial lineages, further contributing to polysaccharide degradation and thus host nutrition (5).

In 2019, Argentinian researchers identified a new, closely related species to A. willinki sampling the Perito Moreno glacier also in Santa Cruz, Argentina.  The new species, A., morenensis, differs from A. willinki in that the latter has a larger size, apterous condition, has large compound eyes, its head is wider than its prothorax, and lacks ocelli. The Argentinian team also provided 18S rRNA and COI gene sequences and morphological characteristics that further differentiate A. morenensis from A. willinki (6).

Insect

Order: Plecoptera

Family: Gripopterygiidae

Subfamily: Paragripopteryginae

Genus: Andiperla

Species: Andiperla willinki

References

1.      Aubert, J. (1956) Andiperla willinki n. sp., Plécoptère nouveau des Andes Patagonie. Mitteilungen der Schweizerischen entomologischen Gesellschaft, 29(2), 229–232.

2.      Ganey, G. Q., Loso, M. G., Burgess, A. B., and Dial, R. J. 2017. The role of microbes in snowmelt and radiative forcing on an Alaskan icefield. Nat Geosci 10, 754-759.

3.      Musilova, M., Tranter, M., Wadham, J., Telling, J., Tedstone, A., Anesio, A.M. 2017. Microbially driven export of labile organic carbon from the Greenland ice sheet. Nat Geosci 10, 360-365.

4.      Takeuchi, N., Kohshima, S. 2004, A snow algal community on Tyndall glacier in the southern Patagonia icefield, Chile. Arctic Antarct Alp Res 36: 92–99.

5.      Murakami, T., Segawa, T., Takeuchi, N., Barcaza-Sepulveda, G., Labarca, P., Kohshima, S., Hongoh, Y. 2018. Metagenomic analyses highlight the symbiotic association between the glacier stonefly Andiperla willinki and its bacterial gut community. Environmental Microbiology 20 (11), 4170-4183.

6.      Pessacq, P., Rivera-Pomar, R. 2019. A new Andiperla Aubert (Plecoptera, Gripopterygidae) species from the Perito Moreno Glacier, Argentina. Zootaxa 4664 (2): 251–260