A new millipede-parasitizing horsehair worm, Gordius chiashanus sp. nov., at medium altitudes in Taiwan (Nematomorpha, Gordiida)

By

Chiu, Ming-Chung
Huang, Chin-Gi
Wu, Wen-Jer
Lin, Zhao-Hui
Chen, Hsuan-Wien
Shiao, Shiuh-Feng

Type

Article

Date of Publication

2020

Original Publication

ZooKeys

Volume

941

Pages

25--48

Subjects

definitive host , immature stage , parasitic life cycle , terrestrial adaptation

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.941.49100

 

Abstract

Gordius chiashanussp. nov., a newly described horsehair worm that parasitizes the Spirobolus millipede, is one of the three described horsehair worm species in Taiwan. It is morphologically similar to G. helveticus Schmidt-Rhaesa, 2010 because of the progressively broadening distribution of bristles concentrated on the male tail lobes, but it is distinguishable from G. helveticus because of the stout bristles on the mid-body. In addition, a vertical white stripe on the anterior ventral side and areoles on the inside wall of the cloacal opening are rarely mentioned in other Gordius species. Free-living adults emerged and mated on wet soil under the forest canopy in the winter (late November to early February) at medium altitudes (1100–1700 m). Mucus-like structure covering on the body surface, which creates a rainbow-like reflection, might endow the worm with high tolerance to dehydration. Although Gordius chiashanussp. nov. seems to be more adaptive to the terrestrial environment than other horsehair worm species, cysts putatively identified as belonging to this hairworm species found in the aquatic paratenic host, Ephemera orientalis McLachlan, 1875, suggest the life cycle of Gordius chiashanussp. nov. could involve water and land. The free-living adults emerged from the definitive hosts might reproduce in the terrestrial environment or enter an aquatic habitat by moving or being washed away by heavy rain instead of manipulating the behavior of their terrestrial definitive hosts.