open access

https://hdl.handle.net/2115/98946

A new Nectonema nematomorph species parasitic in an alpheid shrimp (Decapoda: Caridea)

英語

2026-02-27

Cambridge University Press

Journal of Helminthology

100

e23

We describe the marine horsehair worm Nectonema shimadai sp. nov., which was parasitic in a snapping shrimp (Alpheus sp.) collected at 4 m depth from the coastal water of Kikaijima Island, Japan, northwestern Pacific. The nematomorph was a female, 49 mm in length and 340 μm in width, salmon-pink when alive, with a translucent anterior body region and a distinct anterior chamber. The 18S sequence from N. shimadai sp. nov. was 12.8%, 9.8%, 9.6%, and 9.3% divergent in Kimura 2-parametar (K2P) distance from Nectonema sp. parasitic in the isopod Natatolana japonensis, Nectonema sp. parasitic in the crab Chionoecetes bairdi, N. munidae, and N. agile, respectively. In an 18S tree, N. shimadai sp. nov. was the sister taxon to a clade comprising three decapod-parasitic species, and species sharing the same host group or ocean were not monophyletic. The tree may reflect genetically distant warm- and cold-water lineages within decapod-parasitic nematomorphs.

学術雑誌論文

Accepted Manuscript

This article has been published in a revised form in Journal of Helminthology. https://doi.org/10.1017/S0022149X26101229. This version is free to view and download for private research and study only. Not for re-distribution or re-use. © copyright holder.

0022-149X

1475-2697