• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.616-626
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• 2023

In May 2023, a free-living marine nematode species from the genus Parapinnanema was identified in the subtidal zone of Ulleungdo Island, the East Sea, Korea. Specimens were collected using the Smith-McIntyre Grab. These specimens exhibited close similarities to Parapinnanema imbricatum from the sublittoral of Moneron Island, particularly in terms of general characteristics, such as the detailed structure of the buccal cavity, the complex and ringed structure of the cuticle, the copulatory apparatus, spinneret, and the female genital system. However, the Korean specimens of Parapinnanema imbricatum also displayed distinctive features compared to the original description, including a relatively elongated body (3,317-4,339 ㎛ vs. 3,100-4,200 ㎛) and a narrower body width (66-77 ㎛ vs. 71-85 ㎛). Additionally, the diameter of the head was relatively shorter(24-29 ㎛ vs. 28-36 ㎛). This paper offers a comprehensive morphological description, along with illustrations and DIC photomicrographs, of P. imbricatum from Korean waters.