Derogenes minor Looss, 1901

Ji, Su-Jung, Jung, Chuleui, Bang, Hyun Woo, Song, Min Ok, Jung, Jongwoo, Yoon, Seong Myeong, Lee, Seunghwan, Keum, Seoyoung, Yang, Hee-Min, Lee, Dongmin, Lee, Geon Hyeok, Oh, Jaeseok, Kim, Kichoon, Park, Hansol, Moon, Heejin, Joharchi, Omid, Kang, Yeseul, Eom, Keeseon S., Lee, Kyung Jin, Eun, Ye, Kim, Taeho, Karanovic, Ivana, Lee, Jeounghee, Choe, Seongjun & Min, Gi-Sik, 2023, Unrecorded species of Korean invertebrates discovered through the project of ‘ Discovery of Korean Indigenous Species’ II, Journal of Species Research 12 (1), pp. 68-89 : 70

3. Derogenes minor Looss, 1901 ( Fig. 3 )

āNjŦō난Ḃů충 (ṵAE)

Material examined. Pohang-si; collected from Spiny red gurnard, Chelidonichthys spinosus , purchased at Jukdo Market ; collected by YS Kang and DM Lee on 3 May 2017 .

Deposition. NIBRIV0000879447.

World distribution. Adriatic Sea and East Sea of Korea.

Diagnosis. Body slender, maximum width at the level of the ventral sucker. The body is slender, fusiform with a sharply pointed posterior end, while the anterior end appears to be more rounded due to the oral sucker. Ventral sucker approximately one and a half times larger than oral sucker. The testes are tandem to slightly oblique, near the edge of the ventral sucker. The two vitelline are larger than other glands.

Remarks. This is the only report of this species since its first report in 1901 and it morphological features match well Looss’s original description, such as short vitelline lobe. Derogenes minor seems like it has a blind seminal receptacle instead of the Laurel’s canal and seminal receptacle.

Figures

Fig. 3. Adult worm of Derogenes minor Looss, 1901. Stained with Iron-hematoxylin solution. Scale bar=50μm.