Limnemertes poyangensis, Gibson & Wang, 2002

Kajihara, Hiroshi, 2025, A taxonomic revision of the freshwater monostiliferous hoplonemertean genus Prostoma Dugès, 1828 (Nemertea: Eumonostilifera): a radical solution or an over-lumping?, Zootaxa 5646 (4), pp. 451-500 : 471

20. poyangensis Gibson & Wang, 2002

Source. In the binomen Limnemertes poyangensis by Gibson & Wang (2002: 186).

Type locality. Poyang Lake, People’s Republic of China, in the northern Jiangxi Province at the junction between the middle and lower reaches of Changjiang (Yangtze) River , 28°25'– 29°45'N, 115°48'– 116°44'E ( Fig. 9 ) .

Etymology. Adjective, poyangensis , - is, - e, meaning “from Poyang”.

Remarks. Limnemertes poyangensis is the type species of Limnemertes Gibson & Wang, 2002 (gender feminine), fixed by original designation (Article 68.2). Gibson & Wang (2002) differentiated Limnemertes from Prostoma mainly by i) being gonochoristic (whereas Prosoma is hermaphroditic), ii) having a short rhynchocoel, less than half the body length (whereas it extends to approximately two-thirds in adult Prostoma ), and iii) the anteriorly divided body-wall longitudinal musculature. The first character is not convincing because the original description of L. poyangensis does not include any photomicrographs of the reproductive system. The second character is dubious because the measurement was conducted on fixed specimens cleared in xylene (ibid., p. 191) rather than on living state or sectioned material, and it may therefore be inaccurate. For the third character, see Discussion. Limnemertes poyangensis is herein considered synonymous with P. clepsinoides until future studies prove otherwise; thus, Limnemertes is a junior synonym of Prostoma ; the name poyangensis has not been combined with Prostoma .

Figures

FIGURE 9. World map showing distribution of 25 nominal species of freshwater monostiliferous hoplonemerteans indicated by boxes and respective species-group names (three subterranean species are indicated with ‘S’ in parentheses); circles, diamond, and triangles indicate localities of DNA-barcoded individuals; circles, Haplogroup 1 from the UK, Sweden (SE), Italy (IT), Macedonia (MK), Japan (JP), New Zealand (NZ), Mexico (MX), Indiana (IN), and Massachusetts (MA); diamond, Haplogroup 2 from Norway (NO); triangles, Haplogroup 3 from Sweden (SE) and California (CA).