Neocaridina aff. denticulata (De Haan, 1844)

Shih, Hsi-Te, Cai, Yixiong, Niwa, Nobuaki, Yoshigou, Hidenori & Nakahara, Yasuhiko, 2024, Fig. 4. A in Positive association between PTN polymorphisms and schizophrenia in Northeast Chinese Han population., Zoological Studies 63 (18), pp. 141-149 : 22-25

Neocaridina aff. denticulata ( Fig. 13 )

Specimens examined: Japan: 3 males, cl 3.5–4.6 mm, ZRC 2023.0221, Sugo R., Yumesaki R i v e r s y s t e m, H i m e j i C i t y, H y o g o P r e f e c t u r e, N34°56'31.9", E134°38'19.0'', coll. N. Niwa, 14 Aug. 2015; 8 males, cl 4.6–5.5 mm, 15 females, cl 5.5–5.9 mm, ZRC 2023.0222, Oura upstream way (on Oura Dam), Izuharamachi-koura, Tsushima City, Nagasaki Prefecture, N34°14'1.9'', E129°17'45.7'', coll. H. Yoshigou, 15 Dec. 2016; 7 males, cl 5.2–6.0 mm, 10 females, cl 4.5–7.4 mm, ZRC 2023.0223, Takahama R., Mitsushimamachi-kechikou, Tsushima-shi, Tsushima City, Nagasaki Prefecture, N34°15'32.4'', E129°18'47.5'', coll. H. Yoshigou, 16 Dec. 2016.

Remarks: Neocaridina aff. denticulata is similar to N. denticulata in the general appearance of the rostrum, the absence of sexual dimorphism in the third pereiopods, and the appendix masculina of the male second pleopods. However, it can be distinguished by its relatively shorter rostrum which reaches to or near to the end of the antennular peduncle (vs. mostly reaching beyond the antennular peduncle in N. denticulata ); the exopod of the male first pleopods is 1.5 times as long as wide (vs. 1.2 times in N. denticulata ); and the carpus of the first pereiopods is stouter ( Fig. 13 ) (vs. slender in N. denticulata ).

Its distribution is confined to western Japan, encompassing western Honshu and Kyushu. The phylogenetic relationship with other species ( Fig. 3 ) suggests that it is most probably a cryptic native species, which may have long been mistaken for N. denticulata .

Figures

Fig. 13. Neocaridina aff. denticulata Kubo, 1938. (A) cephalothorax and cephalic appendages, lateral view; (B) telson; (C) distal portion of telson; (D) preanal carina; (E) scaphocerite; (F) 1st pereiopod; (G) 2nd pereiopod; (H) 3rd pereiopod; (I) the same, dactylus; (J) 5th pereiopod; (K) the same, dactylus; (L) male 1st pleopod; (M) male 2nd pleopod; (N) uropodal diaeresis. Scale bars: A, E = 2 mm; B, D, F–H, J = 0.5 mm; C, I, K, L, M, N = 0.2 mm (male, cl 5.5 mm, ZRC 2023.0222, Oura upstream way (on Oura Dam), Izuharamachi-koura, Tsushima City, Nagasaki Prefecture, N34°14'1.9'', E129°17'45.7'', coll. H. Yoshigou, 15 Dec. 2016).

Fig. 3. Bayesian inference (BI) tree for species of the genus Neocaridina from the East Asia Arc and the related taxa from East Asia, based on the cytochrome c oxidase subunit I (COI) gene. Probability values at the nodes represent support values for BI and maximum likelihood (ML). Only support values> 50% are shown on the nodes. For haplotype names, see table 1. *, sequences downloaded from GenBank.