Parasesarma dumacense ( Rathbun, 1914 )

Li, Jheng-Jhang, Shih, Hsi-Te & Ng, Peter K. L., 2019, Fig. 1. Norileca indica and its protandrous hermaphroditic reproductive system. A in Chloeia incerta de Quatrefages 1866, Zoological Studies 58 (40), pp. 1-23 : 19-20

Parasesarma dumacense ( Rathbun, 1914) ( Fig. 12C, D )

Sesarma (Parasesarma) dumacensis Rathbun, 1914: 80 ; Tesch 1917: 146.

Parasesarma dumacense — Ng et al. 2008: 222; Rahayu & Ng 2010: 15, figs. 11–14; Maenosono & Naruse 2015: 3, figs. 2A–C, 3, 11A, B.

Material examined: 1 ò (13.9 × 11.1 mm) (NCHUZOOL 15704), coll. C.-Y. Chi et al., 12 Jun. 2019; 1 ò (23.9 × 19.1 mm) (NCHUZOOL 16088), coll. C.-Y. Chi et al., 19 Aug. 2019. See Rahayu & Ng (2010: 15) for additional material.

Remarks: This species was previously only reported in Luzon and Cebu, Philippines ( Rathbun 1914; Rahayu and Ng 2010), as well as the Ryukyus, Japan (Maenosono and Naruse 2015). Parasesarma dumacense is sister to P. ungulatum , but the phylogenetic relationship of the two species is not clear ( Fig. 13 ). The species has been treated at length by Rahayu and Ng (2010) and there is no need to elaborate on its taxonomy here.

DNA ANALYSIS

The molecular analysis of the COI marker, with 658 base pairs, comprised 23 species of Parasesarma from 85 specimens ( Table 1). The BI tree, with ML support values on the nodes ( Fig. 13 ), shows that the three new species in this study are well supported genetically. Parasesarma sanguimanus is distinct, but closely related to P. bidens and P. cricotus . The three species form a main clade with P. bengalense and P. guttatum . Parasesarma aurifrons is sister to P. liho , although the node is only moderately supported. The two species and P. paucitorum form a main clade, sister to another main clade, composed of P. lenzii , P. kui Li, Rahayu & Ng, 2018 , and P. macaco Li, Rahayu & Ng, 2018 . Parasesarma gemmatum is sister to P. anambas , but their phylogenetic positions cannot be confirmed from the tree at the moment.

Figures

Fig. 12. Coloration in life. (A, B) Parasesarma lenzii (De Man, 1895), male (CW about 15 mm, not collected) from Tanzih Fishing Port, Hengchun, Pingtung, Taiwan; (C, D) P. dumacense (Rathbun, 1914), male (23.9 × 19.1 mm, NCHUZOOL 16088) from Dongsha Island, Taiwan.

Fig. 13. A Bayesian inference (BI) tree for species of Parasesarma, based on the cytochrome c oxidase subunit I (COI) gene. Probability values at the nodes represent support values for BI and maximum likelihood (ML). For haplotype names, see table 1.