Penaeus tenellus Bate, 1888: 270 Parapenaeopsis tenella Hall 1962: 26 Racek & Dall 1965: 108 Yu & Chan 1986: 126 Perez Farfante & Kensley 1997:121 Lee et al. 1999: 446 Parapenaeopsis tenellus Liu 1955: 16 Dall 1957: 221 Batepenaeopsis tenella Sakai & Shinomiya 2011: 498 De Grave & Fransen 2011: 213 Shinomiya & Sakai 2016: 505 Batepenaeopsis moresbyensis Shinomiya & Sakai, 2016: 498 On the penaeid shrimps of the genus Parapenaeopsis Alcock, 1901 (Crustacea, Decapoda) from Taiwan Hsu, Yen-Cheng Chan, Tin-Yam Zootaxa 2023 2023-11-01 5361 2 221 236 4784ecae-c478-4d8b-9f3d-4f87ed5829e9 (Bate, 1888) Bate 1888 [151,588,1724,1751] Malacostraca Penaeidae Parapenaeopsis GBIF Animalia Decapoda 8 229 Arthropoda species tenella  ( Figs. 4, 6e)      Penaeus tenellus Bate, 1888: 270( typelocality: Japan).    Parapenaeopsis tenella—  Hall 1962: 26, figs 100, 100a, b;  Racek & Dall 1965: 108, pl. 8-fig. 10, pl. 13-fig. 8;  Yu & Chan 1986: 126., 1 unnumbered fig;  Perez Farfante & Kensley 1997:121;  Lee et al.1999: 446.    Parapenaeopsis tenellus—  Liu 1955: 16, pl. 4–2, 5–6–9;  Dall 1957: 221, fig. 29.    Batepenaeopsis tenella—  Sakai & Shinomiya 2011: 498, figs. 2A, 4C;  De Grave & Fransen 2011: 213;  Shinomiya & Sakai 2016: 505: figs 4–5.  ?   Batepenaeopsis moresbyensis Shinomiya & Sakai, 2016: 498, fig 3 ( typelocality: Papua New Guinea).   Material examined.   Keelung City,  29 Jun 1982, 1 femalecl 16.7 mm( NTOU M02392);   27 Feb 1989, 1 malecl 8.9 mm, 1 femalecl 8.9 mm( NTOU M02495).   Miaoli County,  20 Mar 2001, 2 malescl 9.0– 9.5 mm, 4 femalescl 12.7–14.2 mm( NTOU M02393).   Diagnosis.Rostrum with 7–8 dorsal teeth but lacking epigastric tooth; horizontal and nearly straight, ventral border slightly concave, reaching between middle of second segment and middle of distal segment of antennular peduncle. Longitudinal suture long and extending to nearly posterior carapace. Pereiopods I and II bearing basial spines but lacking epipods. Pereiopod III without basial spine. Abdominal somites I–II without dorsal carina. Telson without movable lateral spinules. Male with normal endopod at pleopod II; petasma with small distomedian projections, distolateral projections triangularly elongated and directed proximolaterally. Female thelycum with anterior plate semicircular, surfaces sunken, posterior part with median longitudinal groove; posterior plate with anterior margin concave and broadly notched medially.  Coloration.Body generally reddish brown with color at posterior margins of abdominal somites deeper.   Distribution.Widely distributed in the Indo-West Pacific from Pakistanto Northern Australiaand Japan; at depths of 5.5–50 m( Pérez Farfante & Kensley 1997; Chan 1998).   Remarks.  Parapenaeopsis tenellais rather uncommon in Taiwan. Shinomiya & Sakai (2016)recently split  P. tenellainto two species mainly by the length of rostrum and pereiopods, naming the long rostrum and pereiopod form as  P. moresbyensis( Shinomiya & Sakai, 2016). The shape of the thyleum is also argued to be different between  P. tenellaand  P. moresbyensisby Shinomiya & Sakai (2016)but the difference is very subtle and difficult to comprehend. Moreover, the two species appeared to be geogrpahically separated with  P. tenellarestricted to the north from Japanto the South ChinaSea while  P. morebyensisis a southern species distributed from the South ChinaSea to Australiaand India. The charateristics of the Taiwanese material, however, are intermediate between  P. tenellaand  P. moresbyensis. The larger female from Keelung (NTOU M02392, Fig. 6e) has shorter rostrum and pereiopods and fits the characteristics of  P. tenellaas defined by Shinomiya & Sakai (2016). The other two specimensfrom Keelung (NTOU M02495) both have the rostrum broken while the pereiopods are longer and fit the characteristic of  P. moresbyensis.The two malesfrom Miaoli (NTOU M02393) have shorter rostrum but longer pereiopods. Of the four femalesfrom Miaoli (NTOU M02392), two have longer rostrum but shorter pereiopods, one has longer rostrum and longer pereiopod I but shorter pereiopod IV (pereiopod V missing in this specimen) while the other with the rostrum broken and shorter pereiopods. Actually Shinomiya & Sakai (2016)already noticed that some speicmens in Chinathey identified as  P. tenellahave characterisitc intermediate between  P. tenellaand  P. moresbyensis. More extensive studies including molecular genetic analysis will be necessary to determine if  P. moresbyensisis a valid species. 4439689311 [393,1164,1738,1765] 1982-06-29 NTOU Keelung City 9 230 M02392 1 1 Keelung 4439689302 1989-02-27 NTOU 9 230 M02495 2 1 1 Keelung City 4439689361 2001-03-20 NTOU Miaoli County 9 230 M02393 6 4 2 Miaoli