Plesionika semilaevis Bate 1888

Plesionika semilaevis Bate, 1888 (Fig. 3) Zoea I. Size: CL, 0.37 mm (0.32-0.39 mm); TL, 2.41 mm (2.30-2.46 mm). (n = 10) Carapace (Fig. 3A, B, D): Slightly dorsoventrally flattened; rostrum slightly curved and slender, shorter than antennular peduncle; dorsal anterior and posterior processes present; anteroventral margin bearing 1 strong pterygostomian spine and 3 denticles; eyes sessile. Antennule (Fig. 3E): Peduncle unsegmented, slender and bearing 1 small tubercle; endopod with 1 long, plumose seta; exopod unsegmented with 1 spatulate seta, 3 aesthetascs, 1 plumose seta. Antenna (Fig. 3F): Peduncle unsegmented with 1 sharp basal spine distally; endopod unsegmented, with 1 long plumose seta and 1 sharp, slender spine terminally; exopod 6-segmented, 9 plumose setae on inner margin, 1 seta on apex and 2 plumose setae on outer margin, 1 tubercle on first segment at proximal position in inner margin. Mandible (Fig. 3G): Palp absent; right and left slightly asymmetrical, right incisor with 3 terminal teeth; left incisor with 4 teeth (1 subterminal + 3 terminal) and lacinia mobilis. Maxillule (Fig. 3H): Coxal endite with 7 (2 simple subterminal + 5 terminal plumose) setae; basial endite with 2 strong, cuspidate setae and 3 simple setae; endopod unsegmented with 6 setae forming 3 groups: basal group with 1 small, simple seta and 2 sparsely plumose setae; median group with 2 sparsely plumose setae; distal group with only 1 long sparsely plumose seta; exopod absent. Maxilla (Fig. 3I): Coxal endite bilobed with 9 + 4 plumose setae; basial endite bilobed with 4 + 4 plumose setae; endopod with 9 (3 + 2 + 1 + 1 + 2) setae; scaphognathite margin with 5 plumose setae. First Maxilliped (Fig. 3J): Coxa with 4 plumose setae; basis with 12 plumose setae; endopod 4-segmented with 3, 1, 2, 4 (1 outer + 3 terminal) setae; exopod unsegmented, armed distally with 4 (1+3) long, plumose natatory setae. Second Maxilliped (Fig. 3K): Coxa with 1 plumose seta; basis with 7 plumose setae; endopod 4-segmented with 3, 1, 2, 5 (1 outer + 4 terminal) setae; exopod unsegmented, armed distally with 5 (2+3) long plumose natatory setae. Third Maxilliped (Fig. 3L): Coxa without setae; basis with 4 plumose setae; endopod 4-segmented with 2, 1, 2, 4 (1 outer + 3 terminal) setae; exopod unsegmented, armed distally with 5 (2+3) long, plumose natatory setae. Pereiopods: Absent. Pleon (Fig. 3A, C): With 5 somites, no spines or setae. Pleopods: Absent. Uropod: Absent. Telson (Fig. 3A): Subtriangular, posterior margin with row of minute spinules as well as 7 + 7 plumose setae, outermost 2 pairs only plumose on inner margin.
Published as part of Jiang, Guo-Chen, Landeira, José M., Shih, Tung-Wei & Chan, Tin-Yam, 2018, First zoeal stage of Plesionika crosnieri Chan & Yu, 1991, P. ortmanni Doflein, 1902, and P. semilaevis Bate, 1888, with remarks on the early larvae of Plesionika Bate, 1888 (Crustacea, Decapoda), pp. 385-395 in Zootaxa 4532 (3) on pages 388-389, DOI: 10.11646/zootaxa.4532.3.4, http://zenodo.org/record/2615449
{"references":["Bate, C. S. (1888) Report of the Crustacea Macrura collected by H. M. S. Challenger during the years 1873 - 76. Report of the scientific results or the Foyage of H. M. S. Challenger, Zoology, 24, XC + 1 - 42."]}