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) Author Jiang, Guo-Chen Author Landeira, José M. Author Shih, Tung-Wei Author Chan, Tin-Yam text Zootaxa 2018 2018-12-19 4532 3 385 395 journal article 27743 10.11646/zootaxa.4532.3.4 66b6bf79-2beb-4681-819f-d154d57ceff8 1175-5326 2615449 BCEB9275-016D-4001-963C-3C080B0585E5 Plesionika crosnieri Chan & Yu, 1991 ( Fig. 1 ) Zoea I. Size: CL, 0.34 mm ( 0.27-0.48 mm ); TL, 2.60 mm ( 2.44-2.97 mm ). (n = 10) Carapace ( Fig. 1A, B, D ): Slightly dorsoventrally flattened; rostrum slightly curved and slender, longer than antennular peduncle; dorsal anterior and posterior processes present; anteroventral margin bearing 1 strong pterygostomian spine and 3 denticles; eyes sessile. Antennule ( Fig. 1E ): 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. 1F ): 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 the first segment at proximal position in the inner margin. Mandible ( Fig. 1G ): 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. 1H ): Coxal endite with 7 (2 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; and distal group with only 1 long sparsely plumose seta; exopod absent. Maxilla ( Fig. 1I ): 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. 1J ): Coxa with 3 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. 1K ): Coxa without setae; basis with 9 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. 1L ): 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 ( Figs. 1A, C ): With 5 somites, no spines or setae. Pleopods : Absent. Uropod : Absent. Telson ( Fig. 1A ): Subtriangular, posterior margin bearing row of minute spinules as well as 7 + 7 plumose setae, outermost 2 pairs only plumose on inner margin.