Molecular phylogeny of interstitial Polycopidae ostracods (Crustacea) and descriptions of a new genus and four new species Author Tanaka, Hayato Author Tsukagoshi, Akira Author Karanovic, Ivana text Zoological Journal of the Linnean Society 2014 2014-09-26 172 2 282 317 http://dx.doi.org/10.1111/zoj.12176 journal article 10.1111/zoj.12176 0024-4082 5314650 PARAPOLYCOPE SUBTIDALIS SP. NOV. ( FIGS 17–23 ) Type series Holotype : adult male (SUM-CO-2219), right valve length 228 μm and height 159 μm, left valve length 221 μm and height 156 μm, soft parts mounted on slide and valves preserved in a cardboard cell slide, paratypes : ten adult males (SUM-CO-2220–2229) and six adult females (SUM-CO-2230–2235). Type locality The holotype specimen was collected from Mihouchihama Beach , Shizuoka City , Shizuoka Prefecture , the Pacific coast of central Japan , 35°00′51′′N , 138°31′07′′E ( Fig. 1B ), on 31 July 2012 ; interstitial environment at 20 cm below the sand surface at 2 m seaward from the low tide shoreline. The substrate consisted mainly of very coarse sand with gravels . Diagnosis Carapace elliptical in lateral view. Carapace surface covered with a number of shallow pits. Serration along anterior margin with 21 and 22 sharp processes on right valve and left valve, respectively. Anterior part of male upper lip with blunt anterodorsal projection and long, tapering spine that curves around the anterior and ventral margins. Basis of fifth limb bearing two dorsal plumose setae. Uropodal projection of male short, with numerous small spines or barbs. Male copulatory organ consisting of a wavy tube. Figure 17. Parapolycope subtidalis sp. nov. , male holotype (SUM-CO-2219). A, internal lateral view of left valve; B, internal lateral view of right valve. Scale bar = 100 μm. Figure 18. Scanning electron micrographs of valves of Parapolycope subtidalis sp. nov. A, B, male paratype (SUM- CO-2221); C, D, male paratype (SUM-CO-2222); E, male paratype (SUM-CO-2223); F, G, female paratype (SUM-CO- 2232); H, I, female paratype (SUM-CO-2230); J, female paratype (SUM-CO-2233). A, external lateral view of right valve (RV); B, external lateral view of left valve (LV); C, internal lateral view of LV; D, internal lateral view of RV; E, dorsal view of carapace; F, external lateral view of RV; G, external lateral view of LV; H, internal lateral view of LV; I, internal lateral view of RV; J, dorsal view of carapace. Scale bar = 50 μm. Description of adult male Carapace ( Figs 17 , 18A–E , 19 ). Right valve length 221– 228 μm and height 148–159 μm, left valve length 210– 221 μm and height 148–156 μm ( Table 4 ). Carapace elliptical in lateral view. Carapace surface covered with a number of shallow pits ( Fig. 18A, B ). Serration along anterior margin with 21 and 22 sharp processes on right valve and left valve, respectively ( Fig. 17 ). Adductor muscle scars round and consisting of three closely spaced scars ( Fig. 17 ). Marginal infold of each valve developed along anterior to posteroventral margins ( Figs 18C, D , 19B, G, H, N ). Along inner margin of right valve, bar and groove on anterodorsal to dorsal end ( Fig. 18A ), one socket (part of hinge structure) developed at dorsal end ( Fig. 18C ), posterior bar on mid-dorsal to posteri- or end ( Fig. 18D, E ), bar and groove on posterior end to mid-posteroventral end ( Fig. 18F ). Along inner margin of left valve, bar and groove on anterodorsal to dorsal end ( Fig. 18I ), one knob (part of hinge structure) developed at dorsal end ( Fig. 18J ), bar on mid-dorsal to posterior end ( Fig. 18K, L ), and bar along posteroventral margin ( Fig. 18M ). Figure 19. Scanning electron micrographs of valves of Parapolycope subtidalis sp. nov. , internal lateral view, male paratype (SUM-CO-2222). A–G, right valve; H–N, left valve. A, anterodorsal bar and groove; B, anterior part of marginal infold; C, socket at dorsal end of hinge structure; D, posterodorsal bar of hinge structure; E, posterior element of hinge structure; F, posteroventral bar and groove; G ventral part of marginal infold; H, anterior part of marginal infold; I, anterodorsal bar and groove; J, knob at dorsal end of hinge structure; K, posterodorsal bar of hinge structure; L, posterior element of hinge structure; M, posteroventral bar; N, ventral part of marginal infold. Bellonci organ. Absent. Upper lip ( Figs 20A , 21A ). Anterior part with blunt anterodorsal projection and long, tapering spine that curves around the anterior and ventral margins. Figure 20. Parapolycope subtidalis sp. nov. A–E, male holotype (SUM-CO-2219); F, male paratype (SUM-CO-2220). A, left lateral view of upper lip; B, antennula, arrowhead indicates inward bulge; C, antenna (A2); C′, endopodite of A2; D, mandibula; E, maxillula (Mxl); E′, precoxa of Mxl; E″, coxa of Mxl; F, fifth limb. Abbreviations: ba, basis; cx, coxa; en, endopodite; ep, epipodite; ex, exopodite; pc, precoxa. Scale bar = 50 μm. Figure 21. Scanning electron micrographs of male soft parts of Parapolycope subtidalis sp. nov. A, C, D, male paratype (SUM-CO-2224); B, male paratype (SUM-CO-2225). A, left lateral view of upper lip; B, left lateral view of fifth limb; C, left lateral view of posterior trunk segment, uropod, and uropodal projection; D, left lateral view of uropodal projection with numerous small spines. Antennula ( Fig. 20B ). Uniramous, four articulated podomeres. First podomere rectangular, with tufts of setulae on dorsal margin, lateral surface and ventrodistal end. Second podomere same length as first podomere, proximal two-thirds of dorsal cuticle thick and with inward bulge, with one annulated setulous seta at dorsoproximal end, one cluster of setae on distal third of dorsal margin, setulae on dorsoproximal and dorsodistal margins, and one tuft of setulae on lateral surface. Third podomere about four-fifths as long as first podomere, with one short annulated seta at dorsodistal end and five ventrodistal setae consisting of one with large disc- shaped sucker, one with minute setulae, one with comblike setulae, and two simple setae. Fourth podomere small, with five long annulated setae. Antenna ( Fig. 20C, C′ ). Typically biramous, with exopodite and endopodite consisting of nine and three podomeres, respectively. Basis triangular, tapered distally. Exopodite: first podomere one-third as long as basis. Second podomere one-quarter as long as first podomere; podomere length decreasing in size from third to eighth, each podomere with one long annulated seta; ninth (distal-most) podomere very small, with one long annulated seta at proximal, one medium annulated seta with short process and setulae, and one short seta at distal end. Endopodite ( Fig. 20C′ ): first podomere about one-third as long as basis. Second podomere twothirds as long as first podomere, with three setae along dorsal margin consisting of one medium and two short, and six annulated setae at distal consisting of three long, one long with some filaments, one medium, and one short. Third podomere one-quarter as long as first podomere, with one stout, hook-shaped claw extending backward, one long annulated seta at ventral margin, and two long annulated and one short setae at distal end. Figure 22. Parapolycope subtidalis sp. nov. A, male holotype (SUM-CO-2219), right lateral view of posterior trunk segment, uropod, and copulatory organ; B, female paratype (SUM-CO-2231), left lateral view of posterior trunk segment, uropod, and copulatory organ. Abbreviations: fs, female spermatheca; urp, uropodal projection. Scale bar = 50 μm. Figure 23. Parapolycope subtidalis sp. nov. , female paratype (SUM-CO-2231). A, left lateral view of upper lip; B, antennula, arrowhead indicates inward bulge; C, antenna except part of exopodite. Abbreviations: ba, basis; en, endopodite; ex, exopodite. Scale bar = 50 μm. Mandibula ( Fig. 20D ). Coxal endite with four sharp teeth. Basis with three plumose annulated setae on ventral margin and one plumose seta on dorsal margin. Endopodite consisting of two podomeres. First podomere Table 4. Dimension of valves of Parapolycope subtidalis sp. nov. from the type locality

Length (μm)	Height (μm)
Mean	Observed range	N	Mean	Observed range	N
Male	RV	223	217–228	8	153	148–159	8
LV	210	210–221	8	152	148–156	8
Female	RV	239	233–245	5	162	154–168	5
LV	231	226–237	5	160	153–166	5

LV, left valve; RV, right valve. with one plumose seta on ventral margin near proximal end and two plumose long setae at dorsodistal end. Second podomere very small with setulae on dorsal margin, bearing one medially plumose and one clawlike setulous setae. Maxillula ( Fig. 20E, E′ , E″). Precoxa ( Fig. 20E′ ) with seven plumose setae of different lengths. Coxa ( Fig. 20E ″) with one short and one medium plumose setae on lateral surface near ventroproximal margin, one medium and three long plumose setae on ventral margin. Basis with two medium and one long plumose setae on ventral margin, and setulae along dorsal margin. First podomere of endopodite with one plumose seta dorsodistally, and two long annulated setae at ventroproximal margin. Second podomere, with one long annulated and one long setulous setae, and two long, stout setulous setae with few bilateral spines. Exopodite consisting of two podomeres. First podomere with setulae along dorsal margin. Second podomere with one very long, stout setulous seta, three long and two medium setulous setae, one long annulated seta on ventral margin, and one tuft of setulae on dorsal margin. Fifth limb ( Fig. 20F ). Coxa bearing epipodite with 12 long plumose setae, and two short setulous setae on dorsodistal margin. Basis with two plumose setae along dorsal margin, one slender setulous seta on ventral margin. Endopodite with one medium and one long plumose seta. Exopodite one stout setulous seta. Uropod ( Figs 21C, D , 22A ). Left lamella with three stout claws, one short proximal spine dorsally, and two rows of setae on anteroventral surface. Right lamella with four stout claws, one short proximal spine dorsally, and ventrodistally situated, short, straight uropodal projection with numerous short spines or barbs. Male copulatory organ ( Fig. 22A ). Arising from outer surface of body on left side of terminal trunk segment as a long, wavy tube. Description of adult female Mandibula, maxillula, and fifth limb similar to those of adult male. Carapace ( Fig. 18F–J ). Right valve length 233– 245 μm and height 154–168 μm, left valve length 226– 237 μm and height 153–166 μm ( Table 4 ). Upper lip ( Fig. 23A ). Semicircular in lateral view, with tapering conical, anterodorsal projection similar to that of male. A number of setae on ventral lateral surface. Antennula ( Fig. 23B ). Uniramous, four articulated podomeres. First podomere rectangular, with tufts of setulae on dorsal margin, lateral surface, and ventrodistal end. Second podomere same length as first podomere, proximal two-thirds of dorsal cuticle thick and with inward bulge, with one annulated setulous seta at dorsoproximal end, one cluster of setae on distal third of dorsal margin, setulae on dorsoproximal and dorsodistal margins. Third podomere about twothirds as long as first podomere, with three short simple setae at distal end. Fourth podomere small, with five long annulated setae. Antenna ( Fig. 23C ). Only second and third podomeres of endopodite differing from those of adult male. Second podomere, with one seta on dorsodistal end and six annulated setae at distal consisting of four long, one medium, one short. Third podomere one-quarter as long as first podomere, one long annulated seta at ventral margin, and two long annulated and one short setae at distal end. Uropod ( Fig. 22B ). Each lamella with four claws and one short proximal spine dorsally. Both lamella with three spines and one rows of setae on anteroventral surface. Female copulatory organ ( Fig. 22B ). Female spermatheca bearing villus-like structure in lateral view. Dimensions See Table 4 . Distribution Miho-uchihama Beach ( Shizuoka Pref. type locality 35°00′51′′N , 138°31′07′′E ), Kiiohsima-sue ( Wakayama Pref. 33°27′12′′N , 135°49′20′′E ). All specimens were collected by Hayato Tanaka from interstitial pore water in Japan . Etymology Subtidal, referring to the habitat of this species. Remarks The carapace and appendages of Pa. subtidalis sp. nov. are similar to those of Parapolycope psittacina Tanaka & Tsukagoshi, 2013a . The most notable difference between the two species is in the morphology of the male upper lip, which in Pa. subtidalis bears a slender projection, which is absent in Pa. psittacina . The chaetotaxy of the mandibula and fifth limb of the two species are also different.