Parapolycope subtidalis, Tanaka & Tsukagoshi & Karanovic, 2014

Tanaka, Hayato, Tsukagoshi, Akira & Karanovic, Ivana, 2014, Molecular phylogeny of interstitial Polycopidae ostracods (Crustacea) and descriptions of a new genus and four new species, Zoological Journal of the Linnean Society 172 (2), pp. 282-317 : 300-307

publication ID	https://doi.org/ 10.1111/zoj.12176
DOI	https://doi.org/10.5281/zenodo.10542094
persistent identifier	https://treatment.plazi.org/id/03AEFF7E-FFE2-FFBF-FC5C-F16BFE4F95F6
treatment provided by	Marcus
scientific name	Parapolycope subtidalis
status	sp. nov.

Treatment

PARAPOLYCOPE SUBTIDALIS View in CoL SP. NOV.

( FIGS 17–23 View Figure 17 View Figure 18 View Figure 19 View Figure 20 View Figure 21 View Figure 22 View Figure 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 View Figure 1 ), 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 GoogleMaps .

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.

Description of adult male

Carapace ( Figs 17 View Figure 17 , 18A–E View Figure 18 , 19 View Figure 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 View Figure 18 ). Serration along anterior margin with 21 and 22 sharp processes on right valve and left valve, respectively ( Fig. 17 View Figure 17 ). Adductor muscle scars round and consisting of three closely spaced scars ( Fig. 17 View Figure 17 ). Marginal infold of each valve developed along anterior to posteroventral margins ( Figs 18C, D View Figure 18 , 19B, G, H, N View Figure 19 ). Along inner margin of right valve, bar and groove on anterodorsal to dorsal end ( Fig. 18A View Figure 18 ), one socket (part of hinge structure) developed at dorsal end ( Fig. 18C View Figure 18 ), posterior bar on mid-dorsal to posteri- or end ( Fig. 18D, E View Figure 18 ), bar and groove on posterior end to mid-posteroventral end ( Fig. 18F View Figure 18 ). Along inner margin of left valve, bar and groove on anterodorsal to dorsal end ( Fig. 18I View Figure 18 ), one knob (part of hinge structure) developed at dorsal end ( Fig. 18J View Figure 18 ), bar on mid-dorsal to posterior end ( Fig. 18K, L View Figure 18 ), and bar along posteroventral margin ( Fig. 18M View Figure 18 ).

Bellonci organ. Absent.

Upper lip ( Figs 20A View Figure 20 , 21A View Figure 21 ). Anterior part with blunt anterodorsal projection and long, tapering spine that curves around the anterior and ventral margins.

Antennula ( Fig. 20B View Figure 20 ). 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′ View Figure 20 ). 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′ View Figure 20 ): 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.

Mandibula ( Fig. 20D View Figure 20 ). 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

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′ View Figure 20 , E″). Precoxa ( Fig. 20E′ View Figure 20 ) with seven plumose setae of different lengths. Coxa ( Fig. 20E View Figure 20 ″) 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 View Figure 20 ). 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 View Figure 21 , 22A View Figure 22 ). 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 View Figure 22 ). 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 View Figure 18 ). 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 View Figure 23 ). 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 View Figure 23 ). 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 View Figure 23 ). 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 View Figure 22 ). 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 View Figure 22 ). 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 GoogleMaps

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.