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 SETOUCHIENSIS
SP. NOV.
(
FIGS 10–16
)
Type series
Holotype
: adult male (SUM-CO-2201), right valve length 294 μm and height 220 μm, left valve length 288 μm and height 217 μm, soft parts mounted on slide and valves preserved in a cardboard cell slide,
Paratypes
:
eight adult
males (SUM-CO-2202–2209) and
nine adult
females (SUM-CO-2210–2218).
Figure 11.
Scanning electron micrographs of valves of
Parapolycope setouchiensis
sp. nov.
A, B, male paratype (SUM- CO-2202); C, D, male paratype (SUM-CO-2203); E, male paratype (SUM-CO-2204); F, G, female paratype (SUM-CO- 2211); H, I, female paratype (SUM-CO-2212); J, female paratype (SUM-CO-2213). 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.
Type locality
The
holotype
specimen was collected from
Kitagi island
Beach
,
Kasaoka City
,
Okayama Prefecture
, the
Seto
inland sea of
Japan
,
34°22′29′′N
,
133°31′54′′E
(
Fig. 1C
), on
11 October 2009
; interstitial environment at
20 cm
below the sand surface at
5 m
inland from the low tide shoreline. The substrate consisted mainly of very coarse, decomposed granite sand
.
Diagnosis
Carapace oval in lateral view. Carapace surface covered with a number of shallow pits. Serration along anterior margin with 24 and 22 sharp processes on right valve and left valve, respectively, a dorsal-most process of right valve prominently large. Uropodal projection of male long, with numerous prominent spines or barbs. Three claws on each uropodal lamella in female. Male copulatory organ consisting of extending helical tube.
Figure 12.
Scanning electron micrographs of valves of
Parapolycope setouchiensis
sp. nov.
, internal lateral view, male paratype (SUM-CO-2203). A–F, right valve; G–L, 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, ventral part of marginal infold; G, anterior part of marginal infold; H, anterodorsal bar and groove; I, knob at dorsal end of hinge structure; J, posterodorsal bar of hinge structure; K, posteroventral bar; L, ventral part of marginal infold.
Description of adult male
Carapace (
Figs 10
,
11A–E
,
12
). Right valve length 285– 297 μm and height 208–220 μm, left valve length 280– 292 μm and height 211–218 μm (
Table 3
). Carapace oval in lateral view. Carapace surface covered with a number of shallow pits (
Fig. 11A, B
). Serration along anterior margin with 24 and 22 sharp processes on right valve and left valve, respectively (
Fig. 10
), a dorsal-most process of right valve prominently large. Adductor muscle scars oval and consisting of three closely spaced scars (
Fig. 10
). Marginal infold of each valve developed along anterior to posteroventral margins (
Figs 11C, D
,
12B, F, G, L
). Along inner margin of right valve, bar and groove on anterodorsal to dorsal end (
Fig. 12A
), one socket (part of hinge structure) developed at dorsal end (
Fig. 12C
), posterior bar on mid-dorsal to posteri- or end (
Fig. 12D
), bar and groove on posterior to midposteroventral end (
Fig. 12E
). Along inner margin of left valve, bar and groove on anterodorsal to dorsal end (
Fig. 12H
), one knob (part of hinge structure) developed at dorsal end (
Fig. 12I
), bar on mid-dorsal to posterior end (
Fig. 12J
), and bar along posteroventral margin (
Fig. 12K
).
Figure 13.
Parapolycope setouchiensis
sp. nov.
A, B, D, F, male holotype (SUM-CO-2201); C, E, male paratype (SUM- CO-2202). A, right lateral view of upper lip; B, antennula (A1; arrowhead indicates inward bulge); B′, seta with comblike setulae of A1; C, antenna (A2) except exopodite; C′, exopodite of A2; D, mandibula; E, maxillula (Mxl); E′, precoxa of Mxl; E″, coxa of Mxl; F, fifth limb (L5); F′, one of the epipodites of L5. Abbreviations: ba, basis; cx, coxa; en, endopodite; ep, epipodite; ex, exopodite; pc, precoxa. Scale bar = 50 μm.
Figure 14.
Scanning electron micrographs of male soft parts of
Parapolycope setouchiensis
sp. nov.
A, B, male paratype (SUM-CO-2205); C, D, male paratype (SUM-CO-2206). A, right lateral view of upper lip; B, right lateral view of broad chitinous hook of upper lip; C, right lateral view of posterior trunk segment, uropod, and uropodal projection; D, right lateral view of uropodal projection with numerous prominent spines.
Bellonci organ. Absent.
Upper lip (
Figs 13A
,
14A, B
). Broad chitinous hook and a chain of cone-shaped setae on right lateral side. Distal part with anteroventral protrusion, tapering to wrinkled, and papilla-shaped termination in lateral view.
Antennula (
Fig. 13B, B′
). Uniramous, four articulated podomeres. First podomere quadrate, with setulae on dorsal margin, lateral surface and ventrodistal end. Second podomere about 1.5 times as long as first podomere, proximal half of dorsal cuticle thick and with an inward bulge, with one annulated setulous seta at dorsoproximal end, one cluster of setae on middle of dorsal margin, and three tufts of setulae on lateral surface. Third podomere about two-thirds as long as first podomere, with one short, simple seta at dorsodistal end and five ventrodistal setae consisting of one seta with large disc-shaped sucker, one seta curving at tip armed with five falciform spines and minute setulae, one seta with comb-like setulae, and two simple setae. Fourth podomere small, with five long annulated setae.
Antenna (
Fig. 13C, C′
). Typically biramous, with exopodite and endopodite consisting of nine and three podomeres, respectively. Basis triangular tapered distally. Exopodite: first podomere half as long as basis. Podomere length decreasing in size from second 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 one short seta at distal end. Endopodite: first podomere half as long as basis. Second podomere two-thirds as long as first podomere, with three setae along dorsal margin consisting of one medium annulated and two short, and six annulated setae at distal consisting of three long, one long with some filaments, one medium, 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 one long and one medium annulated seta at distal end.
Figure 15.
Parapolycope setouchiensis
sp. nov.
A, male holotype (SUM-CO-2201), left lateral view of posterior trunk segment, uropod, and copulatory organ; B, female paratype (SUM-CO-2210), right lateral view of posterior trunk segment, uropod, and copulatory organ. Abbreviations: fs, female spermatheca; urp, uropodal projection. Scale bar = 50 μm.
Mandibula (
Fig. 13D
). Coxal endite with four sharp teeth. Basis with three plumose setae on ventral margin and one annulated setulous seta on dorsal margin. Endopodite consisting of two podomeres. First podomere with two annulated plumose setae on ventral margin near proximal end and two annulated plumose long setae at dorsodistal end. Second podomere very small with setulae on dorsal margin, bearing one medially plumose and one claw-like, setulous annulated seta.
Maxillula (
Fig. 13E, E′
, E″). Precoxa (
Fig. 13E′
) with ten annulated plumose setae of different lengths. Coxa (
Fig. 13E
″) with one short and one medium plumose setae on lateral surface near ventroproximal margin, one short plumose setae on lateral surface near ventral middle margin, three medium plumose setae on ventral margin, and two tufts of setulae on dorsal margin. Basis with one short, one medium annulated, and two long plumose setae on ventral margin, and setulae along ventral and dorsal margins. First podomere of endopodite with one annulated setulous seta dorsodistally, and one long annulated and one long plumose seta at ventroproximal margin. Second podomere with two long, annulated 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
Figure 16.
Parapolycope setouchiensis
sp. nov.
, female paratype (SUM-CO-2210). A, right lateral view of upper lip; B, antennula; C, antenna except part of exopodite. Arrowhead indicates inward bulge. Abbreviations: ba, basis; en, endopodite; ex, exopodite. Scale bar = 50 μm.
Table 3.
Dimension of valves of
Parapolycope setouchiensis
sp. nov.
from the type locality
Length (μm) |
Height (μm) |
Mean |
Observed range |
N
|
Mean |
Observed range |
N
|
Male |
RV |
292 |
285–297 |
6 |
216 |
208–220 |
6 |
LV |
286 |
282–292 |
6 |
216 |
211–218 |
6 |
Female |
RV |
309 |
301–319 |
6 |
227 |
218–234 |
6 |
LV |
307 |
294–321 |
6 |
226 |
219–234 |
6 |
LV, left valve; RV, right valve.
one very long, stout setulous seta, four long and three medium annulated setae on ventral margin, and one tuft of setulae on dorsal margin.
Fifth limb (
Fig. 13F, F′
). Coxa bearing epipodite with 12 long plumose setae and two short setulous setae on dorsodistal margin. Basis with three plumose setae along dorsal margin and one slender, annulated setulous seta on ventral margin. Endopodite with one short, plumose annulated, one medium annulated, and two long plumose setae. Exopodite with one stout setulous seta.
Uropod (
Figs 14B, C
,
15A
). Left lamella with three stout claws and three rows of setae on anteroventral surface. Right lamella with four stout claws and ventrodistally situated uropodal projection, which is long, flexible, and covered with numerous prominent spines.
Male copulatory organ (
Fig. 15A
). Arising from outer surface of body on left side of terminal trunk segment as a long stretched helically tube.
Description of adult female
Mandibula, maxillula, and fifth limb similar to those of adult male.
Carapace (
Fig. 11F–J
). Right valve length 301– 319 μm and height 218–234 μm, left valve length 294– 321 μm and height 219–234 μm (
Table 3
).
Upper lip (
Fig. 16A
). Semicircular in lateral view. A number of setae on lateral surface.
Antennula (
Fig. 16B
). Uniramous, four articulated podomeres. First podomere quadrate, with two tufts of setulae on dorsal margin. Second podomere about 1.5 times as long as first podomere, proximal half of dorsal cuticle robust and with inward bulge, with one annulated setulous seta at dorsoproximal end, one cluster of setae on middle of dorsal margin, and two tufts setulae on lateral surface. Third podomere about two-thirds as long as first podomere, with one short simple seta at dorsodistal end, two short simple setae on ventrodistal end, and setulae along dorsal margin. Fourth podomere small, with five long annulated setae.
Antenna (
Fig. 16C
). Only second and third podomeres of endopodite differing from those of adult male. Second podomere, with one annulated setulous seta on dorsodistal end and six annulated setae at distal consisting of three long, one long with some filaments, one medium, one short. Third podomere one-quarter as long as first podomere, with one long annulated seta at ventral margin, and one long and one medium annulated seta at distal end.
Uropod (
Fig. 15B
). Each lamella with three claws. Right lamella with three rows of setae on anteroventral surface.
Female copulatory organ (
Fig. 15B
). Female spermatheca double twisted tube in lateral view.
Dimensions
See
Table 3
.
Distribution
Tai Beach
(
Kyoto Pref.
35°34′53′′N
,
135°14′09′′E
),
Komatsubara
(
Kagawa Pref.
34°15′10′′N
,
134°22′33′′E
),
Aji
(
Kagawa Pref.
34°23′48′′N
,
134°07′44′′E
),
Kitagi island
Beach
(
Okayama Pref.
type
locality,
34°22′29′′N
,
133°31′54′′E
),
Meotoura
(
Miyazaki Pref.
31°29′36′′N
,
131°23′04′′E
),
Injo Beach
(
Kagoshima Pref.
30°33′27′′N
,
131°01′32′′E
).
All
specimens were collected by
Hayato Tanaka
from interstitial pore water in
Japan
.
Etymology
This species is named after the
type
locality, the
Seto
inland sea of
Japan
.
Remarks
Appendage morphology of
Pa. setouchiensis
sp. nov.
is similar to that of
Parapolycope spiralis
Tanaka & Tsukagoshi, 2010
. However, the new species can be easily distinguished from
Pa. spiralis
by the characteristics of the male uropodal projection. Namely, males of the new species bear a number of prominent spines on the uropodal projection, whereas they are absent in
Pa. spiralis
.