Neocypridella fossulata ( Daday, 1910 )

Savatenalinton, Sukonthip, 2022, Redescription of Neocypridella fossulata (Daday, 1910) (Crustacea: Ostracoda) and description of a new subfamily, Zootaxa 5093 (1), pp. 83-93 : 85-91

Neocypridella fossulata ( Daday, 1910)

( Figs 1–5 )

Syn.: Cypridella fossulata Daday, 1910

Syn.: Cypretta reticulata Lowndes, 1932

Syn.: Cyprinotus lowndesi Gauthier, 1939

Syn.: Eucypris tumida Klie, 1939

Syn.: Eucypris brevis Rome, 1962

Syn.: Eucypris palustris Rome, 1962

Material examined. Four females from the Daday collection from the Hungarian Natural History Museum, Budapest (sample number 1916-63).

Lectotype (here designated). Female, soft parts dissected in glycerine on a sealed glass slide and valves stored dry in a micropalaeontological slide (D63-2).

Paralectotypes (here designated). One dissected female (D63-1) stored as the lectotype; two undissected females (D63-3-1, D63-3-2) stored dry in micropalaeontological slides.

Diagnosis. Cp in lateral view subglobular, anterior and posterior margins widely rounded, Cp slightly oblique with LV slightly more tumid than RV. RV with submarginal anterior selvage and with inwardly displaced posterior selvage. LV with short anteroventral inner list. Valve surface with shallow pits and scattered thin setae.

A1 seven segmented with small Wouters organ, aesthetasc Ya long (c. 3 times length of terminal segment). A2 with divided penultimate segment, natatory setae long, the 6 th accompanying seta reaching c. 2/3 of length of next segment. β-and γ- setae on Md-palp markedly large. Mx1-palp with subquadrate terminal segment, basal segment without laterally subapical seta, two large bristles on third endite smooth. T1 with a-, b-, d-setae, protopodite with c. 16 distal setae. T2 with d1 and d2 setae markedly long and subequal in length, T2 penultimate segment divided. T3 with apical pincer organ, h3 seta short (c. twice length of seta h2). CR slender, length of ramus c. 1.8 times of Ga claw, length of Gp claw c. 2/3 of that of Ga claw, Sa seta very short, Sp seta long, almost reaching half length of Gp claw. CR attachment slender with slim vb and db and subequal in length.

Measurements (in μm). Female. Cp (n = 3), L = 869 – 950, H = 628 – 700, W = 592 – 650. LV (n = 1), L = 909, H = 682; RV (n = 1), L = 869, H = 684.

Abbreviated redescription of female

Cp in lateral view ( Fig 1A ) subglobular, greatest height situated slightly before mid-length, anterior and posterior margins widely rounded, posteriorly slightly narrower rounded. LV overlapping RV anteriorly, ventrally and posteriorly. Valve surface weakly pitted with scattered thin setae.

Cp in caudal view ( Fig 1B ) oblique with LV slightly more tumid than RV. Cp in dorsal and ventral views ( Figs 1C, D ) subovate, with greatest width situated at mid-length.

LV in interior view ( Figs 1E , 2A, B ) with dorsal margin strongly arched, greatest height situated slightly before mid-length, anterior and posterior margins widely rounded, anterior selvage not inwardly displaced, calcified inner lamella anteriorly slightly broader than posteriorly, with short anteroventral inner list and weak posterior inner list.

RV in interior view ( Figs 1F , 2C, D ) with anterior marginal selvage and inwardly displaced posterior selvage, calcified inner lamella narrow, anteriorly broader than posteriorly, without anterior inner list.

A1 ( Fig 3A ): first segment wide and stout, with small proximal Wouters organ, one long subapical dorsal seta (reaching tip of next segment) and two long apical ventral setae. Second segment slightly wider than long, with one short apical dorsal seta (not reaching mid-length of next segment) and small Rome organ. Third segment bearing two setae (one long dorso-apical seta, one shorter ventro-apical seta), length of shorter one c. 2/3 that of fourth segment. Fourth segment with two long dorsal setae and two subequal, shorter ventral setae (reaching beyond tip of next segment). Fifth segment dorsally with two long setae, ventrally with two (one long, one shorter) setae, shorter one reaching tip of terminal segment. Penultimate segment with four long apical setae. Terminal segment with three (two long, one short) apical setae and aesthetasc Ya, the latter long (c. 3 times length of terminal segment or c. 1.3 times that of short apical seta).

A2 ( Fig 3B ): exopodite with three (one long, two short) setae, the long one reaching beyond tip of first endopodal segment. First endopodal segment with five long (reaching beyond tip of terminal claws) and one shorter accompanying setae, length of latter seta c. 2/3 of penultimate segment, aesthetasc Y relatively long (almost half the length of the ventral side of the segment), apical ventral seta long, reaching far beyond tip of terminal segment. Penultimate segment divided, distally with three long serrated claws (length c. two times that of penultimate segment), aesthetasc y2 short (not reaching tip of terminal segment), z1–z3 setae long; this segment medially with two (one long, one shorter) dorsal setae (length of short one c. 3/4 of that of long one) and four ventral setae of unequal length (t1–t4). Terminal segment with two serrated claws (GM and Gm), g-seta and aesthetasc y3, length of Gm c. 2/3 of that of GM, g-seta long (slightly longer than aesthetasc y3), length of aesthetasc y3 c. half of that of accompanying seta.

Md with coxa ( Fig 3C ) and Md-palp ( Fig 4A ): first segment of palp with two large setae (s1 and s2), one long and slender seta and a relatively long and smooth α-seta. Second segment dorsally with three unequal long apical setae, length of shortest c. 1/3 of that of longest; ventrally with a group of three long hirsute setae, one shorter hirsute seta and β-seta, the latter markedly large, cone-shaped and plumose. Penultimate segment consisting of three groups of setae: dorsally with a group of four unequal, long, subapical setae; laterally with large apical γ-seta and three further smooth apical setae, γ-seta relatively large, hirsute, long (length c. 2.7 times of that of terminal segment) with strongly pointed tip; ventrally with two (one long, one short) apical setae, short one reaching beyond mid-length of terminal segment. Terminal segment bearing three claws and two setae.

Mx1 ( Fig 4B ) with two-segmented palp, three endites and a large branchial plate (the latter not shown). Basal segment of palp with a group of five long, unequal apical setae and one medially subapical seta, the latter seta short (not reaching mid-length of terminal segment), terminal segment subquadrate, slightly tapering towards the end, apically with three claws and three setae. Two large bristles on third endite smooth. One long and one shorter sideways-directed bristles on first endite.

T1 ( Figs 4C–D ): protopodite with two short a-setae, and one longer b- and d-setae, distally with 16 (13 apical, three subapical) hirsute setae of unequal length. Endopodite a weakly built palp with three unequal apical setae, the central one the longest.

T2 ( Fig 5A ) with seta d1 and d2 slim, markedly long and subequal in length. Second segment with short e-seta (reaching half-way of penultimate segment). Penultimate segment divided, proximal segment bearing long f-seta (reaching beyond tip of terminal segment), distal segment with a pair of apical setae (long g-seta and one minute spine-like seta). Terminal segment with two (one dorsally, one ventrally) apical h1 and h3 setae (length of h3 seta c. 2/3 of that of h1 seta) and a long and curved serrated claw (h2).

T3 ( Fig 5B ) a cleaning limb. First segment with long d1, d2, dp setae. Second segment with long apical eseta (reaching half-way of next segment). Third segment with medially short f-seta (not reaching tip of segment). Terminal segment with apical pincer (h2), one short h1 seta and one short, reflexed subapical h3 seta, length of the latter c. 2 times of h2 length or 0.7 times of third segment.

CR ( Fig 5C ) slender, ramus long, length c. 1.8 times of Ga claw, Ga and Gp claws thin, length of Gp claw c. 2/3 of that of Ga claw, Sa seta short (length c. 1/5 of that of Ga), Sp seta longer, almost reaching mid-length of Gp claw.

CR attachment ( Fig. 5D ) slender, with db and vb slim and subequal in length.

Figures

FIGURE 1. Neocypridella fossulata (Daday, 1910). A. Cp right lateral view (paralectotype: D63-3-1). B. Cp, caudal view (ditto). C. Cp, dorsal view (paralectotype: D63-3-2). D. Cp, ventral view (ditto). E. LV, internal view (lectotype: D63-2). F. RV, internal view (ditto). Scale bar = 200 μm. Arrows point toward the anterior end.

FIGURE 2. Neocypridella fossulata (Daday, 1910), lectotype (D63-2).A. Posterior part of LV, internal view. B. Anterior part of LV, internal view. C. Anterior part of RV, internal view. D. Posterior part of RV, internal view. Scale bar = 200 μm.

FIGURE 3. Neocypridella fossulata (Daday, 1910), lectotype (D63-2). A. A1. B. A2. C. Md-coxa. Scale bar = 100 μm.

FIGURE 4. Neocypridella fossulata (Daday, 1910), lectotype (D63-2). A. Md-palp. B. Mx1. C. T1. D. protopodite of T1. Scale bar = 50 μm for A–B; 100 μm for C; 40 μm for D.

FIGURE 5. Neocypridella fossulata (Daday, 1910), lectotype (D63-2). A. T2. B. T3. C. CR. D. CR attachment. Scale bar = 100 μm.