Dentocypria chantaranothaii, Savatenalinton, Sukonthip, 2017

Savatenalinton, Sukonthip, 2017, A new genus and four new species of subfamily Cyclocypridinae (Crustacea, Ostracoda) from Thailand, Zootaxa 4243 (2), pp. 329-365 : 339-344

Dentocypria chantaranothaii n. gen. n. sp.

( Figs 7–10 )

2016 Physocypria sp. 3—Savatenalinton & Suttajit: 11, Table 2. 2010 Physocypria sp. 3—Savatenalinton & Martens: 30.

Holotype. Male, soft parts dissected in glycerine on a sealed slide, valves stored dry in a micropalaeontological slide (MSU-ZOC.154).

Allotype. Female, stored like the holotype (MSU-ZOC.155).

Paratypes. One dissected male (MSU-ZOC.156) stored like the holotype, four undissected males (MSU- ZOC.157–160) stored dry in micropalaeontological slides, one dissected female (MSU-ZOC.161) stored like the holotype, six undissected females (MSU-ZOC.162–167) stored dry in a micropalaeontological slide and c. 30 males and 40 females in 70% ethanol.

Repository. All specimens are deposited in the MSU-ZOC.

Type locality. Nong Naree (swamp), Phetchabun Province. Material collected on 28 Sep. 2005, coordinates: 16° 26΄ 23˝ N and 101° 08΄ 29˝ E. Accompanying ostracod fauna: Bradleycypris vittata ( Sars, 1903) , Bradleytriebella decorata ( Sars, 1903) , Chrissia sp., Hemicypris exigua Broodbakker, 1983 , Pseudostrandesia calapanensis ( Tressler, 1937) , P. gaetani Savatenalinton & Martens, 2010 , P. mamarilorum ( Victor & Fernando, 1981) , P. phetchabunensis Savatenalinton & Martens, 2010 , P. thailandensis Savatenalinton & Martens, 2010 , Sarcypridopsis sp., Strandesia kraepelini ( Müller, 1906) .

Other localities. 1) Roadside canal, Phichit Province . Material collected on 27 Sep. 2005 and 13 Feb. 2006, coordinates: 16° 30΄ 30˝ N and 100° 11΄ 00˝ E. Accompanying ostracod fauna: Cyprinotus uenoi Brehm, 1936 , Hemicypris reticulata ( Klie, 1930) , Bradleytriebella lineata ( Victor & Fernando, 1981) , Dentocypria aequiloba n. gen. n. sp., Dentocypria smithi n. gen. n. sp., Cypridopsine sp. 2) Wangwa canal, Phichit Province . Material collected on 27 Sep. 2005, coordinates: 16° 30΄ 30˝ N and 100° 11΄ 00˝ E. Accompanying ostracod fauna: Dentocypria smithi n. gen. n. sp.

Etymology. The species is named in honour of Prof. Dr. Pranom Chantaranothai (Khon Kaen University, Thailand) for his considerable and invaluable contributions to taxonomy in Thailand. Prof. Dr. Pranom is a great taxonomist, he is my inspiration to do taxonomic research.

Diagnosis. Carapace in lateral view markedly elongated, dorsal margin evenly arched, valve surface smooth, CpD elliptical. Male A2 with transformed t2 and t3 setae not reaching tip of terminal segment. CR: Sa c. half as long as Ga, Sp long (reaching slightly beyond tip of ramus). Right prehensile palp of male T1 with large distal protrusion on first segment. Hemipenis with a-lobe slightly longer than b-lobe, a-lobe elongated, b-lobe subtriangular with pointed and slightly dorsally curved tip.

Differential diagnosis. The elongated carapace shape in lateral view of Dentocypria chantaranothaii n. gen. n. sp. is prominently different from other species in the genus and also in the subfamily Cyclocypridinae , in which the valves are commonly short in lateral view relative to height.

Measurements (mean, in µm). Female, LV (n = 5), L = 563, H = 336; RV (n = 5), L = 544, H = 339; Carapace (n = 10), L = 538, H= 321, W = 258. Male, LV (n = 5), L = 484, H = 261; RV (n = 5), L = 467, H = 269; Carapace (n = 10), L = 459, H = 274, W = 212.

Description of female. Carapace in lateral view ( Fig. 7 A) elongated, anterior margin slightly narrower rounded than posterior margin, LV overlapping RV anteriorly, ventrally and posteriorly, dorsal margin evenly arched, greatest height situated at mid-length, valve surface smooth.

CpD ( Fig. 7 B) elliptical, with greatest width situated at mid-length.

LVi ( Fig. 7 C) with selvage slightly inwardly displaced along the anterior margin, internal tooth on anteroventral part and tubercle-sockets anteriorly and posteriorly, calcified inner lamella wide anteriorly and posteriorly, with one weak inner list anteriorly.

RVi ( Fig. 7 D) with weak submarginal selvage anteriorly, complementary pit of internal tooth on antero-ventral part, valve margin tuberculated anteriorly and posteriorly, posterior tubercles more prominent than anterior ones, calcified inner lamella wide anteriorly and posteriorly, with one inner list anteriorly.

A1 ( Fig. 8 A): first segment with proximal Wouters organ, one long dorso-subapical seta (reaching beyond tip of segment) and two long ventro-apical setae. Second segment slightly wider than long, with one long dorso-apical seta (reaching mid-length of third segment) and small Rome organ. Third segment bearing two (dorso-apical and ventro-apical) setae, both setae long, reaching beyond tip of fourth segment. Fourth segment with two long dorsal setae and two subequal ventral setae, longer one of which reaching beyond tip of fifth segment. Fifth segment dorsally with two long setae, ventrally with two (one long, one shorter) setae, short 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 y a, length of latter c. 3/4 of that of short apical seta.

A2 ( Fig. 8 B): exopodite with three (one long, two short) setae, long one reaching beyond tip of first endopodal segment. First endopodal segment with five long (reaching tip of terminal claws) and one short natatory setae, length of shortest seta c. 1/4 of that of penultimate segment, aesthetasc Y long, ventro-apical seta long, reaching beyond tip of terminal segment. Penultimate segment undivided, distally with three serrated claws (G1, G2, G3), G2 short (length c. half of that of G1), aesthetasc y2 very long (reaching beyond tip of terminal segment), z1 seta short, z2–z3 setae long; this segment medially with two unequally long dorsal setae (long one reaching slightly beyond tip of terminal segment), four ventral setae (t1–t4) of unequal length (shortest one (t1) not reaching tip of segment) and ventral aesthetasc y1, latter short (not reaching tip of segment). Terminal segment distally with two serrated claws (GM and Gm), length of Gm c. 3/4 of that of GM; medially with ventral aesthetasc y3, length of aesthetasc y3 c. half of that of accompanying seta.

Md-palp ( Fig. 8 C) as in D. mesquitai n. gen. n. sp. with few differences: apical γ-seta long (reaching slightly beyond tip of terminal segment), terminal segment very elongated (length c. 3 times width), bearing two claws, one long seta and two short setae.

Mx1 ( Fig. 9 A) as in D. mesquitai n. gen. n. sp. with few differences, e.g. sideways-directed bristles on first endite unequally long, length of long one c. 3.4 times that of short one.

T1 ( Fig. 9 B) as in D. mesquitai n. gen. n. sp. with different setae lengths.

T2 ( Fig. 9 C) as in D. mesquitai n. gen. n. sp. with few differences, e.g. h3 seta of terminal segment long (not spine-like) and serrated claw (h2) almost as long as penultimate segment.

T3 ( Fig. 9 D) as in D. mesquitai n. gen. n. sp. with few differences, e.g. first segment with long d2, dp setae, d1 seta short (length almost half of that of dp seta).

CR ( Fig. 9 E) as in D. mesquitai n. gen. n. sp. with few differences, e.g. length of Gp c. 4/5 of Ga, Sa short (length c. half of that of Ga), Sp long (reaching slightly beyond tip of ramus).

CR attachment ( Fig. 9 F) as in D. mesquitai n. gen. n. sp.

Description of male. Carapace and valves ( Fig. 7 E–H) as in female, but somewhat smaller. All limbs as in female, except for terminal two segments of A2 ( Fig. 10 A) and T1 ( Fig. 10 B–C).

A2 with divided penultimate segment, transformed t2 and t3 setae long, but not reaching tip of terminal segment. Setae z1 and z2 of penultimate segment transformed into claws; claw G1 reduced; claw G3 reduced to seta (reaching slightly beyond tip of terminal segment); Gm on terminal segment of A2 reduced, appearing smaller and shorter (length c. half of that of GM).

T1 with asymmetrical prehensile palps (endopodites). First segment of right prehensile palp ( Fig. 10 B) with large distal subtriangular protrusion and bearing one short apical spine; second segment large, elongated. Left prehensile palp ( Fig. 10 C) elongated with first segment bearing two long apical spines; second segment narrow, curved and pointed.

Hemipenis ( Fig. 10 D): a-lobe elongated, b-lobe subtriangular, with pointed end, b-lobe slightly shorter than alobe.

Zenker organ ( Fig. 10 E) elongated, length c. 2.5 times width, set with seven chitinous spiny whorls. Remarks. The new species is superficially similar to Physocypria dumonti Martens, 1982 . It can be distinguished by its bigger size, the more elongated shape of the carapace in lateral and dorsal views, the chaetotaxy (for example the long Sa of CR) and the morphology of the hemipenis and the male T1-palps (see Martens 1982).

Figures

FIGURE 7. Dentocypria chantaranothaii n. gen. n. sp., female (A – D), male (E – H). A. CpR (MSU. ZOC. 162). B. CpD (MSU. ZOC. 163). C. LVi (MSU. ZOC. 155). D. RVi (MSU. ZOC. 155). E. CpR (MSU. ZOC. 156). F. CpD (MSU. ZOC. 157). G. LVi (MSU. ZOC. 154). H. RVi (MSU. ZOC. 154). Scale bar: A – H = 200 µm.

FIGURE 8. Dentocypria chantaranothaii n. gen. n. sp., female (MSU. ZOC. 155). A. A 1. B. A 2. C. Md-palp. D. Md-coxa. Scale bar: A = 50 µm; B, D = 40 µm; C = 35 µm.

FIGURE 9. Dentocypria chantaranothaii n. gen. n. sp., female (MSU. ZOC. 155). A. Mx 1. B. T 1. C. T 2. D. T 3. E. CR. F. CR attachment. Scale bar: A – B = 35 µm; C – F = 50 µm.

FIGURE 10. Dentocypria chantaranothaii n. gen. n. sp., male (MSU. ZOC. 154). A. A 2. B. right prehensile palp. C. left prehensile palp. D. hemipenis. E. Zenker organ. Scale bar: A = 44 µm; B – D = 50 µm; E = 110 µm.