Gurayacypris danielopoli, Savatenalinton, 2024

Gurayacypris danielopoli , new species

( Figs. 1–9 View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig )

Material examined. Holotype: Male , soft parts dissected in glycerine on a sealed slide, valves stored dry on a micropalaeontological slide ( MSU-ZOC.398), rice field, Kantharawichai District, Maha Sarakham Province, Thailand (16.267 N, 103.252 E), coll. S Savatenalinton, 15 June 2021. GoogleMaps

Allotypes: Female, stored like the holotype ( MSU-ZOC.402), same data as holotype GoogleMaps .

Paratypes: 3 males, soft parts dissected in glycerine on a sealed slide, carapaces stored dry on micropalaeontological slides ( MSU-ZOC.399 – 401) ; 2 females, soft parts dissected in glycerine on a sealed slide, carapaces stored dry on micropalaeontological slides ( MSU-ZOC.403 – 404); c . 3 males and 3 females in 70% ethanol, deposited in the Science Faculty Museum ( MSU, Thailand) and 2 males and 2 females in 70% ethanol deposited at the Lee Kong Chian Natural History Museum ( Singapore), same data as holotype GoogleMaps .

Measurements (μm). Male. Cp (n = 3): L = 806 – 832, H = 577 – 580, W = 442 – 458, LV (n = 2): L = 823 – 826, H = 574 – 577, RV (n = 2): L = 829 – 832, H = 577 – 581. Female. Cp (n = 2): L = 794 – 800, H = 580 – 582, W = 457 – 459, LV (n = 2): L = 828 – 831, H = 568 – 571, RV (n = 2): L = 822 – 825, H = 568 – 571.

Diagnosis. Cp in lateral view subovate, sexually dimorphic, female posteroventral spur on LV subtriangular with pointed tip, valve surface not strongly ornamented, third segment of A1 with two short setae, natatory setae of A2 long, penultimate segment of A2 divided and G1 seta with skewed tip, Mx1 third endite with six Zahnborsten, terminal part of female T1 palp with broad, dome-shaped terminal part and pointed apical tip, masticatory processes of T1 with 14 bristles, distal margin of basal segment of male T1 left palp without projection, T2 sexually dimorphic with more elongated in male and with three longer setae on male terminal segment, CR without sa seta, ramus more elongated and curved in male, CR attachment with several distal loops, Hp subovate, ms short (not protruding beyond edge of ls) with gently curved dorsal margin, ls subtriangular with pointed tip directing outward, ZO with numerous spiny whorls.

Differential diagnosis. Gurayacypris danielopoli , new species, can mainly be distinguished from G. kangraensis by the more rounded dorsal part of Cp in lateral view, the larger Cp size, the protruded triangular spur on the postero-ventral part of the female LV (small blunt-tipped spur in G. kangraensis ), the absence of a pointed protrusion on the distal margin of the basal segment of the left prehensile palp and the triangular ls of the Hp with a pointed tip directed outwards.

Description of male. Cp in lateral view ( Fig. 1A, E–F View Fig ) subovate, greatest height situated c. mid-length, dorsal margin evenly arched, anterior margin broadly rounded with anteroventral corner, posterior margin more narrowly rounded with apex at c. mid-height, ventral margin straight; eye tubercle not prominent, situated at antero-dorsal part; valve surface not strongly ornamented, set with tiny pustules anteriorly, weak reticulation (stronger in posterior part than in other parts) and rimmed pore setae ( Fig. 1B View Fig ).

Cp in dorsal view ( Fig. 1C, G–H View Fig ) elliptical, greatest width situated at mid-length, posterior part more broadly rounded than anterior one, both anterior and posterior extremities with small pointed tips.

Cp in ventral view ( Fig. 1D, I–J View Fig ) elliptical with flattened ventral surface and strong oval concavity posteriorly, forming sharply defined oval structure with irregularly curved margins, strongly concave area situated in third part of length. Outer lists prominent, anteriorly curved outwards towards around mouth zone.

LV in interior view ( Fig. 3G, I–J View Fig , 4A View Fig ) with flange positioned anteriorly and strong concavity at postero-ventral corner, anterior selvage inwardly displaced, calcified inner lamella narrow with one inner list, groove present along ventral margin.

RV in interior view ( Fig. 3H, K–L View Fig , 4B View Fig ) as in LV, but anterior flange wider and groove present along anterior and ventral margins.

A1 ( Fig. 5A View Fig ): 7-segmented; first segment with a long subapical dorsal seta (reaching beyond tip of next segment), two unequally long subapical ventral setae, Wouters organ absent. Second segment wider than long, with one markedly long dorso-apical seta (reaching tip of next segment), Rome organ absent. Third segment very long bearing two (one dorso-, one ventro-) apical setae, both setae remarkably short. Fourth segment with two long dorsal setae and one very short ventral seta. Fifth segment dorsally with two long setae, ventrally with two short setae, the longer one reaching slightly beyond middle of next segment, another one spine-like. Penultimate segment with four long setae. Terminal segment with three (two long, one short) apical setae and an aesthetasc ya, length of shortest seta c. 2/3 of aesthetasc ya.

A2 ( Fig. 5B View Fig ): protopodite with one proximal seta and two ventral setae. Exopodite with three (one long, two short) setae, the long one reaching tip of first endopodal segment. First endopodal segment with five long natatory setae and accompanying very short seta (reaching c. 1/5 of penultimate segment), aesthetasc Y slender and long (reaching tip of the segment), ventro-apical seta long (reaching tip of terminal segment). Penultimate segment divided; proximal subsegment with two short dorsal setae (the longer seta reaching mid-length of next segment, length of short seta c. 1/2 of long one) and two ventral setae (t setae), the long one reaching slightly beyond tip of next segment, length of shorter one c. 4/5 of long one); distal subsegment apically with three claws (G1–G3), claw G1 with skewed tip and reduced in length (shorter than that of female), claw G3 reduced to short seta (length c. 2/3 of that of terminal segment) and z1–z3 setae, z1 seta modified to long seta (short seta in female), z2 short (not reaching middle of next segment), z3 intermediate in length (reaching tip of next segment). Terminal segment very elongated with two claws (GM and Gm) and an aesthetasc y3, g-seta not seen, claw GM slender, seta-like and slightly shorter than claw Gm, length of aesthetasc y3 c. half-length of Gm, accompanying seta slightly longer than aesthetasc y3.

Md ( Fig. 6A–E View Fig ): Md-coxa ( Fig. 6A View Fig ) slender distally set with rows of teeth (large dorsally and smaller ventrally) and with one dorso-subapical seta, the latter small and short (not reaching base of teeth). Md-palp ( Fig. 6B View Fig ): first segment with two large setae (S1 and S2), one slender, long seta and α-seta with broad first half, narrower second half and long needle-like tip ( Fig. 6C View Fig ), S1 seta smaller than S2 seta ( Fig. 6E View Fig ). Second segment dorsally with two unequal long apical setae; ventrally with a group of four hirsute setae ( Fig. 6D View Fig ) and β-seta, the latter slim and dome-shaped with a pointed tip ( Fig. 6C View Fig ). Penultimate segment consisting of three groups of setae: dorsally with a group of four subapical setae (intermediated length); laterally with an apical γ–seta and three further thin and short apical setae, the former thin and short (reaching slightly beyond tip of terminal segment) ( Fig. 6C View Fig ); ventrally with one hirsute, large, and long apical setae. Terminal segment elongated (length c. two times of width) bearing two long claws and two shorter setae.

Mx1 ( Fig. 6F View Fig ) with a 2-segmented palp, three endites and a branchial plate; basal segment of palp with a group of four short, but unequal, apical setae and two (one short, one longer) subapical setae, the short one reaching slightly beyond tip of basal segment), terminal segment subquadrate, with three claws and three setae. Third endite bearing six large bristles (Zahnborsten) with distal serration. First endite basally with two remarkably long and large setae.

T1 ( Fig. 7A–B View Fig ): protopodite with two a-setae, distally with 14 hirsute setae (10 apically, four subapically), prehensile palps (endopodites) strongly asymmetrical. Left prehensile palp ( Fig. 7A View Fig ) smaller than right one, with first segment subquadrate-shaped, second segment elongated with blunt tip. Right prehensile palp ( Fig. 7B View Fig ) with first segment very elongated, second segment long and thin, distally narrower towards pointed tip.

T2 ( Fig. 7D View Fig ) elongated, without d setae and sexually dimorphic (stubbier in female— Fig. 7E View Fig ). Second segment with one very short apical e-seta. Penultimate segment divided, proximal segment (a) bearing one very short apical f-seta; distal segment (b) with short spine-like apical g-seta. Terminal segment with a claw h2 and two (one dorsally, one ventrally) long apical h1 and h3 setae, the former transformed into claw and larger than h2.

T3 ( Fig. 8A View Fig ): first segment with d1, d2 and dp setae, all setae intermediate in length with needle-like tip. Second segment with one long apical e-seta (almost reaching tip of next segment). Third segment with medially one long f-seta (reaching slightly beyond tip of terminal segment). Terminal segment without pincer organ and bearing three long setae (h1–h3), h1 and h2 setae claw-like, h3 seta reflexed with length c. 4/5 of that of third segment.

CR ( Fig. 8B View Fig ) elongated, without sa seta and sexually dimorphic with more elongated and curved ramus in male (shorter and less curved ramus in female – Fig. 8C View Fig ). Claws Ga and Gp thin and very long, claw Gp slightly shorter than claw Ga, sp seta long (length c. 1/3 of that of claw Ga),

male sp seta shorter than that of female (reaching beyond mid-length of claw Ga – Fig. 8C View Fig ).

CR attachment ( Fig. 8D–E View Fig ) complex with several distal loops, main branch with few small branching.

Hp ( Fig. 9A–B View Fig ) subovate, ms short (not protruding beyond edge of ls) with gently curved dorsal margin, ls large, subtriangular with pointed tip directing outward; internal postlabyrinthal spermiduct without loop.

ZO ( Fig. 9C View Fig ) elongated with numerous spiny whorls and funnel-shaped ends.

Description of female. Cp and valves ( Figs. 2 View Fig , 3A–F View Fig , 4C–D View Fig ) generally as in male, but obviously different in postero-ventral part of valves. Postero-ventral part of LV with protruded triangular spur (sharply curved and without spur in male), postero-ventral part of RV gently curved with rounded corner (sharply curved in male). Cp in ventral view with less strong posterior concavity than that of male.

All limbs as in male, except for last two segments of A2 ( Fig. 5C View Fig ), T1 ( Fig. 7C View Fig ), T2 ( Fig. 7E View Fig ) and CR ( Fig. 8C View Fig ). Longest t setae on penultimate segment of A2 longer than those of male; z1 seta shorter, claw G1 long with skewed tip, claw G3 long, seta-like ( Fig. 5C View Fig ). T1 palp (endopodite) elongated with broad, dome-shaped terminal part and pointed apical tip ( Fig. 7C View Fig ). T2 less elongated with claw-like h2 seta long, but shorter than that of male; h1 and h3 setae shorter than h2 seta, h3 seta claw-like ( Fig. 7E View Fig ). CR shorter than that of male, sp seta remarkably long, ramus less elongated and slightly curved ( Fig. 8C View Fig ).

Etymology. The species is named in honor of Prof. Dr. Dan L. Danielopol (University of Graz, Austria) in recognition of his outstanding work on ostracods.

Ecology. The Indian G. kangraensis was taken from a permanent water body. However, the Thai new species was found in a rice field, which is a man-made temporary water body. Apart from other accompanying ostracod species in the type locality, large branchiopods ( Cyzicus sp. and Lynceus sp. ) which typically inhabit temporary water bodies, were also encountered in the type locality.