Thaicypris panhai, Savatenalinton, 2022

Savatenalinton, Sukonthip, 2022, On Thaicypris panhai gen. et sp. nov., a new herpetocypridine ostracod (Crustacea: Ostracoda: Cyprididae) from Thailand, European Journal of Taxonomy 787 (1), pp. 86-103 : 89-98

Thaicypris panhai gen. et sp. nov.

urn:lsid:zoobank.org:act:A9E0AEBE-99FD-4CDD-9744-F950EDA7BD79

Figs 1–7

Diagnosis

Cp in lateral view elongated (length ca 2.2 mm in female, ca 2 mm in male), greatest height situated at ⅔ of length, Cp in dorsal view elongated with widened posterior half, greatest width situated at ⅔ of length, valve surface smooth, LV overlapping RV on all sides. LV with a prominent double posterior inner list and a weak antero-ventral inner list. RV with prominent and raised, inwardly displaced selvage at postero-ventral part appearing not parallel to valve margin and without anterior and posterior inner list. Fused zone of LV wider than RV, especially at postero-ventral part of LV, marginal pore canals present. Calcified inner lamella of both valves wide anteriorly, narrower posteriorly. A1 with small Rome organ and small Wouters organ. Natatory setae on A2 long (reaching tip of terminal claws), male A2 with clawlike z1 and z2 setae, considerably reduced claw G1, claw G3 and GM reduced to thin setae, claw Gm large with strong teeth, length of GM ca half of length of Gm. Md-palp with three claws and four setae on terminal segment, α-seta elongated, with narrow base and long, needle-like tip, β-seta stout and set with a few long and strong setules, γ-seta large, elongated, distally covered with long setules ca ⅔ of its length. Mx1-palp with spatulated terminal segment, basal segment with seven setae, two large bristles on 3 rd endite smooth. Setae d1 and d2 on T2 of medium length and subequal. CR symmetrical, ramus and claws slender, Sp seta long and slender (true seta), reaching beyond tip of ramus, claw Ga long, claw Gp short (less than half length of claw Ga). CR attachment with basal triangle and two-branched distal part. Male T1 palps asymmetrical, right palp with subtriangular terminal segment, left palp with hook-like terminal segment, terminal segment of both palps with small pointed projection at inner base. Medial lateral shield of hemipenis proximally knob-like rounded and markedly long, beak-like distally.

Differential diagnosis

As Thaicypris gen. nov. is monospecific at present, the differential diagnosis is largely the same as for the genus.

Etymology

The species is named in honor of Prof. Dr Somsak Panha (Chulalongkorn University, Thailand) for his outstanding work on animal biodiversity in Thailand and Southeast Asia as well as for his effort to encourage young scientists in taxonomy and systematics studies in Thailand for a long time.

Type material

Holotype THAILAND – Maha Sarakham Province  ♀ (soft parts dissected in glycerine on a sealed glass slide and valves stored dry on a micropalaeontological slide); Nong Bua (swamp), Kantharawihai District ; 16.319372° N, 103.29637° E; 19 Jun. 2021; MSU-ZOC.314 .

Allotype THAILAND – Maha Sarakham Province  ♂ (stored as the holotype); same collection data as for holotype; MSU-ZOC.315 .

Paratype THAILAND – Maha Sarakham Province  1 ♀ (stored as the holotype); same collection data as for holotype; MSU-ZOC.316 .

Type locality

A total of 2 female and 1 male specimens was collected at the type locality on 19 Jun. 2021. Accompanying ostracod fauna: Bradleystrandesia weberi (Moniez, 1892), Candona sp., Cypretta aculeata Savatenalinton, 2018, Cyprettadopsis sutura Savatenalinton, 2020, Dentocypria mesquitai Savatenalinton, 2017, Metacypris sp., Pseudocypretta maculata Klie, 1932, Pseudostrandesia mamarilorum ( Victor & Fernando, 1981), Pseudostrandesia striatoreticulata (Klie, 1932), Strandesia kraepelini (Müller, 1906), Vestalenula sp.

Description

Female

MEASUREMENTS (in mm). LV: L = 2238, H = 1119; RV: L = 2214, H = 1071.

CP IN LATERAL VIEW. Elongated (length ca 2.2 mm), greatest height situated at ⅔ of length, Cp in dorsal view elongated with widened posterior half, greatest width situated at ⅔ of length, LV overlapping RV on all free margins, valve surface smooth with irregular dark green patches.

LV IN INTERNAL VIEW ( FigS 1A–B , 2A–B , 3A ). With both valve margins rounded, wider rounded posteriorly, dorsal margin arched, ventral margin somewhat straight, submarginal selvage anteriorly, anterior calcified inner lamella wide with weak and incomplete inner list (only on antero-ventral part), posterior calcified inner lamella narrow with a prominent double posterior inner list, fused zone wide and markedly wider at postero-ventral part, marginal pore canals present.

RV IN INTERNAL VIEW ( FigS 1C–D , 2C–D , 3B ).With both valve margins rounded, wider rounded posteriorly, dorsal margin arched, slightly more arched than that of LV, ventral margin somewhat straight, marginal selvage anteriorly, inwardly displaced selvage prominent and raised, on postero-ventral part appearing not parallel to valve margin, calcified inner lamella wide anteriorly, narrow posteriorly, without anterior and posterior inner list, width of fused zone somewhat regular along valve margin, narrower than that of LV, marginal pore canals present.

A1 ( Fig. 4A–C ). Seven-segmented, first segment with one short dorso-subapical seta (not reaching tip of segment), two long ventro-apical setae and small Wouters organ. Second segment ca 1.5 times as wide as long, with one short dorso-apical seta (not reaching mid-length of next segment) and Rome organ small, three-segmented. Third segment bearing two setae: one long dorso-apical (reaching far beyond tip of terminal segment) and one short ventro-apical setae (reaching tip of next segment). Fourth segment with two long dorsal setae and two shorter ventral setae (shortest one reaching mid-length of penultimate segment). Fifth segment dorsally with two long setae, ventrally with two (one long, one shorter) setae, shorter one reaching far beyond tip of terminal segment. Penultimate segment with four long apical setae and one short seta (reaching mid-length of terminal segment). Terminal segment with three (two long, one short) apical setae and long aesthetasc ya, length of aesthetasc ya slightly shorter than that of short seta.

A2 ( Fig. 4D–E ). Basal segment with two proximal setae and one long ventro-apical seta. Exopodite with three (one longer, two short) setae, longer one not reaching half of first endopodal segment. First endopodal segment with five long natatory setae (reaching slightly beyond tips of terminal claws) and one short accompanying seta (length ca 1/4 that of penultimate segment), aesthetasc Y very short and thin, situated at ca 1/4 of its segment length, ventro-apical seta long, extending beyond tip of terminal segment. Penultimate segment undivided, distally with three large, serrated claws (G1–G3), aesthetasc y2 long (reaching slightly beyond tip of terminal segment), z1–z3 setae long, z1 shorter than other z setae, z2–z3 not reaching tip of claws G1–G3; this segment medially with two subequally short dorsal setae and four ventral setae of unequal length. Terminal segment with small ventro-apical projection set with fine marginal setules; distally with two serrated claws (GM and Gm), length of Gm ca ¾ that of GM, and with long g seta and aesthetasc y3, length of aesthetasc y3 shorter than accompanying seta.

MD- PALP ( Fig. 5A–B ). First segment with two large setae (S1 and S2), one long and slender seta, and α-seta, the latter smooth, elongated with long, needle-like tip. Second segment dorsally with three unequally long apical setae, shortest seta almost reaching tip of next segment; ventrally with group of three long setae, one shorter hirsute seta and cone-shaped β-seta with pointed tip and set with a few long and strong setules. Penultimate segment bearing three groups of setae: dorsally with group of four unequal, long, subapical setae; laterally with apical γ-seta and three further apical setae, the former large, elongated (length ca 1.9 times that of terminal segment), distally covered with long setules ca ⅔ of its length, the latter subequal in length (length of the longest seta ca 2 times terminal segment length, the shortest slightly beyond tip of terminal segment); ventrally with two subapical setae, one very long (length ca 3 times that of terminal segment), one shorter (reaching slightly beyond tip of terminal segment). Terminal segment bearing three claws and four setae, length of terminal claws ca 2.8 times that of terminal segment.

MX 1 ( Fig. 5C ). With two-segmented palp, basal segment of palp dorsally with group of six long, unequal apical setae; ventrally with one subapical seta (reaching tip of terminal segment), terminal segment spatulated, apically with three claws and three setae. Two large bristles on third endite smooth. Two sideways-directed bristles on first endite long, subequal in length.

T1 ( Fig. 5D–E ). Protopodite with two short a-setae, subequal in length, and long b-and d-setae, c-seta absent; distally with 10 hirsute apical setae of unequal length and four subapical setae, two of subapical setae short and stout. Endopodite very elongated; weakly built palp with three (one long, two short) apical setae, length of long one ca 2.7 times that of shortest one.

T2 ( Fig. 6A–B ). With d1 and d2 setae subequal in length. Second segment with short e-seta (reaching beyond mid-length of penultimate segment). Penultimate segment divided, medially with long f-seta (reaching beyond tip of terminal segment), distally with apical g-seta and one short accompanying seta (length ca half that of g-seta). Terminal segment with two (one dorsal, one ventral) short apical h1 and h3 setae (subequal in length) and serrated claw (h2), length of h2 longer than that of penultimate segment.

T3 ( Fig. 6C–D ). First segment with long d1, d2 and dp setae, all subequal in length. Second segment with medium-length apical e-seta (reaching mid-length of next segment). Third segment with f-seta (not reaching tip of segment). Terminal segment with pincer organ and bearing short h1 seta, claw-like h2 seta and long h3 seta.

CR ( Fig. 6E–F ). Symmetrical with slender ramus and claws, ventral margin of ramus with tiny setules, claw Ga long (length ca half that of ramus), claw Gp short (less than half length of claw Ga), Sa seta short, Sp seta long and slender (true seta), reaching beyond tip of ramus. CR attachment ( Fig. 6G ) thin, with basal triangle and two-branched distal part.

Male

MEASUREMENTS (in mm). LV: L = 1952, H = 952; RV: L = 1929, H = 905.

Carapace and valves as in female, although somewhat smaller (length ca 2 mm) ( Fig. 1E–H ). All limbs as in female, except for last two segments of A2, T1 and reproductive organs. Penultimate segment of A2 with claw-like z1 and z2 setae, considerably reduced claw G1 and with claw G3 reduced to thin setae; terminal segment with claw GM considerably reduced to thin setae, claw Gm large, with stronger teeth, length of GM ca half length of Gm ( Fig. 4F ). T1-endopodites forming asymmetrical prehensile palps; right palp ( Fig. 7A ) with two subapical spines on basal segment, terminal segment subtriangular; left palp ( Fig. 7B ) with two subapical spines on basal segment, terminal segment hook-like, inner base of terminal segment of both palps with small projection, one on left palp larger than on right palp.

HEMIPENIS ( Fig. 7C ). With ms subrectangular, widely rounded distal margin, without elongated protrusion, vls small and rounded (not finger-like), dls with round margin, without protrusion, distal part of mls proximally knob-like rounded and markedly long, beak-like apically. Postlabyrinthal spermiduct curved, with one loop. Zenker’s organ ( Fig. 7D ) slender, elongated and set with numerous spiny whorls (more than 60 spiny whorls).

Remarks

The basal triangle of the CR-attachment ( Fig. 6C ) was narrow and located on the side of the dorsal branch. This aspect seems to be unusual, which possibly results from the distortion of the structure under the microscope. As only one male specimen has been encountered, the variability of the male appendages and reproductive organs is unknown.

Figures

Fig. 1. Thaicypris panhai gen. et sp. nov.A–D. Holotype, ♀ (MSU-ZOC.314). E–H. Allotype, ♂ (MSU- ZOC.315). A. LV, external view. B. LV, internal view. C. RV, external view. D. RV, internal view. E. LV, external view. F. LV, internal view. G. RV, external view. H. RV, internal view. Arrows point to anterior end of specimen. Scale bar = 500 μm.

Fig. 2. Thaicypris panhai gen. et sp. nov.A–D. Holotype, ♀ (MSU-ZOC.314). E–H. Allotype, ♂ (MSU- ZOC.315). A. LV, internal view, posterior part. B. LV, internal view, anterior part. C. RV, internal view, anterior part. D. RV, internal view, posterior part. E. LV, internal view, posterior part. F. LV, internal view, anterior part. G. RV, internal view, anterior part. H. RV, internal view, posterior part. Scale bar = 100 μm.

Fig. 3. Thaicypris panhai gen. et sp. nov., holotype, ♀ (MSU-ZOC.314). A. LV, internal view. B. RV, internal view. Scale bar = 500 μm.

Fig. 4. Thaicypris panhai gen. et sp. nov. A–E, G. Holotype, ♀ (MSU-ZOC.314). F. Allotype, ♂ (MSU- ZOC.315). A. A1. B. A1, Wouters organ. C. A1, Rome organ. D. A2. E. A2, terminal segment. F. A2, terminal part. G. Md-coxa. Scale bar: A, D, G = 100 μm; B–C, E–F = 50 μm.

Fig. 5. Thaicypris panhai gen. et sp. nov., holotype, ♀ (MSU-ZOC.314). A. Md-palp. B. Md-palp, α, β, γ setae. C. Mx1. D. T1. E. T1, palp (endopodite). Scale bar: A–D = 50 μm; E = 100 μm.

Fig. 6. Thaicypris panhai gen. et sp. nov., holotype, ♀ (MSU-ZOC.314). A. T2. B. T2, terminal segment. C. T3. D. T3, terminal part. E. CR. F. CR, terminal part. G. CR attachment. Scale bar: A, C, E, G = 100 μm; B, D, F = 50 μm.

Fig. 7. Thaicypris panhai gen. et sp. nov., allotype, ♂ (MSU-ZOC.315). A. T1, right palp. B. T1, left palp. C. Hemipenis. D. Zenker organ. Arrows on A–B indicate the small pointed projection at the inner base of the terminal segment. Scale bars: A–C = 50 μm; D = 100 μm.