Hungarocypris suranareeae, Savatenalinton, Sukonthip & Suttajit, Maitree, 2016

Savatenalinton, Sukonthip & Suttajit, Maitree, 2016, A checklist of Recent non-marine ostracods (Crustacea: Ostracoda) from Thailand, including descriptions of two new species, Zootaxa 4067 (1), pp. 1-34 : 19-25

Hungarocypris suranareeae n. sp.

( Figures 5–9 )

Holotype. Male, soft parts dissected in glycerine on a sealed glass slide, valves stored dry in a micropalaeontological slide (MSU-ZOC.132).

Allotype. Female, stored like the holotype (MSU-ZOC.133).

Paratypes. One dissected male (MSU-ZOC.134) stored like the holotype, two whole males (MSU-ZOC.135– 136) stored dry in micropalaeontological slides, two dissected females (MSU-ZOC.137–138) stored like the holotype, two whole females (MSU-ZOC.139–140) stored dry in micropalaeontological slides and a few males and females in 70% EtOH.

Repository. All type specimens are deposited in the Natural History Museum, MSU, Thailand.

Type locality. Huai Yang reservoir, Muang district, Nakhon Ratchasima Province, collected on 13 February 2011, coordinates: 14° 54΄ 30˝ N and 102° 00΄ 01˝ E. Accompanying fauna: Bradleystrandesia weberi (Moniez, 1892) , Bradleytriebella lineata (Victor & Fernando, 1981) , Cypretta sp.1, Cypridopsine sp., Oncocypris rostrata Savatenalinton, 2015 , Physocypria sp.2, Physocypria sp.3, Pseudocypretta maculata Klie, 1932 , Pseudostrandesia calapanensis ( Tressler, 1937) , Pseudostrandesia thailandensis Savatenalinton & Martens, 2010 , Stenocypris cf. major , Stenocypris cf. orientalis, Stenocypris derupta Vávra, 1906 , Strandesia kraepelini ( Müller, 1906) , Tanycypris siamensis Savatenalinton & Martens, 2009 .

Other localities. Huai Grog Lang (stream), Pak Thong Chai district, Nakhon Ratchasima Province, collected on 13 February 2011, coordinates: 14° 41΄ 22˝ N and 102° 00΄ 55˝ E. Accompanying fauna: Bradleycypris vittata ( Sars, 1903) , Bradleystrandesia weberi (Moniez, 1892) , Cypris subglobosa Sowerby, 1840 , Hemicypris ovata Sars, 1903 , Physocypria sp.2, Physocypria sp.3, Pseudocypretta maculata Klie, 1932 , Pseudostrandesia calapanensis ( Tressler, 1937) , Pseudostrandesia gaetani Savatenalinton & Martens, 2010 , Pseudostrandesia mamarilorum (Victor & Fernando, 1981) , Stenocypris cf. orientalis, Strandesia kraepelini ( Müller, 1906) , Strandesia sanoamuangae Savatenalinton & Martens, 2010 .

Etymology. The new species is named after the famous historic heroine, Suranaree, of Nakhon Ratchasima Province, where it was discovered.

Diagnosis. Carapace in lateral view elongated, anterior margin widely rounded, posterior margin more narrowly rounded with pointed posterior extremity on RV, RV somewhat smaller than LV; Carapace in dorsal view sub-elliptical, with compressed and pointed anterior and posterior ends; LV in interior view with strongly calcified inner margin, marginal zone broad with pore canals, serration on postero-ventral part; RV in interior view similar to LV in interior view but with pointed, serrated posterior extremity; Rome organ short, Wouters organ present, aesthetasc Y of A2 short and thin, short, z1 seta short, length of aesthetasc y3 c. 4 times of accompanying seta; βseta of Md-palp slim, long, set with dispersed setules; terminal segment of Mx1-palp short, spatula-shaped, two large bristles on third endite smooth; T2 with seta d2 c. twice the length of seta d1; CR with Ga and Gp subequally long, length of Ga c. half of that of ramus, Sa short (slightly less than half of Ga), Sp1 markedly long (c. 2/3 of Gp), Sp2 long, reaching tip of ramus; right prehensile palp with first segment bearing two long apical spines; second segment large, elongated with wider base, length as long as first segment; Hemipenis with LS subquadrate, blunt end, MS elongated with curved apical end, IS narrow, with pointed end.

Differential diagnosis. Hungarocypris suranareeae n. sp. is similar to H. asymmetrica Victor & Fernando, 1981 in terms of valve asymmetry, with the RV smaller than the LV. It can be distinguished by the carapace shape, which is more elongated in H. asymmetrica , and the morphology of the valves. The posterior end of the left valve is rounded in H.suranareeae n. sp. while it is notched in H. asymmetrica . The valve margin is serrated along the postero-ventral part of the LV and at the pointed posterior extremity of the RV in the new species, whereas there is no serration on valve margins in H. asymmetrica . The serrated valve margin can also be found in H. serrata Chen, 1983 , but while this serration is only present on the RV in H. serrata , it occurs on both valves in the new species.

Measurements (mean, in µm). Female, LV (n = 2), L = 3310, H = 2000; RV (n = 2), L = 3334, H = 1834; Male, LV (n = 2), L = 2976, H = 1762; RV (n = 2), L = 3072, H = 1667.

Ecology. The habitats of Hungarocypris suranareeae n. sp. were densely covered by many macrophytes, e.g. Hydrilla verticillata Royle , Ipomoea aquatica Forssk, Ludnigia adscendens Hara, Salvinia cucullata Roxb. ex Bory , Cyperus spp., Nymphaea spp. The substrates contained a high proportion of organic matter. Hungarocypris suranareeae n. sp. has so far been encountered from two localities only: reservoir and slow-running stream. It occurred at a pH range of 7.37 – 7.94, a temperature range of 25.9 – 29.2 °C and a DO range of 4.30 – 6.37 mg/l.

Description of female. Carapace in lateral view ( Fig. 5 A) elongated, anterior margin widely rounded, posterior margin more narrowly rounded with pointed posterior extremity on RV ( Fig. 5 D–E), greatest high situated at 1/3 of the length, dorsal margin arched with steep sloping down to posterior end, ventral margin straight, valve surface set with disperse shallow pits and setae ( Fig. 5 C).

Carapace in dorsal view subelliptical, with compressed and pointed anterior and posterior ends, greatest width situated at mid-length.

LV in interior view ( Fig. 6 A, D–E) with strong calcified inner margin, marginal zone broad with pore canals, greatest height situated at 1/3 of length, anterior margin widely rounded, posterior margin more narrowly rounded with serration on postero-ventral part, calcified inner lamella narrow anteriorly and posteriorly, without inner list.

RV in interior view ( Fig. 6 B, F–G) with strong calcified inner margin, marginal zone broad with pore canals, greatest height situated at 1/3 of the length, anterior margin widely rounded, posterior end pointed with serration, calcified inner lamella narrow anteriorly and posteriorly, without inner list.

A1 ( Fig. 7 A): first segment with proximal Wouters organ, one long dorso-subapical seta (almost reaching tip of next segment) and two long ventro-apical setae. Second segment wider than long, with one short, spine-like dorsoapical seta and short Rome organ. Third segment bearing two setae: one long dorso-apical seta, reaching tip of fifth segment, and one short ventro-apical seta, reaching half-way of next segment. Fourth segment with two long dorsal setae and two subequal, shorter ventral setae (long one reaching tip of penultimate segment, short one not reaching tip of next segment). Fifth segment dorsally with two long setae, ventrally with two (one long, one shorter) setae, shorter one reaching beyond tip of terminal segment. Penultimate segment with four long setae. Terminal segment with three (two long, one shorter) apical setae and aesthetasc y a, length of the latter equals length of shorter apical seta.

A2 ( Fig. 7 B–C): exopodite with three (one long, two short) setae, long one c. 2/3 of first endopodal segment. First endopodal segment with five long (reaching beyond tip of terminal claws) and one short natatory setae, length of shortest seta reaching more than half way penultimate segment, aesthetasc Y slim, short, ventro-apical seta long, reaching beyond tip of terminal segment, and set with spine-like setules. Penultimate segment undivided, distally with three serrated claws, aesthetasc y2 long (reaching beyond tip of terminal segment), z1 short (length c. 2.5 times of that of terminal segment), z2–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, aesthetasc y3 longer than accompanying seta (length of aesthetasc y3 c. 4 times of accompanying seta), seta g shorter than aesthetasc y3 (length c. 3/4 of that of aesthetasc y3).

Md-palp ( Fig. 7 D): first segment with two large setae (s1 and s2), one slender, long seta and α-seta, the latter long, smooth, thin with wider base. Second segment dorsally with three unequal long apical setae, shortest one reaching tip of penultimate segment; ventrally with group of three long hirsute setae, one shorter hirsute seta and βseta, the latter slim, long, set with dispersed setules (not plumose). Penultimate segment consisting of three groups of setae: dorsally with group of four unequal, long, subapical setae; laterally with apical γ-seta and three smooth apical setae, the former stout, hirsute, long (length c. 2 times of that of terminal segment); ventrally with two (one long, one shorter) apical setae, length of long one c. 2 times of that of short one. Terminal segment ( Fig. 7 E) bearing three slim claws and four setae.Md-coxa ( Fig. 6 F) normal form as that of Cyprididae .

Mx1 ( Fig. 8 A) with two-segmented palp, three endites and large branchial plate; basal segment of palp with group of five long, unequal apical setae and two (one dorsally, one medially) subapical setae, the former long, the latter shorter (reaching tip of terminal segment), terminal segment short, spatula-shaped, apically with three claws and three setae. Two large bristles on third endite smooth. Sideways-directed bristles on first endite subequally long.

T1 ( Fig. 8 B): protopodite with two subequally long a-setae (length of long one c. 2 times of that of short one), long b and short c and long d-setae, distally with 15 hirsute setae of unequal length. Endopodite weakly built palp with three unequal apical setae.

T2 ( Fig. 8 C) with seta d2 c. twice the length of seta d1. Second segment with long e-seta (reaching half of next segment). Penultimate segment divided, proximal segment (a) bearing long f-seta, reaching less than tip of distal segment (b), distal segment with pair of apical setae (long g-seta, one tiny, spine-like). Terminal segment with two (one dorsally, one ventrally) apical h1 and h3 setae and serrated claw (h2).

T3 ( Fig. 8 D) cleaning limb. First segment with long d1, d2, dp setae. Second segment with long apical e-seta (length c. 3/4 of that of next segment).Third segment with medially long f-seta (reaching tip of segment). Terminal segment with apical pincer and three setae, one short h1 seta, one claw-like h2 seta and one subapical h3 seta, length of the latter c. 2/3 of that of third segment.

CR ( Fig. 8 E) well-developed, with ventral margin serrated, Ga and Gp subequally long, serrated, length of Ga c. half of that of ramus. Sa short (slightly less than half of Ga), Sp1 markedly long (c. 2/3 of Gp), Sp2 long, reaching tip of ramus.

CR attachment ( Fig. 8 F) thin, without distal branches.

Description of male. Carapace and valves ( Fig. 5 B, 6H–I) as in female, but somewhat smaller. All limbs as in female, except for last two segments of A2 ( Fig. 9 A) and T1 ( Fig. 9 B–C).

Setae z1 and z2 of penultimate segment of A2 transformed into claws; claw G1 reduced, appearing smaller and shorter; claw G3 reduced to seta; Gm on terminal segment of A2 reduced, appearing smaller and shorter (length slightly less than half of that of GM); each claw distally with 2 rows of strong denticles (only one row present in figure).

T1 with asymmetrical prehensile palps (endopodites). Right prehensile palp ( Fig. 9 B) with first segment bearing two long apical spines; second segment large, elongated with wider base, length as long as first segment. Left prehensile palp ( Fig. 9 C) with first segment bearing two short apical spines; second segment narrow and pointed, length as long as first segment.

Hemipenis ( Fig. 9 D) with LS subquadrate, blunt end, MS elongated with curved apical end, IS narrow, with pointed end, internal postlabyrinthal spermiduct with one loop.

Zenker organ ( Fig. 9 E) markedly elongated, length c. 6 times width, set with many chitinous spiny whirls.

Figures

FIGURE 5 Hungarocypris suranareeae n. sp., female (A, C – D, MSU-ZOC. 135), male (B, E, MSU-ZOC. 139). A. carapace, left lateral view; B. carapace, right lateral view; C. valve surface of A.; D. posterior part of A.; E. posterior part of B. Scale bar = 500 Μm for A – B; = 50 Μm for C; 100 Μm for D – E.

FIGURE 6 Hungarocypris suranareeae n. sp., female (A – G, MSU-ZOC. 133), male (H – I, MSU-ZOC. 132). A. LV, internal view; B. RV, internal view; C. muscle scars of A.; D. postero-ventral part of A.; E. antero-ventral part of A.; F. antero-ventral part of B.; G. postero-ventral part of B.; H. LV, internal view; I. RV, internal view. Scale bar = 500 Μm for A – B, H – I; = 100 Μm for C – G.

FIGURE 7 Hungarocypris suranareeae n. sp., female (MSU-ZOC. 133). A. A 1; B. A 2; C. enlargement of apical seta of second segment of A 2; D. Md-palp; E. terminal segment of Md-palp; F. Md-coxa. Scale bar = 100 Μm for A – B, D – F; 63 Μm for C.

FIGURE 8 Hungarocypris suranareeae n. sp., female (MSU-ZOC. 133). A. Mx 1; B. T 1; C. T 2; D. T 3; E. caudal ramus. Scale bar = 100 Μm for A – B; 200 Μm for C – E.

FIGURE 9 Hungarocypris suranareeae n. sp., male (MSU-ZOC. 132). A. terminal part of penultimate segment and terminal segment of A 2; B. right prehensile-palp, C. left prehensile-palp; D. hemipenis; E. Zenker organ. Scale bar = 100 Μm for B – D.