Strandesia sanoamuangae Savatenalinton & Martens, 2010

Figs 1–3

Re-description

Female

Cp in lateral views (Figs 1 A–B) subovate and dorsally arched with greatest height at about 2 ⁄5 of total length; anterior and posterior margins rounded, posterior margin narrower. CpRL (Fig. 1B) with LV overlapping RV anteriorly, ventrally and posteriorly; overlap greatest antero-ventrally and anteriorly; periphery of LV visible dorsally. CpD (Fig. 1F) and CpV (Fig. 1E) sub-elliptical, with greatest height at mid length, sloping to blunt anterior and posterior extremities; LV with anterior extremity almost perpendicular to the anteroposterior axis. CpV (Fig. 1E) with LV margin sinuous with weak protrusion towards RV slightly posterior to greatest width. CpFr (Fig. 1H) not oblique, but with LV larger than RV, ventrally enveloping the RV. Cp with surface ornamented with tiny tubercles, small pits and thickly rimmed pores with sensilla, the latter in lower density (Fig. 1G). Central area of Cp surface in ventral view and particularly on RV without tubercles; pores with sensilla not rimmed. Central area of LV surface in dorsal view without tubercles; pores with sensilla not rimmed. LVi (Fig. 1C) with calcified inner lamella wider anteriorly, an internal groove and an inner list present along valve margin. RVi (Fig. 1D) with calcified inner lamella wider anteriorly and without selvage or inner list.

A1 (Fig. 2A) with seven segments. All segments with apical setae. First segment with one short dorsal seta and two long ventro-apical setae. Wouter’s Organ not observed. Second segment trapezoid-like with one short dorso-apical seta and one large (more than half the length of the segment) Rome Organ (R) at the ventral side. Third segment longest of all segments with two short apical setae, one dorsal and one ventral. Fourth segment with two long dorsal and two short ventral setae; one of the short setae approximately half as long as other. Fifth segment with three long dorsal and one short ventral seta. Sixth segment with four long apical setae. Seventh segment with one short aesthetasc (Ya), one short seta of equal length to Ya and two long setae.

A2 (Fig. 2 B–C) biramous with two-segmented protopod, a reduced exopod and three endopodal segments. First protopodal segment with three short setae; one proximal and two unequal ventral setae. Second protopodal segment with one long seta. Exopod a small plate with one long seta and two very short but unequal setae. First endopodal segment with one ventral aesthetasc (bulbous but elongated), one long apical seta reaching beyond the last endopodal segment and six natatory setae (five long and one short); the long natatory setae extending beyond tips of apical claws. Second endopodal segment with two unequal dorsal setae; a group of four ventral setae (“t”-setae), two long and two short; one short seta approximately equalling the length of the terminal segment; three serrated apical claws (G1, G2 and G3) and three apical setae (z1, z2 and z3). Terminal segment with two serrated claws, one long (GM) and one short (Gm); one aesthetasc fused over a short distance with an accompanying seta and one g-seta.

Md Palp (Fig. 2 D–F) with four segments. First segment with four ventral setae; two long plumose setae, one long smooth seta and one short α-seta; this segment also with a small respiratory plate (not shown). Second segment with four ventral setae (one stout hirsute β-seta about ⅔ the length of α-seta, three long hirsute setae and one short smooth seta) and three dorsal subapical setae (one long, one about ⅔ the length of first and the shortest about ¼ of first). Third segment with six apical setae (one γ-seta hirsute at the distal half of its length, four longer smooth setae and one short seta about ⅔ the length of the terminal segment) and four unequal dorsal subapical setae. Fourth segment (Fig. 2F) with three claws and three setae apically, claws longer than setae.

Md coxa (Fig. 2G) elongated and robust with an apical row of highly sclerotized teeth, largest at the dorsal edge with a general decrease in size toward the ventral edge. Teeth interspersed with setae with two notably strong setae covered with small setules ventral to the two largest teeth respectively and two short unequal hirsute setae ventral to the last tooth. Dorso-distal side of coxa with one short but stout seta.

Mx1 (Fig. 3A) (chaetotaxy incompletely illustrated) with a protopod, a two-segmented palp (endopod), three masticatory lobes (endites) and a large branchial plate (the latter not illustrated). Proximal segment of palp with six distal setae in close proximity (most ventral one longest but not reaching beyond the longest seta on second segment of palp) and one more proximal, short and slender seta. Second segment sub-quadrate, with three distal claws and three distal setae. Third endite with two large, weakly serrated distal bristles and a proximal seta reaching ⅓ of the length of the bristles. First endite with two sidewaysdirected bristles (one approximately half the length of the other) and two slender proximal setae not reaching distal edge of endite.

T1 protopodite (Fig. 3B) with b- and d-setae subequal, b-seta about 4 ⁄5 the length of d-setae. Protopodite with 14 mostly serrated setae; ten apical and four subapical. Palp (endopodite, not illustrated) elongated, with 3 unequal apical setae.

T2 (Fig. 3C) a walking leg with five segments. First segment with hirsute seta (d1). Second segment with hirsute seta (d2); d2 being ca ⅓ the length of d1. Third segment with one subapical hirsute seta (e). Fourth segment with two sub-segments (4a and 4b respectively); segment 4a with one long apical hirsute seta (f) and segment 4b with one seta (g), shorter than seta f and not reaching the end of the terminal segment. Fifth segment with one apical claw (h2) and one short ventral seta (h1) and one short dorsal seta (h3).

T3 (Fig 3 D–E) a cleaning limb with three segments. First segment (the protopod) with three long setae (d1, d2 ventrally and dp dorsally); d1 and d2 with approximately equal length; dp longer than d1 and d2 reaching distal edge of first endopodal segment. First endopodal segment with ventro-subapical seta e. Terminal endopodal segment with subapical seta f and distal edge as pincer; seta f not reaching distal edge of terminal segment. Distal edge of terminal segment with one comb-like seta (h2), one small recurved seta and one longer and distally hirsute seta (h3); seta h2 half the length of seta h3; seta h1 not observed.

CR (Fig. 3G) slender and straight with ventral side weakly serrated, a proximal weakly serrated claw, a distal weakly serrated claw, a proximal hirsute seta and a distal smooth seta. Proximal claw ¾ of the length of distal claw. Proximal seta about ⅓ of the length of distal seta.

CR attachment (Fig. 3F) stout, with Triebel’s loop in the middle of the distal part of main brand. Distal arc enclosing Triebel’s loop obtusely connecting to short db; vb well-developed.

Male

Unknown.

Measurements

See Table 2.

Material examined

NEW CALEDONIA – Province Nord • 1 ♀; Koumac, Grottes de Koumac, up from Sentier de la Vierge; 20°30ˊ55.8˝ S, 164°19ˊ55.9˝ W; 113 m a.s.l.; 5 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-HYNC- 1104 • 1 ♀; Koumac, Grottes de Koumac, up from Sentier de la Vierge; 20°32ˊ2.5˝ S, 164°19ˊ40.1˝ W; 32 m a.s.l.; 6 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1107 • 1 ♀; Koumac, Grottes de Koumac, up from Sentier de la Vierge; 20°32ˊ2.5˝ S, 164°19°40.1˝ W; 32 m a.s.l.; 6 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1108 • 1 ♀; Koumac, Koumac River; 20°32°23˝ S, 164°16ˊ4.2˝ W; 2 m a.s.l.; 7 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1110 • 3 ♀; Koumac, Koumac River; 20°32ˊ23˝ S, 164°16ˊ4.2˝ W; 2 m a.s.l.; 7 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1111 • 1 ♀; Koumac, Néhoué River, downstream of RT1/ RM13 road crossing; 20°25ˊ1.7˝ S, 164°13ˊ12.9˝ W; 45 m a.s.l.; 7 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1121 • 1 ♀; Kaala Gomen, River Iouanga. near Tegon; 20°41ˊ1.9˝ S, 164°23ˊ40.7˝ W; 4 m a.s.l.; 9 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1127 • 1 ♀; Kaala Gomen, River Iouanga, near Gamai; 20°41ˊ13.9˝ S, 164°29ˊ9.7˝ W; 16 m a.s.l.; 9 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1129 • 25 ♀♀; Kaala Gomen, Kouadjo drainage, tributary of Iouanga Riv.; 20°38ˊ48˝ S, 164°27ˊ28.8˝ W; 84 m a.s.l.; 9 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1131 • 20 ♀♀; Kaala Gomen, River Ouémou, between Ouemou and Oueholle; 20°36ˊ15.3˝ S, 164°33ˊ16.7˝ W; 129 m a.s.l.; 9 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1135 • 1 ♀; Hienghene, Hienghene River; 20°44ˊ2.8˝ S, 164°54ˊ3.1˝ W; 10 m a.s.l.; 13 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1148 • 100 ♀♀; Hienghene, Hienghene River; 20°44ˊ2.8˝ S, 164°54ˊ3.1˝ W; 10 m a.s.l.; 13 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1150 • 1 ♀; Hienghene, Hienghene River; 20°44ˊ22.4˝ S, 164°52ˊ35.9˝ W; 11 m a.s.l.; 14 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1154 • 1 ♀; Hienghene, Hienghene River; 20°44ˊ22.4˝ S, 164°52ˊ35.9˝ W; 11 m a.s.l.; 14 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1155 • 5 ♀♀; Hienghene, Hienghene / Tiendanite branch; 20°44ˊ22.4˝ S, 164°52ˊ35.9˝ W; 11 m a.s.l.; 14 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1156 • 1 ♀; Hienghene, Hienghene / Tiendanite branch; 20°44ˊ23.1˝ S, 164°52ˊ35.4˝ W; 11 m a.s.l.; 14 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC- 1157 • 5 ♀♀; Hienghene, Hienghene / Tiendanite branch; 20°44ˊ23.1˝ S, 164°52ˊ35.4˝ W; 11 m a.s.l.; 14 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1158 • 5 ♀♀; Hienghene, Oué Hava, Tipindje River drainage; 20°45ˊ37.5˝ S, 165°1ˊ39.3˝ W; 19 m a.s.l.; 15 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1164 • 1 ♀; Hienghene, Oué Hava, Tipindje River drainage; 20°45ˊ37.5˝ S, 165°1ˊ39.3˝ W; 19 m a.s.l.; 15 Nov. 2016; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC- 1165 • 1 ♀; Hienghene, Pwé Hiit (Pwé Ciit); 20°46ˊ59.1˝ S, 165°5ˊ49.7˝ W; 30 m a.s.l.; 16 Nov. 2016; leg. J. Higuti & K. Martens; MNHN MNHN-HYNC-1172 • 15 ♀♀; Houailou, Rivière La Túú - Tuu River; 21°15ˊ53˝ S, 165°35ˊ49.8˝ W; 7 m a.s.l.; 14 Nov. 2017; leg. J Higuti & K. Martens; MNHN MNHN-HYNC-1272 • 1 ♀; Kouaoua, Fa Uru, right bank tributary of the Kouaoua River; 21°29ˊ2.1˝ S, 165°46ˊ41.6˝ W; 26 m a.s.l.; 21 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-2522 • 20 ♀♀; Ponérihouen, Goyeta; 21°5ˊ55.2˝ S, 165°21ˊ20.4˝ W; 13 m a.s.l.; 29 May 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-2587 • 2 ♀♀; Touho, Ouanache; 20°44ˊ51˝ S, 165°3ˊ41.1˝ W; 11 m a.s.l.; 31 May 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-3005 • 4 ♀♀; Voh, Temala River drainage; 20°51ˊ10.9˝ S, 164°42ˊ5.6˝ W; 23 m a.s.l.; 2 Jun. 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-3013 • 3 ♀♀; Voh, Temala River drainage; 20°51ˊ9.9˝ S, 164°42ˊ1.7˝ W; 16 m a.s.l.; 2 Jun. 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-3014 • 2 ♀♀; Voh, Congo River drainage; 20°55ˊ15.7˝ S, 164°44ˊ56˝ W; 20 m a.s.l.; 2 Jun. 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-3018 – Province Sud • 30 ♀♀; Bourail, Rivière du Cap - Embouchure; 21°30ˊ45.6˝ S, 165°17ˊ42˝ W; 8 m a.s.l.; 11 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC- 1248 • 3 ♀♀; Bourail, Puéo River; 21°28ˊ43.3˝ S, 165°31ˊ39.5˝ W; 35 m a.s.l.; 13 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1264 • 20 ♀♀; Bourail, Puéo drainage - Tribu Bouirou; 21°26ˊ19.1˝ S, 165°31ˊ55.4˝ W; 171 m a.s.l.; 13 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1265 • 50 ♀♀; Bourail, Boghen drainage; 21°35ˊ43.1˝ S, 165°33ˊ10.3˝ W; 8 m a.s.l.; 13 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1268 • 1 ♀; Bourail, Boghen drainage; 21°35ˊ43.1˝ S, 165°33ˊ10.3˝ W; 8 m a.s.l.; 13 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1269 • 5 ♀♀; Bourail, Nera River; 21°34ˊ56.8˝ S, 165°29ˊ43.6˝ W; 6 m a.s.l.; 15 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1274 • 10 ♀♀; La Foa, tributary of La Foa Riv.; 21°42ˊ31.8˝ S, 165°48ˊ26.2˝ W; 7 m a.s.l.; 16 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-1285 • 5 ♀♀; Boulouparis, Oua Tchoué drainage; 21°47ˊ33.7˝ S, 166°0ˊ55.5˝ W; 235 m a.s.l.; 18 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-2502 • 5 ♀♀; Boulouparis, reservoir; 21°50ˊ54˝ S, 165°55ˊ35.5˝ W; 58 m a.s.l.; 18 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-2505 • 10 ♀♀; Boulouparis, reservoir; 21°50ˊ52.6˝ S, 165°55ˊ41.7˝ W; 62 m a.s.l.; 18 Nov. 2017; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-2508 • 5 ♀♀; Thio, Xwê Xârâge (Karingué) at Merigu; 21°41ˊ8.2˝ S, 166°5ˊ20.7˝ W; 58 m a.s.l.; 23 May 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-2546 • 1 ♀; Thio, reservoir; 21°35ˊ54.4˝ S, 166°12ˊ35.4˝ W; 6 m a.s.l.; 25 May 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-2562 • 200 ♀♀; Thio, reservoir on side of RP10; 21°35ˊ50.4˝ S, 166°12ˊ35˝ W; 11 m a.s.l.; 25 May 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-2564 • 2 ♀♀; Paita, Small lake at Mango Pépinière; 21°59ˊ2.5˝ S, 166°12ˊ56.7˝ W; 11 m a.s.l.; 7 Jun. 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-3063 • 50 ♀♀; Paita, Small lake at Mango Pépinière; 21°59ˊ2.6˝ S, 166°12ˊ55˝ W; 20 m a.s.l.; 7 Jun. 2018; J. Higuti & K. Martens leg.; MNHN MNHN-HYNC-3064.

Remarks

The present populations from New Caledonia have been identified as Strandesia sanoamuangae (Savatenalinton & Martens, 2010) from Thailand, because of the strong resemblance in shape and ornamentation of the carapace. There are some small morphological differences in the New Caledonian populations: the carapace is slightly less arched in the dorsal and ventral views at its greatest width; its sinuous protrusion in the ventral view is slightly anterior to the greatest carapace width; the LV overlap of the RV is slightly narrower, and the periphery of the LV is inconspicuous at the dorsal margin in the right lateral view. Also, the LV of the Thai specimens of S. sanoamuangae seems to lack the pronounced inner list that is visible in the specimens from New Caledonia, but this could be a matter of degree of calcification, and we assume this list is also present in the Thai specimens.

Strandesia sanoamuangae also somewhat resembles Strandesia perakensis (Victor & Fernando, 1981), but the carapace of this latter species lacks tubercles and is set with long sensilla and spines. The small pits on its Cp are also markedly visible from the inner view of the valves (see illustrations in Victor & Fernando 1981 and the re-description in Savatenalinton & Martens 2010).

Even though the present species seems easily identifiable, we decided to document its range extension with a full re-description as convergent evolution in non-marine ostracods in general, and in the Cypricercinae in particular, is very high. See for example the cases of Rudjakoviella prolongata (Triebel, 1962) from a Venezuelan Island and Strandesia bicornuta Hartmann, 1964 from southern India and of Bradleytriebella lineata (Victor & Fernando,1981) and Neostrandesia striata Ferreira et al., 2019 (Ferreira et al. 2019).