Cypricercus xhosa, Savatenalinton, Sukonthip & Martens, Koen, 2009

Savatenalinton, Sukonthip & Martens, Koen, 2009, Redescription of the type species of Strandesia Stuhlmann, 1888 and Cypricercus Sars, 1895 (Crustacea, Ostracoda, Cypricercinae), with a description of a new species of Cypricercus from South Africa, Zootaxa 2007, pp. 1-42 : 13-20

Cypricercus xhosa sp. nov.

( Figs 7–12 )

Material examined. Males and females from type locality and several other localities (see below).

Holotype. Male, soft parts dissected in glycerine in a sealed slide, valves stored dry in a micropalaeontological slide (LEN 20C).

Allotype. Female, dissected and stored as the holotype (LEN 20D).

Paratypes. Five males (O.C. 2982–2983, MSU-ZOC 0 11, MSU-ZOC 0 12, O.C.3076) and four females (O.C. 2985–2986, MSU-ZOC 0 0 9, MSU-ZOC 010) dissected and stored as the holotype, two males (O.C.2984, O.C.3078) and two females (O.C.2987, O.C.3077) stored in micropalaeontological slides after use for SEM, several undissected paratypes kept in 70% ethyl alcohol.

Repository. Holotype, allotype and 10 (5 males, 5 females) undissected paratypes kept in 70% ethyl alcohol are deposited in Albany Museum (Grahamstown, South Africa). Thirteen dissected and undissected (7 males, 6 females) paratypes and most of wet undissected paratypes are deposited in the Ostracod Collection of the R.B.I.N.Sc. and MSU.

Type locality. Rhino Ridge Pool 6, Thomas Baines Natural Reserve (T.B.N.R.), Grahamstown, South Africa ( RSA /89/20) (Coordinates: 33° 23ˏ 42˝ S and 26° 30ˏ 10˝ E), collected by K. Martens, F. de Moor and H. Barber, 30 November 1989. Accompanying ostracod fauna: Heterocypris calva ( Rome, 1965) , Ramotha producta ( Sars, 1924) , Sarscypridopsis trigonella ( Sars, 1924) .

Other localities. Thirteen other localities around Grahamstown, South Africa, collected by K. Martens, F. de Moor and H. Barber between 24 November and 12 December 1989. The range of conductivity was 109–1588 µScm -1, of temperature 20.5–34.2 ° C and of pH 6.7–8.

Etymology. Named after the indigenous tribe, the Xhosa , who inhabit the region from which the species is described.

Measurements (in μ m). Female: LV (n=2), L = 1940, H = 767.5; RV (n=2), L = 1970, H = 756.5; W = 652. Male: LV (n=1), L = 1730, H = 651; RV (n=1), L = 1730, H = 643; W = 550.

Diagnosis. Carapace in lateral view elongated (height less than half of the length), anterior margin rounded, posterior margin with distinctively pointed protuberance (RV protruding more than LV). LV strongly overlapping RV anteriorly. Carapace in dorsal view with posterior end appearing as an unequal, bifurcated extremity with the spine of the RV being longer. LV anteriorly with anteroventral inner list. RV with submarginal anterior selvage. Rome organ on A1 small and short. Natatory setae on A2 long (reaching the end of claws of terminal segment). Caudal ramus long and slim, with finely serrated ventral margin. Hemipenis small, medial shield round, lateral shield small, subquadrate.

Differential diagnosis. Cypricercus xhosa sp. nov. belongs to a group of Cypricercus species with posterior spine-like protuberances. This group comprises C. ariariensis ( Roessler, 1986) , C. centrurus ( Klie, 1940) , C. episphaenus G.W. Müller, 1908 , C. unicornis De Deckker, 1981 and C. variabilis ( Roessler, 1986) . The new species is generally similar to C. ariariensis , C. episphaenus and C. variabilis . It can be distinguished from them by the anteroventral inner list, a narrower carapace in lateral and dorsal view, the large anterior overlap (LV>RV) and by the fact that posterior protuberances are present on both valves (in the other species on the RV only). In dorsal view, the posterior end of Cypricercus xhosa sp. nov. is unequally bifurcate. This character is unique within the genus Cypricercus .

Additional description of female. Carapace in lateral view ( Fig 7 A–B) elongated (length c. 2.5 times the height); anterior margin rounded, posterior margin with distinctively pointed protuberances; RV protruding more than LV; dorsal margin slightly curved, greatest height near the middle; ventral margin almost straight, with posterior part curved upward to the caudal protuberance; LV largely overlapping RV anteriorly and slightly ventrally.

Carapace in dorsal view ( Fig 7 C) elongated, narrow (length c. 2.6 times the width); both ends with particularly unequal LV and RV margins: anteriorly LV largely overlapping RV, posteriorly LV less protruding than RV. Surface of valves relatively smooth, with scattered thin setae.

Carapace in ventral view ( Fig 7 D) with RV margin bearing a narrow outer list; LV margin without outer list, medially slightly protruding.

FIGURE 9. Cypricercus xhosa sp. nov., A–C, E–F, H: Female; D, G: Male. A. A1 (MSU-ZOC 010). B. A2 (ditto). C. A2, terminal segment (ditto). D. A2, terminal part (MSU-ZOC 011). E. Md-palp (MSU-ZOC 009). F. Md-palp, terminal segment (ditto). G. α, β, γ-setae of Md-palp (MSU-ZOC 011). H. Md-coxa (MSU-ZOC 0 10). Scale bars: A–D, G–H: 100 µm; E–F: 50 µm.

LV ( Fig 8 A, E–F) in inner view with a long connected groove along anterior, ventral and posterior margins; anterior part with broadly rounded valve margin and incomplete inner list situated at the anteroventral part. Inner lamella calcified, somewhat reticulated, broad anteriorly, narrow posteriorly. Posterior valve margin with spine-like protuberance.

RV in inner view ( Fig 8 B, G–H) with anterior and posterior selvage; anterior part distinctly inwardly displaced along the entire anterior margin; inner lamella broad, without inner list; posterior end of both valves with medial, spine-like protuberance.

A1 (Fig 9A): first segment with proximally small, tube-like Wouters organ, 1 dorsal subapical seta and 2 long ventral apical setae. Second segment wider than long, with 1 short dorsal apical seta and a short, small ventral subapical Rome organ. Third segment bearing 2 (1 dorsally, 1 ventrally) long apical setae, extending beyond the end of the fourth segment. Fourth segment with dorsally 2 long setae and ventrally 2 setae, 1 long, 1 short, the long one reaching the end of the fifth segment, the short one considerably less than half of the fifth segment. Fifth segment with 3 long and 1 short setae, the latter reaching beyond the end of the terminal segment. Sixth segment with ventrally 3 long setae, dorsally 2 (1 long, 1 spine-like) setae. Terminal segment with 3 (2 long, 1 short) setae and aesthetasc ya, the latter considerably shorter than the short apical seta.

A2 (Fig 9B): exopodite with 3 (2 short, 1 long) setae, the longest one c. two-thirds of the length of the second segment. Natatory setae on first endopodial segment long, the shortest one considerably less than half of the penultimate segment; aesthetasc Y short. Penultimate segment undivided, with distally 3 serrated claws and with apical aesthetasc y2 reaching slightly beyond the end of the terminal segment; z1–z3 setae long; medially with 2 (1 long, 1 short) anterior setae (the short seta slightly more than half of the long one) and 4 posterior setae (t1–t4). Terminal segment (Fig 9C) with 2 claws (GM and Gm), a short g-seta and aesthetasc y3, the latter considerably shorter than accompanying seta.

Rake-like organ stout, T-shape with 8 blunt teeth.

Md-palp (Fig 9E–G): first segment with 2 large setae, 1 long seta and relatively long, 2-segmented, smooth α-seta. Second segment dorsally with 3 apical (2 long, 1 shorter) setae, the shortest one slightly less than the length of the penultimate segment and ventrally with a group of setae (3 hirsute, 1 long) and the β–seta, the latter plumose, cone-shape. Penultimate segment consisting of 3 groups of setae: dorsally with a group of 4 (3 long, 1 shorter) subapical setae; laterally with apical γ–seta, 3 smooth subapical setae, the former stout, hirsute, long (slightly less than twice the length of the terminal segment); ventrally with 1 long and 1 short (reaching the end of terminal segment) apical seta. Terminal segment bearing 3 setae and 3 claws.

Mx1 ( Fig 10 A) with 2-segmented palp; basal segment with a group of 5 long apical setae and 2 (1 long, 1 shorter) subapical setae; terminal segment elongated, with 3 claws and 3 setae. The third endite with 2 large serrated bristles and c. 8 other setae. Sideways-directed bristles on first endite unequal, the longest c. twice as long as the shortest.

T1 ( Fig 10 B–D): protopodite with 2 short a-setae, 1 long b-seta, 1 long d-seta and with 14 hirsute, unequal apical setae ( Fig 10 B). Endopodite palp weakly built and set with 3 apical setae. Exopodite a respiratory plate with (5+1) large, hirsute setae.

T2 ( Fig 10 E) with 2 slightly hirsute d-setae, d2 c. half the length of d1. Second segment with 1 long apical seta (c. two-thirds of the length of penultimate segment). Penultimate segment divided; a-segment bearing 1 long apical seta, b-segment with a group of 2 (1 short, 1 spine-like) apical setae. Terminal segment with 2 (1 apically, 1 subapically) long setae and a serrated claw.

T3 ( Fig 10 F–G) a cleaning limb. First segment with 3 long setae. Second segment with 1 apical seta. Third segment undivided, with medially 1 lateral seta. Terminal segment with an apical pincer and 1 reflexed subapical seta.

Caudal ramus ( Fig 10 I–J) unusually long and slim, finely serrated along the ventral margin; both claws relatively straight, serrate, distal claw c. one third of ramus, proximal claw c. one-fourth of ramus (as long as distal seta). Distal seta slightly hirsute, over c. two-thirds of its length; proximal seta very thin, long (considerably longer than the distal end of ramus). Attachment of the caudal ramus ( Fig 10 H) slender, with Triebel’s loop in the middle branch, dorsal branch slim, ventral branch elongate, with distally swollen end.

Additional description of male. Carapace and valves ( Fig 7 E–J, Fig 8 C–D) as in the female, but relatively smaller. All limbs as in the female, except for A2 (Fig 9D) and T1 ( Fig 11 B–C) with sexual dimorphism.

Penultimate segment of A2 with setae z1 and z2 claw-like, G1 a small claw and G3 reduced to a seta. Terminal segment with reduced Gm (smaller, shorter).

T1 with asymmetrical prehensile palps, right palp ( Fig 11 C) with relatively small triangular lobe and 2 apical spines, left palp ( Fig 11 B) with elongated, curved lobe and 2 spines.

Zenker’s organ ( Fig 11 D, 12B–G) elongated (c. 3.7 times the width), with approximately 28 spiny whorls and with distal end plate presenting a crown of petal-like structures.

Hemipenis ( Fig 11 A, 12A) small, with medial shield rounded, lateral shield subquadrate and with a symmetrical penile attachment situated at the proximal connected bases. Postlabyrinth spermiduct curved, forming 2 (1 large, 1 small) loops.

Figures

FIGURE 7. Cypricercus xhosa sp. nov., A – D: Female; E – J: Male. A. Carapace, right lateral view (O. C. 2987). B. Carapace, left lateral view (ditto). C. Carapace, dorsal view (O. C. 3077). D. Carapace, ventral view (ditto). E. Carapace, right lateral view (O. C. 2984). F. Carapace, left lateral view (ditto). G. posterior end of carapace in left lateral view (ditto). H. Carapace, dorsal view (O. C. 3078). I. Carapace, ventral view (ditto). J. Posterior end of carapace in ventral view (ditto). Scale bars: A – F, H – I: 500 µm; G: 50 µm; J: 100 µm.

FIGURE 8. Cypricercus xhosa sp. nov., A – B, E – H: Female; C – D: Male. A. LV, internal view (MSU-ZOC 010). B. RV, internal view (ditto). C. LV, internal view (MSU-ZOC 011). D. RV, internal view (ditto). E. LV, posterior part (MSU- ZOC 010). F. LV, anterior part (ditto). G. RV, anterior part (ditto). H. RV, posterior part (ditto). Scale bars: A – B: 500 µm; E – H: 200 µm.

FIGURE 10. Cypricercus xhosa sp. nov., female. A. Mx 1 (MSU-ZOC 0 10). B. T 1, apical part of protopodite (ditto). C. T 1, palp (ditto). D. T 1, a-, b-, d-setae (ditto). E. T 2 (ditto). F. T 3 (ditto). G. T 3, apical pincer (ditto). H. Attachment of caudal ramus (MSU-ZOC 009). I. Caudal ramus (MSU-ZOC 0 10). J. Caudal ramus, claws and setae (ditto). Scale bars: A – B, G: 50 µm; C – F: 100 µm; H – I: 200 µm.

FIGURE 11. Cypricercus xhosa sp. nov., male. A. Hemipenis (MSU-ZOC 0 11). B. Left prehensile palp (ditto). C. Right prehensile palp (MSU-ZOC 0 12). D. Zenker’s organ (MSU-ZOC 0 11). Scale bars: 100 µm.

FIGURE 12. Cypricercus xhosa sp. nov., male. A. Hemipenis (O. C. 3097). B. Zenker’s organ (using 7 % KOH, 36 hours) (ditto). C. Zenker’s organ (using NaOCl) (O. C. 3098). D. Detail of proximal end plate (ditto). E – F. Detail of distal end plate (ditto). G. Detail of spiny whorls (ditto). Scale bars: A – C: 100 µm; D – G: 20 µm.