Cypriconcha hypsophila, Díaz, Analía R. & Lopretto, Estela C., 2009

Díaz, Analía R. & Lopretto, Estela C., 2009, A new species of Cypriconcha Sars (Crustacea: Ostracoda) from high mountain wetlands of Argentina, Zootaxa 2291, pp. 51-64 : 53-61

Cypriconcha hypsophila new species

( Figs. 2–6 )

Etymology: from Greek hypsos = high; philia = affection, fondness—because of the occurrence of this species in high mountain wetlands.

FIGURE 3. Cypriconcha hypsophila n. sp. (a) Ƥ, An1. Allotype (MLP 26138). (b) Ƥ, Rome organ. Allotype (MLP 26138). (c) Ƥ, An2. Allotype (MLP 26138). (d) Ƥ, An2, detail of distal chaetotaxy. Allotype (MLP 26138). (e) 3, An2, detail of distal chaetotaxy. Holotype (MLP 26137). Abbreviations: r: Rome organ; ya, Y, y1, y2, y3: aesthetascs; g, t1-4, z1-3: setae; G1, G2, G3, GM, Gm: claws. Scale (in μm) = 100 for a, c; 50 for d, e; 20 for b.

FIGURE 4. Cypriconcha hypsophila n. sp. (a) Ƥ, Md. Allotype (MLP 26138). (b) 3 detail of the mandibular palp. Holotype (MLP 26137). (c) 3 Md. Holotype (MLP 26137). (d) Ƥ, maxillular palp and masticatory processes. Allotype (MLP 26138). (e) Ƥ rake-like organ. Allotype (MLP 26138). (f) Ƥ T1. Allotype (MLP 26138). (g) 3 left T1. Holotype (MLP 26137). (h) 3 right T1. Holotype (MLP 26137). Abbreviations: s1, s2, α, β, γ, d, c, b: setae; so, s1-2, so3: sensory organs. Scale (in μm) = 100 for a, b, c; 50 for d, e, f, g, h.

FIGURE 5. Cypriconcha hypsophila n. sp. (a) Ƥ, T2. Allotype (MLP 26138). (b) Ƥ, T3. Allotype (MLP 26138). (c) Ƥ, T3, detail of distal segment. Allotype (MLP 26138). (d) 3 T3, detail of distal segment. Holotype (MLP 26137). (e) Ƥ, genital lobe. Allotype (MLP 26138). (f) 3 hemipenis. Holotype (MLP 26137). (g) 3 bursa copulatrix. Holotype (MLP 26137). (h) Ƥ, attachtment of caudal ramus. Allotype (MLP 26138). (i) Ƥ, caudal ramus. Allotype (MLP 26138). (j) 3 Zenker organ. Holotype (MLP 26137). Abbreviations: d1, p z1: setae; CL: claw-like seta; Lo: concave lobe; bc: bursa copulatrix; db: dorsal branch; vb: ventral branch; Sa: anterior seta; Sp: posterior seta; Ga: anterior claw; Gp: posterior claw. Scale (in μm) = 100 for a, b, e, f, h, i, j; 50 for c, d, g.

Type locality: Vega Los Aparejos (27° 40' 56.8" S – 68° 26' 40.6" W), Tinogasta County, Catamarca Province, Argentina.

Type material: deposited in the Colección de Invertebrados from the Museo de La Plata, Argentina (catalogue number between brackets).

Holotype: a male with soft parts dissected in polyvinyl-lactophenol on a sealed slide and with valves stored dry on a micropaleontological slide ( MLP 26137).

Allotype: a female dissected and stored in the same manner as the holotype ( MLP 26138).

Paratypes: 26 females and 16 males with soft parts dissected in glycerine on a sealed slide and with their valves stored dry for scanning electron microscopy ( MLP 26139) after metallization.

Description ( Fig. 2 ): the carapace is very large in size, thin, transparent, and sexually dimorphic. The males' ( Figs. 2 f–j) carapace is subovoidal, shorter, and posteriorly higher than the females' and with a rounded posteroventral shape. The dorsal margin is strongly arched posteriorly with the greatest height at about 2/3 length. The ventral margin is strongly concave medially. The anterior margin is rounded and somewhat acuminate anteroventrally, while the posterior margin is broadly rounded. The greatest length is located in the lower half of the valves. In dorsal view the carapace is biconvex with the maximum width behind mid-length. The females' ( Figs. 2 a–e) carapace is subtrapezoidal in lateral view, with the greatest length at mid-height and the greatest height behind mid-length. The dorsal margin is convex posteriorly; the ventral margin is strongly concave in the anterior part; the anterior margin is lower than the posterior one and evenly rounded. The eggs are reddish. The left valve overlaps the right valve in both dorsal and ventral margin. The lateral surface is smooth; a delicate reticulation at the anterior and posterior margins is present ventrally. The anterior normal pores are numerous; the inner lamella is well developed, broader anteriorly; the vestibula is also well developed. The hinge is adont. Muscle scars are conspicuous and visible on both the exterior and the interior sides of the valve. The adductors have a group of eight scars; the mandibular scars consist of two anteroventral and two anterodorsal scars. The color of the valves is light green to transparent. Holotype: LV: L = 1.66, H = 0.86; RV: L = 1.73, H = 0.83. Allotype: LV: L = 1.83, H = 0.93; RV: L = 1.79, H = 0.93. Paratypes: Ƥ, (n = 26) LV: L = 2.31 ± 0.06 (1.6 – 2.33), H = 1.12 ± 0.16 (0.8 – 1.18); RV: L = 2.18 ± 0.00902 (1.6 – 2.19), H = 1.02 ± 0.00989 (0.8 – 1.03); 3, (n = 16) LV: L = 2.27 ± 0.015 (1.5 – 2.23), H = 1.086 ± 0.035 (1.09 – 1.2); RV: L = 2.21 ± 0.012 (1.5 – 2.23), H = 1.087 ± 0.0057 (1.09 – 1.2).

Anatomy of the soft parts. An1 (Fig. 3a) is seven-segmented, the chaetotaxy is identical for males and females. The first segment of the protopodite has two long serrate dorsal setae and one short ventral seta; second segment of the protopodite with one ventral seta. The Rome organ is shown in Fig. 3b. First segment of the endopodite with one long serrate dorsal seta and one ventrally situated serrate seta, the second segment with two short serrate dorsal setae and two long ventral setae, one being setose and both with pseudochaetae at their base. The third segment of the endopodite dorsally with two short plumose setae and several pseudochaetae, and ventrally with two long smooth setae. The fourth segment with four long natatory setae, the dorsalmost being plumed, and one short serrated ventral seta. Last segment of endopodite with two long and one short ventral seta. The aesthetasc ya has the same length as the shorter seta of the same segment.

An2 (Figs. 3c–e) is five-segmented. The chaetotaxy of the first three segments is identical for males and females. The first segment of the protopodite with one ventro-proximal and two ventro-distal long setae, the second segment with one long ventral seta. The reduced exopodite with two short and one long setae. First segment of endopodite with a ventro-proximal aesthetasc Y, five long and one short plumose natatory setae extending to the distal edge of the penultimate segment, and one long serrate ventro-distal seta. Differences in chaetotaxy of An2 of males and females are limited to the last two segments. In the female (Fig. 3d), the second segment has two unequal medio-dorsal setae and four unequal ventral t-setae, while the aesthetasc (y1) is ventrally inserted and proximal to the t-setae. The external side has three subapical dorsal z-setae, a ventroapical aesthetasc (y2), and two medium-sized (G1, G3) plus one small (G2) claws. Last segment with one medium dorso-apical two-serrated claw (GM), a small (Gm) claw, a smooth seta (g), and an aesthetasc (y3), fused at the base with a plumose seta. The claws G1–G3, GM, Gm armed with a double row of small teeth. In the males (Fig. 3e) there is only one z-seta (z3), it occurring on the external side of the forth segment. The two most dorsal z-setae (z1-2) are formed as two long claws, which are positioned slightly different to the situation in females. G1 is a medium claw in the female, but only a short one in the male; G2 is a small claw in the female, but a medium-sized one in the male; G3 is a strong medium-sized claw in the female, but is reduced to a medium-sized seta beside aesthetasc y 2 in the males. Last segment with one medium oneserrated claw (GM), one short serrate claw (Gm), one seta (g), and a long aesthetasc (y3) fused at the base with a smooth seta. G1, G2 and z1 bear a double row of small teeth; z2, GM, Gm with a single row of small teeth.

Md (Figs. 4a–c) Protopodite (coxa) with seven main cuspate teeth, the first one being bicuspate with a small pappose seta inserted on the external surface and the rest tricuspate. Two serrate setae are between the first and second tooth and one serrate seta between the second and third tooth; in contrast, microspines are present between the following teeth. At the inner angle one spiny and two plumose setae are inserted, while the dorsal edge bears a single plumose seta. The masticatory surface of mandible with molar-shaped processes. Exopodite (respiratory plate) with five apical and one plumose mid-dorsal setae and with fine pseudochaetae ventrally from the mid-ventral side to the distal border of the plate. The mandibular palp (without sexual dimorphism) has four segments: The first has three ventro-distal setae: one long smooth seta on the interior edge; a plumed s1 seta, and a second plumed s2 mid-dorsal seta also present. The second segment with three subequal dorsal setae. Ventral side with two long subequal setae: a narrow smooth seta and one long smooth mid-dorsal seta. Dorsal side of third segment with a group of five smooth subapical setae and apically with a claw-like seta, a plumed seta, and a hirsute seta. Ventral side of third segment with two smooth unequal setae. Terminal segment apically with three claw-like setae and two smooth setae. The only sexual dimorphism in this appendages is the chaetotaxy of the exopodite (respiratory plate) with five apical plumose and one smooth mid-dorsal seta running parallel to the edge of the plate. The ventral side bears two short smooth setae in males (missing in females) and lots of pseudochaetae from the mid-ventral side up to the distal border of the plate.

The rake-like organ (Fig. 4e) is T-shaped with seven teeth.

The Mx (Fig. 4d) is identical in males and females; with a two-segmented palp, three endites, and a large respiratory plate. The first segment of the palp is elongated with five dorso-apical setae, two of which are plumose, and two smooth subapical setae. The second segment is rectangular, bearing six setae apically, three of which are longer and thicker than the others. Third endite with a long plumose mid-lateral seta on the ventral side; on the dorsal edge there is one short hirsute subapical seta with a swollen base, along with two smooth and one plumose dorso-apical setae and six smooth apical setae, two of the latter being large and stout Zahnborsten. The second and first endites with groups of apical setae, and the first endite with two plumose setae at the base along with two serrate subapical setae. Respiratory plate with 20-22 rays, 4-5 of which directed ventrally.

T1 (Figs. 4f–h) is sexually dimorphic. In the female the protopodite has two plumose (d, c) setae, though some specimens have additionally a plumed b-seta. Masticatory process with four plumose subapical plus nine unequal apical setae, two of the latter being thicker and serrate. The exopodite (respiratory plate) has six rays. The endopodite with three plumose unequal setae on the apical side; on the dorsal side are fine pseudochaetae. In the male, the protopodite has two plumose (b, d) setae, while the masticatory process is as in the female. The exopodite (respiratory plate) carries six rays; the endopodite is a two-segmented prehensile palp, the left one being the larger. The first segment of the left palp is distally dilated, and on the ventral side are two subapical sensory organs (so1, 2). The second segment is more curved with a subapical sensory organ (so3). The right palp is shorter. Here, the first segment of the endopodite is rounded with an apical sensory organ (so); the second segment is slender with one apical sensory organ (so3).

T2 (Fig. 5a) is a walking limb without sexual dimorphism. The protopodite has one long plumose seta (d1) ventrally inserted. The endopodite consists of four segments. First segment with three plumose unequal setae ventrally, second segment with one long plumose subapical seta, third segment with two plumose unequal seta apically, fourth segment apically with one long curved claw (h2), one plumose ventro-apical seta (h1), and a plumose subapical seta (h3) on the dorsal edge.

T3 (Figs. 5b–d) is a cleaning limb without sexual dimorphism. The protopodite has three plumose setae. The endopodite consists of three segments. First segment with one plumose subapical seta, second segment with one plumose seta medially inserted; third and fourth segments form the pincer-shaped organ. The last segment has two setae—the shorter strongly bent, serrate; the longer claw-like (CL)—along with a serrate, concave lobe (Lo) with fine pseudochaetae. The pseudochaetal formations M1 and M2 are well developed. Seta pz1 is also present.

CR (Fig. 5i) is symmetrical, slender, and nearly straight. The entire posterior edge is serrated and shows patches of denticles at its base. The anterior (Ga) and posterior (Gp) claws are two-serrate, with the Ga being longer. The anterior (Sa) and posterior (Sp) setae are subequally long and serrated. Sp located close to Gp.

CRa (Fig. 5h) is slender and without loops, with the ventral branch (vb) more curved than the dorsal branch.

In the hemipenis (Fig. 5f) the medial shield (ms) is larger than the lateral shield (ls); the labyrinth is sclerotized, consisting of 3 parts (d1-d3); the tubular part of the internal spermiduct has three loops, and the bursa copulatrix (bc) is a curved organ situated distally (Fig. 5g).

Zenker organ (Fig. 5j) large and well developed with 31–35 spinous whorls.

Female genital lobe (Fig. 5e) with a subquadrangular and bilobated ventral lobe.

Figures

FIGURE 2. Cypriconcha hypsophila n. sp. (a) Ƥ, LV, external view. Allotype (MLP 26138). (b) Ƥ, RV, external view. Allotype (MLP 26138). (c) Ƥ, LV, internal view. Allotype (MLP 26138). (d) Ƥ, RV, internal view. Allotype (MLP 26138). (e) Ƥ, carapace, dorsal view. Paratypes (MLP 26139). (f) 3, LV, external view. Holotype (MLP 26137). (g) 3, RV, external view. Holotype (MLP 26137). (h) 3, LV, internal view. Holotype (MLP 26137). (i) 3, RV, internal view. Holotype (MLP 26137). (j) 3, carapace, dorsal view. Paratypes (MLP 26139). Scale (in mm) = 200 for a, c, h, i; 500 for b, d, e, f, g, j.

FIGURE 6. Cypriconcha hypsophila n. sp. (a, b) Ƥ, electronic microphotograph of eggs. Allotype (MLP 26138). (c) 3, electronic microphotograph of Zenker organ. Holotype (MLP 26137). Scale (in μm) = 50 for a, b; 100 for c.