Keysercypria ivanae, Díaz & Lopretto, 2011

Díaz, Analía R. & Lopretto, Estela C., 2011, A new species of Keysercypria Karanovic (Crustacea: Ostracoda) from Argentina, Zootaxa 3063 (1), pp. 64-68 : 64-67

publication ID	https://doi.org/ 10.11646/zootaxa.3063.1.5
DOI	https://doi.org/10.5281/zenodo.5295655
persistent identifier	https://treatment.plazi.org/id/03F6BE19-FA0B-FFBA-FF3A-FAF1FB1137D1
treatment provided by	Felipe
scientific name	Keysercypria ivanae
status	sp. nov.

Treatment

Keysercypria ivanae n. sp.

( Figs 1 View FIGURE 1 & 2 View FIGURE 2 )

Type locality. Atalaya, Magdalena County (35º 02’ S – 57º 32’ W). Buenos Aires Province, Argentina .

Type material. Deposited in the Invertebrate Collection of the Museum of 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 26498).

Allotype. A female dissected and stored in the same manner as the holotype ( MLP 26499).

Paratypes. 1 female and 5 males dissected and stored in the same manner as the holotype ( MLP 26500) .

Etymology. From Ivana Karanovic. The species is named after Dr Ivana Karanovic from the Hanyang University, Seoul, as an acknowledgment of her great contribution to this study.

Description. Male's carapace is ovoid in anterior view. Greatest height is situated behind the middle. The calcified inner lamella is well developed on both the anterior and posterior margins. Hinge is adont. LV slightly overlaps the RV posteriorly. External surface with delicate reticulation, and numerous pores. Tiny pustules present on outer and inner margin both anteriorly and posteriorly and on both valves as well. In lateral view, greatest height is situated behind the mid-length. Both margins rounded. Anterior margin curved, and ventral margin ventrally slightly convex around mouth region. Females’ carapace subovoidal and slightly bigger than male. Greatest L around mid-length. Anterior margin slightly truncated. Posterior margin rounded. Surface smooth with delicate hear-like setae and without pustules on free margins.

Anatomy of the soft parts. An1 ( Fig. 2a View FIGURE 2 ) is 7-segmented. First segment with two postero-dorsal subequal setae and one antero-ventral setae. Second segments apically with one anterior seta. Third segment apically with one anterior and one postero-dorsal setae. Fourth and fifth segments with two long anterior setae and one short posterior seta each. Sixth with four long subequal apical setae. Terminal segment with three long apical setae and aesthetasc y a.

An2 ( Fig. 2b–c View FIGURE 2 ) is 5-segmented in females and 6-segmented in males. The chaetotaxy of the first three segments is identical for males and females. First segment of protopodite with two short subapical ventral seta, second segment with one long subapical ventral seta distally situated. The reduced exopodite with two short and one long setae. First segment of endopodite with a ventro-proximal aesthetasc Y, and four long and one short natatory setae extending beyond the tips of terminal claws. Differences in chaetotaxy of An2 of males and females are limited to the last two segments. Female ( Fig. 1c View FIGURE 1 ) penultimate segment one short medio dorsal seta, three ventral subequal t-setae and a short aesthetasc (y 1) inserted proximally to the t-setae; this segment also with 3 subequal subapical z-setae, one aesthetasc (y 2) and two long (G 1, G 3) and one short (G 2) claws. Terminal segment apically bearing two long subequal (GM) and (Gm) claws. In males ( Fig. 1b View FIGURE 1 ) in the penultimate segment only t 3 is present with a long aesthetasc (y 1). The two most anterior short z-seta (z 1-2) transformed into two short claws. Z 3 is short. Terminal segment with aesthetasc y 3, one medium claw (Gm) and one long claw (GM).

Md ( Fig. 2d View FIGURE 2 ) protopodite with six teeth, one serrated seta between first and second teeth and two short apical setae on the anterior side. Mandibular palp 4-segmented. First segment with two smooth and two serrated S 1 and S 2 setae. Second segment with one plumose seta, one β- seta and one long serrated seta apically inserted. Third segment with four subapical smooth setae and one ventro-apical seta. Terminal segment with four apical setae, two of which claw-like. Exopodite (respiratory plate) with five long plumed setae.

Rlo ( Fig. 2e View FIGURE 2 ) without visible teeth.

Mx ( Fig. 2f View FIGURE 2 ) with 2-segmented palp, three endites, and a large respiratory plate. First segment of the palp subquadrate. Second segment short with three apical claw-like setae. Each endite with three claw-like setae. Respiratory plate with 19 rays.

T1 ( Figs 2g –i View FIGURE 2 ) sexually dimorphic. Female ( Fig. 2g View FIGURE 2 ) protopodite with one plumose (d) seta. Masticatory process with 10 apical setae. In males the masticatory with process with three plumose and four smooth subequal setae. Exopodite (respiratory plate) with six rays; endopodite is 2-segmented and transformed into prehensile palps, right one being larger. First segment of right palp ( Fig. 2h View FIGURE 2 ) large and subrectangular, second segment subtriangular. No sensory organs. Left palp ( Fig. 2i View FIGURE 2 ) shorter. First segment large and rectangular, second segment very curved with one apical sensory organ (so 3).

T2 ( Fig. 2j View FIGURE 2 ) endopodite consisting of four segments. First segment of endopodite with one smooth“e” seta, second segment with a short ventro-apical “f” seta, third segment with a short ventro-apical “g” seta. Fourth segment apically with a terminal claw h 2 and two shorter setae h 1 and h 3.

T3 ( Fig. 2k View FIGURE 2 ) protopodite with one long dp seta. Seta d 2 and d 1 absent. First segment of endopodite with one short “e” seta, second fused with the following one and with one short “f” seta. Terminal segment with three setae of different L h 1 and h 2. Seta h 1 being at least twice shorter than h 2 and one long reflex seta h 3.

CR ( Fig. 2l View FIGURE 2 ) symmetrical, slender, nearly straight. Anterior (Sa) and posterior (Sp) setae of different L. Sp situated medially on caudal ramus.

CRa ( Fig. 2m View FIGURE 2 ) slender and without loops, with the ventral branch (vb) shorter than the anterior branch.

Hem. ( Fig. 2o View FIGURE 2 ) has one large distal lobe “a”. Lobe b is thin and pointed.

ZO ( Fig. 2n View FIGURE 2 ) large and well developed with 5 spinous whorls. Total L 250 µm, end plates diameter 60 µm and braces of end plates L 7 µm. Maximum L of spines: 35 µm and diameter of central tube 6 µm. End plates “hat-like”. Oblique disposition of end plates in relation to the central tube very clear. Numerous long, radiating rigid spines present and arranged from thick chitinous bands lieying upon the central tube itself. Surface of central tube ribbed. Number of chitinous whorls five and spines diagonally situated to the central tube and parallel to the end-plates. Number of braces on end-plates 18.

Female genital lobe with a conical process.

Remarks and affinities. The new species differs from the other nine species presently belonging to Keysercypria Karanovic, 2011 , by the absence of the setae d 1 and d 2 on the basal segment of the third thoracopod and by a filamentous inner lobe on the hemipenis. Keysercypria ivanae n. sp. has tubercles present on both valves and on both anterior and posterior margins. This is so far unique feature in the genus, as in K. obtusa (Klie, 1940) , K. circinata (Würdig & Pinto, 1993) , and K. pellucida (Sars, 1901) tubercles are absent or barely visible (but only on one of the valves), while in all other representatives the tubercles are clearly visible, but only on the RV. Karanovic (2011) reported sexual dimorphism in the L of the seta "h3" on the T2 (in males of K. affinis and K. deformis , this seta is considerably longer than in females). This character is not recorded in our species. Seta “e” on the same appendage is short, i.e., not exceeding distal end of the terminal segment, like in the most representatives of the genus, except in K. deformis .