Pseudocandona claudinae Higuti & Martens 2014, sp. nov.

Pseudocandona claudinae sp. nov.

urn:lsid:zoobank.org:act: 198F7F5F-49D0-4883-845A-386E0CAA4970

Figs 8–9

Diagnosis

Valves in lateral view elongated and with dorsal margin rounded, greatest height situated well behind the middle; anterior calcified inner lamella in both valves broader than very narrow posterior calcified inner lamella. Carapace in dorsal and ventral views relatively narrow; LV overlapping RV on all sides.

Seta h1 less than half the length (ca. 1/3) of seta h2. Caudal ramus with distal seta clearly developed, not spine-like.

Etymology

The new species is named in honour of Claudine Behen (RBINS), in recognition of her continued technical assistance with the line drawings of ostracod limbs over many years at RBINS.

Type material

All type material was collected on 4 Oct. 2012 by the authors and students, by hand net with mesh size 160 µm. See Table 1 for measurements of water chemistry at time of collecting.

Holotype

♀, with soft parts dissected in glycerine in a sealed slide, and with valves stored dry in a micropalaeontological slide (MZUSP 32682).

Paratypes

3 ♀♀ dissected and stored like the holotype (MZUSP 32683, OC3365, OC3366); a ♀ carapace stored dry in micropalaeontological slides (MZUSP 32684).

Type locality

BRAZIL: Matagal Stream in Upper Paraná River floodplain in sediment amongst grasses and other terrestrial vegetation in very shallow water (named littoral in Table 1). Coordinates: 22º54’26.4” S, 53º32’27.7” W.

Differential diagnosis

Pseudocandona claudinae sp. nov. can be distinguished from P. antilliana, P. caribbeana and P. cubensis by the elongated shape of the valves and the rounded dorsal margin. Pseudocandona claudinae sp. nov. appears to be closely related to P. geratsi, but the female valves of P. claudinae sp. nov. resemble those of the males in P. geratsi, while the female valves in this latter species are shorter and higher than those of the male. As no males of P. claudinae sp. nov. are known, the copulatory appendages cannot be

compared. In addition, the attachment of the caudal ramus in P. geratsi has two lateral branches, whereas there is only one in P. claudinae sp. nov.

Pseudocandona claudinae sp. nov. differs from P. annae by the more elongated valves, with a dorsal margin which is fully rounded (with a straight part in P. annae).

Description of female

Valves (Fig 8A–B) small and short, with greatest height situated behind the middle. Anteriorly and posteriorly rather broadly rounded, RV and LV of highly similar shape; anterior calcified inner lamella broadly rounded, posterior calcified inner lamella very narrow and almost disappearing towards the dorsal side.

Carapace in right lateral view (Fig. 8C) showing LV overlapping RV slightly on all sides; external surface of valves smooth. In lateral view dorsally more rounded.

In dorsal view (Fig. 8D), carapace lancet-shaped, sharply pointed anteriorly, more broadly so posteriorly.

Carapace in ventral view (Fig. 8E) lancet-shaped, with anterior side more acutely pointed than posterior side.

Md-palp (Fig. 9A) consisting of 4 segments. Basal segment dorsally carrying the respiratory plate (not shown), ventro-apically with 2 long setae (only one hirsute (= s1), the thin and smooth alpha seta and a short and stout hirsute seta (= s2). Second segment dorso-apically with 2 setae of unequal length, ventrobasally with a short, stout and hirsute seta and ventro-apically with a group of 5 setae: 2 long setae, 2 shorter, and the short and beta-seta. Third segment with a group of 3 dorso-subapical setae of unequal length, all smooth, a central group of two setae, one of which being the gamma seta, and a ventro-apical group of 2 setae, one long and one short, both smooth. Terminal segment subquadrate, chaetotaxy as in P. agostinhoi sp. nov.

T2 (walking limb, Fig. 9C) with 4-segmented endopodite (penultimate segment divided) and elongated. First segment with short seta d1. Knee-segment devoid of seta d2. First segment of endopod elongated, with short ventro-apical seta. Second segment also with one short ventro-apical seta. Third segment with two ventro-apical setae, one short, one very long. Terminal segment with one short apical and one short sub-apical seta and a long apical claw.

T3 (cleaning limb, Fig. 9E) as typical of the family. First segment with three setae, one short medial (d1), one short subapical (d2) and one long apical (dp). Second segment without seta. Penultimate segment with one long subapical seta (g). Terminal segment carrying three setae: 2 long (h2 and h3) and one very short (h1).

Caudal ramus (furca, Fig. 9D) with stout ramus and two stout apical claws. Long proximal setae, distal seta a small spine. Attachment to caudal ramus (Fig. 9B) long and stout, distally bifurcated and with additional lateral branch at ca. mid-length.

Male unknown

Measurements

See Table 3.