Candobrasilopsis elongata, Higuti & Martens, 2014

Higuti, Janet & Martens, Koen, 2014, Five new species of Candoninae (Crustacea, Ostracoda) from the alluvial valley of the Upper Paraná River (Brazil, South America), European Journal of Taxonomy 106, pp. 1-36 : 24-27

Candobrasilopsis elongata sp. nov.

urn:lsid:zoobank.org:act:197FB8BE-2703-4FA6-97CA-2D40A8342325

Figs 10–11

Candonopsis sp. 3 n. sp. in Higuti et al., 2009c: 664.

Candonopsis sp. 3 n. sp. in Higuti et al., 2010: 267.

Diagnosis

A species with very elongated valves, greatest height well behind the middle; in lateral view with dorsal margin straight for more than half the total length. Anterior calcified inner lamella in both valves broad, almost ¼ of total length and with inner margin sinuous, not parallel to valve margin. Both valves externally set with elongated micro-ridges.

Prehensile palps one-segmented. Right prehensile palp set with two subequal and robust lateral setae. Left prehensile palp larger and more elongated, with hook-like distal part, distal tip slightly swollen. Hemipenis atypical of the genus, with leaf-like lobe ls, distally rounded and proximally narrowing, lobe ms broad, distally with almost straight margin, ventro-distally bluntly pointed.

Etymology

The present species is named after the very elongated carapace.

Type material

All type material was collected on 2 Feb. 2011 by JH and students, by washing roots of Eichhornia crassipes ( PAR 461) in a bucket and by filtering the material in a 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 32685 ).

Allotype

A ♀, dissected and stored like the holotype ( MZUSP 32686 ).

Paratypes

Five ♂♂ dissected and stored like the holotype ( MZUSP 32687, MZUSP 32688, MZUSP 32689, OC. 3353, OC. 3354); three ♂ carapaces stored dry in micropalaeontological slides ( MZUSP 32690, MZUSP 32691, MZUSP 32692); five ♀♀ dissected and stored like the holotype ( MZUSP 32693, MZUSP 32694, OC. 3355, OC. 3356, OC. 3357) and a ♀ dissected with valves lost ( MZUSP 32695); four ♀ carapaces

stored dry in micropalaeontological slides ( MZUSP 32696, MZUSP 32697, MZUSP 32698, MZUSP 32699).

Type locality

BRAZIL: Patos Lake in Upper Paraná River floodplain in floating plants ( E. crassipes ). Coordinates: 22º49’48.2” S, 53º33’20.3” W.

Differential diagnosis

Candobrasilopsis elongata sp. nov. differs from C. rochai and C. brasiliensis by the more elongated shape of the valves, and from C. acutis sp. nov., which also has elongated valves, by the presence of external micro-ridges on the valves. Candobrasilopsis elongata sp. nov. can be distinguished from its three congeners by the atypical hemipenis, which has a lobe ls with rounded (not pointed) distal margin, and a lobe ml with almost straight distal margin (not rounded).

Description of male

Carapace in right lateral view ( Fig. 10C ) showing LV overlapping RV slightly on all sides. Carapace, in dorsal ( Fig. 10E ) and ventral views ( Fig. 10F ), narrow and lancet-shaped, with anterior and posterior side pointed, greatest width situated well behind the middle.

Both valves ( Fig. 10A–B ) very elongated, with greatest height situated behind the middle (and bluntly pointed there), anteriorly rather broadly and posteriorly rather narrowly 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; inner margin of anterior calcified inner lamella slightly sinuous in both valves. External surface of both valves striated ( Fig. 10D ).

A1, A2, Mx1, T1-3 as typical of the genus and not illustrated.

Md-palp ( Fig. 11C ) consisting of 4 segments, terminal segment short (L ≤ 1.5 x basal width).

Prehensile palps ( Fig. 11A–B ) one-segmented, distally hook-like and set with two unequal and robust, sub-apical setae; both palps slightly asymmetrical, left prehensile palp ( Fig. 11A ) basally slightly more swollen.

Caudal ramus ( Fig. 11E ) with stout ramus and two stout apical claws. Proximal setae missing, distal seta a small spine. Attachment to caudal ramus ( Fig. 11D ) long and stout, distally bifurcated and with additional lateral branch at ca. mid-length. Length ratio ramus / largest claw = 1.85.

Hemipenis ( Fig. 11F ) atypical of the genus, with lobe ls leaf-like, distally rounded and proximally narrowing, lobe ms broad, distally with almost straight margin, ventro-distally bluntly pointed; an additional small ventral lobe present proximal of lobe ms.Internal labyrinth short and stout, postlabyrinthal spermiduct narrow and straight; internal copulatory process stout, beak-like and sharply pointed.

Description of female

Valves ( Fig. 10G–H ) and Cp ( Fig. 10I–J ) in lateral view similar to those in the male. Cp in D and V views ( Fig. 10K–L ) equally narrow and lancet-shaped, with anterior and posterior side pointed.

Soft parts as typical of the genus and, except for sexually dimorphic ones, similar to those of the male.

Measurements

See Table 3 .

Figures

Fig. 10. Valves of Candobrasilopsis elongata sp. nov. A–F ♂ and G–L ♀. A, G. LV, internal view (A = MZUSP 32687, G = MZUSP 32686). B, H. RV, internal view (B = MZUSP 32687, H = MZUSP 32686). C, I. Cp, right lateral view (C = MZUSP 32690, I = MZUSP 32699). D, J. Cp, right lateral view detail (D = MZUSP 32690, J = MZUSP 32699). E, K. Cp, dorsal view (E = MZUSP 32692, K = MZUSP 32696). F, L. Cp, ventral view (F = MZUSP 32691, L = MZUSP 32697). Scale bars: A–C, E–I, K–L = 500 µm; D, J = 20 µm.

Fig. 11. Limbs of Candobrasilopsis elongata sp. nov. (♂). A. Left prehensile palp (MZUSP 32685). B. Right prehensile palp (MZUSP 32685). C. Md palp (MZUSP 32685). D. Attachment of the caudal ramus (MZUSP 32685). E. Caudal ramus (MZUSP 32685). F. Hemipenis (MZUSP 32685). Scale bars: A–E = 50 µm; F = 100 µm.