Paranacypris samambaiensis, Higuti & Meisch & Martens, 2009
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publication ID |
https://doi.org/ 10.1080/00222930802702506 |
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persistent identifier |
https://treatment.plazi.org/id/54481123-7818-FFF0-08BC-FE839E4949E8 |
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treatment provided by |
Felipe |
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scientific name |
Paranacypris samambaiensis |
| status |
gen. nov., sp. nov. |
Paranacypris samambaiensis gen. nov., sp. nov.
( Figures 2–4 View Figure 2 View Figure 3 View Figure 4 )
Type locality
Lake Samambaia 2, a closed lake in the Taquaruçu system (Mato Grosso do Sul State). Two samples were taken during the sampling campaigns in 2004 (see Table 1) .
Type material
From type locality. Holotype: a dissected female (MZUSP 19289), with soft parts dissected in glycerine in a sealed slide, and valves stored dry in a micropalaeontological slide. Two paratype females, dissected, one (OC.3071) stored as the holotype, the other (MZUSP 19291) only consists of soft parts in a sealed slide, valves are lost. Three paratype females (OC.3072-3074) in toto, only LV and RV (OC.3075), used for scanning electron microscopy and stored dry in micropalaeontological slides. Three in toto paratype females in 70% ethanol (MZUSP 19292).
From Lake Figueira (see Table 1). One paratype female dissected and stored as the holotype (MZUSP 19290), but with one valve lost.
The material is deposited as follows: all OC-numbers are stored in the Ostracod Collection of the Royal Belgian Institute of Natural Sciences (Brussels), the MZUSP numbers are in the Museu de Zoologia da Universidade de São Paulo, Brazil.
See Table 1 for an overview of other localities where this new genus and species was found: Lake Samambaia 1, Lake Walter 1, Walter 2 and Lake Pousada. This material was not used for the present description, these specimens are therefore not paratypes.
Derivation of name
The specific name refers to the type locality, Lake Samambaia .
Diagnosis
Valves elongated, laterally flattened, LV anteriorly with incomplete inner list, RV anteriorly with submarginal inner list and pronounced posterior selvage, externally with anterior sulcus. LV widely overlapping RV anteriorly. A1 with medium-sized, one-segmented Rome organ and small Wouters’ organ. A2 with natatory setae reaching well beyond tip of claws. Mx1 with five ‘‘reversed’’ setae on respiratory plate, Zahnborsten on third endite smooth. T1 with e-seta short, stout and hirsute. Caudal ramus and attachment stout and strong.
Additional description of female
Valves in lateral view ( Figure 2A–C View Figure 2 ) elongated, with anterior margin more broadly rounded than the posterior one; greatest height situated almost in the middle; LV largely overlapping RV anteriorly, and to a lesser degree ventrally. RV in internal view with anterior inner list ( Figure 2J View Figure 2 ) and posteriorly with a clearly inwardly displaced selvage ( Figure 2K View Figure 2 ). LV in interior view with dorsal and ventral remnants of an anterior inner list ( Figure 2H View Figure 2 ), posteriorly without special structures ( Figure 2I View Figure 2 ). In both valves anterior calcified inner lamella wide, posterior one narrow. RV externally with a sulcus close to the anterior margin. LV with external list running almost parallel to the ventral valve margin.
Cp in dorsal view ( Figure 2D View Figure 2 ) with greatest width (about one-third of the length) situated in the middle; anterior overlap LV/RV pronounced ( Figure 2F View Figure 2 ); posteriorly with both valves almost equal ( Figure 2G View Figure 2 ). Cp in ventral view ( Figure 2E View Figure 2 ) with LV overlapping RV along the entire length. External valve surface set with large pores ( Figure 2F,G View Figure 2 ).
A1 ( Figure 3B View Figure 3 ) with seven segments. First segment with two ventral setae and one dorsal seta; Wouters’ organ small. Second segment with one mediodorsal seta; Rome organ of medium size, about half the height of the segment. Third segment more than twice as long as wide, with one shorter ventral and one longer dorsal seta. Fourth segment almost as long as wide, with two long ventral setae and two even longer dorsal natatory setae. Fifth segment slightly longer than wide, also with two long ventral and two longer dorsal natatory setae. Sixth segment about 1.5 times as long as wide, with four long and one short natatory setae. Terminal (seventh) segment about 1.5 times as long as wide, with one shorter seta, one even shorter aesthetasc Ya and two long natatory setae.
A2 ( Figure 3C View Figure 3 ) with exopodite reduced to a small plate, bearing one long and two short setae. Endopodite three-segmented. First segment elongated and stout, aesthetasc Y long and slender (about one-third of length of segment). Five natatory setae reaching well beyond the tips of the end claws; accompanying (sixth) seta just reaching beyond the tip of the second segment. Second segment with two dorsolateral and four ventrolateral setae (t1–4) plus aesthetasc y1; distal chaetotaxy typical of female Cyprididae , with three z-setae and three G-claws, claws G1 and G3 relatively long and slender, claw G2 about half the length of the other two claws, one apical aesthetasc y2. Terminal (third) segment with large claw GM, shorter claw Gm, seta g and short aesthetasc (y3) fused with a seta, the latter longer than the aesthetasc.
Md ( Figure 3A,F View Figure 3 ) with coxal plate distally set with rows of spines and small setae. Palp with a- seta rather long, slender and smooth, b- seta short, stout and hirsute, c- seta large, broad and hirsute in distal two-thirds of its length. First segment with two long barbed setae, one long smooth seta and the alpha seta. Second segment dorsally with a group of three smooth setae, ventrally with three long and smooth and one shorter and hirsute setae as well as the b- seta. Third segment dorsally with four subapical and subequal setae, ventrally with one subapical seta and a short aesthetasc, medially with four setae (three plus c- seta). Terminal segment with three slender claws and three long setae.
Mx1 ( Figure 4E–G View Figure 4 ) with second palp-segment distinctly spatulate, Zahnborsten on third endite smooth. Sideways directed bristles short and smooth. Respiratory plate large and elongate, distally with a row of ca. 18 ‘‘normal’’ rays and five ‘‘reversed’’ rays.
T1 ( Figure 4C View Figure 4 ) with two a- setae, one b- seta and one d- setae, all of normal shape. One e-seta short, stout and hirsute. Distal chaetotaxy of coxal plate consisting of 16 setae of sometimes very different shape and length.
T2 ( Figure 4D View Figure 4 ) with elongated segments and relatively long setae and end claw. First segment with seta d1 long, reaching beyond second segment, this (knee-) segment with seta d2 missing. Third segment with one long ventroapical seta, reaching almost to segment 5. Fourth segment divided into two elongated subsegments: 4a with a ventroapical seta, not reaching tip of segment 4b, this segment with 2 ventroapical setae, one about twice as long as the other. Fifth segment with one subapical seta and one apical seta and one long, thin apical claw.
T3 ( Figure 4A,B View Figure 4 ) a cleaning limb. First segment with three setae. Second segment with one long apical seta. Third segment with one short lateral seta. Distal part of third segment and fourth segment fused to a pincer-shaped organ, bearing one long seta, one seta of medium length, two rows of setulae and one comb-like seta.
Caudal ramus ( Figure 3E View Figure 3 ) distally with two claws, one claw-like posterior seta and one apical seta. Attachment ( Figure 3D View Figure 3 ) with simple distal bifurcation and triangular structure at basis (typical of Herpetocypridinae ).
Males unknown.
Measurements
OC.3075: LV: length 5825 mm, height 5364 mm; RV: length 5788 mm, height 5354 mm; OC.3073: length 5806 mm, height 5354 mm.
Remarks
It is at present difficult to distinguish between generic and specific characters because only one species is known in this genus and because males are unknown. Male copulatory appendages and prehensile palps generally offer the best features to distinguish between species.
Ecology
The species has been found in 12 of more than 132 samples in 48 localities; four of these samples were pleuston, eight were fully benthic. All localities were in closed lakes (i.e. not connected to the main channels of the Paraná floodplain), none in open lakes or in channels. The pH ranged between 5.5 and 7.6, electrical conductivity between 16.9 and 123.8 mS cm 21 and dissolved oxygen between 3.5 and 12 mg l 21. The species was found all year around ( Table 1).
Key to the genera of the Herpetocypridinae
The present key builds on characters identified in the generic diagnoses by Martens (2001), but because of the increased evidence for mosaic evolution (see below), the tribes introduced by Martens (2001) are not used to key out genera.
1 (8) Maxillular (Mx1) palp: terminal segment spatulate. Caudal rami symmetrically built, posterior seta always present, sometimes claw-like....... 2
2 (3) Cleaning leg (3rd thoracopod): penultimate segment at around mid-length with 2 (long) setae (NB: the terminal segment is tiny, barely visible in all Cyprididae View in CoL ).................................. Candonocypris View in CoL
3 (2) Cleaning leg: penultimate segment at around mid-length with one (long) seta................................................. 4
4 (5) Caudal ramus: posterior seta untransformed (a true seta). Length51.5– 2.5 mm ..................................... Herpetocypris View in CoL
5 (4) Caudal ramus: posterior seta transformed, claw-like. Length50.7– 1.5 mm .................................................... 6
6 (7) Walking leg (2nd thoracopod): setae d1 and d2 subequal in length. Length>1.0 mm................................. Ilyodromus View in CoL
7 (6) Walking leg: d1 long, d2 absent. Length, 1 mm ................................ Paranacypris View in CoL gen. nov. (here described, one species)
8 (1) Mx1 palp: terminal segment rectangular, not spatulate. Caudal rami symmetrical or asymmetrical; posterior seta present or absent, when present, claw-like or not................................... 9
9 (12) Caudal rami conspicuously asymmetrical..................... 10
10 (11) Marginal valve zones with conspicuous septa........... Stenocypris
11 (10) These septa always missing............................................... Chrissia View in CoL 5 Gesa Hartmann 5 Parastenocypris Hartmann
12 (9) Caudal rami symmetrical or slightly asymmetrical............... 13
13 (14) Left valve with a conspicuous posteroventral spine......... Acocypris View in CoL
14 (13) Left valve without that spine.............................. 15
15 (18) Caudal ramus: posterior seta long.......................... 16
16 (17) Posterior inner valve margin conspicuously curved........ Stenocypria View in CoL
17 (16) Posterior inner valve margin regularly rounded.................................................... Ampullacypris View in CoL (one species)
18 (15) Caudal ramus: posterior seta short and claw-like or absent......... 19
19 (20) Caudal ramus: posterior seta a conspicuous claw or claw-like seta. Walking leg: setae d1 and d2 subequal in length.............. Psychrodromus View in CoL
20 (19) Caudal ramus: posterior seta either an inconspicuous spinule or absent. Walking leg: d1 two to four times longer than d2............... 21
21 (22) Caudal ramus: posterior seta an inconspicuous spinule or absent. Carapace 1.0–2.0 mm long. Males present or missing. Hemipenis with conspicuous, sclerotized hook-like apical structure on medial shield; post-labyrinthal spermiduct with two to four additional circular whorls... Humphcypris View in CoL
22 (21) Caudal ramus: posterior seta absent. Carapace ca. 1.0 mm long. Males always present. Hemipenis without hook-like apical structure on medial shield; post-labyrinthal spermiduct with up to six additional circular whorls.................................. Somalicypris View in CoL (one species)
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