Strandesia nupelia Higuti & Martens, 2013

Ferreira, Vitor Góis, Higuti, Janet & Martens, Koen, 2020, Taxonomic revision of Strandesia s. s. (Crustacea, Ostracoda) from four Brazilian floodplains, with the description of three new species, Zootaxa 4760 (1), pp. 1-74 : 39-43

7. Strandesia nupelia Higuti & Martens, 2013

( Figs. 21–23 )

2009 Bradleystrandesia gr. elliptica sp. 1—Higuti et al.: 664, Table 1.

2009 Bradleystrandesia obtusata —Higuti et al.: 664, Table 1.

2009 Bradleystrandesia gr. obtusata sp. 5—Higuti et al.: 664, Table 1.

2009 Bradleystrandesia gr. obliqua —Higuti et al.: 664, Table 1.

2010 Bradleystrandesia gr. elliptica sp. 1—Higuti et al.: 267, Table 2.

2010 Bradleystrandesia obtusata —Higuti et al.: 267, Table 2.

2010 Bradleystrandesia gr. obtusata sp. 5—Higuti et al.: 267, Table 2.

2010 Bradleystrandesia gr. obliqua —Higuti et al.: 267, Table 2.

2013 Strandesia nupelia n. sp. —Higuti et al.: 202, Figs. 8 , 9C .

Type locality and material

Baía River , main river of the system, in washed roots of Pistia stratiotes , ( PAR193 ), collected on 10.11.2004 by JH & KM, approximate coordinates: 22°40’37.5” S 53°12’20” W .

Type material (holotype) is stored in the Museum of Zoology of the University of São Paulo (MZUSP), no MZUSP 27458. The paratypes are stored in the MZUSP, no MZUSP 27459, 27460, 27463 and Royal Belgian Institute of Natural Sciences no OC.3287, 3288 ( Higuti et al.2013).

Material examined

One female (MZUSP 40430) was used for soft part illustrations from Baía River (22°40’37.5”S, 53°12’29”W). One female (OC.3290) from Guaraná Lake (22°43’16.8”S, 53°18’12.9”W) and two females (MZUSP 27459, MZUSP 27460) from Baía River (22°40’37.5”S, 53°12’29”W) were used for SEM. All illustrated specimens are from the Paraná River floodplain.

Measurements of illustrated specimens (in mm)

L (n=3): 1.006 –1.044, H (n=1): 0.559, W (n=2): 0.523.

Diagnosis (after Higuti et al. 2013)

CpLl slightly elongated; with the greatest height situated in front of the middle. CpD and CpV with bluntly pointed anterior and posterior extremities. RV with anterior selvage slightly inwardly displaced, and with rounded protruding posterior flange. LV with internal groove along margins. A2 with natatory setae reaching well beyond the tips of the apical claws. CR slender and curved, with ventral margin weakly serrated; its attachment with a triangular Triebel’s loop in the main branch; vb long and straight; db short and slightly curved.

Abbreviated redescription of female (after Higuti et al. 2013)

LVi ( Fig. 21A, G ) without inner list on anterior calcified inner lamella; internal groove from anterior to posterior margins greatest height situated at about 1/3 of the length from the anterior side; anterior margin more broadly rounded than posterior one.

RVi ( Fig. 21B, H ) with anterior selvage slightly inwardly displaced, and with (small) protruding postero-dorsal flange ( Fig. 21F ); greatest height situated at about 1/3 of the length from the anterior side.

CpLl ( Fig. 21C ) slightly elongated, with the greatest height situated in front of the middle.

CpD ( Fig. 21D ) with RV overlapping LV with two flaps, one situated at the anterior end of the hinge, the second at the posterior end of the hinge. CpV (Fig. E) with valve margin of LV very weakly sinuous in the middle. CpFr (Fig. F), weakly oblique, with LV being the lower one.

A1 (not illustrated) with seven segments. First segment with one short subapical and two long apical setae; WO not seen. Second segment wider than long, with one short dorsal seta and a small ventral RO. Third segment with two setae (the smaller with the length of the fourth segment). Fourth segment with four setae (two short and two long). Fifth segment with three long and one short setae. Sixth segment with four long setae. Seventh segment with one short and two long setae, and one aesthetasc ya slightly longer than the short seta.

A2 ( Fig. 22 A-B) with protopodite, exopodite and three-segmented endopodite. Protopodite with two ventral setae; and one long distal seta, reaching beyond tip of first endopodal segment. Exopodite reduced to a small plate, with one long and two unequal short setae. First endopodal segment with one ventral aesthetasc Y, one long apical seta (reaching beyond the tip of the last endopodal segment), one group of five long and one short swimming setae (the five long setae reaching well beyond the tips of the apical claws; the short one reaching the middle of the third segment). Second endopodal segment undivided, with two unequal dorsal setae and a group of four unequal ventral t setae; apically with three claws (G1 and G3 equally long, G2 slightly shorter than G1), three equally long setae (z1, z2 and z3) and a short aesthetasc y2 ( Fig. 22B ). Terminal segment ( Fig. 22B ) with two claws (one long GM; one short, Gm), an aesthetasc y3 with an accompanying seta (seta longer than aesthetasc), fused over a short distance only, and a fine g-seta, the latter shorter than aesthetasc y3 and its accompanying seta.

First segment of Md palp ( Fig. 22 C—chaetotaxy not completely shown) with short (reaching only halfway the length of ss-seta) and smooth α-seta. Second segment ventrally with stout and hirsute ss-seta. Penultimate segment laterally with elongated cone-shaped, distally hirsute γ-seta. Terminal segment almost 1.5x as long as basal width. Md coxa (not illustrated) as typical of the family, elongated with an apical row of strong teeth of variable size, interspaced with some small setae.

Mx1 ( Fig. 22 D—chaetotaxy not completely shown) with three masticatory lobes, a two-segmented palp and a large respiratory plate (the latter not illustrated). Basal segment of palp with six long apical setae, and one short subapical seta. Terminal palp segment, ca. 2x as long as basal width, slightly curved, apically with three claws and three setae. Third endite with two large, distally serrated bristles. Lateral seta on third endite, reaching the tip of the endite. First endite with one sideways-directed bristle, and two long unequal basal setae.

T1 protopodite ( Fig. 22E ) with two short a-setae; b and d-seta equally long. Apically with 10 hirsute setae, subapically with a group of four setae. Endopodite with three unequal long hirsute apical setae (not illustrated).

T2 ( Fig. 22F ) protopodite with seta d1 long and seta d2 shorter, ca. 3/4 of the length of d1. First endopodal seg- ment with one subapical hirsute seta (e). Second endopodal segment medially divided into a- and b-segments; segment “a” with one apical hirsute seta of medium length (f); segment “b” with one shorter seta (g) reaching beyond the end of the terminal segment. Third endopodal segment with one apical claw (h2) and two setae (one ventro-apical seta (h1) with 1/4 the length of h2 and one dorso-apical (h3) seta with half the length of h3).

T3 ( Fig. 23 A—chaetotaxy not completely shown) with three segments. First segment with three long setae (d1, d2, dp). Second segment, longer than wide, with one subapical seta (e). Third segment, also longer than wide, with one lateral, hirsute seta (f); distal part of the third segment fused with fourth segment into a modified pincer, with one apical comb-like seta (h2), one small recurved seta, with 1/5 of the length of the comb-like seta, and one longer and distally hirsute seta (h3). Small tooth-like structures present at the base of the comb-like seta (arrowed in Figure 23A ).

CR ( Fig. 23B ) slender and curved, with ventral margin weakly serrated. Proximal claw 2/3 of the length of distal claw. Proximal seta hirsute, ca. 1/2 of length of distal seta.

CR attachment ( Fig. 23C ) stout, with Triebel’s loop broadly triangular, situated in the main branch; vb long; db short and curved.

Male unknown.

Differential diagnosis (after Higuti et al. 2013)

Strandesia nupelia can be distinguished from the other species in this lineage by the elongated shape of the valves, and the presence of a marginal anterior selvage and a (small) posterior protruding flange on the RV.

Ecology and distribution

Strandesia nupelia was recorded in lentic and lotic environments, associated with a great variety of macrophytes, from different types of life forms, in the Pantanal and Paraná floodplains. This species occurred in acidic to basic environments, with pH range of 3.8–8.4. Electrical conductivity and dissolved oxygen ranges were 11–162.2 µS. cm- 1 and 0.2–8.7 mg. L-1, respectively (see Table 1). Distribution: Brazil.

Figures

FIGURE 8 Carapace and valves of Strandesia galeati nov. sp. A, LVi (MZUSP 40413); B, RVi (MZUSP 40413); C, CpLl (MZUSP 40413); D, CpRl (MZUSP 40413); E, CpD (MZUSP 40413); F, RVi detail of posterior part; G, CpD (MZUSP 40413) posterior margin; H, CpD (MZUSP 40413) anterior margin. Scales bars, A-E, 1.000 μm; F, 500 µm; G, 400 µm; H, 200 µm.

FIGURE 9 Strandesia galeati nov. sp. A, A1 (MZUSP 40411); B, A2 except last segment (MZUSP 40412); C, A2 last segment (MZUSP 40412); D, Md palp showing α, ss, γ setae (MZUSP 40411); E, Mx1 (MZUSP 40412); F, T1 (MZUSP 40412). Scale bars, 50 μm.

FIGURE 21 Carapace and valves of Strandesia nupelia. A, LVi (OC.3290); B, RVi (OC.3290); C, CpLl (MZUSP 27459); D, CpD (MZUSP 27460); E, CpV (OC.3288); F, CpFr (MZUSP 27460); G, LVi detail of posterior margin (OC.3290); H, RVi detail of posterior margin (OC.3290). Scale bars, 200 μm. Reproduced from Higuti et al. (2013) with permission from Brill.

FIGURE 22 Strandesia nupelia. A, A2 except last segment (MZUSP 40430); B, A2 last segment (MZUSP 40430); C, Md palp showing α, ss, γ setae (MZUSP 40430); D, Mx1 (MZUSP 40430); E, T1 (MZUSP 40430); F, T2 (MZUSP 40430). Scale bars, 50 μm.

FIGURE 23 Strandesia nupelia. A, T3 pincer (MZUSP 40430); B, CR (MZUSP 40430); C, CR attachment (MZUSP 40430). Scale bars, 50 μm.