Triangocypretta hirsuta, Ferreira & Higuti & Martens, 2023

Ferreira, Vitor Góis, Higuti, Janet & Martens, Koen, 2023, On a new genus and four new species of the subfamily Cyprettinae (Crustacea, Ostracoda) from Brazilian floodplains, Zootaxa 5343 (5), pp. 401-438 : 404-411

publication ID	https://doi.org/ 10.11646/zootaxa.5343.5.1
publication LSID	lsid:zoobank.org:pub:24E92041-4F5C-42E2-B7A3-401BEA46D2C8
DOI	https://doi.org/10.5281/zenodo.8349153
persistent identifier	https://treatment.plazi.org/id/BD899E60-067C-499D-B51B-73FB6EE02421
taxon LSID	lsid:zoobank.org:act:BD899E60-067C-499D-B51B-73FB6EE02421
treatment provided by	Plazi
scientific name	Triangocypretta hirsuta
status	gen. et spec. nov.

Treatment

Triangocypretta hirsuta View in CoL gen. et spec. nov.

( Figs. 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 , 18A, B View FIGURE 18 )

urn:lsid:zoobank.org:act:BD899E60-067C-499D-B51B-73FB6EE02421

2007? Cypretta sp.1 Higuti et al.: p. 1934, Table 2 View TABLE 2 .

2009? Cypretta sp.1 Higuti et al.: p. 664, Table 1 View TABLE 1 .

2010? Cypretta sp.1 Higuti et al.: p. 644, Table 2 View TABLE 2 .

2010? Cypretta sp.1 Mormul et al.: p. 189.

2015a? Cypretta costata Matusuda et al. : p. 119, Table 1 View TABLE 1 . 2015b? Cypretta costata Matsuda et al. : p. 325, Table 1 View TABLE 1 .

2016? Cypretta sp.1 Higuti & Martens: Appendix I.

2017a? Cypretta sp.1 Higuti et al.: p. 5, Appendix I.

2017b? Cypretta costata Higuti et al. : p. e120, Table 2 View TABLE 2 .

2017? Cypretta costata Campos et al. : p. 38, Table 2 View TABLE 2 .

2017? Cypretta costata Conceiç „o et al.: p. 329, Table 2 View TABLE 2 .

2017? Cypretta costata Pereira et al. : p. 327, Table 2 View TABLE 2 .

2018? Cypretta costata Campos et al. : p. 6, Table 2 View TABLE 2 .

2018? Cypretta costata Conceiç „o et al.: Table S1 View TABLE 1 .

2019? Cypretta costata Campos et al. : p. 375, Table 1 View TABLE 1 .

2020? Cypretta costata Conceiç „o et al. 2020: p. 1677, Table 2 View TABLE 2 . 2020? Cypretta costata Higuti et al. : Table S1 View TABLE 1 .

2021 Cypretta costata Campos et al. : p. 27, Table 1 View TABLE 1 .

Diagnosis

CpD with oval shape, anterior margin blunt, not pointed; Cp surface with setae and shallow pits; CpLl with highly arched dorsal margin; LV with a protrusion on the postero-ventral margin; RV slightly overlapping LV; T2: d 1 and d

2 with similar length.

Type locality

Brazil • Paraná River floodplain. Suja Lake (PAR1511), in the roots of Eichhornia crassipes Leg. VF, JH, KM and students, collected on March 21 st, 2018. Coordinates: 22°40′03.9′′S, 53°12′45.7′′W.

Type material

Holotype: A female, with soft parts dissected in glycerin in a sealed slide and valves stored dry in a micropaleontological slide (MZUSP 44371).

Paratypes: Two female specimens dissected and stored as the holotype (MZUSP 44372 and MZUSP 44373). Four female carapaces stored dry in micropaleontological slides (MZUSP 44374, MZUSP 44375, MZUSP 44376 and MZUSP 44377).

Other material examined

Brazil • Amazon River floodplain—Calado Lake (AMA50). Leg. JH, collected on 15.05. 2012 in the following plants: Salvinia auriculata Aubl. ; Pistia sp. ; Ludwigia sp. ; Azolla sp. Coordinates: 03°18’30.7”S, 60°34’29.0”W. One female specimen dissected and stored as the holotype (MZUSP 44378) and four female carapaces stored dry in micropaleontological slides (MZUSP 44379, MZUSP 44380, MZUSP 44381 and MZUSP 44382). Brazil • Araguaia River floodplain—Japonese Lake I (ARA11) Leg. JH, collected on 03.11. 2011 in the roots of Eichhornia crassipes (Mart.) Solms. Coordinates : 13°21’33.1”S, 50°36’42.9”W. Two female carapaces stored dry in micropaleontological slides (MZUSP 44383 and MZUSP 44384). Brazil • Pantanal, branch of Paraguay River (PAN130). Leg. JH & KM, collected on 27.03. 2012 in the roots of Eichhornia crassipes . Coordinates: 19°24’48.9”S, 57°18’51.3”W. One female carapace stored dry in micropaleontological slides (MZUSP 44385).

Etymology

This species was named after the most striking characteristic, namely the dense coverage by external setae on the surface of the carapace.

Other localities

See Table 2 View TABLE 2 , not all localities included.

Measurements

See Table 1 View TABLE 1

TABLE 1. (Continued)

Description

LVi ( Figs. 2A, G View FIGURE 2 , 18A View FIGURE 18 ) very highly arched (H ca. 3/4 of L), of triangular shape with greatest height situated in the middle; calcified inner lamella wide along anterior margin, absent along ventral margin and narrow along posterior margin; anteriorly with incomplete inner list (running halfway up the anterior margin); postero-ventrally with a strongly inwardly displaced selvage, not running parallel to valve margin (the protrusion), and with inner margin of the calcified inner lamella fortified by an inner list; in between also with a weakly calcified inner list ( Fig. 2G View FIGURE 2 ); ca. 13 septa along the anterior margin.

RVi ( Figs. 2B, H View FIGURE 2 , 18B View FIGURE 18 ) with similar shape as LVi, but with posterior calcified inner lamella somewhat wider; with submarginal groove along anterior and ventral margins; posteroventral inner list without denticules. CpLl and CpRl ( Figs. 2C, D View FIGURE 2 ) also with a triangular shape, with strongly arched dorsal margin and with greatest height also situated in the middle region; external surface densely set with long setae and shallow pits; RV overlapping LV at the dorsal, ventral, and posterior margins. CpD and CpV ( Figs. 2E, F View FIGURE 2 ) with oval shape, W ca. 4/5 of L, situated in the middle; posterior region more broadly rounded than anterior one; anterior margin with a blunt end, not pointed; CpV with RV overlapping LV on all sides, especially in the middle region with a flap; ca. 13 well-developed septa along the anterior margin.

A1 ( Fig. 3A View FIGURE 3 ) consisting of seven segments. The first segment with three setae (two long ventro-apical and one shorter mid-dorsal); Wouters’ organ not seen. Second segment with one dorsal seta, reaching beyond the middle of the third segment; Rome organ not seen. Third segment with one long (dorsal) and one short (ca. 3/4 of the long one) (ventral) apical setae (both reaching beyond tip of fourth segment). Fourth segment with two unequal short ventro-apical setae and two long dorso-apical setae. Fifth segment with two unequal, but short (ventral—the longer one almost reaching the middle of the terminal segment, and the other slightly shorter) and two long (dorsal) apical setae. Sixth segment with four long apical setae. Terminal segment apically carrying one long aesthetasc y a, one short seta (with half the length of y a) and two long setae.

A2 ( Figs. 3B, C View FIGURE 3 ) composed of six segments (two-segmented protopodite, one-segmented exopodite and threesegmented endopodite). Protopodite carrying three ventral setae, two mid-ventral (one of medium length, one short) and one long and hirsute ventro-apical seta. Exopodite consisting of a short plate with three setae, two unequal but both short, and one long (reaching the base of the last endopodite). First endopodal segment with one mid-ventral aesthetasc Y (ca. half the length of the segment); one long and hirsute ventro-apical seta (slightly longer than the segment), five long hirsute natatory setae (reaching the tips of the z setae) and one medium-long seta accompanying the natatory setae (reaching the tip of the terminal segment). Second endopodal segment with one medium and one long mid-dorsal setae (reaching halfway along the G claws), and a group of four mid-ventral t-setae (two equally long, one medium, and one short); three equally long z-setae (z 1, z 2 and z 3); and three claws (G 1 the shorter one; G 2 and G 3, equally long); aesthetasc y 2 not observed. Terminal segment ( Fig.3 C View FIGURE 3 ) with one long claw G M, and one medium claw G m; one aesthetasc y 3 and accompanying seta (slightly longer than y 3); seta g not observed.

MdCoxa ( Fig. 3D View FIGURE 3 ) consisting of an elongated plate with ca. seven apical teeth intercalated with short setae; one hirsute sub-apical seta on the dorsal margin. MdPalp ( Figs. 4B, C View FIGURE 4 ) consisting of four segments. First segment with long setae S 1 and S 2; one long smooth seta and a short and narrow smooth α-seta. Second segment ventrally with a cone-shaped and hirsute β-seta and three long and one medium length setae; dorsally with a group of two unequal but long setae and one short seta (ca. half the length of the long ones). Third segment dorsally with a group of four long setae; apically with four long setae and a cone-shaped, hirsute γ-seta. Last segment ( Fig. 4C View FIGURE 4 ) with three claws and two setae.

Mx1 ( Fig. 4A View FIGURE 4 ) with a respiratory plate (not illustrated), three endites (chaetotaxy not fully illustrated) and a two-segmented palp. First palp segment with a lateral seta of medium length, and six apical setae unequally long. Second palp segment rectangular, c. twice as long as basal width; apically with one very long, two long and three shorter setae, none of them claw-like. Third endite with one short lateral seta and two smooth claws (Zahnborsten). First endite with two subequal but long “sideways directed bristles”. Two basal setae subequal and short.

T1 ( Figs. 4D, E View FIGURE 4 ) composed of an endopodite and a protopodite. Endopodite ( Fig. 4E View FIGURE 4 ) a palp with three apical, hirsute setae, one short, one of medium length and one long. Protopodite with two equally short a-setae and one short d seta; b seta missing; 10 apical hirsute and unequally short setae and three unequally short sub-apical setae.

T2 ( Fig. 5A View FIGURE 5 ) composed of five segments. First segment with seta d 1 short. Second segment with d 2 slightly shorter than d 1. Third segment with seta e of medium length (reaching beyond middle of fourth segment). Fourth segment divided in a and b segments; a segment with long apical f seta ventrally serrated; b segment apically with a short g seta (reaching tip of terminal segment). Terminal segment apically with two short setae h 1 and h 3; and a longer claw h 2, the latter weakly serrated in its distal part.

T3 ( Figs. 5B, C View FIGURE 5 ) composed of four segments. First segment with three setae of medium length, slightly unequal (d 1, d 2 and d p; almost as long as second segment). Second segment with a short apical e seta (reaching halfway the third segment). Third segment with short sub-apical f seta. Distal part of third segment fused with fourth segment ( Fig. 5C View FIGURE 5 ) and forming a pincer-like structure, with a short seta h 1; longer h 2 claw; and hirsute h 3 seta of medium length.

CR ( Fig. 5D View FIGURE 5 ) with long but narrow and weak ramus, two long claws (one apical G a, almost as long as ramus, and one shorter G p sub-apical); one short seta S p on ventral margin, apical seta Sa absent.

CR attachment ( Fig. 5E View FIGURE 5 ) a single short and narrow rod, without bifurcation.

Differential diagnosis

Triangocypretta hirsuta gen. et spec. nov. is the largest of the four species described here (see Table 1 View TABLE 1 ). A clear difference with other species is seen on the CpLl since in the present species the anterior margins are less pointed. Indeed, T. hirsuta gen. et spec. nov.. has an anterior margin which is somehow “straight”, especially in dorsal and ventral views. Compared to T. angustus gen. et spec. nov., T. hirsuta gen. et spec. nov. has an oval shape in CpD and CpV, and its more triangular in CpLl than T. nates gen. et spec. nov. On the T2, the d 1 seta is a similar length to d 2, whereas in the other three species of the new genus the d 1 is shorter than d 2 (especially in T. angustus gen. et spec. nov. and T. nates gen. et spec. nov.).

Ecology

The species was recorded in a wide range of environmental variables: water temperature: 29.5–34.3ºC; pH range: 3.1–6.8; electrical conductivity: 17–48.5 μS. cm-1; dissolved oxygen: 0.8–6.8 mg.L- 1 (see Table 2 View TABLE 2 , not all localities included).