Amphibolocypris arida, Jocque, Merlijn, Brendonck, Luc, Riddoch, Bruce J & Martens, Koen, 2010
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publication ID |
https://doi.org/ 10.5281/zenodo.194264 |
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DOI |
https://doi.org/10.5281/zenodo.6199640 |
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persistent identifier |
https://treatment.plazi.org/id/6C3687EF-557D-FF80-9DC3-F897FAC9FEDA |
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Plazi |
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scientific name |
Amphibolocypris arida |
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sp. nov. |
Amphibolocypris arida sp.nov. Jocque & Martens
( Figs 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )
Type locality: Rock pools near Thamaga, south-eastern Botswana (24° 40’ 30” S, 25° 31’00” E). The pools are situated on granite rocky outcrops, surfacing in a mainly savannah matrix of grasslands and shrubs. The pools are generally shallow (max 20 cm deep) and small (max. 2 m radius), with water temperature reaching up to 37.1 °C at mid day. Based on measurements in 8 pools, habitat waters were characterized by a basic pH varying between 7.3 and 8.8 and were always low in conductivity with values ranging from 27.6 to 69.1 µSm/cm (Jocque, unpubl.). Accompanying ostracod fauna: Heterocypris sp.nov., Heterocypris incongruens , Sarscypridopsis cf gregaria, Potamocypris spec.
Type material: Holotype: a male, with soft parts dissected in glycerine in a sealed slide and with valves stored dry (after use for SEM) in a micropalaeontological slide (OC.3167)
Allotype: a female, with soft parts dissected in glycerine in a sealed slide and with valves stored dry (after use for SEM) in a micropalaeontological slide (OC.3168)
Paratypes: 2 males and 2 females, with soft parts dissected in glycerine in a sealed slide and with valves lost (OC.3166, OC.3169-OC.3171)
Derivation of name: as the species is thus far only known from rock pools in a (semi-) arid area, the specific name refers to this characteristic of its habitat.
Diagnosis: Valves elongated, with anterior margin more broadly rounded, posterior margin bluntly pointed, posterior calcified inner margin narrow, but present. External surface set with elongated microridges. Valves sexually dimorphic, with female valves being more elongated.
Natatory setae on A2 of medium length. T2 with subapical seta claw-like, reaching middle of elongated end claw. CR without proximal seta. Hemipenis with one shield with one club-like expansion, the other shield with two elongated lobes, one pointed, basally inserted, and one distally rounded, more apically inserted. Prehensile palps almost symmetrical, relatively short, with broad base and sickle-shaped.
Additional description of male: Valves in lateral view ( Figs 2 View FIGURE 2 A,B) elongated, weakly calcified, externally set with longitudinal micro-ridges and sparse rimmed pores ( Figs 2 View FIGURE 2 E,F = from female valves). with rounded dorsal margin, anterior margin more broadly rounded than posterior margin, ventral margin slightly sinuous. Valve outline antero-dorsally with a dent. Anterior calcified inner lamella broad, dorsally ending at dent; posterior calcified inner lamella narrow, but present. Muscle scars situated in front of the middle. Carapace in dorsal view very narrow, lancet shape. No overlap between LV and RV.
A1 ( Fig. 3 View FIGURE 3 A) with 7 segments. First segment with 2 ventral setae, no dorsal seta. Second segment with one medio-dorsal seta, Rome and Wouters organs not visible. Third segment more than twice as long and wide, with one shorter ventral and one longer dorsal seta. Fourth segment almost as long as wide, with 2 shorter ventral setae and 2 long dorsal natatory setae. Fifth segment slightly longer than wide, also with two shorter ventral and 2 longer dorsal natatory setae. Sixth segment almost twice as long as wide, with 1 short ventral setae and 4 long natatory setae. Terminal (seventh) segment more than twice as long as wide, with 1 shorter seta, one long aesthetasc Ya (not drawn) and 2 long natatory setae.
A2 ( Fig. 3 View FIGURE 3 B) with exopodite reduced to a small plate, bearing 1 long and 2 short setae. Endopodite 3- segmented. First segment elongated and stout, aesthetasc Y short and club-like, distal part swollen. Natatory setae of unequal length, but all relatively short, mostly not reaching tip of second segment; ventral-most seta the longest. Second segment with 2 dorso-lateral and 3 ventro-lateral setae (2 long, 1 short), distal chaetotaxy typical of male Cyprididae , with setae z2 and z3 changed into claws, z1 a seta and claw G1 turned into a long seta, extending beyond tips of all claws, these claws stout, relatively short and set with strong spines. Terminal segment with claws G M and G m, seta g and aesthetasc y3, basally fused with an accompanying seta.
Md (compare to Figs 3 View FIGURE 3 D,E,E’ = female) with coxal plate distally set with rows of spines and small setae. Palp with alpha-seta short, narrow and smooth, beta-seta short, stout and hirsute, gamma-seta short, broad and hirsute in distal fourth of its length. Second segment dorsally with a group of 3 smooth setae, ventrally with 3 long and smooth and 1 shorter and hirsute setae. Third segment dorsally with 4 subapical setae, ventrally with 1 subapical seta, distally with 3 normal setae and a gamma-seta. Terminal segment with 3 stout claws and 3 small setae.
Mx1 (compare to Fig. 4 View FIGURE 4 A = female) with second palp-segment slightly spatulate, Zahnborsten on third endite smooth.
T1 ( Figs 5 View FIGURE 5 A, B) with 1 a-seta, 1 b- and 1 d-setae. Distal chaetotaxy of coxal plate consisting of 16 setae of sometimes very different shape and length. Prehensile palps almost symmetrical; first segments with large ventral protuberance, set with 1 large sensory organ; second segments sickle-shaped, tapering towards the end, distally with one long and stout sensory organ.
T2 (compare to Fig. 4 View FIGURE 4 B= female) with elongated segments and unusually long setae. First segment with seta d1 reaching into second segment, this (knee-) segment with seta d2 missing. Third segment with 1 long ventro-apical seta, reaching almost to fifth segment. Fourth segment divided into two elongated subsegments: segment 4a with a relatively short ventro-apical seta, not reaching tip of segment 4b, this latter segment with 2 subequal, ventro-apical setae. Fifth (terminal) segment with 1 subapical seta and 1 subapical claw (generic character) and 1 long and thin apical claw.
T3 (compare to Figs 4 View FIGURE 4 C,C’= female) a cleaning limb. First segment with 3 setae. Second segment with 1 long apical seta. Third segment with 1 short lateral seta. Distal part of third and fourth segment fused to a pincer shaped organ, bearing 1 long seta, 1 seta of medium length, set with two rows of setulae and 1 very short seta.
CR ( Fig. 4 View FIGURE 4 E) distally with 2 claws and 1 apical seta, proximal seta missing (generic character). Attachment ( Fig. 4 View FIGURE 4 D = female) slender, with simple distal bifurcation.
Hemipenis ( Fig. 5 View FIGURE 5 C) with a complex of ventral lobes of medial and lateral shields: one shield with one club-like expansion, the other shield with two elongated lobes, one pointed, basally inserted, one distally rounded, more apically inserted.
Additional description of female: Female valves more elongated, dorsal margin bluntly pointed, with greatest height less than ½ the length and situated almost in the middle. Anterior margin more rounded than posterior margin, but both less so than in the male. Calcified inner lamellae and position of muscle scars as in the male.
A1, Md ( Figs 3 View FIGURE 3 D,E,E’), Mx1 ( Fig. 4 View FIGURE 4 A) and T3 ( Fig. 4 View FIGURE 4 C,C’) as in the male.
A2 ( Fig. 3 View FIGURE 3 C) with natatory setae slightly longer than in the male, z1-3 all setae, reaching up to or beyond tips of end claws, the latter more slender and longer than in the male and set with more delicate spines.
T1 ( Fig. 4 View FIGURE 4 F) with palp short and wide, distally with 3 relatively short setae.
T2 ( Fig. 4 View FIGURE 4 B) with segments and setae slightly longer and more slender than in the male.
CR slightly more slender than in the male.
Remarks: Most species in the subfamily Isocypridinae are known to have weakly calcified valves. In the present study, most specimens of A. arida sp.nov. have either weakly calcified, or completely decalcified valves. This means that only few specimens had valves reflecting the true shape, hence the limited number of illustrations of these valves. The longitudinal ridges on the valve surfaces ( Figs 2 View FIGURE 2 E,F) could function as reinforcement of weakly calcified valves.
Measurements (in mm): Male, holotype: RV, L = 1.69, H= 0.65; LV, L= 1.67, H=0.65
Female, allotype: RV, L= 1.58, H= 0.63; LV, L = 1.58, H= 0.64
Differential diagnosis: Amphibolocypris arida sp.nov. differs from the other described species in the genus, the type species A. exigua , by the more elongated valves, with more pointed posterior margin, especially in the female; by the shape of the hemipenis (one large rounded lobe and one narrower lobe in A. exigua , one subquadrate lobe and three more elongated lobes in A. arida ) and of the prehensile palps (proximal segments with more elongated ventral protuberances and more elongated and narrower distal segments with shorter distal sensory organs in A. exigua ).
Two further, as yet undescribed, species from Namibia (Martens, unpubl.) differ from both A. exigua and A. arida sp.nov. in the shape of the hemipenis (see below).
Ecology and distribution: The species is presently known from its type locality only, namely rock pools on a granite outcrop in south-eastern Botswana. From other, as yet unpublished records of other species of Amphibolocypris from Namibia (see above), it would seem that this once monospecific genus might be more speciose than was previously assumed, in which case the individual species could have rather limited distributions.
Other species investigated: As a comparison, two further new species of Amphibolocypris from the western part of southern Africa are mentioned here, and the outlines of the hemipenis given. Due to limitation of material (single specimen, completely decalcified valves), these species are left in open nomenclature.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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