Heterocypris incongruens ( Ramdohr, 1808 )

Heterocypris incongruens ( Ramdohr, 1808)

Figs 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8 , 9 View Figure 9

Cypris incongruens Ramdohr, 1808 : figs 1–12, 15, 16, 19, 20.

Cypris fusca Straus: Fischer 1851: 156–157, pl. VIII, figs 9–13, pl. IX, figs 1–6, pl. XI, figs 10–12.

Cypris incongruens Ramdohr: Brady 1868: 362–364, pl. XXIII, figs 16–22.

Cypris incongruens Ramdohr: Vávra 1891: 95–98, fig. 32.

Heterocypris incongruens (Ramdohr), comb. nov.: Claus 1892: 161.

Heterocypris incongruens (Ramdohr) : Sars 1924: pt. II, p. 116–117, pl. IV, figs 1, 2.

Heterocypris incongruens (Ramdohr): Poulsen 1940: 54–56, fig. 22.

Heterocypris incongruens (Ramdohr): Hartmann 1964: 33–34.

Heterocypris incongruens (Ramdohr): Meisch 2000: 346–351, figs 145, 146 A – E.

Material examined.

Mexico • 10 females (size RV length = 1301–1404 µm, height = 740–803 µm; LV length = 1318–1455 µm, height = 805–853 µm); San Nicolas Tetelco , Mexico City; M. Bonilla-Flores leg. China • 1 female from Luo Ma , STP ( TIP 08-4 ) (size RV length = 1629 µm, height = 917 µm; LV length = 1647 µm, height = 958 µm) ; • 1 female from Taro Co, STP ( TIP 11-84 ) (size RV length = 1231 µm, height = 685 µm; LV length = 1252 µm, height = 697 µm) ; • twelve females from Taro Co, STP ( TIP 11-99 ) (size RV length = 1319–1405 µm, height = 741–826 µm; LV length = 1313–1336 µm, height = 768–807 µm); P. Frenzel leg.

Diagnosis.

(adult female, Figs 6 View Figure 6 , 7 View Figure 7 ) ( Meisch 2000): valves elongated in lateral view. RV is smaller than LV, the latter overlapping the right. The highest part is in the middle of the valves. RV with row of inconspicuous denticles in internal view on both margins, with a narrow inner lamella and inner list (Fig. 6 A 1, A 3, A 4, B 1, B 3, B 4 View Figure 6 ). LV without inner list (Fig. 6 A 2, B 2 View Figure 6 ). On the inner surface of the valve, there are normal, turbine-shaped pores with a bristle. The upper lip has a patch of medially positioned setae located in the middle region, approximately within the first third of the length from the mouth opening. Female genital lobes are subtriangular, the intersection displays a small beak-like projection, but the constriction is not pronounced. The lobes have a nearly straight distal margin.

Dimensions.

Adult females, RV ranges: length = 1136–1648 µm, height = 658–942 µm; LV length = 1134–1671 µm, height = 686–953 µm.

Valves.

External surface with numerous normal pores (Fig. 7 A 5, A 6, B 5, B 6 View Figure 7 ), striations, foveolae in antero-dorsal zone. In lateral view, dorsal side is arched. RV features a thin inner lamella, small crenulated teeth on anterior and posterior margins. LV with a thin inner lamella in internal view. Normal pores on inner surface have a turbine shape with a bristle (Fig. 6 A 6, B 5, B 6 View Figure 6 ), but on external surface, pores present bristles and a rim (Fig. 7 A 7, A 8, B 7, B 8 View Figure 7 ). Color yellowish.

Description of soft parts.

(Figs 8 View Figure 8 , 9 View Figure 9 ) Antennule (Fig. 8 A View Figure 8 ). Seven-segmented: segment I bears two long, setose setae on the posterodistal side and a short seta on the anterodorsal region. Segment II possesses a short seta on the anterior side. Segment III carries two short setae distally. Segment IV with three setae: two long ones on the anterior region and one short seta extending beyond segment V. Segment V features four setae, with those on the ventral side being longer. Segment VI bears a distal α-seta and four long setae. Segment VII with three distal setae, two long and one short. One aesthetasc ya, measuring 103 µm (twice the length of the terminal segment, 45 µm long).

Antenna (Fig. 8 B View Figure 8 ). Five-segmented: coxa with three short setae (illustrated incompletely); robust basis, with one long ventral seta. Exopod with three setae; two short ones and a long one. The first endopodal segment bears a two-segmented aesthetasc (Y) and five long swimming setae in the apical part, reaching to the tip of the claws, and one short seta. The second endopodal segment has four t-setae (t 1 – t 4) and two aesthetascs (y 1 in the posteromedial part and y 2 in the posterodistal part). Distally, this segment bears three long, thin z-setae and three claws (G 1, G 2, and G 3). Claws G 1 and G 3 are approximately equally long, while G 2 is shorter. The terminal segment features an aesthetasc (y 3), one g seta, and claws (GM and Gm). Exopod longest seta measures 147 µm in length, longer than the first (153 µm) and second (106 µm) endopodal segment; the length ratio of the second endopodal segment is 0.72 × that of the exopod longest seta.

Upper lip (Fig. 9 A View Figure 9 ) has a distinctive internal reticulation. Measurements on the upper lip were taken as follows: length (290 µm), height (77 µm), position of the maximum height (208 µm), in accordance with Karan-Žnidaršič and Petrov (2014). A patch of medially positioned setae is in the middle region, approximately within the first third of the length from the mouth opening. Rake-like organ with nine teeth on the right and ten on the left.

Mandibular coxa (Fig. 8 C View Figure 8 ). With seven teeth and one plumose subdistal seta.

Mandibular palp (Fig. 8 D View Figure 8 ). Four-segmented: first segment bears a respiratory plate with six rays of similar length, plus three long distal setae, and an α seta. Second segment with a β seta, with four additional setae, including three long distal ones. Third segment features a γ seta on the apical part, and this same segment has nine setae in the distal region. Fourth segment features five setose setae, each measuring twice the length of the segment.

Maxillula (Fig. 8 E View Figure 8 ). Palp two-segmented: the first one bears a long, smooth seta with four setose setae, and the second segment is quadrangular in shape with five smooth long setae. The third endite holds two serrated two serrated Zahnborsten, plus five distal and a subdistal setae. Second endite with eight setae, and first endite with nine distal setae and two setae with rays in the basal region.

T 1 (Fig. 8 F View Figure 8 ). With two setae a, one b, and one d at the endopod. Exopod with six hirsute rays; protopod with 13 setose distal setae.

T 2 (Fig. 9 B View Figure 9 ). Five-segmented: the first one with a short seta d 1. The second segment bears a long distal seta (e). The third segment has a setose distal seta (f). Segment four possesses a distal long seta (g) with a shorter seta. Segment five with short setae h 1 and h 3 and a claw-like seta h 2 with spinules. The length of the second endopodal segments measures 108 µm, representing 59 % of the length of the claw, which measures 183 µm.

T 3 (Fig. 9 C View Figure 9 ). Four-segmented: first segment bears a short, smooth d 1 - seta. In the distal region, there is a long setose seta d 2, and a seta dp as long as the third segment. Second segment features a setose distal seta (e). Third segment displays a medial f-seta, a reduced h 1 seta in the distal part (fused 4 th segment), a segmented h 2 seta, and a long h 3 setose seta.

Uropodal ramus (Fig. 9 D View Figure 9 ). Elongated structure with two distal claws — Ga (174 µm), exceeding Gp (122 µm) in length — and one shorter setose Sp (94 µm). A Sa seta is present, shorter than Sp, and two caudal ramus attachments are observed.

Female genital lobes (Fig. 9 E View Figure 9 ) have an intersection with a triangular shape. General shape of lobes is elongated and relatively broad; curvature of lobes is more open and straighter; shape of apex is pointed, without truncation.

Reproduction.

Commonly asexual populations ( Meisch 2000), with records of males from a man-made pond, Kahramanmaraş, Turkey ( Yavuzatmaca and Külköylüoğlu 2019), and several sexual records in Europe ( Horne and Martens 1999)

Distribution.

Recorded from numerous places, it is cosmopolitan ( Meisch 2000).

Habitat.

The species predominantly inhabits temporary ponds with vegetation cover ( Meisch 2000; Mischke 2012). In accordance with our limnological data (Table 1 View Table 1 ), this species was found in freshwater to brackish, alkaline to oxygenated waters (average 3.8 mg / l). Ganning (1971) found this species up to a salinity of 16 psu at the Baltic Sea coast.