Typhlocypris pratensis (Hartwig, 1901)
- Dataset
- GBIF Backbone Taxonomy
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Ostracoda
- order
- Podocopida
- family
- Candonidae
- genus
- Pseudocandona
- species
- Pseudocandona pratensis
description
(Hartwig, 1901) (Figs. 6 C-E, 7) Synonymy. [non] Candona compressa n. sp. - Kaufmann, 1900: p. 371, Pl. 27, Figs. 4 - 6, Pl. 28, Figs. 6 - 11, Pl. 31, Fig. 18
description
Description. Female: Shell almost rectangular in shape (Fig. 6 C), L = 0.8 mm. Greatest H situated behind middle, equaling 55 % of L. Dorsal margin rounded toward posterior end, and sloping towards anterior end, with a slight sinusoid depression antero-dorsally. Both anterior and posterior margins rounded, posterior one wider. Ventral margin almost straight, except around middle where slightly concave. Anterior and posterior inner calcified lamella narrow (Fig. 6 E). Surface of the shell covered with hair-like setae originating from well-defined ringed openings (Fig. 6 D). A 1 (Fig. 7 A) 7 - segmented. First segment anteriorly with one proximal and one distal seta; posteriorly same segment with two long setae situated distally. Second and third segments with one antero-distal seta each (none of the two setae reaching distal margins of following segments). Fourth segment with one short postero-distal and two long antero-distal setae. Fifth segment with the same chaetotaxy as fourth one. Sixth segment with short α-seta, two long and one short seta. Terminal segment with aesthetasc (ya) which approximately 1.5 times longer than seventh segment, one short posterior seta, and two long setae. L ratio between last five segments equal: 1: 1.6: 1.8: 1.9: 1.7. Segments one and two, and two and three articulated. A 2 (Fig. 7 B) with 3 - segmented endopod. Basal segment with two setae. Protopod with one long seta. Exopod reduced to plate with one long and two short setae. First endopodal segment with two postero-distal setae (unequally) long, and aesthetasc Y which not reaching distal end of first endopodal segment. Aesthetasc y 1 situated slightly above four t setae, one more short seta present posteriorly on same segment. Claw G 2 reduced, but exceeding terminal segment, claws G 1, G 3, GM, long, Gm equaling 2 / 3 of GM. All z-setae normal and not transformed in claws. Aesthetasc y 2 short, y 3 as long as terminal segment. L ratio between endopodal segments: 4.3: 2.8: 1. Md (Fig. 7 D) with 4 - segmented palp, stout coxa and exopod carrying vibratory setae. First segment internally with two long setae (pappose one being S 1), seta S 2 short and plumose, while α- seta smooth and tiny. Following segment with two long setae externally and a group of 5 + 2 setae internally on segment. Third segment with three long outer extero-distal setae, two medio-distal setae (γ-seta smooth) and two intero-distal setae (one long, other short). Terminal segment with two strong claws and three setae situated more internally on segment. Mxl (Fig. 7 C). Palp 2 - segmented. First segment with four setae distally, three plumose, one smooth. Terminal segment with two claws and four setae. Third endite with several claws and several setae. L 5 (Fig. 7 E). Protopod of with one a, one b, and one d-seta. Endopod with three apical setae unequal in L. L 6 (Fig. 7 F) 5 - segmented. Penultimate segment with posterior margin sometimes undivided. Basal segment with d 1 seta. All setae (e, f, and g) present on endopod. Terminal segment with one strong claw, only lightly serrated. Terminal claw 1.3 times as long as three terminal segments combined. L 7 (Fig. 7 G) 5 - segmented, penultimate segment subdivided. Basal segment with d 1 and d 2 setae shorter than dp, all three setae serrulate. Setae e and f missing, while seta g long and serrulate. Terminal segment with one short and two long setae. Length ration between h 1, h 2 and h 3 setae: 1: 2.7: 2.7. UR (Fig. 7 I) with stout ramus and both claws and setae present. Posterior seta exceeding distal margin of ramus. Anterior claw slightly longer than posterior one. L ratio between anterior margin, anterior and posterior claws equaling: 1.4: 1.2: 1. Both claws serrated. Attachment of UR (Fig. 7 H) with one dorsal and one ventral branch. Genital field rounded without any projections.
discussion
Remarks and affinities. Typhlocypris (Pseudocandona) pratensis (Hartwig, 1901) is relatively common species in Europe (Meisch, 2000), with a wide ecological tolerance and often unequal proportion of males and females in its populations. It belongs to the compressa - group of the genus, defined by the presence of 5 + 2 setae on the inner side of the second segment of the Md-palp, a 5 - segmented L 7, and the seta h 1 on the terminal segment of the same appendage much longer than the segment itself. Although we have not found males, we positively identify the species collected from Korea as P. pratensis because of the valve shape, morphology of the UR, and the length of G 2, which is longer than the terminal segment. This last feature clearly distinguishes T. (P.) pratensis from, T. (P.) compressa (Koch, 1838), T. (P.) insculpta (Müller, 1900), T. (P.) regisnikolai (Karanovic & Petkovski, 1999), and T. (P.) sucki (Hartwig, 1901) where the G 2 on the female A 2 is considerably shorter. Only T. (P.) albicans (Brady, 1864) has the same length of the G 2 claw as T. pratensis, but these two species can easily be distinguished by the carapace shape, because the posterior end is much higher in T. pratensis, and T. albicans is more elongated in lateral view.
materials_examined
Material examined. One female (NIBRIV 0000270972) dissected on one slide (shell not kept) from Gangwon-do, South Korea, 2011 / 04 / 23, collectors Choi & Kim. One female (NIBRIV 0000270973) dissected on one slide, shell on SEM stub, one female (NIBRIV 0000270 974) in alcohol from Banbyeoncheon (River), Andong, Gyeongsangbuk-do, South Korea, 36 ̊ 32.386 ′ N 128 ̊ 49.036 ′ E, 2012 / 04 / 05, collector I. Karanovic.