Pseudocandona abei, Smith & Janz, 2008
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publication ID |
https://doi.org/ 10.1080/00222930802361030 |
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persistent identifier |
https://treatment.plazi.org/id/6530807D-EC07-FF97-AC3C-FC22FC07FF11 |
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treatment provided by |
Carolina |
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scientific name |
Pseudocandona abei |
| status |
sp. nov. |
Pseudocandona abei sp. nov.
( Figures 26A,B View Figure 26 , 27 View Figure 27 and 28 View Figure 28 )
Type locality
Southern basin of Lake Biwa, north shore of Karasuma Peninsular, locality 81 (35 ° 04921.00N, 135 ° 56908.30E), depth 0.1 m, around root mat below willow tree.
Type material
Holotype LBM 1430003332 View Materials , female, appendages mounted on a glass slide, valves stored in a micropalaeontological cavity slide . Paratype LBM 1430003333 View Materials , female, appendages mounted on a glass slide, valves stored in a micropalaeontological cavity slide . Paratype LBM 1430003331 View Materials , female, whole carapace stored in a micropalaeontological cavity slide .
carapace, dorsal view, anterior to right (LBM 1430003339); (G) detail of carapace surface (LBM 1430003338). (H–J) Physocypria nipponica . (H) Whole carapace, right lateral view (LBM 1430003342); (I) whole carapace, left lateral view (LBM 1430003343); (J) whole carapace, dorsal view, anterior to left (LBM 1430003344). Scale bar below G represents 398 Mm for A and B, 526 Mm for C and D, 294 Mm for E and F, 43 Mm for G, and 329 Mm for H–J.
Derivation of name
Named in honour of the late Professor Katsumi Abe, Shizuoka University.
Diagnosis
Bean-shaped carapace in lateral view, with equally rounded anterior and posterior margins, gently rounded dorsal margin and slightly concave ventral margin. Maximum height at mid-length. An2 claw G2 less than half the length of G1 claw, setae z1–3 very reduced and short. L7 four-segmented, with long g seta and very long h1 seta, approximately half the length of setae h2 and h3. UR thick, robust and stubby, claw Ga approximately equal length to dorsal margin of ramus, Sp seta long.
Description
Carapace length 672–722 Mm, height 378–403 Mm, H/L50.56. Carapace bean-shaped with anterior and posterior margins equally rounded. Dorsal margin smoothly rounded, ventral margin slightly concave. Inner calcified lamella slightly thicker along anterior margin compared with posterior margin. Valves smooth and white.
An1 with eight segments, first two of which fused together forming one large article. First segment with one long dorsal seta. Second segment with one seta on dorsal margin and two long sub-apical setae on ventral edge. Third segment quadrate with one dorsal–apical seta. Fourth segment quadrate with no setae. Fifth segment quadrate with two long dorsal–apical setae and one tiny ventral–apical seta. Sixth segment elongate with two long dorsal–apical setae and one short ventralapical seta. Seventh segment with three long and one short apical setae. Final segment with one long, one medium length and one short setae, and aesthetasc ya.
An2 with very slender and relatively short Y aesthetasc. Setae z1–3 all reduced, not reaching past the end of final segment. Claw G2 approximately 45% the length of claw G1; claws G1 and G3 relatively elongate. Claw Gm slender and approximately 60% length of claw GM.
Md palp with short and very slender alpha seta. Beta seta short and slender with 3+1 setae. Gamma seta slender, smooth and long. Coxa well-developed with seven teeth.
Mx palp two-segmented with elongate first segment supporting four apical setae. Second segment small and quadrate, with three long and two short apical setae.
L5 with well-developed endite supporting approximately 14 setae. Branchial plate reduced to two setae. Palp large and inflated with three short, terminal setae.
L6 five-segmented, with first segment bearing relatively long d1 seta. Setae e and f of second and third segments respectively, both equal in length to next respective segment. Fourth segment with g seta twice as long as fifth segment. Fifth segment with short h1 seta, tiny h3 seta and well-developed claw.
L7 four-segmented, first segment with d1 and d2 setae both shorter than dp seta. Third segment with very long g seta. Final segment small and quadrate, with h1 seta approximately half the length of h2 and h3 setae.
UR thick and robust, ramus with straight ventral margin and slightly curved dorsal margin. Claw Ga slightly longer than Gp, Gp approximately 64% length of ramus. Seta Sp almost four times longer than Sa.
Remarks
This species comes closest to Pseudocandona geratsi Broodbakker, 1983 , known from Venezuela, in terms of the general carapace shape and morphology of the appendages. Pseudocandona abei sp. nov. differs in that the maximum height of the carapace is at mid-length (towards the posterior in P. geratsi ), the height-tolength ratio equals 0.56 (0.54 for P. geratsi ), the UR is significantly shorter and stubbier (relative to the length of the terminal claws), and the h1 seta on the L7 is much longer at half the length of seta h2 and h3 (h1 is much shorter in P. geratsi ). The carapace shape also resembles that of Pseudocandona szoecsi (Farkas, 1958) , but P. szoecsi has notably unequal valve shape, the hinge is less curved and almost straight anteriorly of mid-length, maximum height is posterior of mid-length, the UR is significantly longer (relative to the length of the terminal claws), and the L7 h1 seta is reflexed and much shorter compared with P. abei sp. nov.
This species was found in small numbers in the littoral zone of the Karasuma Peninsula on a peaty substrate. We have also recovered this species from Otsu, Shiga Prefecture (34 ° 58905.40N; 135 ° 56931.20E) and Kanazawa, Ishikawa Prefecture (36 ° 30946.10N; 136 ° 38932.60E). In Otsu it was found in a slowly flowing stream approximately 3 km south-east, and 45 m higher, of the lake. The stream had many emergent marcophytes and a muddy substrate with lots of leaf litter. In Kanazawa it was found on a muddy substrate in a marshy area covered with reeds in very shallow water (depth 2–3 cm). No males, or evidence of males (i.e. spermatozoa in the females) were found. Locality 81 in Figure 1 View Figure 1 .
Subfamily CYCLOCYPRIDINAE Kaufmann, 1900
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