Cypria matzkeae, Smith & Janz, 2008

Smith, Robin J. & Janz, Horst, 2008, Recent species of the Family Candonidae (Ostracoda, Crustacea) from the ancient Lake Biwa, Central Japan, Journal of Natural History 42 (45 - 46), pp. 2865-2922 : 2913-2916

publication ID

https://doi.org/ 10.1080/00222930802361030

persistent identifier

https://treatment.plazi.org/id/6530807D-EC1B-FF92-AC09-FEEAFDD5FCC8

treatment provided by

Carolina

scientific name

Cypria matzkeae
status

sp. nov.

Cypria matzkeae sp. nov.

( Figures 26 View Figure 26 E–G, 29 and 30)

Type locality

Lake Biwa, south-western part of northern basin, locality 56 (35 ° 13954.10N; 135 ° 57949.60E), depth 2 m, substrate large pebbles, sand and gravel.

Type material

Holotype LBM 1430003340 View Materials , male, appendages mounted on a glass slide, valves stored in a micropalaeontological cavity slide . Allotype LBM 1430003341 View Materials , female, appendages mounted on a glass slide, valves stored in a micropalaeontological cavity slide . Paratype LBM 1430003338 View Materials , whole carapace stored in a micropalaeontological cavity slide (locality 42) . Paratype LBM 1430003339 View Materials , whole carapace stored in a micropalaeontological cavity slide (locality 42) .

Derivation of name

Named in honour of Dr Renate Matzke-Karasz (Ludwig-Maximilian University, Munich) in recognition of her work on the Cyclocypridinae .

Diagnosis

Carapace small, with straight ventral margin, highly arched dorsal margin, and maximum height at mid-length. Anterior margin slightly more inflated than posterior margin. Dorsal view very compressed. Carapace surface covered with many fine longitudinal striations. An2 with very long swimming setae, over twice the length of terminal claws. Male L5 palps asymmetrical, left palp terminating with smaller and more tightly curved hook compared with right. Hp a and b lobes approximately equal in length, both thickened, but lobe b thicker and more curved than a.

Description

Carapace length 520–566 Mm, height 309–350 Mm, H/L50.58–0.63. Ventral margin straight, dorsal margin highly arched, with maximum height at mid-length. Anterior margin more inflated than posterior margin. Left valve overlaps right valve. Dorsal view very compressed, anterior end pointed, posterior end rounded. Surface of valves covered with striations. Carapace colour yellow-brown with dark brown patches at mid-dorsal area and at anteroventral area.

An1 with eight segments, first two of which are fused together forming one large article. First segment with tiny Wouters organ on apical–dorsal edge. Second segment with long dorsal seta and two long apical–ventral setae. Third segment quadrate with one apical–dorsal seta. Fourth segment widens distally, with one apical–dorsal seta. Fifth segment with two long apical–dorsal setae and one short apical–ventral seta. Sixth segment with two long apical–dorsal setae and two short apical–ventral setae. Seventh segment with four long setae and one short, robust seta. Final segment with one long seta, two short setae and short aesthetasc ya.

An2 with long Y aesthetasc reaching to end of third segment. Male setae t2 and t3 long, slender with inflated, rounded ends.

Md palp large with four segments, final segment very elongate supporting three claw-like setae and one short seta.

Mx endites all short and stubby and palp two-segmented. First palp segment elongate and robust with three slender and one robust setae on outer apical edge, and one robust hirsute seta on inner edge. Final palp segment small and slightly elongate supporting three long, robust setae and one shorter, slender seta.

L 5 male palps asymmetrical. Left palp elongate, rectangle in shape with straight sides, terminating with tightly curved hook. Right palp thicker than left, with convex sides and terminating with wider and less tightly curved hook compared with left palp.

L6 first segment lacking both d1 and d2 setae. Second segment elongate with slender e seta reaching to end of third segment. Third segment with slender f seta, shorter than length of segment. Fourth segment with short g seta. Final segment with very short h3 seta, longer h1 seta and long claw h2.

L7 first segment with seta d1 twice length of seta d2, seta dp slender and shorter than second segment. Second segment with short, slender e seta. Third segment undivided with f seta at mid-length and with very tiny g seta. Final segment with short h2 seta, slightly longer h1 seta and long, reflexed hirsute h3 seta.

UR robust. Distal half of rami with two rows of setulae running along length. Seta Sp relatively long and inserted at mid-length position of rami. Seta Sa short and slender. Claw Gp approximately 80% length of Ga.

Hp with rounded base supporting two distal processes. Process a with slightly curved outer edge and strongly curved inner edge. Process b approximately equal in length to process a and hook shaped distally.

Remarks

Okubo (2004) reported a Cypria species from Lake Biwa, but did not illustrate or describe it. This species is similar to both Cypria exsculpta (Fischer, 1855) and Cypria turneri Hoff, 1942 in that all three species have long swimming setae on the An2 and have many fine longitudinal striations on the carapace. Cypria exsculpta differs in that the carapace is much more rounded in lateral view, is larger (760–890 Mm), and has a much more truncated b lobe on the Hp compared with C. matzkeae sp. nov. C. turneri is a similar size to C. matzkeae sp. nov. but is less elongate, has a different shaped right male L5 palp, and considerably differently shaped a and b lobes of the Hp.

Cypria matzkeae sp. nov. was found at 10 localities mostly in the southern area of the northern basin, ranging from 2 to 31.1 m depths. Localities 6, 42, 54, 56, 57, 61, 62, 63, 67 and 82 in Figure 1 View Figure 1 .

Kingdom

Animalia

Phylum

Arthropoda

Class

Ostracoda

Order

Podocopida

Family

Cyprididae

Genus

Cypria

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