Cyclocypridinae Kaufmann, 1900

Hiruta, Shimpei F. & Mawatari, Shunsuke F., 2013, Ostracods (Crustacea) from Sarobetsu Marsh, Northern Hokkaido, Japan: Taxonomy and Phenology with Description of Pseudocandona tenuirostris sp. nov., Species Diversity 18, pp. 57-74 : 67-68

publication ID	https://doi.org/ 10.12782/sd.18.1.057
publication LSID	lsid:zoobank.org:pub:CF9B52C8-3340-417A-BDEB-8DAB70B7A99E
persistent identifier	https://treatment.plazi.org/id/03A26772-6B30-862A-FF6E-F9716A1EF783
treatment provided by	Felipe
scientific name	Cyclocypridinae Kaufmann, 1900
status

Treatment

Subfamily Cyclocypridinae Kaufmann, 1900 View in CoL Physocypria nipponica Okubo, 1990

( Figs 12–16 View Fig View Fig View Fig View Fig View Fig )

Physocypria nipponica Okubo, 1990: 3 , figs 1E–H, 2B, E, F; Smith and Janz 2008: 2916, figs 26H–J, 32A–C.

Material examined. ZIHU 3909 View Materials , 1 male, site E ( Table 1, Fig. 1 View Fig ), 6 August 2005, dissected, soft parts mounted on 19 slides; ZIHU 3910 View Materials , 1 female, same site, 6 August 2005, dissected, soft parts mounted on 18 slides; ZIHU 3911 View Materials , 1 male, same site, 19 June 2007; mounted on stubs for SEM observation .

Description of male. Carapace ( Figs 12A, B View Fig , 13A, B View Fig ) 0.57 mm long, 0.37 mm high (ZIHU 3909), 0.56 mm long, 0.39 mm high (ZIHU 3911). Dorsal margin of carapace more or less strongly arched. In dorsal view, left valve overlaps right valve at both ends. In frontal view, carapace distinctly asymmetrical; right valve overlaps left valve with conspicuous dorsal hump. Antero- and postero-ventral margins of right valve each with row of pustules; pustules situated on list formed by outer lamella of valve, rather than on selvage ( Fig. 12C, D View Fig ).

Antennule ( Fig. 13C View Fig ) seven-segmented. First two podomeres fused, with two long apico-ventral setae and one mid-dorsal seta. Third podomere with one apico-dorsal seta and externo-ventral Rome organ. Fourth podomere quadrate, with one apico-ventral seta and one apico-dorsal seta. Fifth podomere quadrate, with two apico-ventral setae and one very long and one long apico-dorsal setae. Sixth podomere quadrate, with two apico-ventral setae and two very long apico-dorsal setae. Seventh podomere quadrate, with two very long apico-ventral setae and two very long and one medium-long apico-dorsal setae. Eighth podomere elongate, with one claw, two long and one short apical setae, and aesthetasc ya.

Antenna ( Fig. 13D View Fig ) five-segmented. Penultimate segment subdivided. First podomere with two proximal setae (not depicted in Fig. 13D View Fig ) and one long apico-ventral seta. Second podomere with one apico-ventral plumose seta and mid-ventral aesthetasc Y. Exopodite (Exo) situated on proximal part of second podomere; consisting one long and two short setae. Third podomere with one long and one shorter apico-ventral setae, two apico-dorsal setae, and two apical male bristles (t2 and t3); natatory setae (5+1) very long, extending beyond tips of terminal claws by ca 70% of their total length. Fourth podomere with long G 1 and G 3, shorter G 2, long apical seta, and mid-ventral seta. Fifth podomere with slender GM, shorter Gm, mid-ventral setae, and aesthetasc y 3.

Mandible ( Fig. 14A View Fig ) consisting of coxal plate and 4-segmented palp. Coxal plate with seven teeth and antero-lateral seta. First podomere of palp with external vibratory plate (Exo), one inner seta and two plumose setae, and simple alpha seta. Second podomere of palp with two outer apical setae. Setal group on second podomere with three long plumose setae, one inner seta, and one plumose beta seta. Third podomere of palp with three outer apical setae, three midapical setae, and smooth externo-distal gamma seta. Fourth podomere of palp apically with two setae, one short seta, and one plume-tipped claw.

Maxillula ( Fig. 14B View Fig ) with elongate vibratory plate, three masticatory processes, and two-segmented palp.

Maxilliped ( Fig. 14D, E View Fig ) with asymmetrical clasping organ, vibratory plate (Exo), one long-plumed and two short antero-proximal setae, one plumose antero-apical seta, and one short postero-apical seta. Finger of right clasping organ ( Fig. 15D View Fig ) strongly developed, apically with one long process and one short, tooth-shaped process. Left finger ( Fig. 15E View Fig ) hook-shaped, distal end of finger curved outward, proximal part with two setae. Vibratory plate with six filaments. Masticatory process with numerous apical setae and filaments.

Walking leg ( Fig. 14F View Fig ) five-segmented. Second podomere with conspicuously long antero-apical seta. Terminal claw (h 2) slender, curved.

Cleaning leg ( Fig. 15A View Fig ) four-segmented. First podomere with three setae. Third podomere with one seta in middle. Fourth podomere with one long (h 3) and two short (h 1, h 2) apical setae.

Uropodal ramus ( Fig. 15B View Fig ) with two parallel rows of setulae, anterior seta, and well-developed posterior seta situated in relatively distal part of ramus. Two terminal claws lacking denticles.

Outer process (a) of hemipenis slender slightly curved, longer than inner process (b) ( Fig. 15C View Fig ). Outer edge of peniferum stout at about middle part. The labyrinth of spermiduct well developed and stout at proximal part. The brusa complex (e) pointed.

Zenker’s organ ( Fig. 16 View Fig ) with 5+2 internal rings of spines.

Description of female. Carapace 586 µm long, 394 µm high (ZIHU 3910). Carapace similar to that of male, but slightly larger.

Antenna ( Fig. 13E View Fig ) four-segmented. First and second podomeres and natatory setae similar to those of male. Third podomere with long G 1 and G 3, shorter G 2, one long and two shorter apical setae, one medium-long and one short midventral setae, and one mid-dorsal seta. Fourth podomere with GM, Gm, one mid-ventral seta, and aesthetasc y 3.

Palp of Maxilliped ( Fig. 14C View Fig ) simple, non-segmented, with three apical setae.

The other parts of female similar to male.

Remarks. Our specimens from Sarobetsu Marsh generally agree with the original description of Physocypria nipponica (cf. Okayama, Okubo 1990) and the subsequent report from Lake Biwa ( Smith and Janz 2008), but show some minor differences: the distal processes of the hemipenis seem to be less curved in the Sarobetsu specimens than in the specimens from Okayama and Lake Biwa; the widest position of the peniferum appears slightly different between our specimens and the illustrations by Okubo (1990) and Smith and Janz (2008); the clasping organs ( Fig. 15D, E View Fig ) are more slender than in the Lake Biwa specimens than in our specimens; the left clasping organ ( Fig. 15E View Fig ) has a more slender apical hook-like process in Lake Biwa specimens than in our specimens; and there are two setae distally on the left clasping organ in our specimens, while only one seta is present in the Lake Biwa specimens. These differences are so slight that, for now, we refer the Sarobetsu population to Ph. nipponica .

Smith and Janz (2008) mentioned the similarity between Ph. nipponica and Ph. kraepelini Müller, 1903 , pointing out the necessity of further investigation to confirm the possible synonymy of these species. The description of Ph. kraepelini which distributed around Palearctic region by Meisch (2000) indicates that the structure of the hemipenis is different between the two taxa. In Ph. kraepelini , the peniferum is quite angular and the outer edge is stout proximally. However, there is no information on variation in the outer edge of hemipenis in either of these two taxa. For the time being, we regard Ph. nipponica is a valid species.