Candoninae 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 : 58-59

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/03A26772-6B3B-8625-FC1D-FE646CB5F887
treatment provided by	Felipe
scientific name	Candoninae Kaufmann, 1900
status

Treatment

Subfamily Candoninae Kaufmann, 1900 Cryptocandona sp. ( Figs 3–6 View Fig View Fig View Fig View Fig )

Material examined. ZIHU 3912 View Materials , 1 female, site C ( Table 1, Fig. 1 View Fig ), 5 November 2005, dissected, soft parts mounted on 16 slides; ZIHU 3913 View Materials , 1 female, same site, 8 October 2005, soft parts mounted on 14 slides; ZIHU 3914 View Materials , 3915 View Materials , 2 females, same site, 6 November 2007, mounted on stubs for SEM observation .

Description of female. Carapace ( Figs 3A, B View Fig , 4A, B View Fig ) 0.97–0.99 mm long, 0.44–0.47 mm high (n =4); elongate in lateral view, highest just behind mid-length, broadly round- ed at anterior and posterior ends, slightly concave ventrally; conspicuously narrow in dorsal view, pointed at anterior and posterior ends. Valves very thin, transparent, with pearly luster; short, fine setae present on anterior, posterior, and ventral margins; other parts of surface with a few fine setae.

Antennule ( Fig. 4C View Fig ) seven-segmented. First two podomeres fused, with two dorsal setae and two long apico-ventral setae. Third podomere quadrate, with apico-dorsal seta. Fourth podomere quadrate, with apico-ventral seta. Fifth and sixth podomeres both quadrate; each with two long apico-dorsal setae and one apico-ventral seta. Seventh podomere elongate, with two long, one medium-long, and one short apical setae. Eighth podomere elongate and slender, with one long and two shorter apical setae and aesthetasc ya.

Antenna ( Fig. 4D View Fig ) four-segmented. First podomere with two antero-proximal setae and one long apico-ventral seta. Second podomere with one apico-ventral seta, aesthetasc Y, and exopodite (Exo); exopodite consisting of one long and two very short setae. Third podomere with long G 1 and G 3, shorter G 2, two apical setae, two mid-dorsal setae, four midventral setae, apico-ventral aesthetasc y 2, and postero-vental aesthetasc y 1. Fourth podomere with GM, shorter Gm, one apical seta, and aesthetasc y 3.

Mandible ( Fig. 5A, B View Fig ) consisting of coxal plate and foursegmented palp. Coxal plate with seven strong teeth and several setae of various lengths at distal end, and one antero-lateral plumose seta (plumage not shown in Fig. 5A, B View Fig ). First podomere with vibratory plate (Exo) externally, one long and one short inner-distal plumose setae, one long antero-distal seta, and alpha seta. Second podomere with group of three setae, one medium-long and one beta innerdistal setae, and two outer apical setae. Third podomere with three outer middle setae, one outer apical seta, one mid-apical gamma seta, two medium-long setae, and two short inner apical setae. Fourth podomere with one distally plumed claw, one terminal claw, and one medium-long and one shorter apical setae.

Maxillula ( Fig. 5C View Fig ) with elongate vibratory plate ( Fig. 5D View Fig ), three masticatory processes, and two-segmented palp.

Maxilliped ( Fig. 5E View Fig ) with non-segmented palp, vibratory plate, one antero-proximal seta, one antero-distal seta, and one postero-distal seta. Palp with three apical setae. Vibratory plate (Exo) with two filaments. Masticatory process slender, with numerous setae.

Walking leg ( Fig. 6A View Fig ) five-segmented. Terminal claw (h 2) slender and long.

Cleaning leg ( Fig. 6B View Fig ) four-segmented. First podomere with three setae. Second podomere with one apical seta. Third podomere with one apical and one middle setae. Fourth podomere with one long (h 3), one medium-long (h 2), and one shorter (h 1) setae.

Uropodal ramus ( Fig. 6C View Fig ) with anterior seta and posterior seta. Two terminal claws with tiny denticles.

Remarks. Positive identification of our female specimens is difficult, as examination of male copulatory organs is necessary. Considering 12 species recognized in Cryptocandona (cf. Meisch 2000), nevertheless, our material is morphologically similar to C. reducta ( Alm, 1914) ( Alm 1914; Meisch 2000) and C. brehmi ( Klie, 1934) ( Namiotko and Danielopol 2002) in the overall proportions of the soft parts and carapace shape. Our specimens, however, exhibit a mix of character states from these two species ( Table 2): the carapace length in our specimens is 0.97–0.99 mm (0.90– 1.02 mm in C. reducta , 0.82 mm in C. brehmi ); the number of setae on left and right antennule is symmetrical (symmetrical in C. reducta , asymmetrical in C. brehmi ); GM and G 3 on the antenna are shorter (longer in C. reducta , shorter in C. brehmi ) than 0.8 times EI; and the genital lobe protrudes slightly (protrudes slightly in C. reducta , flat in C. brehmi ). Furthermore, in our specimens, the posterior seta on the uropod is relatively short; it is 12–14% the length of the anterior margin of the caudal ramus, while it is 16–25% and 15–16%, respectively, in C. reducta and C. brehmi . Cryptocandona reducta is widely distributed in Europe, with some populations reproducing sexually ( Klie 1925, 1940; Pax 1942; Hartmann et al. 1999) and others solely parthenogenetically (e.g., Meisch 2000); C. brehmi is only known from the type series, consisting of two juveniles and two females, from a pool in a cave at “Hirowagara”, Sakuho-machi, Nagano Prefecture, Japan ( Klie 1934).