Biapertura sibirica ( Sinev, Karabanov et Kotov, 2020 )

Garibian, P. G. & Chertoprud, E. S., 2022, First records of Cladocera and Copepoda from Chukchagir Lake and its basin (Khabarovsk Territory, Far East of Russia), Arthropoda Selecta 31 (1), pp. 10-18 : 15

Biapertura sibirica ( Sinev, Karabanov et Kotov, 2020)

Fig. 3 a–g .

PARTHENOGENETIC FEMALE. Length of examined individual 0.84 mm, height 0.47 mm. Body ( Fig. 3 a ) ovoid, moderately compressed laterally, maximum height approximately at middle. Dorsal and posterior margin of valves convex, ventral margin weakly convex. Anteroventral, Postero-dorsal and postero-ventral angles broadly rounded. Postero-dorsal angle with two denticles ( Fig. 3 c–d ), ventral margin with row of setae. Head relatively small, with ocellus and eye, rostrum pointed down, relatively narrow. Head shield with two connected major head pores and two lateral head pores ( Fig. 3 b ). Postabdomen ( Fig. 3 e ) large, subrectangular, moderately high. Ventral margin straight, distal margin almost straight, distal angle rounded. Dorsal margin slightly convex, straight in postanal portion and weakly concave in anal portion. Postanal angle not defined, preanal angle well exspresed. Postanall margin with 13 well-developed deticles, lateral portion with 14 clusters of setulles. Postabominal claw moderately long, basal spine long and slender. Limb I with IDL with three seta, seta 1 large and broad, claw-like, seta 2 and 3 with thin setulae in distal part, ODL with one long setulaeted setae ( Fig. 3 f–g ).

COMMENTS. B. sibirica is wide distributed in NorthEast Palearctic. Previously this specie regarded as form of Biapertura affinis (Leydig, 1860) , but a detailed recent revision confirmed its species status [ Sinev et al., 2020] within the genus Biapertura Smirnov, 1971 [Sinev, 2020].

Figures

Fig. 3. Parthenogenetic females of Biapertura sibirica (a–g) from Chukchagir Lake, 300 m from mouth of the Bikkitckan River: a — lateral view; b — posterior portion of head shield; c–d — postero-ventral margin of valves; e — postabdomen; f–g — limb I and IDL of limb I; Coronatella rectangula (h–l) from Chukchagir Lake, 300 m from mouth of the Bikkitckan River: h — lateral view; i — posteroventral margin of valves; j — postabdomen; k–l — limb I and IDL of limb I. Scale bars: 0.1 mm. Рис. 3. Партеногенетические самки Biapertura sibirica (a–g) иЗ оЗера Чукчагирское, 300 м от устьЯ реки Биккиткан: a — вид сбоку; b — ЗаднЯЯ часть головного Щита; c–d — Задне-нижний край створки; e — постабдомен; f–g — торакопод I и внеШнЯЯ дистальнаЯ долЯ торакопода I; Coronatella rectangula (h–l) иЗ оЗера Чукчагирское, 300 м от устьЯ реки Биккиткан: h — вид сбоку; i — Задне-нижний край створки; j — постабдомен; k–l — торакопод I и внеШнЯЯ дистальнаЯ долЯ торакопода I. МасШтабнаЯ линейка: 0,1 мм.