Claassenia brachyptera Brinck, 1954

Teslenko, Valentina A., 2024, Eggs of Perlidae (Insecta, Plecoptera) of the Russian Far East, Zootaxa 5551 (1), pp. 91-115 : 96

Claassenia brachyptera Brinck, 1954

Figs. 19−29

Material examined. Russia, Far East, Amurskaya Oblast : 1♀, Zeya River , Amur River basin, Zagan village , 02.08.2005, coll. T. Tiunova; 1♀, Zeya River, Sokhatino village , 19.07.2006, coll. T. Tiunova; 9♂, Zeya River, 1 km above the bridge near the Krasnoyarovo village , Amur River basin, 20.08.2004, coll. V. Teslenko; 3♂, 1♀, Bureya River , Amur River basin, 500 m below the Kulikovka village , 17.08.2003, coll. T. Tiunova; Primorsky Krai, 9♂, 12♀, Ussuri River , Amur River basin, below the Kamenka village , 07.05.1993, coll. V. Teslenko; 2♂, 1♀, the Bolshaya Ussurka River , Amur River basin, a channel below the Zvenigorodka village , 20.07.1996, coll. T. Tiunova.

Egg. Spindle-shaped ( Figs. 19−20 , 24−25 ), with a total length of 472−485 μm and an equatorial width of 370−380 μm (n=4). Collar is low, button-like, and shoulder-wide ( Figs. 20–21 ). Anchor is wide and short, cap-shaped; the anchor surface is studded with mushroom bodies distributed irregularly and densely towards the peripheral anchor margin ( Fig. 19 ). On an uncleaned egg, the anchor is covered with a sticky and gummy-like extrachorionic layer that makes it difficult to separate individual eggs ( Figs. 28–29 ). The anchor top is sunken and reveals several additional, sophisticated attachment structures, such as long papillary projections ( Fig. 24 ). The chorion surface is smooth or covered with weak hexagonal FCI’s; the pits are also weak and barely observable; the anterior pole is covered with more prominent follicle cell impressions ( Figs. 19−20, 22−23 ); and the shoulder surrounding the collar is smooth without FCIs ( Fig. 21 ). The extrachorionic layer of the uncleaned egg bears a single large (a few times larger than globular bodies on the anchor) mushroom body over each follicle cell impression on the anterior pole ( Figs. 25–26 ). Micropylar row subequatorial ( Figs. 19−20, 22 ), orifices set in small cup-like depressions with long, smooth, and open sperm guides extending from cup rims, canals slanted ( Figs. 22−23 ), and an extrachorion layer around orifices covered with rosettes that look like flowers ( Figs. 24, 27 ).

Comments. Eggs of other East Asian Claassenia Wu, 1934 species have not been studied sufficiently to compare them with those of C. brachypterа . However, the eggs of C. brachypterа have features similar to those of the Nearctic species C. sabulosa ( Banks, 1900) in habitus, size, structure of the chorion and micropyles, and the armature of the extrachorion layer on the anterior pole ( Stark & Sivec 2010). It should be noted that the range of C. brachyptera borders on another East Asian species, C. radiata Klapálek, 1916 . However, it is not possible to compare the eggs of these species since there is no egg description for C. radiata .

Distribution. East Palaearctic species is distributed widely in the temperate zone of the Asian mainland. This species occurs in Siberia (south of the Krasnoyarskiy Krai, Sayan Mountains, and Yenisei River) and the Far East (south of Yakutia, Amurskaya Oblast, Jewish Autonomous Oblast, Khabarovsk Krai, and Primorsky Krai).

Figures

FIGURES 19–23. Claassenia brachyptera Brinck, 1954. Russia, Far East, Primorsky Krai, Ussuri River, Amur River basin, below the Kamenka village. Egg, cleaned. 19. Habitus, cap-like anchor with small globular bodies, micropylar row, lateral. 20. Habitus, without anchor, lateral. 21. Collar and shoulder, dorsolateral. 22. Anterior pole, micropylar row, chorion structure, lateral. 23. Micropyle, orifice with sperm guide.

FIGURES 24–29. Claassenia brachyptera Brinck, 1954. Russia, Far East, Primorsky Krai, Ussuri River, Amur River basin, below the Kamenka village. Egg, uncleaned. 24. Habitus, extrachorionic layer, anchor with long papillary projections, lateral. 25. Habitus, anterior pole with extrachorionic layer, lateral. 26. Anterior pole with extrachorion layer bearing large mushroom bodies in each FCI, lateral. 27. Micropylar row, orifices surrounded by rosettes. 28. Anchor with a sticky and gummy layer, caudal. 29. Eggs connected via attachment anchor discs.