Perla persica Zwick, 1975

Teslenko, Valentina A., Palatov, Dmitry M. & Semenchenko, Alexander A., 2024, Overview of the Caucasian Perla Geoffroy, 1762 (Plecoptera: Perlidae) based on morphological and molecular data with description of two new species, Zootaxa 5507 (1), pp. 1-56 : 10-17

Perla persica Zwick, 1975

Figs. 24‒49

Zwick, 1975: 392‒394, figs. 19‒23 (original description);

Zwick, 1978: 236 (synonymy proposed);

Sivec & Stark, 2002: 13 (as Perla caucasica ).

Remarks. In our collections, a few specimens from Iran and North Ossetia-Alania correspond to the original description of P. persica in Zwick (1975). Zwick (1978) considered the possibility of a synonymy between P. persica and P. abbreviata , but without studying the holotype of P. abbreviata , this question remained unresolved. Nevertheless, both species were proposed to be considered synonyms of P. caucasica based on a comparison of the eggs of topotype specimens from Alborz with the eggs of P. caucasica from the Caucasus ( Sivec & Stark 2002). Notably, the female subgenital plate of the P. persica ( Fig. 30 ) and P. caucasica specimens, as well as the chorion structures ( Figs. 36‒41 ) and larvae appearance ( Figs. 42‒49 ), are very similar, except for the body color of P. persica adults, which is much darker and more contrasting ( Figs. 24‒27 ) than that of P. caucasica . Additionally, males of P. persica are brachypterous ( Fig. 24 ), whereas the wing length of P. caucasica males is usual. Upon closer examination of the male genitalia of P. persica , several morphological differences were discovered that are important and diagnostic. Perla persica and P. caucasica can be clearly distinguished by the male hemitergal structure and chaetotaxy of the penis. The shape of the hemitergal hook of P. caucasica is tapered towards its rounded apex ( Figs. 2, 5 , 7 ). The hemitergal hook of P. persica is distinguished by a plump, rounded rectangular tip in profile and, at the same time, an almost spatula-like flat shape in dorsal view ( Figs. 28‒29, 31‒32 ). The penis of P. caucasica is armed with two brushes of setae: a typical apical brush and an additional small ventral brush of tiny setae ( Figs. 10 , C‒D). In contrast, the penis of P. persica bears a single apical brush of setae at the apex ( Figs. 32‒35 ). In our opinion, these significant morphological differences indicate that P. persica should be considered a valid species rather than a synonym of P. caucasica . Reinstating the original name of Perla persica from synonymy on external and internal morphological features of males is proposed.

DNA barcoding. GenBank accession numbers are PP216463-PP216464 and PP216468-PP216469. According to phylogenetic relationships, P. persica and P. caucasica would be monophyletic if not for the specimen P. caucasica TVA 364 from Adygea, which fell into the clade of P. persica . The DNA barcode of this specimen was identical to P. persica TVA 199 therefore the minimum interspecies distances were zero ( Table 2 ). Four methods of species delimitation united both species into a single mOTU ( Fig. 160 ). This indicates that P. persica and P. caucasica are closely related species and have a recent common ancestor. Further molecular study with nuclear markers is needed to resolve the discrepancy between morphological and molecular characters.

Material examined. Iran: 3♂, 4♀, 5 larval ♂, 2 larval ♀, 2 exuvia, Central Alborz, Mazandaran province, Zarrin Kamar village, Nurrud River , Haraz River Basin , altitude 1900 m above sea level, 36.205033 N, 51.82055 E, 25. VI. 2019, coll. D. Palatov. Russia, Republic of North Ossetia-Alania : 2♂, 2♀, 3 exuvia, Alagirsky District, Komdon River, in the area of the Tsey Gorge , Tseydon River Basin , Terek River Basin , altitude 1832 M above sea level, 42.803514 N, 43.933395 E; 25.07.2021, coll. D. Palatov ; 1 larva, Prigorodny District, Mairamadag River, Terek River Basin , altitude 690 m above sea level, 42.993308 N, 44.49815 E, coll. D. Palatov.

Distribution. Iran: Alborz Mountains, Fars, Teheran, and Mazandaran Provinces. Perla persica was found in the streams and rivers of the northern slopes of the Greater Caucasus, Russia, and North-Ossetia-Alania for the first time ( Fig. 159 ). The species was found in the Komdon River, which flowed down steeply by waterfalls on the dry slope of the Tsey Gorge in a narrow bushy ravine. The river has a width of 3−4 m, a bottom with pebbles and stones without fouling, water current of 0.3−0.7 m /s, and an altitude of 1700−1900 m above sea level.

The ecological differences between P. persica and P. caucasica are currently difficult to assess due to the scarcity of information about their environments. In our collections, both species were found together in the Mairamadag River ( Table 1 ). However, according to our collections and the original description ( Zwick 1975), P. persica inhabits mainly an altitude of 1770–1900 m above sea level. Perla caucasica , as we assume, is a relatively low-mountain and warm-water species and has been recorded at altitudes of up to 700 m.

Figures

FIGURE 159. The map of the Perla species distribution in Caucasus according to our data. Perla caicasica—pink, P. persica— green, P. kiritshenkoi—blue, P. schapsugica sp. nov.—white, P. pallida—yellow, and P. palatovi sp. nov.—red.

FIGURE 160. Ultrametric Bayesian inference (BI) tree inferred from the cytochrome c oxidase I (COI) gene fragment and the results of species delineation of the genus Perla Geoffroy, 1762, and out-group Kamimuria coreana. Bayesian posterior probabilities (> 0.7) are noted above the tree nodes. Vertical bars correspond to molecular operational taxonomic units by ASAP, mPTP, GMYC, and BINs of BOLD. The color of the specimens indicates the development stage of stoneflies in accordance with the legend, while the sequences obtained in this study are in bold.

FIGURES 24‒27. Perla persica Zwick, 1975. Central Alborz, Iran, Mazandaran province, Zarrin Kamar village, Nurrud (Noor?) River, Haraz River Basin. 24. Habitus, male, dorsal. 25. Habitus, female, dorsal. 26. Head and pronotum, male, dorsal. 27. Head and pronotum, female, dorsal.

FIGURES 28‒31. Perla persica Zwick, 1975. CentralAlborz, Iran, Mazandaran province, Zarrin Kamar village, Nurrud (Noor?) River, Haraz River Basin. 28. Male abdominal tip, dorsal. 29. Mesal field with longitudinal serrated ridges and hemitergal hooks covered with sensilla basiconica, dorsal, cleared. 30. Female abdominal tip, dorsal. 31. Mesal field with longitudinal serrated ridges and hemitergal hooks covered with sensilla basiconica, lateral, cleared.

FIGURES 32‒35. Perla persica Zwick, 1975. Central Alborz, Iran, Mazandaran province, Zarrin Kamar village, Nurrud (Noor?) River, Haraz River Basin. 32. Mesal plate, hemitergal hooks, and artificially everted penis, cleared, dorsal. 33. Penis, ventral. 34. Chaetotaxy of the penis, dorsal. 35. Chaetotaxy of the penis, ventral.A. Densely arranged longitudinal rows of heavy sclerotized serrate sclerites. B. The longitudinal rows of leaf-shaped scales with small spines. C. Pointed brown spines in the apical brush.

FIGURES 36‒41. Perla persica Zwick, 1975. Central Alborz, Iran, Mazandaran province, Zarrin Kamar village, Nurrud (Noor?) River, Haraz River Basin. Egg. 36. Appearance with mushroom-shaped anchor plate and micropylar row, lateral. 37. Appearance without anchor, with micropylar row, lateral. 38. Mushroom-shaped anchor plate covered with globular bodies, lateral. 39. Collar, lateral. 40. Chorion structure. 41. Micropyles, orifices with thin raised rims.

FIGURES 42‒43. Perla persica Zwick, 1975. Central Alborz, Iran, Mazandaran province, Zarrin Kamar village, Nurrud (Noor?) River, Haraz River Basin. Larvae, males, habitus, dorsal. Variation of the pattern.

FIGURES 44‒49. Perla persica Zwick, 1975. Central Alborz, Iran, Mazandaran province, Zarrin Kamar village, Nurrud (Noor?) River, Haraz River Basin. Larva. 44. Left and right mandibles, ventral. 45. Left lacinia, galea, maxillary palpus, ventral. 46. Left hind leg, dorsal. 47‒49. Chaetotaxy of the left cercus, lateral. 47. Basal cercal segments. 48. Middle cercal segments. 49. Apical cercal segments.

FIGURES 1‒6. Perla caucasica Guérin-Méneville, 1843. Caucasus: Russia, Adygea, Belaya River; Republic of North Ossetia- Alania, Mairamadag River. Georgia, Sukhum District, Kelasuri River. 1. Habitus, male, dorsal. 2. Male abdominal tip, dorsal. 3. Head and pronotum, male, dorsal. 4. Female subgenital plate, ventral. 5. Mesal field with longitudinal serrated ridges, dorsolateral, and hemitergal hooks covered with sensilla basiconica, lateral, cleared. 6. Hemitergal hooks covered with sensilla basiconica, caudal, cleared.

FIGURES 7–10. Perla caucasica Guérin-Méneville, 1843. Caucasus, Russia, Adygea, Belaya River. 7. Hemitergal hooks and artificially everted penis, dorsal. 8. Penis, ventral. 9. Chaetotaxy of artificially everted penis, dorsal. A. Densely arranged longitudinal rows of heavy sclerotized serrate sclerites on the tube of the penis. B. Scales with small spines. 10. Same, ventral. C. Tiny spines in the ventral brush. D. Pointed brown spines in the apical brush.