Stenasellus, Dollfus, 1897

Jugovic, Jure, Malek-Hosseini, Mohammad Javad, Issartel, Colin, Konecny-Dupré, Lara, Kuntner, Matjaž, Fatemi, Yaser, Flot, Jean-François, Douady, Christophe J. & Malard, Florian, 2024, A second species of Stenasellus Dollfus, 1897 (Isopoda, Stenasellidae) from sulfidic groundwater of Iran described using morphological and molecular methods, European Journal of Taxonomy 968, pp. 256-274 : 268

Key to Central and Western Asian species of Stenasellus

1. Body dorsal surface setose; pleopod III–V endopods distally monolobate ........................................ ...................................................................... S. asiaticus Birstein & Starostin, 1949 ( Turkmenistan)

– Body dorsal surface smooth; pleopod III–V endopods distally bilobate .......................................... 2

2. Male pleopod II exopod segment II small, with less than five marginal setae, appendix masculina flat and swollen ....................................................................................................................................... 3

– Male pleopod II exopod segment II large, with more than eight marginal setae, appendix masculina elongate and distally acute ................................................................................................................ 4

3. Male pleopod II protopodite heart-shaped .......................... S. grafi Magniez & Stock, 2000 ( Oman)

– Male pleopod II protopodite trapezoid ............................ S. henryi Magniez & Stock, 2000 ( Oman)

4. Appendix masculina distolateral margin fringed with tiny setae ....................................................... ..................................................................................... S. messanai Magniez & Stock, 2000 ( Oman)

– Appendix masculina distolateral margin without setae .................................................................... 5

5. Antenna squama with three robust setae, male exopodite of pleopod I apical margin with a row of ~6 simple fine setae; pleopod II exopodite about 1.4 times as long as maximum width; pleopods III–V endopodite bilobed (<<half of their lengths) .......... S. vermeuleni Magniez & Stock, 2000 ( Oman)

– Antenna squama with two robust setae ............................................................................................ 6

6. Male pleopod I protopodite longer than its width, with 1–2 coupling hooks on its mesial margin, setae on exopodite of male pleopod I along mesial and apical margins, apical margin with a row of ≥~8 simple fine setae; male pleopod II exopodite ≥ 1.5 times as long as its greatest width; pleopods III–V endopodite bilobed (<<half of their lengths) .......................................................................... 7

– Male pleopod I protopodite shorter than its width, with a single coupling hook on its mesial margin, setae on exopodite of male pleopod I only along apical margin with a row of ~5 simple fine setae; male pleopod II exopodite subequal in length and greatest width; pleopods III–V endopodite bilobed (>> half of their lengths) .......... S. stygopersicus Jugovic, Malek-Hosseini & Issartel sp. nov. ( Iran)

7. Male pleopod I protopodite with a single coupling hook on its mesial margin, apical margin of pleopod I exopodite with a row of ~18 simple fine setae; male pleopod II exopodite>2 (~2.4) times as long as greatest width ..................................................................................................................... .......................... S. tashanicus Khalaji-Pirbalouty, Fatemi, Malek-Hosseini & Kuntner, 2018 ( Iran)

– Male pleopod I protopodite with a pair of coupling hooks on its mesial margin, apical margin of pleopod I exopodite with a row of ~8 simple fine setae; male pleopod II exopodite about 1.5 times as long as greatest width ................................... S. taitii Messana & Argano, 2019 ( Socotra, Yemen)