Ivanova (Kazus) N.A.1*, Kazakova D.M.1,2 2026. Taxonomic differences in the microstructure of the integument in males of the genus Nannocalanus Sars, 1925 (Calanoida: Calanidae) // Arthropoda Selecta. Vol.35. No.1: 26–31 [in English].
1 Shirshov Institute of Oceanology of the Russian Academy of Sciences, Nakhimovsky ave. 36, Moscow 117997 Russia.
2 Immanuel Kant Baltic Federal University, A. Nevsky str. 14, Kaliningrad 236041 Russia.
* Corresponding author
Natalia Ivanova (Kazus): ivanova.na@atlantic.ocean.ru, https://orcid.org/0009-0007-8162-3902
Diana Kazakova: kazakova.dm@atlantic.ocean.ru https://orcid.org/0009-0009-7505-3506
doi: 10.15298/arthsel.35.1.04
ABSTRACT. Males of three species of the genus Nannocalanus Sars, 1925 could be identified by the location of integumental pores on the abdomen. Males of two species from the northern Indian Ocean, Nannocalanus major Sewell, 1929 and N. sewelli Kazus, 2009, differ in the location of pores on the first and second segments of the abdomen. At the same time, both of them clearly differ from N. minor (Claus, 1863) from the Mediterranean Sea, which is the type species of this genus. The distinguishing feature for the former two species is one pair of pores on the dorsal side in the middle part of the second, third and fourth segments of the abdomen, which is missing in N. minor.
KEY WORDS: Nannocalanus, Calanidae, taxonomic differences, integumental pores.