Halisotoma boneti (Delamare, 1953)

Janion-Scheepers, Charlene, Potapov, Mikhail & Deharveng, Louis, 2023, New and little-known Isotominae (Collembola, Isotomidae) from South Africa, Zootaxa 5346 (3), pp. 337-347 : 344-345

Halisotoma boneti (Delamare, 1953)

Figs 36–39

Material: Western Cape, “Blouberg 3”, Bloubergstrand, near Cape Town , 33.804613°S, 18.46228°E, collected specimens with fine brush by floatation of pebble sand on beach, 11.06. 2019, coll. C. Janion-Scheepers & M. Potapov.

Material from Northern Hemisphere: Atlantic: Portugal, coast N of Porto, Vila Cha, Labruge beach (beach ca. 6 km S Vila do Conde), by hand on rocks temporarily covered by sea, 41.28705°N, 8.732358°W, 15.08.2012 (sample POR-033), coll. L. Deharveng, X. Sun, D.H. Wu, A. Bedos.

Mediterranean Sea : France, étang de Leucate, Aude (11), salt lake near the sea, 42.895685 °N, 3.028946°W, 20.06.1982 (sample 11-109), 31.05.1998 (sample 11-222), 10.05.2017 (samples 11-353, 11-354), coll. L. Deharveng and A. Bedos.

Black Sea: Crimea, near Yalta, Nikitski Botanic Garden, shingly beach, by floatation, 44.506°N, 34.24°E, 23.09.2021; Crimea, near Evpatoria, sand-shingly beach, by floatation, 45.187°N 33.428°E, 25.09.2021; all coll. M.Potapov, N.Kuznetsova.

Sea of Azov : Crimea, Kazantip, shelly beach, by floatation, 45.447°N, 35.846°E, 22.09.2021 ; Crimea , Arabatskaya Strelka, between Solyanoye and Kamenskoye, shelly beach, by floatation, 45.306°N, 35.46°E, 26.09.2021 ; all coll. M.Potapov, N.Kuznetsova.

Distribution. This is the first record for the Southern Hemisphere. Widely distributed in Mediterranean of the Northern Hemisphere ( Potapov 2001). Fjellberg (2009) also recorded this species from the Black Sea, Sea of Azov, and Central Atlantic (Canary Islands). It is recently registered in Baltic Sea ( Russia: Curonian Spit, A. Babenko, pers. comm.) where it is probably more rare.

Remarks. The species was clearly defined by Fjellberg (2009). In line with the new definition, our specimens have one expanded and serrated chaeta on tibiotarsi II (Fig. 38), enlarged and serrated lower branch of maxillary palp (Fig. 37), thickened A7 chaeta on tibiotarsi III (Fig. 36), two chaetae on retinaculum, and normal labial palp (b3–b4 guards set separately, and H chaeta not reduced). In all examined material (including from South Africa), the labial palp of this species has two medial processes: one in front of guard A and another on inner side of guard B (Fig. 39).

We also collected many individuals of a presumably new species of Halisotoma from Cape Point National Park, floatation of sand on beach, 14 June 2019, coll. C. Janion-Scheepers & M. Potapov. It shares with H. boneti one (not two) serrated chaeta on tibiotarsi II, thickened A7 chaeta, normal labial palp and labrum. It is smaller (adults of ~ 1 mm) and differs by normal branches of maxillary palp, 5–8 chaetae on tenaculum, and 5 (vs 8) ommatidia (with 2 posterior smaller). The species also has considerably expanded lateral process in labial palp, unlike its congeners.