Bioacoustics of Bakuella granulifera

Remarks. A total of 12 species belongs to the genus Bakuella ( Agamaliev and Alekperov, 1976 ; Borror and Wicklow, 1983 ; Mihailowitsch and Wilbert, 1990 ; Eigner and Foissner, 1992 ; Song et al. , 1992 ; Foissner et al. , 2002 ; Foissner, 2004 ; Chen et al. , 2013 ; Jo et al. , 2015 ). Of these, B. pampinaria pampinaria Eigner & Foissner, 1992 and B. edaphoni Song, Wilbert & Berger, 1992 are most similar to B. granulifera based on their multiple buccal cirri, multiple midventral rows, and three dorsal kineties ( Eigner and Foissner, 1992 ; Song et al. , 1992 ). Considering the body shape, midventral row and yellowish cortical granules, B. granulifera is the most similar to B. pampinaria pampinaria Eigner & Foissner, 1992 . However, the former differs from the latter in the number of buccal cirri (5-11 vs. 3-6), frontoterminal cirri (2-3 vs. 5-8), and transverse cirri (8-12 vs. 2-5) ( Eigner and Foissner, 1992 ). Bakuella granulifera differs from B. edaphoni Song, Wilbert & Berger, 1992 in the number of midventral cirri rows (2-5 vs. 5-10) ( Song et al. , 1992 ). The morphology of the Korean population corresponds to the type population from Namibia , but the former population differs from the type population in body size (128-185 × 40-65 μm vs. 274-396 × 77-144 μm) and the number of cirri of rearmost midventral row (6-9 vs. 9-14) ( Foissner et al. , 2002 ). The Korean population morphology corresponds to the Chinese population, but the former population differ in number of cirri of rearmost midventral row (6-9 vs. 8-18) ( Chen et al. , 2020b ). 1 2 3 4 5 6 1. Bakuella granulifera MT 800874 - 1 6 40 41 42 2. Bakuella granulifera KY 873998 0.001 - 7 39 40 41 3. Bakuella granulifera KJ 958489 0.004 0.004 - 37 38 39 4. Bakuella incheonensis KR 024011 0.026 0.025 0.024 - 10 2 5. Bakuella litoralis KR 024010 0.026 0.026 0.024 0.006 - 12 6. Bakuella subtropica KC 631826 0.027 0.026 0.025 0.001 0.008 - The bold letters indicate the differences between the population of Bakuella granulifera . The 18S rRNA gene sequence of B. granulifera was 1749 bp in length (GenBank accession number: MT800 874). The closest species to B. granulifera in the genus Bakuella based on the pairwise distance of the 18S rRNA sequences is B. incheonensis . The intraspecific variation of B. granulifera was 0.001 -0.004 and the pairwise distance between B. granulifera and B. incheonensis was 0.026 ( Table 3 ). As mentioned above, the Korean population can be distinguished from the type population in terms of body size and the number of cirri of rearmost midventral row. These differences can be discussed at the subspecies level rather than the same species. However, unfortunately, the 18S rRNA gene sequences of the type population has not been reported. In addition, the Chinese population lacks morphological information. Thus, in order to clarify, information of the morphology and gene sequences of other populations of B. granulifera is needed. Deposition. The voucher slide with protargol­impregnated specimens is deposited in the National Institute of Biological Resources in Korea (NIBRPR0000110228).