Bioacoustics of Bolua

The genus Bolua was originally described as monotypic ( Ünal 1999 ). It was later revised by Uluar et al. (2022) using an integrative approach combining morphology, male calling songs, and sequences from four different gene segments, through which intraspecific diversity within the genus was characterized. Because species delimitation in Uluar et al. (2022) was primarily based on DNA sequence data, the authors provided information only for examined specimens, considering it potentially misleading to speculate about unexamined localities reported in other publications. Ünal (2025) , however, rejected the diversity framework proposed in that study on a genetic basis and synonymized the two newly described species. In Ünal (2025: 39–40) , both the text and the figures related to Bolua differ in style from his other text and earlier publications. In this work, rather than presenting a limited number of visual or descriptive statements, he attempted to express his claims of variation through numerous photographs of male abdominal terminals. At first glance, this may be seen as a positive attempt to provide visually based empirical support for his claims. However, when no measurements are made and no quantitative analyses are performed, the resulting information cannot be considered empirical and does not constitute sufficient evidence for systematic evaluation. Interpretations based on non-quantified phenotypic differences are equivalent to the logic of a “spot-the-difference” puzzle. For instance, by assigning specific landmark points to the cerci shown in the 26 abdominal terminal photographs and conducting a geometric morphometric analysis, the degree of variation could have been statistically tested, and the author’s claims could have been evaluated meaningfully. However, instead of such an approach, a purely qualitative phenotypic comparison was preferred. This method allows readers to make their own subjective interpretations of the degree of variation by directly comparing photographs, thereby opening the door to interpretative bias. Below, additional comparative material is provided to assist in evaluating these assessments more objectively. The essential question here is whether these photographs have any potential to test the three-species hypothesis proposed by Uluar et al. (2022) . The answer is clearly no. The photo set corresponds to the distribution areas of two of the species recognized by Uluar et al. (2022) , Bolua turkiyae Ünal, 1999 and B. bursaensis Uluar & Çıplak, 2022 , primarily the former. However, none of the photographs include representatives from the range of B. balikesirensis Uluar & Çıplak, 2022 . Uluar et al. (2022) explicitly stated that the shape of the cerci distinguishes B. balikesirensis from the other two species, while B. turkiyae and B. bursaensis are either indistinguishable or only subtly differentiated (a case of a conserved phenotype but deep genetic divergence). It is therefore unclear on what basis B. balikesirensis , which is not even represented among the examined specimens, was synonymized with B. turkiyae . From a scientific standpoint, the expected procedure would have been to visit the Balıkesir locality (the type locality of B. balikesirensis ), collect new specimens, generate DNA sequence data, and then evaluate the synonymy—provided that the data were generated and reported with due respect for accuracy. Using data belonging to B. turkiyae and B. bursaensis to justify the synonymization of B. balikesirensis with B. turkiyae involves serious methodological inconsistencies. Therefore, the data presented in Ünal (2025) lack explanatory value in support of the proposed synonymy and, in fact, are consistent with the findings of Uluar et al. (2022) . The paragraph above was presented not to discuss whether the synonymization of the species are correct or incorrect, but rather to illustrate the methodological approach adopted by Ünal (2025) . Ünal (2025) disregards the empirical evidence supporting the three species hypotheses proposed by Uluar et al. (2022) . In contrast, the recognition of these species as independent entities in Uluar et al. (2022) was made within the framework of the criteria that we previously defined and that every taxonomist should be expected to know, namely reproductive unity, genetic unity, ecological unity, and phylogenetic distinctiveness. Are these species independent phylogenetic entities? Do they represent separate reproductive communities and, consequently, independent gene pools? Has each adapted to a distinct ecological zone? The data presented in Uluar et al. (2022) answer all of these questions clearly and without any doubt in the affirmative.These species diverged from a common ancestor approximately five million years ago and have persisted as independent entities to the present day. Each represents an allopatric population that has undergone both genetic and ecological differentiation. The distribution of the genus being restricted to northwestern Anatolia (and its absence from other parts of Anatolia ), contrary to Ünal’s (2025) claim, indicates narrow ecological preferences. Moreover, distinct differences in male calling song between B. balikesirensis and B. bursaensis (unfortunately the song of B. turkiyae is not known) well align with the case listed above. For comparison, the COI genetic divergence among the species described by Uluar et al. (2022) is around 8–9%, a value even similar with the COI genetic divergence between a human and a chimpanzee (whose common ancestor lived approximately five million years ago). This level of divergence exceeds the average intraspecific COI differences reported among animal species in the literature ( Hebert et al. 2003 ; Zhang & Bu 2022 ) and thus strongly supports the view that these taxa represent independent entities. Furthermore, each species possesses more than fifty unique apomorphic DNA base positions, as clearly indicated in Uluar et al. (2022) . For this reason, we recommend that readers examine Ünal (2025) and Uluar et al. (2022) together and compare the presented data to form their own evaluations. All sequences used in Uluar et al. (2022) are publicly available in GenBank, and any researcher can download and re-analyze them to verify these conclusions.