Rhinogobius sp.

Zarei, Fatah, Esmaeili, Hamid Reza, Abbasi, Keyvan, Kovačić, Marcelo, Schliewen, Ulrich K. & Stepien, Carol A., 2022, Gobies (Teleostei: Gobiidae) of the oldest and deepest Caspian Sea sub-basin: an evidence-based annotated checklist and a key for species identification, Zootaxa 5190 (2), pp. 151-193 : 182-183

38. Rhinogobius sp. ( Fig. 35 )

Distribution and habitat: Introduced in the Hari River, South Caspian Sea, Namak, Urmia and Tigris River basins. Lives exclusively in freshwater habitats. The population that settled in Iran also has penetrated into Azerbaijan and Georgia, and likely occurs in Armenian and the Black Sea basin (but currently is unverified; Zarei et al. 2021).

Remarks: The species identification of introduced Rhinogobius samples into Iran, Central Asia and the Caucasus, has been debated. Abdoli et al. (2000), and Coad & Abdoli (2000) provisionally identified the Hari River basin ( Iran) samples as R. similis Gill, 1859 and considered them conspecific with the species collected in the Kara-Kum Canal, Turkmenistan. They considered this an accidental introduction from the eastern Asian Amur River basin into Iran via the Tedzhen/Hari River, although R. similis is more widely distributed. Vasil’eva & Kuga (2008) regarded the Rhinogobius introduced to Central Asia as R. cheni (Nichols, 1931) , a Chinese species of the Yangtze River drainage. After re-description of R. similis by Suzuki et al. (2016), Sadeghi et al. (2019) confirmed that the Iranian samples differed from R. cheni and R. similis , and identified it R. lindbergi Berg, 1933 , the northernmost species of the genus described from Russia (Amur and Ussuri Rivers). Rhinogobius taxonomy however, has undergone considerable confusion; and molecular and morphological phylogenetic studies have targeted only a small set of species. Molecular data by Zarei et al. (2021) provided new information about the Iranian and the Caucasian Rhinogobius samples: (i) indicating that they share a mitochondrial DNA COI haplotype and likely are a single species; (ii) this supports their taxonomic recognition by Sadeghi et al. (2019), indicating that the Iranian and Caucasian samples do not belong to R. similis ; and (iii) that they likely belong to the R. brunneus species complex, which was (prior to introductions) primarily endemic to Japan. Zarei et al. (2021) did not include autochthonous R. lindbergi in their analysis; however, allozyme comparisons with seven Japanese congeners by Sakai et al. (2000) indicate that R. lindbergi is only distantly related to these Japanese congeners. Therefore, the species identity of the Iranian, Central Asian and Caucasian samples of Rhinogobius is currently ambiguous. Accordingly, Zarei et al. (2021) and the present study here identify these samples only to the genus level.

Material examined: ZM-CBSU S015 & ZM-CBSU F72, 56, Anzali Wetland, Gilan Province, Iran.

Figures

FIGURE 35. Rhinogobius sp., Anzali Wetland, Gilan Province, Iran.