Spatial morphometric plasticity of spirlin Alburnoides bipunctatus (Bloch, 1782) phenotype from the Nišava River, Serbia, Danube basin

Abstract

Variation of 22 morphometric and 4 meristic characters of the species Alburnoides bipuuctatus from Nišava River were analyzed. Specimens were collected from four sampling stations along the putative mesohabitat gradient of river influence and were grouped into the categories with similar total length. Morphometric characters varied immensely between different mesohabitats outlining morphometric plasticity. Among several morphometry features that were influenced by different mesohabitats the most observable differences were noted for: postocular distance, anal fin height, minimal body height and preanal length. Regarding the meristic features, number of soft rays in the anal fin did varied significantly among sampling stations while fourth hard ray in the anal fin for this species was reported for the first time ever. Pharyngeal teeth formula of spirlin also showed variability across different mesohabitats. In conclusion, it appears that spirlin express a big morphological plasticity in relation to spatial and mesohabitat distribution and there is a possibility that spirlin from Nišava River is a complex of neospecies in formation/morphotypes/ecotypes rather than a single population.

Keywords

• Alburnoides bipunctatus
• Cyprinidae
• mesohabitat
• phenotype plasticity