Reproductive biology of an endemic fish, Alburnoides qanati Coad and Bogustkaya, 2009 (Teleostei: Cyprinidae) from Southern Iran

Abstract

This study provides fundamental information on some key aspects of the reproductive traits of qanati tailor fish, Alburnoides qanati, an Iranian endemic, poorly studied cyprinid fish species. Sampling was performed on a monthly basis during one year (from March 2011 through February 2012) from a tributary of endorheic Kor River Basin, Southern Iran. The results of data analyzing showed that the sex ratio in the population of qanati tailor fish is 1:1 except for those in January and April. Based on the size, shape and weight of the gonads, degree of occupation of the body cavity, presence or absence of ripe oocytes, diameter of the oocytes in the ovary, and histological observations, five typical gonad maturation stages were described for females using macroscopic and microscopic criteria. Based on the percentage of the late gonad maturation stage (V) and high frequency of large oocytes it was concluded that A. qanati spawns during spring with its peak in April. These results were in accordance with those of three reproductive indices (gonado-somatic, modified gonado-somatic and dobriyal). Absolute fecundity was obtained between 732 and 2368. Study on its eggs by scanning electron microscopy (SEM) revealed that the fish have adhesive eggs, which could explain its low fecundity compared to other cyprinids.