Survey of Gastrointestinal contents Kapoordandan-e Geno, Aphanius ginaonis (Holly, 1929) associated with hot spring cyanobacteria of the Geno - Bandar Abbas

Aphanius ginaonis is exclusive to the Geno hot spring, located in the Hormozgan province. In this paper some biological aspects of Aphanius ginaonis and contents of its digestive tract and its relation with cyanobacteria (blue-green algae) in the Geno hot spring was examined. Sampling was conducted monthly, samples were fixed in 5% formalin immediately after fishing and transferred to the Ichthyology lab for next steps. In this study the biological characters such as total length, standard length, length of gut, total weight and weight of gut where measured and the sex was determined. Then the digestive tract was opened and its contents were investigated. The contents of each part of digestive tract were examined separately, which were mostly contain cyanobacteria. The digestive tract cyanobacteria were identified by using the valid identification key and determined that Spirulina subsalsa is the most common cyanobacteria in digestive tract in A.ginaonis. It seems that this fish species diet is mostly herbivorous but sometimes also feeds on aquatic insect larvae. As regards in habitat of Geno tooth-carp, 32 species of cyanobacteria have been identified, on the other hand various species of Spirulina are rich of protein, it seems that A.ginaonis are able to identificate and select among various species of cyanobacteria.