The orobranchial structures in four neotropical silversides (Teleostei: Atherinopsidae) related with feeding habits

The morphology of the orobranchial structures in fish generally reflects the feeding habits and food preferences of a species and is key in understanding the process and habits of fish feeding. This work describes the orobranchial structures of four neotropical silversides (Teleostei: Atherinopsidae): the Mexican pike silverside Chirostoma estor , the Mexican blacknose silverside Chirostoma promelas , the Argentinian silverside Odontesthes bonariensis and Patagonian pejerrey Odontesthes hatcheri , and correlates their morphological features with existing information on gut contents and feeding habits in adult fish. Results of the compared and analysed data in the present study portray an integrative view of the specialised habits of the different species. Significant morphological differences, which are related to primary feeding habits of four species, were found. C. promelas shows to be more piscivorous compared to O. hatcheri, which has main benthic habits, while O. bonariensis and C. estor have more zooplanktivorous preferences. This information provides knowledge of feeding habits and ecological interactions of these species and their prey.