Size estimation of Synbranchus marmoratus and Synbranchus madeirae (Teleostei) based on isolated cranial and post-cranial bones

Abstract

The remains of South American swamp-eels are commonly recovered in pre-Columbian archaeological sites and swamp-eels are an important prey of piscivorous predators. In an attempt to assess the size classes of modern and archaeological fish from Bolivia, here we provide allometric regression equations for Synbranchus marmoratus and S. madeirae, resulting in total body length estimations on the basis of isolated skeletal elements. A total of 68 modern skeletons for Synbranchus marmoratus and 82 for Synbranchus madeirae were analysed. Measurements were taken on cranial (dentary, ectopterygoid, neurocranium, articular, hyomandibular, cleithrum) and post-cranial bones (first and second precaudal vertebrae). Our study shows that bone elements are highly correlated with total body lengths, which allows for a reliable reconstitution of Synbranchus size for paleontological, archaeological and dietary studies.