Digestive Tract and the Muscular Pharynx/Esophagus in Wild Leptocephalus Larvae of European Eel (Anguilla anguilla)

Several aspects of the biology European eel ( Anguilla anguilla ) larvae are still unknown; particularly, information about their functional development and feeding is sparse. In present study, we histologically characterize digestive system wild caught specimens leptocephalus larvae. The aim was to provide more understanding how food may be ingested mechanically processed in larvae, discuss this context its hypothesized strategy. Larvae were Sargasso Sea during “Danish Eel Expedition 2014” with Danish research vessel Dana. larval sizes ranged from 7.0 23.3 mm standard length (SL) at catch. We found that mouth/pharynx, especially anterior esophagus, surrounded by a multi-layered striated muscle tissue epithelium mouth/pharynx had rough filamentous surface, followed epithelial columnar cells multiple cilia esophagus. This suggests an expandable pharynx/esophagus, well-suited for transportation likely food-crushing or grinding function. tract consisted straight esophagus intestine ventrally aligned within body, linearly correlated (SL). intestinal part constituted up 63% total tract. typical absorptive structure, brush border well-developed villi structure. Some observed intestine, but any surrounding muscularis not observed. liver along posterior pancreatic located intestine. Our findings support hypothesis ingest easily digestible gelatinous plankton and/or marine snow aggregates. muscular ciliated appear sufficient ensure nutrient transport absorption through