北部薩南海域に来遊したジンベエザメの餌生物

抄録

The prey of whale sharks (Rhincodon typus) visiting the northern Satsunan area (western North Pacific Ocean) was investigated using microscopic and metabarcoding analysis of their faecal pellets. The stable isotope ratios of the dorsal fin and faecal pellets from the whale sharks were compared with those of their potential prey (plankton and fish larvae). Microscopic analysis identified protozoans (foraminifera) and metazoans (copepods, ostracods, and amphipods) but unclassified material was predominant in their faecal pellets. Metabarcoding analysis detected metazoans in the faecal pellets, represented by copepods, ostracods, amphipods, hydrozoans, and tunicates. Comparison of stable isotope ratios (δ¹³C and δ¹⁵N) from their dorsal fin and faecal pellets with those of zooplankton in the northern Satsunan area showed different feeding histories for the whale sharks appearing in the northern Satsunan area.