The Trophic Relationships of Sympatric Fish Species of the Genera Opisthocentrus and Pholidapus (Perciformes: Opisthocentridae) in the Sea of Japan

• Published in: Russian journal of marine biology 2022-06, Vol.48 (3), p.149-157
• Main Authors: Rutenko, O. A., Ivankov, V. N., Kiyashko, S. I., Nekrasova, N. A.
• Format: Article
• Language: English
• Subjects: Aquatic crustaceans; Aquatic invertebrates; Aquatic organisms; Biomedical and Life Sciences; Carbon; Carbon isotopes; Carbon sources; Crustaceans; Fish; Food; Food supply; Foods; Freshwater & Marine Ecology; Genera; Isotopes; Life Sciences; Marine fishes; Niches; Nitrogen; Nitrogen isotopes; Original Papers; Perciformes; Phylogeny; Prey; Shellfish; Soft tissues; Species; Stomach content; Sympatric populations; Trophic relationships
• ISSN: 1063-0740; 1608-3377
• DOI: 10.1134/S1063074022030075

Trophic relationships of four sympatric fish species of the family Opisthocentridae (Perciformes), that is, Opisthocentrus ocellatus , O. tenuis , O . zonope , and Pholidapus dybowskii , were studied by analyzing their stomach contents and signatures of stable nitrogen and carbon isotopes (δ 15 N and δ 13 C) in soft tissues. The mean carbon isotope signature values ranged from –20.04 ± 0.95 to –15.44 ± 0.98, which indicated a wide range of primary carbon sources. The highest nitrogen isotope signature values (10.71 ± 0.55) and the maximum isotope niche width were recorded for Ph. dybowskii . Amphipods are the major food item of all the fish species under study, which was confirmed by a significant overlap of their isotope niches. The partitioning of trophic niches is explained by the selective consumption of prey crustaceans that are specific to each of the fish species and also by the use of aquatic invertebrates from different taxonomic groups as an additional food supply. The Schoener’s similarity index, calculated on the basis of relative abundances of food items identified to species, showed no competitive relationships between all of the fish species under study. The values of the index between the most phylogenetically close species O. ocellatus and O. tenuis were at a minimum.