FIGURE 5.

Dual isotope (δ¹³C and δ¹⁵N) plot of macrobenthos, fish, submerged macrophytes, Microseira wollei, plant debris, bottom sediment, and POM from the southern basin of Lake Biwa. (a) Each point of macrobenthos and fish shows a value for an individual specimen, except for oligochaetes. Triangles: Fish, diamonds: Macrobenthos, and squares: Submerged macrophyte. Asellus hilgendorfii* were decarbonated using acid treatment. POM and bottom sediment (Sed) were from sites 35 (BC zone) and 36 (SM zone), respectively. (b) Mean δ¹³C and δ¹⁵N values with error bars (standard deviation) for each category of samples. Number labels are 1: M. salmoides, 2: L. macrochirus, 3: T. brevispinis, 4: P. altivelis, 5: S. asotus, 6: Leech, 7: C. floridanus, 8: Tanypodid, 9: A. hilgendorfii, 10: A. hilgendorfii decarbonated, 11: J. naritai, 12: K. biwae, 13: Oligochaete, 14: M. wollei, 15: E. densa, 16: E. nuttallii, 17: H. verticillata, 18: P. maackianus, 19: Plant debris, 20: POM35, 21: POM36, 22: Sed35, and 23: Sed36. Categories with a single specimen (S. asotus and oligochaete) are presented without error bars.