Swimming ability and physiological response to swimming fatigue in kuruma shrimp, <i>Marsupenaeus japonicus</i>

Abstract

The swimming endurance of kuruma shrimp, Marsupenaeus japonicus (11.04 ± 2.43 g) at five swimming speeds (23.0, 26.7, 31.0, 34.6 and 38.6 cm s-1) was determined in a circulating flume at 25.7 ± 0.7°C. The plasma glucose and total protein, hepatopancreas and pleopods muscle glycogen concentrations were determined before swimming and immediately after swimming to evaluate physiological effect of
swimming. Swimming endurance of M. japonicus decreased as swimming speed increased. The relationship between swimming endurance (t, s) and swimming speed (v, cm s-1) could be described by the logarithmic model as: t = -6881Ln (v) + 26090, R2 = 0.97 (P < 0.01). The swimming ability index (SAI), defined as SAI = 90000
vdt was found to be 32.43 cm. Metabolic rates of plasma glucose (Mpg, mol ml-1 s-1) and pleopods muscle glycogen (Mmg, mg g-1 s-1) during swimming to fatigue increased as swimming speed increased. The relationship between Mpg or Mmg and swimming speed (v, cm s-1) could be described by the exponential model as: Mpg = 3E-06e0.140v, R2 = 0.98 (P<0.01) or Mmg = 4E-06e0.137v, R2 = 0.95 (P<0.01), respectively. Swimming to fatigue led to severe loss of plasma glucose and hepatopancreas glycogen concentrations (P<0.05). Plasma glucose and pleopods muscle glycogen might be used as energy source during swimming.