Abstract
Mysids Tenagomysis chiltoni and T. novaezealandiae are abundant in southern New Zealand estuaries. Size-specific oxygen consumption rates of adult females of T. chiltoni and T. novaezealandiae were measured under salinities 0-1, 5, 10, 15, 20, 25, 30 and 33-34 at 5 °C and 20 °C in relation to body size. We predicted that, irrespective of salinity variations, the larger individuals would show lower size-specific oxygen consumption rates than smaller ones. Body size and the changes in salinity were not significantly related to the size-specific oxygen consumption rates of T. chiltoni and T. novaezealandiae, probably because of the small size range of individuals measured. At 20 °C, size-specific oxygen consumption rates were significantly higher than those at 5 °C for T. novaezealandiae, but not for T. chiltoni. Within the tolerable range of salinity variation, small differences in body size are possibly not important for energetics of adult Tenagomysis spp.