The First Record of Peritoneal Cavity Temperature Recording in Free-Swimming Dolphin Fish Coryphaena hippurus by Using Archival Tags, on the East Coast of Taiwan

Abstract

The ambient water temperature and peritoneal cavity temperature of two dolphin fish Coryphaena hippurus, in relation to their vertical movements were examined using archival tags, on the east coast of Taiwan. The peritoneal cavity temperature of the dolphinfish nearly corresponds to the ambient water temperature on a half-day scale, suggesting that they are typical ectothermic fish. This is quite different from Thunnus species, such as big eye, T.obesus and bluefin tuna, T. orientalis, as reported elsewhere. It is known that dolphinfish are predominantly confined to the surface mixed layer, in contrast to the immature bluefintuna that repeatedly dive across the thermocline for short periods; this is when the horizontal distributions of these species overlap. By using a simple heat budget model, we compared the thermo conservation abilities of dolphinfish and immature bluefin tuna, which revealed that the peritoneal cavity temperature of dolphinfish showed more rapid decrease when they dived beyond the thermocline that of the immature bluefin tuna that could maintain a relatively constant body temperature. This is one possible reason why these two species display such markedly different patterns of vertical movement, which is influenced by the thermocline.

Behavioural thermoregulation linked to foraging in blue sharks

“…A similar pattern was reported for bigeye tunas (Malte et al 2007), a regionally endothermic species with enhanced physiological thermoregulation capabilities (Holland et al 1992). Narrower ranges of body temperature than ambient temperature associated with repeated dives have been reported for other pelagic fishes, including bigeye tunas (Malte et al 2007), ocean sunfish (Nakamura et al 2015), dolphin fish Coryphaena hippurus (Furukawa et al 2015), swordfish Xiphias gladius (Stoehr et al 2018), and whale sharks Fig. 4 Allometry of whole-body heat transfer coefficients in fishes.…”

Two-way habitat use between reefs and open ocean in adult greater amberjack: evidence from biologging data

“…Since the water in which fish live has high thermal conductivity, the ability of fish to maintain their body temperature during vertical movement is a factor that can be used to determine their vertical distribution and the duration of vertical movement. For ex ample, in fishes with low physiological thermal tolerance, such as ectothermic dolphinfish Coryphaena hippurus (Furukawa et al 2015), the duration of vertical movement below the thermocline is limited to a short period of time. Bigeye tuna Thunnus obesus, an endothermic fish (Holland et al 1992), and swordfish Xiphias gladius, a regional endothermic fish (Stoehr et al 2018), both have high physiological thermal tolerance and can remain below the thermocline for longer periods of time.…”