Notes: Oxygen Consumption by Larval Japanese Medaka with Inflated or Uninflated Swim Bladders

Abstract

Inflation and regulation of swim bladder volume enables fish to maintain position within the water column with minimal energy cost. Larvae whose swim bladders fail to inflate must move to stay suspended and would be expected to use additional energy to maintain position. As a relative measure of extra effort expended by fish with uninflated swim bladders, oxygen consumption rates at 26°C were compared for larval Japanese medaka Orvzias latipes with inflated and uninflated swim bladders. During the first 24 h after hatching, oxygen consumption rates were significantly higher for larvae with uninflated swim bladders (1.75 ± 0.13 μg O2·h−1·larva−1) than for those with inflated swim bladders (0.92 ± 0.05 μg O2·h−1·larva−1); after 96 h, oxygen consumption rates had decreased for all larvae to about 0.6 μg O2·h−1·larva−1. For larvae held in sealed containers for 72 h without access to free surface air, the volume of air‐saturated water required to maintain an adequate concentration of dissolved oxygen (>6 mg/L) was greater when swim bladders were uninflated (55 mL/ larva) than when swim bladders were inflated (36 mL/ larva).

Diluted bitumen causes deformities and molecular responses indicative of oxidative stress in Japanese medaka embryos

“…Medaka are physoclistic, as are percids and sunfishes, having a distinct gas gland for maintaining swim bladder inflation and buoyancy. It has been suggested that the disruption of the air-water interface for the initial inflation of the swim bladder is of particular concern for this species (Fournie et al, 1999;Marty et al, 1995). In contrast, physostomous fishes without a gas gland must gulp air to regulate swim bladder inflation (e.g., salmonids, sturgeons, cyprinids), and would likely endure more serious impacts from dilbit exposure relating to swim bladder in new hatchlings as well as effects in adult life stages if exposed in a spill area.…”

Assessing barotrauma among angled snapper (Pagrus auratus) and the utility of release methods

“…For example, venting P. auratus immediately alleviated their intracoelomic pressure, so that they regained buoyancy control and orientation and, after release, were able to swim away much faster than untreated fish. In the wild, fish that quickly return to their habitat could have a lower probability of other unaccounted mortality or sublethal impacts, including predation (Keniry et al, 1996;Overton et al, 2008), oxygen demand (Marty et al, 1995), energy expenditure (Strand et al, 2005), stress from warm surface water temperatures (Shasteen and Sheehan, 1997), or sun exposure (Keniry et al, 1996), or even being struck by boats (Gravel and Cooke, 2008).…”

PFOS affects posterior swim bladder chamber inflation and swimming performance of zebrafish larvae

“…Larvae that fail to inflate the swim bladder use additional energy to maintain position in the water column (Lindsey et al, 2010;Marty et al, 1995). This energy expenditure might explain the decreased length and swimming speed seen in larvae exposed to PFOS.…”