title: Gill remodelling and growth rate of striped catfish Pangasianodon hypophthalmus under impacts of hypoxia and temperature.
abstract: Gill morphometric and gill plasticity of the air-breathing striped catfish (Pangasianodon hypophthalmus) exposed to different temperatures (present day 27°C and future 33°C) and different air saturation levels (92% and 35%) during 6weeks were investigated using vertical sections to estimate the respiratory lamellae surface areas, harmonic mean barrier thicknesses, and gill component volumes. Gill respiratory surface area (SA) and harmonic mean water - blood barrier thicknesses (HM) of the fish were strongly affected by both environmental temperature and oxygen level. Thus initial values for 27°C normoxic fish (12.4±0.8g) were 211.8±21.6mm2g-1and 1.67±0.12μm for SA and HM respectively. After 5weeks in same conditions or in the combinations of 33°C and/or PO2of 55mmHg, this initial surface area scaled allometrically with size for the 33°C hypoxic group, whereas branchial SA was almost eliminated in the 27°C normoxic group, with other groups intermediate. In addition, elevated temperature had an astounding effect on growth with the 33°C group growing nearly 8-fold faster than the 27°C fish.
authors: College of Aquaculture and Fisheries, Can Tho University, Vietnam; Zoophysiology Section, Department of Biological Sciences, Aarhus University, Denmark. Electronic address: lemyphuong00@bios.au.dk.
authors: Le My
authors: LM
authors: Phuong
authors: College of Aquaculture and Fisheries, Can Tho University, Vietnam.
authors: Do Thi Thanh
authors: DT
authors: Huong
authors: Stereology and Electron Microscopy Laboratory, Centre for Stochastic Gemetry and Advanced Bioimaging, Aarhus University, Denmark.
authors: Jens Randel
authors: JR
authors: Nyengaard
authors: Zoophysiology Section, Department of Biological Sciences, Aarhus University, Denmark.
authors: Mark
authors: M
authors: Bayley
mesh_terms: D000818:Animals; D017756:Aquaculture; D002397:Catfishes / Q000254:growth & development / Q000469:parasitology / Q000502:physiology*; D015687:Cell Hypoxia; D002149:Energy Intake; D005880:Gills / Q000254:growth & development / Q000469:parasitology / Q000502:physiology*; D057232:Global Warming; D007091:Image Processing, Computer-Assisted; D008853:Microscopy / Q000662:veterinary; D059208:Parasite Load; D020545:Respiratory Mucosa / Q000254:growth & development / Q000469:parasitology / Q000502:physiology; D045483:Rivers; D013045:Species Specificity; D013312:Stress, Physiological; D013785:Thailand; D000071436:Thermotolerance; D013997:Time Factors; D015430:Weight Gain
keywords: Gill morphometric; Gill plasticity; Growth performance; Pangasianodon hypophthalmus