title: Effects of potassium ion supplementation on survival and ion regulation in Gulf killifish Fundulus grandis larvae reared in ion deficient saline waters.
abstract: Teleost fish often live in an environment in which osmoregulatory mechanisms are critical for survival and largely unknown in larval fish. The effects of a single important marine ion (K(+)) on survival and ion regulation of larval Gulf killifish, an estuarine, euryhaline teleost, were determined. A four-week study was completed in four separate recirculating systems with newly hatched larvae. Salinity in all four systems was maintained between 9.5 and 10‰. Two systems were maintained using crystal salt (99.6% NaCl) with K(+) supplementation (1.31±0.04mmol/L and 2.06±0.04mmol/L K(+); mean±SEM), one was maintained with crystal salt and no K(+) supplementation (0.33±0.05mmol/L K(+)), the fourth system was maintained using a standard marine mix salt (2.96±0.04mmol/L K(+)), the salt mix also included standard ranges of other ions such as calcium and magnesium. Larvae were sampled throughout the experiment for dry mass, Na(+)/K(+)-ATPase (NKA) activity, whole body ion composition, relative gene expression (NKA, Na(+)/K(+)/2Cl(-) cotransporter (NKCC) and cystic fibrosis transmembrane conductance regulator (CFTR)), and immunocytochemistry staining for NKA, NKCC, and CFTR. Larvae stocked into water with no K(+) supplementation resulted in 100% mortality within 24h. Mortality and dry mass were significantly influenced by K(+) concentration (P≤0.05). No differences were observed among treatment groups for NKA activity. At 1dph NKA mRNA expression was higher in the 0.3mmol [K(+)] group than in other treatment groups and at 7dph differences in intestinal NKA and CFTR staining were observed. These data indicate that the rearing of larval Gulf killifish may be possible in ion deficient water utilizing specific ion supplementation.
authors: Louisiana State University Agricultural Center, Aquaculture Research Station, Baton Rouge, LA, USA.
authors: Calvin
authors: C
authors: Fisher
authors: Charlotte
authors: C
authors: Bodinier
authors: Adam
authors: A
authors: Kuhl
authors: Christopher
authors: C
authors: Green
mesh_terms: D000818:Animals; D002414:Cations, Monovalent / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism; D023781:Fundulidae / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D007814:Larva; D011188:Potassium / Q000378:metabolism*; D054712:Salinity; D012965:Sodium Chloride / Q000378:metabolism; D028021:Sodium-Potassium-Chloride Symporters / Q000235:genetics / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D002414:Cations, Monovalent; D028021:Sodium-Potassium-Chloride Symporters; D014867:Water; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D012965:Sodium Chloride; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium