Variation in thermal tolerance and routine metabolism among spring- and stream dwelling freshwater sculpins (Teleostei: Cottidae) of the southeastern United States

Abstract— Evolutionary theory predicts that some aquatic organisms may adapt by directional selection to limiting physical environmental conditions, yet empirical data are conflicting. We sought to test the assumption that sculpins (family Cottidae) inhabiting thermally stable springs of the southeastern United States differ in temperature tolerance and metabolism from populations inhabiting more thermally labile stream habitats. Spring populations of pygmy sculpins ( Cottus pygmaeus ) and Ozark sculpins ( C. hypselurus ) differed interspecifically in thermal tolerance from populations of stream-dwelling mottled ( C. bairdi ) and Tallapoosa sculpins ( C. tallapoosae ), and both stream and spring populations of banded sculpins ( C. carolinae ). No intra- or interspecific differences in thermal tolerance were found among populations of C. bairdi, C. talla poosae , or C. carolinae . Cottus pygmaeus acclimated to 15°C differed intraspecifically in routine metabolism from fish acclimated to 20° and 25°C. Cottus pygmaeus and stream-dwelling C. bairdi and C. carolinae acclimated to temperatures of 20° and 25°C showed no interspecific differences in routine metabolism. Our results suggest that some spring-adapted populations or species may be more stenothermal than stream-dwelling congeners, but a greater understanding of the interactions of other physical and biological factors is required to better explain micro- and macro habitat distributions of eastern North American sculpins.     

驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼形态观察

对驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼的形态特征进行了详细的观察与研究,描述了从受精卵到仔、稚、幼鱼各发育期的时间和形态特征变化。结果表明,在水温25-26℃、盐度30的海水中,受精卵历时27 h 25 min完成整个胚胎发育过程,经历从卵裂、囊胚、原肠、神经胚到肌节形成、各器官的逐渐形成、变化、完善等一系列的胚胎发育和变化过程;根据其卵黄囊消长情况、鳞片的覆盖状态、体色发生的不同变化以及第二背鳍和腹鳍的消长,将胚后发育分为仔、稚、幼鱼3个阶段。在水温22-26℃、盐度29-31、DO≥5 mg/L的条件下,2-3 d仔鱼卵黄囊消失,开口摄食;生长发育至31 d,仔鱼已变态进入稚鱼期;培育至57 d,稚鱼完成变态,成为幼鱼。第二背鳍棘和腹鳍棘的生长与收缩等石斑鱼类早期发育的共性生长特征及其体表特性体色变化特征为驼背鲈胚后发育过程中最明显的特征。     

Anguilla huangi Teng, Lin, and Tzeng, 2009, is a junior synonym of Anguilla luzonensis Watanabe, Aoyama, and Tsukamoto, 2009

Anguilla luzonensis and A. huangi were each described in 2009 using eels obtained from northern Luzon Island. We examined the taxonomic status of these two groups of eels using morphological and molecular genetic characters. There were no significant differences in two vertebrae counts between eels of A. luzonensis and A. huangi. Mitochondrial 16S ribosomal RNA and cytochrome b genes sequences were obtained and compared among 28 specimens of A. luzonensis, the holotypes of A. luzonensis and A. huangi, and one specimen of the other 15 anguillid species. The specimens of A. luzonensis exhibited almost identical sequences, including the holotype, with only a few site differences, and the genetic difference between the holotypes of A. luzonensis and A. huangi was within the range of differences of specimens of A. luzonensis. The other anguillid species were genetically very different from A. luzonensis and A. huangi, although A. interioris is a closely related species. It is clear that A. luzonensis and A. huangi are the same species, and according to the principle of priority in zoological nomenclature, A. luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 is the valid species name, and A. huangi Teng, Lin, and Tzeng, 2009 is a junior synonym of A. luzonensis.     

Effect of Salinity on Embryonic Development,Hatchability, and Growth of African Catfish,Clarias gariepinus,Eggs and Larvae

Abstract

Effects of salinity on embryonic development and growth of African catfish, Clarias gariepinus, eggs and larvae were studied. Eggs were incubated at 27-29°C in 2,4,6,8, and 10 ppt sodium chloride. Rate of embryonic development was delayed in all salt solutions by 15, 15,28 and 30 minutes, in 2,4,6, and 8 ppt sodium chloride, respectively, when compared with the control group (0% salt); total mortality occurred at 12 hours after gastrula stage in the 10 ppt concentration. Percentage hatching was 45.1,47.7, 59.5,49.2, and 26.6% while percentage deformity was 10.4, 16.1, 52.0, 28.6, and 71.6% in 0, 2, 4, 6, 8, and 10 ppt salt treatments, respectively. There were significant differences (P <0.05) in the hatching percentage and in deformity percentage between 4, 6, and 8 ppt. Rate of yolk absorption was significantly faster in the control and 2 ppt salt treatments, but slower in 4, 6, and 8 ppt. Rate of increase in length was slower with increasing salinity. The optimum salinity for African catfish eggs and was between 0-2 ppt and acceptable up to 6 ppt. The results suggest that increasing salinity delayed hatching and development of African catfish eggs and larvae, respectively, as well as increased the deformity of the larvae.     

Effect of Temperature on Growth,Energy Budget,and Physiological Performance of Green,White, and Purple Color Morphs of Sea Cucumber,Apostichopus japonicus

As an intertidal species, Apostichopus japonicus is subject to diel and seasonal temperature fluctuations. Color variation is a distinct characteristic of A. japonicus, and a new color morph, purple A. japonicus, was recently found on the coast of Rushan, Weihai City. This study was conducted to compare the performance of green, white, and purple color morphs of A. japonicus at different water temperatures to help improving aquaculture technology and management. In this study, green, white, and purple color morphs of juvenile A. japonicus (1.5 ± 0.1 g) were cultured at 10, 14, 18, 22, and 26 C for 60 d, according to the suitable temperature range for sea cucumber growth. Temperature was shown to have a significant effect on growth, energy budget, and physiology of sea cucumbers (P < 0.05). Specific growth rates, feed conversion efficiencies, and the proportion of energy allocated to growth of all three color morphs were optimal at 18 C. Activities of the enzymes related with oxidative stress, immune response, and digestion were determined. Superoxide dismutase (SOD) and trypsin activities generally reached a maximum in all three color morphs at 18 C. The purple color morph of A. japonicus was higher in growth rate, food conversion efficiency, and proportion of energy allocated to growth than green and white color morphs at 18 and 22 C, consistent with its higher trypsin and SOD activity, indicating the mutual effect of growth and physiology. At 18, 22, and 26 C, the green color morph had the highest level of lysozyme activity and purple color morph had the lowest, indicating possible infection by external pathogens of green color morph, which might be caused by high temperature. These results suggested that the optimum temperature for culture of the three color morphs was approximately 18 C, the purple had a better adaption to high temperature, and the green and white color morphs may be more susceptible to thermal stress than the purple color morph.     

Influence of density and background color to stress response, appetite, growth, and blind-side hypermelanosis of flounder, Paralichthys olivaceus

To study the relevance of density and background color to stress response, appetite, and growth in olive flounder, Paralichthys olivaceus, we reared two duplicate groups of juveniles (total length 4.46 ± 0.06 cm, body weight 0.77 ± 0.03 g) in flat-bottom aquaria with dark-green (control) and white backgrounds for 120 days. We measured cortisol and glucose levels in blood and calculated the daily food intake, food conversion efficiency, survival rate, and growth rate. To study the relevance of density and background color to malpigmentation (hypermelanosis) on the blind side, we also compared malpigmented ratios and prepro-melanin-concentrating hormone mRNA activities in the brain between the dark-green and white background groups, as well as between a relatively lower density (60 days) and higher density (120 days). Although we measured relatively higher levels of cortisol and glucose in the white background group and over 200 % of coverage area [PCA]), the bright background failed to induce an acute stress response of more than 20 ng/ml cortisol and 40 mg/dl glucose both in 60 days and 120 days, but did enhance appetite and growth. Also, a bright background color delayed hyperpigmentation only at a low density below 200 % PCA, but did not inhibit malpigmentation at a high density of more than 200 % PCA. In addition, below 200 % PCA, expression of MCH mRNA was significantly higher in the white group, but the level was reversed and was lower in the white group at more than 200 % PCA. In conclusion, although did not induce a high stress response over 200 % PCA, the bright background color resulted in a moderate increasing of cortisol level in blood below 20 ng/ml and enhanced appetite and growth. Moreover, at a density below 200 % PCA, the bright color inhibited hypermelanosis with high MCH mRNA activity, but at more than 200 % PCA did not inhibit malpigmentation, and the fish showed low MCH mRNA activity, indicating that the inhibitory effect of a bright background color on hypermelanosis is density dependent.     

Effects of Dietary Savory and Myrtle Essential Oils on Growth,Survival, Nutritional Indices,Serum Biochemistry,and Hematology of Farmed Rainbow Trout,Oncorhynchus mykiss,Fry

The effects of diets containing different levels of essential oils from savory Satureja khuzestanica Jamzad and myrtle Myrtus communis L and an immunity complement were investigated on growth, survival, nutritional indices, serum biochemistry, and hematology of farmed rainbow trout, Oncorhynchus mykiss, fry (n = 4500; 5 ± 2 g). The essential oils were dosed as 300 and 500 mg/kg diet. After 60 d, the fish fed 300 mg/kg of the essential oils showed the highest counts of white blood cells (P < 0.05). The same treatment revealed the greatest levels of hematocrit, total protein, and albumin, but glucose and cholesterol values significantly decreased compared with the control (P < 0.05). Feeding fish with 300 mg/kg of the essential oils led to highest records of specific growth rate and survival rate but the lowest feed conversion ratio (FCR), and those fed with immunity complement attained the lowest values of growth parameters. The fry fed with immunity complement and 300 mg/kg of myrtle essential oil achieved the highest and lowest FCR values, respectively. The results indicate that dietary supplementation of 300 mg/kg of the above essential oils exert positive impacts on the growth performance, feeding efficiency, and hematological factors in O. mykiss.     

盐化幅度、速度及方式对凡纳滨对虾仔虾生长和存活率的影响

本研究测定了盐化幅度(3/d、6/d、9/d、12/d和15/d)、盐化速度(1、3、6、12和18 h/次)和盐化方式(前期盐化、中期盐化、后期盐化和间隔盐化)与凡纳滨对虾(Litopenaeus vannamei)仔虾生长发育、活力和存活率的关系。研究结果显示,不同盐化幅度、盐化速度和盐化方式均显著影响盐化标粗过程中仔虾的生长发育、活力和存活率(P<0.05)。综合考虑生长性能、苗种活力和存活率等因素,最适盐化幅度为3~6/d,在该盐化幅度范围内,仔虾存活率可达74.07%~78.83%;盐化幅度超过9/d时,仔虾存活率显著下降(P<0.05),其中,盐化幅度达到15/d时,存活率仅为43.37%。过快的盐化速度导致存活率和活力显著下降,盐化速度>1 h/次时,仔虾死亡率接近50%;随着盐化速度的放缓,仔虾生长速度加快,盐化速度为6~18 h/次时,生长速度维持稳定,日增重量为1.48~1.51 mg。在盐化方式方面,后期盐化和间隔盐化时,苗种的质量和存活率优于前期盐化和中期盐化,仔虾活力表现为间隔盐化>后期盐化>中期盐化>前期盐化。综合考虑,仔虾的最适盐化幅度为3~6/d,最佳盐化速度为6~12 h/次,后期盐化和间隔盐化更有助于仔虾保持较好活力和较高存活率。本研究通过探讨凡纳滨对虾苗种盐化标粗的最适盐化幅度、盐化速度和盐化方式,丰富了凡纳滨对虾高盐环境抗逆性研究,为凡纳滨对虾苗种的盐化标粗生产实践提供了理论支持。     

Effects of levamisole,echinacea, and thyme oral administration on growth factors,blood parameters,and immunity in beluga,Huso huso

A total of 180 fish (95.50 g) were fed with 0.1% levamisole, 0.5% thyme, and 0.5% echinacea crude extract for 60 days. The control group received no stimulant. The results of growth parameters indicated a significant positive effect of levamisole in comparison with the control group, though it was not significantly different from echinacea and thyme treatments (P > 0.05). No mortalities were observed in the treatments. Feed conversion ratio and protein efficiency ratio did not differ significantly between the treatments. The highest numbers of white and red blood cells and the greatest amounts of hemoglobin and hematocrit were detected in the levamisole treatment, showing significant differences with the other groups in the percentage of hemoglobin only (P < 0.05). The highest levels of MCH and MCHC were also measured in the levamisole treatment. Differential count of white blood cells revealed no significant differences in neutrophil and lymphocyte levels with the control. There was a significant increase in the percentage of eosinophil in the levamisole treatment alone. No significant differences were recorded in total protein, albumin, and aspartate aminotransferase and alanine aminotransferase enzymes. Levamisole treatment displayed the highest activities of glutathione peroxidase and lysozyme as well as the greatest amount of immunoglobulin. So 0.1 levamisole yielded better results in the growth, blood, and immunity parameters and can be used as a stimulant without injuring body organs.     

Ctenocephalides canis and Ctenocephalides felis infestations of dogs and cats. Biology of the agent, epizootiology, pathogenesis, clinical signs, diagnosis and control

A review is presented of the biology, epizootiology, pathogenesis, clinical features, diagnosis and treatment of canine and feline Ctenocephalides canis and C. felis infestation. Also data are given on the prevalence of fleas in dogs and cats during a year at the 1st Animal Medical Hospital, Munich Veterinary Faculty. 5.5% of the dogs and 18.9% of the cats were infested with fleas.     

Meristics and Morphometrics of Golden Shiner,Notemigonus crysoleucas,Rudd, Scardinus erythrophthalmus,and Their Reciprocal F1 Hybrids

Rudd, Scardinus erythrophthalmus, a European minnow, has been hybridized with golden shiner, Notemigonus crysoleucas, in an attempt to produce sterile hybrids. If these hybrids are to be used as bait, easy means of differentiating the parental species and their hybrids is needed to ensure that no rudd are being sold. The scale pattern along the keel is the easiest and quickest way to distinguish the two species and their hybrids: the keel is raised and scaleless in the golden shiner, and it has 6-9 scales in the rudd; in hybrids, the keel is scaled, but the scales have different shapes and insertions than those in the rudd. No other phenotype can be used to positively identify these groups. No phenotype can be used to separate the reciprocal hybrids.     

Coral communities of Biscayne Bay,Florida and adjacent offshore areas: diversity,abundance, distribution,and environmental correlates

• 1. Hardbottom habitats of Biscayne Bay, a shallow lagoon adjacent to the city of Miami, Florida, USA, contain a limited number of coral species that represent a small subset of the species found at nearby offshore hardbottom and reef habitats of the Florida Reef Tract. Although the physical characteristics of this basin make it a marginal environment for coral growth, the presence of dense populations of Siderastrea radians and Porites furcata indicate that these, as well as other corals that are found at lower densities, are able to tolerate extreme and fluctuating conditions. Three factors, temperature, sedimentation, and salinity, appear to limit coral abundance, diversity, and distribution within Biscayne Bay.
• 2. Temperatures exhibit high frequencies of extreme high and low values known to cause coral stress and mortality elsewhere. Similarly, sedimentation rates are very high and sediment resuspension caused by currents, storms and boating activities commonly bury corals under sediment layers. Sediment burial was shown experimentally to influence growth and mortality of S. radians.
• 3. The salinity of Biscayne Bay is influenced by freshwater inputs from canal, sheetflow and groundwater sources that create a near‐shore environment with low mean salinity and high salinity fluctuation. Coral communities along this western margin have the lowest coral density and species richness. Chronic exposure to low salinity was shown experimentally to cause a decrease in the growth of S. radians.
• 4. The location of Biscayne Bay, downstream of a large restoration effort planned for the Everglades watershed, highlights the need to understand the relationship between the physical environment and the health of benthic communities. The data presented here provide the type of scientific information needed so that management decisions can take into account the potential impacts of human activities on the health of coral populations that are already near their tolerance limits for temperature, salinity, and sedimentation.

Copyright © 2003 John Wiley & Sons, Ltd.     

Relative growth,survival and harvestability of bighead carp,silver carp,and their reciprocal hybrids

Growth and survival in the primary rearing phase (42 days) for bighead carp, silver carp, bighead × silver carp (BHC × SC), and silver × bighead carp (SC × BHC) in ponds and concrete tanks stocked at 370 500 fry/ha were studied. Mean survival for fishes in ponds was 93%, that in tanks was 73%. Yields among all fishes averaged 338 kg/ha. The growth rates of fishes in ponds were similar; in tanks, silver carp grew faster than the bighead carp.Growth, survival, and harvestability by seine during the secondary rearing phase (60-day duration) for the same groups of fish were studied. Fingerlings (0.9 g mean weight) were stocked in earthen ponds at 49 400 fish/ha and 98 800 fish/ha. Mean survival of fishes at low stocking rate was 77%, similar to that (71%) for the high stocking rate. Fish yields were similar at the low stocking rate. At the high rate, the BHC × SC yield (846 kg/ha) was greater than the SC × BHC yield (582 kg/ha). The BHC × SC and SC × BHC had greater mean weights at low stocking rate than at high stocking rate. The mean weights for bighead carp were similar at both rates. Bighead carp and the reciprocal hybrids were more easily harvested by seine than silver carp.     

Comparative studies of the growth,survival, and reproduction of diploid and triploid Kumamoto oyster,Crassostrea sikamea

Triploid oysters have been used for farming to improve growth but have not been created in the Kumamoto oyster, Crassostrea sikamea, which is one of the crucial aquaculture species on the southern coast of China. In the present study, triploids were created using cytochalasin B to inhibit polar body II release in C. sikamea, with the untreated oysters as controls. Triploidy rates of 87 and 57.67%, on average, were obtained in larvae and adults, respectively. Larval growth and survival of the triploid were significantly lower than that of the controls (p < 0.05). In contrast, the triploid postlarvae and adults had a significant growth advantage over the controls (p < 0.05) during the period of 180 (December) to 450 days (September of the next year). Moreover, the triploids clearly exhibited significant sterility in the reproductive season. The glycogen and triglyceride contents in the gonad, adductor muscle, mantle, and gill were higher in triploids than in controls from 180 to 450 days. As a result, high physiological energy supply was strongly correlated with superior growth and reduced reproduction in triploid C. sikamea. The triploid C. sikamea is an excellent oyster species and can be used to improve growth for C. sikamea farming.     

Effect of temperature,volume of ova batches,and addition of a diluent,an antibiotic,oxygen and a protein inhibitor on short-term storage capacities of turbot,Psetta maxima,ova

The effect of different parameters on short-term storage capacity of turbot ova was assessed over a 45-h period after ova collection for fertilization rates and over a 9-h period after ova collection for hatching rates. Increasing the volume of ova sampling from 0.5 to 2.5 mL, as well as adding an antibiotic–antimicotic solution or oxygen did not significantly change the storage capacity of ova. Regarding the hatching rates, a higher storage ability was recorded at 8 and 13 °C, compared to 3 °C. The mean composition of the ovarian fluid was determined (n = 57 spawns). Use of a diluent mimicking the ovarian fluid significantly decreased the storage ability as assessed by the fertilization rates but did not modify the hatching rates. Diluting ova in an artificial ovarian fluid deprived of calcium significantly decreased the fertilization and hatching rates during the storage period. Furthermore, addition or not of soybean trypsin inhibitor (Sigma T 9003) to the artificial ovarian fluid deprived of calcium did not significantly change the results. Storage capacity of control batches of ova was low: at 13 °C, without any diluent and when ova were fertilized 3 h after stripping, the hatching rate was lowered to 62.4 ± 29.4 % (mean ± SD) of the initial value.     

Effects of Carbohydrate‐Rich Alternative Feedstuffs on Growth,Survival, Body Composition,Hematology, and Nonspecific Immune Response of Black Pacu,Colossoma macropomum,and Red Pacu,Piaractus brachypomus

To facilitate economical culture of black pacu, Colossoma macropomum, and red pacu, Piaractus brachypomus, in the Amazon region of South America, we assessed locally available alternative energy sources for practical diets. We tested the effects of control diets (containing wheat products) versus diets with different Amazonian feedstuffs (yucca, Manihot sculenta, plantain, Musa paradisiaca, or pijuayo, Bactris gasipaes) on the performance of the pacus in three feeding trials. Black pacu (22.5 ± 0.03 g; Trial 1) or red pacu (2.56 ± 0.01 g; Trial 2) were fed diets containing 30% wheat bran (control) or cooked or uncooked yucca, plantain, or pijuayo for 12 wk. In Trial 3, larger black pacu (86.9 ± 6.4 g) were grown to market size in 24 wk on similar diets. Weight gain, feed conversion, survival, alternative complement activity, and lysozyme were similar among diets. Hepatosomatic index, liver glycogen, and dry matter were affected by diet in Trials 1 and 2, but effects were not consistent among trials. In Trial 3, protein efficiency ratio was lower in fish fed the diet containing wheat middlings. However, relative to wheat bran or wheat middlings, all feedstuffs tested were effective energy sources for juvenile black pacu and red pacu.     

南极鱼类DNA条形码及分子系统进化研究

本文采用COI基因兼并引物对15种36个南极鱼类DNA进行扩增测序,并结合Gen Bank已有序列进行联配分析,对南极鱼2科22属43种共97条COI基因片段(539 bp)进行序列比较和系统发生关系研究,探索了DNA条形码技术在辅助鱼类物种鉴定和分类中的适应性与可行性。结果分析表明,43种南极鱼科和鳄冰鱼科的鱼类COI基因的平均碱基组成为T:31.9%、G:18.3%、A:22.2%和C:27.6%,具有明显的碱基偏倚性。南极鱼类的种间平均距离为0.157,种内平均遗传距离为0.002,种间平均遗传距离是种内平均距离的79倍;系统分析结果显示,除南极小带腭鱼(Cryodraco antarcticus)和罗斯海小带腭鱼(Cryodraco atkinsoni)外,其余的鱼类皆能够形成独立的分支,且与形态学分支一致。由此可见,DNA条形码对南极鱼亚目鳄冰鱼科和南极鱼科鱼类能够进行有效的物种鉴定,基于COI基因所建的NJ(neighbor-joining)树对物种分类具有较为准确的辨识力。系统发生关系表明,DNA条形码可以对除南极小带腭鱼(Cryodraco antarcticus)和罗斯海小带腭鱼(Cryodraco atkinsoni)外的南极鱼物种进行鉴定,不仅可以作为形态学的辅助手段为南极鱼分类系统的必要补充和佐证,并且可以用于探讨南极鱼类近缘种的系统发育关系。     

Surface disinfection of Pacific threadfin, Polydactylus sexfilis, and amberjack, Seriola rivoliana, eggs

The effects of exposing the eggs of Pacific threadfin and amberjack eggs (AEs) to different concentrations of hydrogen peroxide for 5 min on hatch rate and survival were assessed in a series of experiments using a petri dish model rearing system. Despite significant inter‐batch variation in hatch rate, it was shown that eggs of both species could be safely exposed to up to 11 340 mg L⁻¹ H₂O₂ for 5 min. Exposure to 34 230 mg L⁻¹ H₂O₂ for 5 min was shown to be lethal to AEs at a late stage of development. In two further experiments, it was demonstrated that Pacific threadfin eggs were resistant to all tested concentrations of a range of polyvinylpyrrolidone iodine (PVP‐I) concentrations and contact times (up to 1000 mg L⁻¹ PVP‐I for 10 min). The level of bacteria adhering to the eggs of both species was highly variable. Where eggs were heavily colonized (>10⁴ cfu egg⁻¹), hydrogen peroxide concentrations of at least 11 340 mg L⁻¹, or PVP‐I concentrations higher than 500 mg L⁻¹ for 10 min, were required for effective sterilization. In less colonized batches, rinsing in sterile seawater or exposure to lower (550 mg L⁻¹) concentrations of H₂O₂ was sufficient to result in high apparent levels of surface sterility (<1 cfu egg⁻¹).     

Demand and effect of potassium,magnesium, and calcium chlorides on hemolymph parameters,immune-related gene expression,and growth of Litopenaeus vannamei,Boone (1931) under biofloc technology

The ionic composition of culture water may be a more important limiting factor than the salinity itself and may lead to osmotic stress which may influence growth and survival of shrimp culture. The uptake rate and the effect of magnesium chloride (MgCl₂), calcium chloride (CaCl₂), and potassium chloride (KCl) salts in juveniles of whiteleg shrimp (Litopenaeus vannamei) cultured with biofloc technology (BFT) was evaluated for 62 days in seawater (30 practical salinity unity). Five treatments were analyzed in triplicate: T1; control (water exchange rate of 5% daily), T2; adding CaCl₂?+?MgCl₂?+?KCl, T3; adding MgCl₂?+?KCl, T4; adding CaCl₂?+?KCl, and T5; adding CaCl₂?+?MgCl₂. Mineral salts were added to water and the response of experimental parameters: physicochemical variables of water quality, osmotic pressure, total hemocyte count, glutathione peroxidase gene expression, superoxide dismutase, and zootechnical variables of the shrimp was assessed. The uptake of single chloride salts (CaCl₂, MgCl₂, and KCl) by shrimp varied as a function of the concentrations and the ratio of these three ions. Magnesium deficiencies in the culture medium increased CaCl₂ and KCl uptake without showing gene expression of SOD and GPx. The best survival rate was obtained by adding the three ions (T2) and the control (T1, water exchange of 5%). We concluded that L. vannamei can be maintained by the addition of essential chloride ions in BFT without water replacement.