| 1376 | Animals |
| 364 | Female |
| 285 | Perches (physiology) |
| 254 | Male |
| 209 | Perches (metabolism) |
| 206 | Perches |
| 184 | Perches (genetics) |
| 130 | Species Specificity |
| 127 | Fresh Water |
| 123 | Perches (parasitology) |
| 115 | Phylogeny |
| 107 | Perches (growth & development) |
| 103 | Fish Diseases (parasitology) |
| 101 | Molecular Sequence Data |
| 95 | Water Pollutants, Chemical (analysis) |
| 94 | Water Pollutants, Chemical (toxicity) |
| 89 | Ecosystem |
| 87 | Time Factors |
| 81 | Humans |
| 80 | Environmental Monitoring |
| 77 | Seasons |
| 77 | Perches (anatomy & histology) |
| 74 | Housing, Animal |
| 73 | Fishes (metabolism) |
| 65 | Base Sequence |
| 63 | Chickens (physiology) |
| 62 | Liver (metabolism) |
| 60 | Genetic Variation |
| 59 | Temperature |
| 59 | Fishes |
| 58 | Perches (classification) |
| 52 | Water Pollutants, Chemical (metabolism) |
| 51 | Sequence Analysis, DNA |
| 50 | Fish Diseases (epidemiology) |
| 48 | Behavior, Animal |
| 47 | DNA, Mitochondrial (genetics) |
| 46 | Population Dynamics |
| 45 | Amino Acid Sequence |
| 44 | Evolution, Molecular |
| 43 | Host-Parasite Interactions |
| 43 | Food Chain |
| 42 | Population Density |
| 42 | Biological Evolution |
| 42 | Animal Welfare |
| 41 | Models, Biological |
| 40 | Mercury (analysis) |
| 40 | Analysis of Variance |
| 39 | Lakes |
| 39 | Environmental Monitoring (methods) |
| 38 | Microscopy, Electron |
| 38 | Fresh Water (chemistry) |
| 36 | Retina (cytology) |
| 35 | Trematode Infections (veterinary) |
| 35 | Sweden |
| 35 | Predatory Behavior |
| 34 | Geography |
| 34 | Environment |
| 33 | Tissue Distribution |
| 33 | Diet |
| 33 | Body Size |
| 31 | Trematode Infections (parasitology) |
| 30 | Retina (physiology) |
| 30 | Perciformes (physiology) |
| 30 | Liver (drug effects) |
| 29 | Muscles (metabolism) |
| 29 | Light |
| 29 | Hydrogen-Ion Concentration |
| 29 | Environmental Exposure |
| 29 | Chickens |
| 28 | Sequence Alignment |
| 28 | Rivers |
| 28 | Prevalence |
| 28 | Genetics, Population |
| 27 | Water Pollutants, Chemical (pharmacokinetics) |
| 27 | Oviposition |
| 27 | Microsatellite Repeats |
| 27 | Finland |
| 27 | Cloning, Molecular |
| 27 | Behavior, Animal (physiology) |
| 26 | Liver (chemistry) |
| 26 | Housing, Animal (standards) |
| 25 | Polymerase Chain Reaction |
| 25 | Adaptation, Physiological |
| 24 | Reproduction |
| 24 | Fresh Water (analysis) |
| 24 | Fishes (physiology) |
| 23 | Fishes (parasitology) |
| 23 | Dose-Response Relationship, Drug |
| 23 | Cyprinidae (physiology) |
| 23 | Body Weight |
| 22 | Sequence Homology, Amino Acid |
| 22 | Perches (immunology) |
| 22 | Fisheries |
| 22 | Feeding Behavior |
| 21 | Ontario |
| 21 | Animal Husbandry (methods) |
| 20 | Selection, Genetic |
| 20 | Seawater |
| 20 | Predatory Behavior (physiology) |
| 20 | Perches (blood) |
| 20 | Lakes (chemistry) |
| 20 | Gills (drug effects) |
| 19 | Polychlorinated Biphenyls (analysis) |
| 19 | Perches (microbiology) |
| 19 | Food Contamination |
| 19 | Fish Diseases (pathology) |
| 18 | Sex Factors |
| 18 | Perciformes (metabolism) |
| 18 | Gills (metabolism) |
| 18 | Electrophoresis, Polyacrylamide Gel |
| 18 | Biomechanical Phenomena |
| 18 | Animal Husbandry |
| 17 | Polymorphism, Genetic |
| 17 | Mercury (metabolism) |
| 17 | Kinetics |
| 17 | Histocytochemistry |
| 17 | Gills (parasitology) |
| 17 | Cyprinidae (parasitology) |
| 17 | Aquaculture |
| 17 | Age Factors |
| 16 | Sex Characteristics |
| 16 | Regression Analysis |
| 16 | Perciformes |
| 16 | Oceans and Seas |
| 16 | Models, Genetic |
| 16 | Larva (physiology) |
| 16 | Helminthiasis, Animal (parasitology) |
| 16 | Fishes (anatomy & histology) |
| 16 | Fish Proteins (genetics) |
| 16 | Bayes Theorem |
| 15 | Social Behavior |
| 15 | Sexual Behavior, Animal |
| 15 | Reproduction (physiology) |
| 15 | Rats |
| 15 | RNA, Messenger (genetics) |
| 15 | Quebec |
| 15 | Photic Stimulation |
| 15 | Muscles (chemistry) |
| 15 | Microsatellite Repeats (genetics) |
| 15 | Membrane Potentials (drug effects) |
| 15 | In Vitro Techniques |
| 15 | Immunohistochemistry |
| 15 | Gills (pathology) |
| 15 | Fishes (classification) |
| 15 | Fish Diseases (virology) |
| 15 | Alleles |
| 14 | Trout (metabolism) |
| 14 | Risk Assessment |
| 14 | Reverse Transcriptase Polymerase Chain Reaction |
| 14 | Retina (metabolism) |
| 14 | Reproduction (drug effects) |
| 14 | Liver (enzymology) |
| 14 | Larva (growth & development) |
| 14 | Insecticides (analysis) |
| 14 | Haplotypes |
| 14 | Genotype |
| 14 | France |
| 14 | Feeding Behavior (physiology) |
| 14 | DNA, Complementary (genetics) |
| 14 | DNA Primers |
| 14 | Biodiversity |
| 14 | Adult |
| 13 | United States |
| 13 | Sequence Homology, Nucleic Acid |
| 13 | Random Allocation |
| 13 | RNA, Messenger (metabolism) |
| 13 | Photoreceptor Cells (physiology) |
| 13 | Perches (virology) |
| 13 | Oviposition (physiology) |
| 13 | Muscle, Skeletal (metabolism) |
| 13 | Middle Aged |
| 13 | Lizards (physiology) |
| 13 | Linear Models |
| 13 | Gene Expression Regulation |
| 13 | Esocidae (metabolism) |
| 13 | Czech Republic |
| 13 | Copper (toxicity) |
| 13 | Brain (enzymology) |
| 13 | Biological Markers (analysis) |
| 12 | Video Recording |
| 12 | Trematoda (isolation & purification) |
| 12 | Trematoda (growth & development) |
| 12 | Russia |
| 12 | Rivers (chemistry) |
| 12 | Retina (drug effects) |
| 12 | Poultry Diseases (etiology) |
| 12 | Pesticide Residues (analysis) |
| 12 | Organ Size |
| 12 | Neurons (cytology) |
| 12 | Mice |
| 12 | Mercury (toxicity) |
| 12 | Mercury (pharmacokinetics) |
| 12 | Hydrocortisone (blood) |
| 12 | Gene Expression Regulation (drug effects) |
| 12 | Fishes (genetics) |
| 12 | Fish Diseases (microbiology) |
| 12 | Europe |
| 12 | Cestode Infections (veterinary) |
| 12 | Cells, Cultured |
| 12 | Birds (physiology) |
| 12 | Australia |
| 12 | Adolescent |
| 11 | Water Pollutants (toxicity) |
| 11 | Swimming |
| 11 | Polymerase Chain Reaction (veterinary) |
| 11 | Poland |
| 11 | Phenotype |
| 11 | Muscle, Skeletal (chemistry) |
| 11 | Molecular Weight |
| 11 | Microscopy, Electron, Scanning |
| 11 | Methylmercury Compounds (analysis) |
| 11 | Metals, Heavy (analysis) |
| 11 | Likelihood Functions |
| 11 | Gonads (drug effects) |
| 11 | Geologic Sediments (chemistry) |
| 11 | Fresh Water (parasitology) |
| 11 | Eggs (standards) |
| 11 | DNA (genetics) |
| 11 | Cyprinidae |
| 11 | Cyprinidae (metabolism) |
| 11 | Conservation of Natural Resources |
| 11 | Color |
| 11 | Cestode Infections (parasitology) |
| 11 | Cadmium (analysis) |
| 10 | Trematode Infections (epidemiology) |
| 10 | Trematoda (classification) |
| 10 | Stress, Physiological |
| 10 | Risk Factors |
| 10 | Principal Component Analysis |
| 10 | Perciformes (parasitology) |
| 10 | Perches (embryology) |
| 10 | Ovary (metabolism) |
| 10 | Oncorhynchus mykiss (metabolism) |
| 10 | Locomotion (physiology) |
| 10 | Lipid Metabolism |
| 10 | Larva |
| 10 | Kidney (metabolism) |
| 10 | Kainic Acid (pharmacology) |
| 10 | Helminths (classification) |
| 10 | Great Lakes Region |
| 10 | Germany |
| 10 | Geologic Sediments (analysis) |
| 10 | Genetic Markers |
| 10 | Gene Expression Profiling |
| 10 | Food Contamination (analysis) |
| 10 | Fish Diseases (transmission) |
| 10 | Ecology |
| 10 | Dopamine (pharmacology) |
| 10 | Darkness |
| 10 | Chromatography, High Pressure Liquid |
| 10 | Chickens (growth & development) |
| 10 | Cell Nucleus (genetics) |
| 10 | Cell Line |
| 10 | Cadmium (toxicity) |
| 10 | Cadmium (metabolism) |
| 10 | Birds |
| 10 | Africa, Eastern |
| 9 | Weight Gain |
| 9 | Water Pollution, Chemical (statistics & numerical data) |
| 9 | Staining and Labeling |
| 9 | Spectrophotometry, Atomic |
| 9 | Rabbits |
| 9 | Poultry Diseases (epidemiology) |
| 9 | Perciformes (genetics) |
| 9 | Parasitic Diseases, Animal (parasitology) |
| 9 | Ovary (drug effects) |
| 9 | Norway |
| 9 | Nesting Behavior |
| 9 | Motor Activity |
| 9 | Metals, Heavy (pharmacokinetics) |
| 9 | Metals (analysis) |
| 9 | Liver (pathology) |
| 9 | Life Cycle Stages |
| 9 | Heterozygote |
| 9 | Helminthiasis, Animal (epidemiology) |
| 9 | Genome |
| 9 | Fish Proteins (metabolism) |
| 9 | Esocidae (physiology) |
| 9 | Environmental Exposure (analysis) |
| 9 | Dopamine (physiology) |
| 9 | Copper (metabolism) |
| 9 | Copper (analysis) |
| 9 | Color Perception (physiology) |
| 9 | Circadian Rhythm |
| 9 | Canada |
| 9 | Cadmium (pharmacokinetics) |
| 9 | Blotting, Western |
| 9 | Bass (metabolism) |
| 9 | Aggression |
| 9 | Aged |
| 9 | Africa |
| 8 | Zinc (pharmacology) |
| 8 | Zinc (analysis) |
| 8 | Waste Disposal, Fluid |
| 8 | Testosterone (analogs & derivatives) |
| 8 | Superior Colliculi (physiology) |
| 8 | Rhabdoviridae Infections (veterinary) |
| 8 | Retinal Rod Photoreceptor Cells (physiology) |
| 8 | Retinal Cone Photoreceptor Cells (physiology) |
| 8 | Reproducibility of Results |
| 8 | Polychlorinated Biphenyls (toxicity) |
| 8 | Phylogeography |
| 8 | Photoperiod |
| 8 | Perciformes (anatomy & histology) |
| 8 | Organ Specificity |
| 8 | New York |
| 8 | Models, Statistical |
| 8 | Metals (toxicity) |
| 8 | Locomotion |
| 8 | Intestines (parasitology) |
| 8 | Hybridization, Genetic |
| 8 | Gonads (metabolism) |
| 8 | Genetic Speciation |
| 8 | Gene Flow |
| 8 | Fluorescent Antibody Technique |
| 8 | Fish Diseases (metabolism) |
| 8 | Fish Diseases (immunology) |
| 8 | Equipment Design |
| 8 | Energy Metabolism |
| 8 | Electrophysiology |
| 8 | Eating |
| 8 | DNA Primers (genetics) |
| 8 | Cytochrome b Group (genetics) |
| 8 | Competitive Behavior |
| 8 | Circadian Rhythm (physiology) |
| 8 | Cestoda (anatomy & histology) |
| 8 | Cell Count |
| 8 | Carps |
| 8 | Cannibalism |
| 8 | Calcium (metabolism) |
| 7 | gamma-Aminobutyric Acid (pharmacology) |
| 7 | Zooplankton |
| 7 | Xenopus |
| 7 | Wisconsin |
| 7 | Water Pollutants (analysis) |
| 7 | Water (chemistry) |
| 7 | Trout |
| 7 | Trematoda (physiology) |
| 7 | Trees |
| 7 | Testosterone (blood) |
| 7 | Testis (drug effects) |
| 7 | Survival Analysis |
| 7 | Salmonidae (metabolism) |
| 7 | Retinal Rod Photoreceptor Cells (cytology) |
| 7 | Retinal Ganglion Cells (physiology) |
| 7 | Retina (ultrastructure) |
| 7 | Retina (growth & development) |
| 7 | Retina (chemistry) |
| 7 | Poultry Diseases (prevention & control) |
| 7 | Polychlorinated Biphenyls (pharmacokinetics) |
| 7 | Polychlorinated Biphenyls (metabolism) |
| 7 | Pigmentation |
| 7 | Parasites (classification) |
| 7 | Ovum (physiology) |
| 7 | Ovary (physiology) |
| 7 | Organ Size (drug effects) |
| 7 | Oocytes (growth & development) |
| 7 | Oocytes (drug effects) |
| 7 | Nickel (toxicity) |
| 7 | Neurons (physiology) |
| 7 | Neurons (metabolism) |
| 7 | Mortality |
| 7 | Models, Theoretical |
| 7 | Mexico |
| 7 | Italy |
| 7 | Introduced Species |
| 7 | Industrial Waste |
| 7 | Hypergravity |
| 7 | Helminths (isolation & purification) |
| 7 | Great Britain |
| 7 | Glutamates (pharmacology) |
| 7 | Glucosephosphate Dehydrogenase (metabolism) |
| 7 | Gills (chemistry) |
| 7 | Gene Frequency |
| 7 | Fishes (immunology) |
| 7 | Fishes (growth & development) |
| 7 | Fish Proteins (immunology) |
| 7 | Feathers |
| 7 | Enzyme-Linked Immunosorbent Assay (veterinary) |
| 7 | Endocrine System (drug effects) |
| 7 | Eggs |
| 7 | Diet (veterinary) |
| 7 | Dark Adaptation (physiology) |
| 7 | DNA, Ribosomal (genetics) |
| 7 | DDT (analysis) |
| 7 | Cytochromes b (genetics) |
| 7 | Cytochrome P-450 Enzyme System (metabolism) |
| 7 | Cytochrome P-450 CYP1A1 (metabolism) |
| 7 | Cues |
| 7 | Chromosome Mapping |
| 7 | Child |
| 7 | Chickens (genetics) |
| 7 | Cesium Radioisotopes (analysis) |
| 7 | Cattle |
| 7 | Brain (metabolism) |
| 7 | Blotting, Southern |
| 7 | Blotting, Northern |
| 7 | Biotransformation |
| 7 | Biometry |
| 7 | Biological Markers (metabolism) |
| 7 | Behavior, Animal (drug effects) |
| 7 | Bass |
| 7 | Aromatase (metabolism) |
| 7 | Aquaculture (methods) |
| 7 | Animals, Wild |
| 7 | Animal Husbandry (standards) |
| 6 | Zinc (toxicity) |
| 6 | Zinc (pharmacokinetics) |
| 6 | Zinc (metabolism) |
| 6 | Weightlessness |
| 6 | Water |
| 6 | Water Pollutants, Radioactive (analysis) |
| 6 | Vocalization, Animal (physiology) |
| 6 | Vision, Ocular (physiology) |
| 6 | Trout (physiology) |
| 6 | Triiodothyronine (blood) |
| 6 | Tanzania |
| 6 | Switzerland |
| 6 | Swimming (physiology) |
| 6 | Sperm Motility (drug effects) |
| 6 | Spectrophotometry |
| 6 | Sex Differentiation (drug effects) |
| 6 | Sensitivity and Specificity |
| 6 | Retina (anatomy & histology) |
| 6 | RNA, Ribosomal, 16S (genetics) |
| 6 | Phosphorylation |
| 6 | Parasitic Diseases, Animal (epidemiology) |
| 6 | Paper |
| 6 | Ovum (chemistry) |
| 6 | Oocytes (metabolism) |
| 6 | Oncorhynchus mykiss |
| 6 | North America |
| 6 | Neurons (ultrastructure) |
| 6 | Motor Activity (physiology) |
| 6 | Minnesota |
| 6 | Metals (metabolism) |
| 6 | Lighting |
| 6 | Lead (analysis) |
| 6 | Larva (anatomy & histology) |
| 6 | Intestinal Mucosa (enzymology) |
| 6 | Intestinal Diseases, Parasitic (veterinary) |
| 6 | Immunoenzyme Techniques |
| 6 | Gram-Negative Bacterial Infections (veterinary) |
| 6 | Foot Diseases (veterinary) |
| 6 | Flight, Animal |
| 6 | Fishes (blood) |
| 6 | Fish Proteins (chemistry) |
| 6 | Fish Diseases (physiopathology) |
| 6 | Fish Diseases (mortality) |
| 6 | Fatty Acids (metabolism) |
| 6 | Facility Design and Construction |
| 6 | Epithelium (ultrastructure) |
| 6 | Energy Metabolism (physiology) |
| 6 | Ectoparasitic Infestations (veterinary) |
| 6 | Demography |
| 6 | Dark Adaptation |
| 6 | DNA, Mitochondrial (chemistry) |
| 6 | Cytochrome P-450 CYP1A1 (analysis) |
| 6 | Cyprinidae (growth & development) |
| 6 | Copper (pharmacokinetics) |
| 6 | Climate Change |
| 6 | Cats |
| 6 | Carbon Isotopes (analysis) |
| 6 | Calcium (analysis) |
| 6 | Cadmium (pharmacology) |
| 6 | Breeding |
| 6 | Brain Chemistry |
| 6 | Brain (ultrastructure) |
| 6 | Brain (cytology) |
| 6 | Bone and Bones (physiology) |
| 6 | Body Size (physiology) |
| 6 | Biomass |
| 6 | Baltic States |
| 6 | Animal Nutritional Physiological Phenomena |
| 6 | Aging |
| 6 | Adaptation, Ocular (physiology) |
| 5 | Zooplankton (physiology) |
| 5 | Water Pollution |
| 5 | Water Movements |
| 5 | Waste Water (toxicity) |
| 5 | Ultraviolet Rays |
| 5 | Triiodothyronine (pharmacology) |
| 5 | Thyroxine (blood) |
| 5 | Synapses (ultrastructure) |
| 5 | Stochastic Processes |
| 5 | Spermatozoa (drug effects) |
| 5 | Social Environment |
| 5 | Snails (parasitology) |
| 5 | Sexual Behavior, Animal (physiology) |
| 5 | Salmonidae |
| 5 | Rhabdoviridae Infections (virology) |
| 5 | Retinal Ganglion Cells (cytology) |
| 5 | Receptors, GABA (drug effects) |
| 5 | Receptors, GABA (chemistry) |
| 5 | Radioimmunoassay |
| 5 | Protozoan Infections, Animal |
| 5 | Posture |
| 5 | Ponds (chemistry) |
| 5 | Polycyclic Hydrocarbons, Aromatic (metabolism) |
| 5 | Polycyclic Hydrocarbons, Aromatic (analysis) |
