| 762 | Animals |
| 202 | Fishes (physiology) |
| 184 | Male |
| 182 | Female |
| 149 | Fishes (genetics) |
| 143 | Fishes |
| 128 | Fishes (metabolism) |
| 103 | Molecular Sequence Data |
| 89 | Fishes (anatomy & histology) |
| 87 | Phylogeny |
| 86 | Fishes (growth & development) |
| 76 | Species Specificity |
| 67 | Base Sequence |
| 65 | Amino Acid Sequence |
| 41 | Water Pollutants, Chemical (toxicity) |
| 36 | Sequence Analysis, DNA |
| 34 | Time Factors |
| 34 | Fishes (blood) |
| 33 | Immunohistochemistry |
| 30 | Rivers |
| 30 | Cloning, Molecular |
| 29 | Spermatozoa (physiology) |
| 29 | Fishes (embryology) |
| 28 | Microscopy, Electron, Scanning |
| 27 | Liver (metabolism) |
| 27 | Fishes (classification) |
| 25 | Temperature |
| 25 | Fresh Water |
| 24 | Tissue Distribution |
| 24 | Hydrogen-Ion Concentration |
| 24 | Fishes (immunology) |
| 24 | Biological Evolution |
| 23 | Water Pollutants, Chemical (analysis) |
| 23 | Evolution, Molecular |
| 23 | Environmental Monitoring |
| 22 | Humans |
| 22 | Endangered Species |
| 22 | Aquaculture |
| 21 | Fish Proteins (genetics) |
| 21 | Ecosystem |
| 20 | Sequence Homology, Amino Acid |
| 20 | Sequence Alignment |
| 20 | DNA, Mitochondrial (genetics) |
| 19 | Osmolar Concentration |
| 19 | Genetic Variation |
| 18 | Water Pollutants, Chemical (metabolism) |
| 18 | Liver (drug effects) |
| 18 | China |
| 17 | Salinity |
| 17 | Microscopy, Electron |
| 17 | Fish Diseases (parasitology) |
| 16 | Hydrocortisone (blood) |
| 16 | Fish Diseases (virology) |
| 15 | In Vitro Techniques |
| 15 | Fish Proteins (metabolism) |
| 15 | Dose-Response Relationship, Drug |
| 15 | Conservation of Natural Resources |
| 14 | Spermatozoa (cytology) |
| 14 | Seawater |
| 14 | Polyploidy |
| 14 | Polymorphism, Genetic |
| 14 | Chromatography, High Pressure Liquid |
| 14 | Brain (metabolism) |
| 13 | Spermatozoa (drug effects) |
| 13 | Sperm Motility (drug effects) |
| 13 | Polymerase Chain Reaction |
| 13 | Microsatellite Repeats |
| 13 | Larva (growth & development) |
| 13 | Fishes (parasitology) |
| 13 | Fish Diseases (pathology) |
| 13 | Fish Diseases (epidemiology) |
| 12 | Sperm Motility (physiology) |
| 12 | Siberia |
| 12 | Seasons |
| 12 | Rivers (chemistry) |
| 12 | Microscopy, Electron, Transmission |
| 12 | Iran |
| 12 | DNA, Complementary (genetics) |
| 11 | Sodium-Potassium-Exchanging ATPase (metabolism) |
| 11 | Reverse Transcriptase Polymerase Chain Reaction |
| 11 | Ovum (physiology) |
| 11 | Hybridization, Genetic |
| 11 | Fisheries |
| 11 | Fish Proteins (chemistry) |
| 11 | Environment |
| 11 | Diet |
| 11 | DNA Primers |
| 10 | Sperm Motility |
| 10 | Russia |
| 10 | Reproduction (physiology) |
| 10 | RNA, Messenger (metabolism) |
| 10 | RNA, Messenger (genetics) |
| 10 | Ovary (metabolism) |
| 10 | Oocytes (drug effects) |
| 10 | Microsatellite Repeats (genetics) |
| 10 | Liver (enzymology) |
| 10 | Genotype |
| 10 | Genetics, Population |
| 10 | Gene Expression Profiling |
| 10 | Canada |
| 10 | Brain (anatomy & histology) |
| 10 | Age Factors |
| 9 | United States |
| 9 | Reproduction |
| 9 | Pituitary Gland (chemistry) |
| 9 | Oxygen Consumption |
| 9 | Oceans and Seas |
| 9 | Molecular Weight |
| 9 | Kidney (metabolism) |
| 9 | Karyotyping |
| 9 | Intestines (metabolism) |
| 9 | Genome |
| 9 | Gene Expression Regulation |
| 9 | Fishes (microbiology) |
| 9 | Fish Diseases (microbiology) |
| 9 | Electrophoresis, Polyacrylamide Gel |
| 9 | Copper (toxicity) |
| 9 | Cell Differentiation |
| 9 | Amino Acids (analysis) |
| 9 | Adaptation, Physiological |
| 8 | Xenopus laevis |
| 8 | Water Pollutants, Chemical (pharmacokinetics) |
| 8 | Swimming |
| 8 | Swimming (physiology) |
| 8 | Spermatozoa (ultrastructure) |
| 8 | Spermatozoa (metabolism) |
| 8 | Sequence Homology, Nucleic Acid |
| 8 | Repetitive Sequences, Nucleic Acid |
| 8 | Oocytes (metabolism) |
| 8 | Oocytes (growth & development) |
| 8 | Muscles (metabolism) |
| 8 | Kinetics |
| 8 | Kidney (drug effects) |
| 8 | Gills (metabolism) |
| 8 | Gills (drug effects) |
| 8 | Fish Diseases (mortality) |
| 8 | DNA Virus Infections (veterinary) |
| 8 | DNA (analysis) |
| 8 | Cryopreservation (methods) |
| 8 | Cell Line |
| 8 | Cadmium (toxicity) |
| 8 | Body Weight |
| 8 | Biological Assay |
| 8 | Atlantic Ocean |
| 7 | Water-Electrolyte Balance (physiology) |
| 7 | Trematode Infections (veterinary) |
| 7 | Transcriptome |
| 7 | Testosterone (blood) |
| 7 | Stress, Physiological |
| 7 | Reference Values |
| 7 | RNA, Transfer (genetics) |
| 7 | RNA, Ribosomal (genetics) |
| 7 | Population Dynamics |
| 7 | Pituitary Gland (metabolism) |
| 7 | Pituitary Gland (cytology) |
| 7 | Ovary (cytology) |
| 7 | Nucleic Acid Conformation |
| 7 | Muscle, Skeletal (metabolism) |
| 7 | Liver (chemistry) |
| 7 | Hot Temperature |
| 7 | Histocytochemistry |
| 7 | Gonads (metabolism) |
| 7 | Genome, Mitochondrial |
| 7 | Gene Expression |
| 7 | Gas Chromatography-Mass Spectrometry |
| 7 | Feeding Behavior (physiology) |
| 7 | Embryo, Nonmammalian |
| 7 | California |
| 7 | Body Size |
| 7 | Blood Glucose (analysis) |
| 7 | Antioxidants (metabolism) |
| 7 | Animal Feed |
| 7 | Alleles |
| 6 | Vitellogenins (biosynthesis) |
| 6 | Transcription Factors (genetics) |
| 6 | Testis (metabolism) |
| 6 | Testis (cytology) |
| 6 | Survival Analysis |
| 6 | Superoxide Dismutase (metabolism) |
| 6 | Spermatozoa (enzymology) |
| 6 | Sodium (blood) |
| 6 | Serotonin (metabolism) |
| 6 | Sequence Homology |
| 6 | Semen Preservation (methods) |
| 6 | Rats |
| 6 | Radioimmunoassay |
| 6 | Principal Component Analysis |
| 6 | Population Density |
| 6 | Polymorphism, Single Nucleotide |
| 6 | Ploidies |
| 6 | Oxidative Stress (drug effects) |
| 6 | Oocytes (ultrastructure) |
| 6 | Oocytes (cytology) |
| 6 | Muscles (chemistry) |
| 6 | Models, Biological |
| 6 | Microscopy, Electron, Scanning (veterinary) |
| 6 | Metals, Heavy (analysis) |
| 6 | Lethal Dose 50 |
| 6 | Larva (metabolism) |
| 6 | Immunity, Innate |
| 6 | Hemoglobins (metabolism) |
| 6 | Hemoglobins (chemistry) |
| 6 | Hemoglobins (analysis) |
| 6 | Haplotypes |
| 6 | Gills (enzymology) |
| 6 | Gills (cytology) |
| 6 | Genetic Markers |
| 6 | Fish Proteins |
| 6 | Fatty Acids (analysis) |
| 6 | Diet (veterinary) |
| 6 | Diencephalon (cytology) |
| 6 | DNA, Complementary |
| 6 | DNA, Complementary (chemistry) |
| 6 | DNA Virus Infections (virology) |
| 6 | DNA (chemistry) |
| 6 | Cluster Analysis |
| 6 | Chromatography, Gel |
| 6 | Cells, Cultured |
| 6 | Carps (metabolism) |
| 6 | Brain Mapping |
| 6 | Biomarkers (metabolism) |
| 6 | Animal Feed (analysis) |
| 6 | Analysis of Variance |
| 6 | Aging |
| 6 | Adenosine Triphosphate (metabolism) |
| 6 | Acclimatization (physiology) |
| 5 | Zinc (toxicity) |
| 5 | Water-Electrolyte Balance |
| 5 | Vitellogenins (genetics) |
| 5 | Trematoda (classification) |
| 5 | Testis (growth & development) |
| 5 | Telencephalon (anatomy & histology) |
| 5 | Semen Preservation (veterinary) |
| 5 | Semen Analysis (veterinary) |
| 5 | Semen (physiology) |
| 5 | Semen (chemistry) |
| 5 | Selenium (metabolism) |
| 5 | Retina (cytology) |
| 5 | Respiration |
| 5 | Reproduction (drug effects) |
| 5 | Rana temporaria |
| 5 | RNA, Messenger (biosynthesis) |
| 5 | Protein Structure, Secondary |
| 5 | Prevalence |
| 5 | Polymorphism, Restriction Fragment Length |
| 5 | Pituitary Gland (physiology) |
| 5 | Oxidative Stress |
| 5 | Ovary (growth & development) |
| 5 | Organ Specificity |
| 5 | Oocytes (physiology) |
| 5 | Oncorhynchus mykiss (metabolism) |
| 5 | Olfactory Mucosa (ultrastructure) |
| 5 | Nucleic Acid Hybridization |
| 5 | Neurosecretion |
| 5 | Myocardium (ultrastructure) |
| 5 | Mutation |
| 5 | Molecular Sequence Annotation |
| 5 | Mitosis |
| 5 | Lipid Metabolism |
| 5 | Lead (analysis) |
| 5 | Larva |
| 5 | Larva (cytology) |
| 5 | Kidney (physiology) |
| 5 | Kidney (enzymology) |
| 5 | Intestines (enzymology) |
| 5 | Insulin-Like Growth Factor I (genetics) |
| 5 | In Situ Hybridization, Fluorescence |
| 5 | Hypoxia (physiopathology) |
| 5 | Gills (pathology) |
| 5 | Geography |
| 5 | Genetic Loci |
| 5 | Gene Library |
| 5 | Gene Expression Regulation, Developmental |
| 5 | Gene Expression Regulation (drug effects) |
| 5 | Gene Duplication |
| 5 | Europe |
| 5 | Estuaries |
| 5 | Environmental Exposure |
| 5 | Embryo, Nonmammalian (cytology) |
| 5 | DNA, Mitochondrial |
| 5 | DNA Virus Infections (mortality) |
| 5 | DNA Primers (genetics) |
| 5 | DNA (metabolism) |
| 5 | DNA (genetics) |
| 5 | Cytoplasmic Granules (ultrastructure) |
| 5 | Cryoprotective Agents (pharmacology) |
| 5 | Cryopreservation |
| 5 | Cryopreservation (veterinary) |
| 5 | Conserved Sequence |
| 5 | Climate Change |
| 5 | Circular Dichroism |
| 5 | Carbon Dioxide (metabolism) |
| 5 | Calcium (metabolism) |
| 5 | British Columbia |
| 5 | Brain Chemistry |
| 5 | Brain (cytology) |
| 5 | Blood Proteins (analysis) |
| 5 | Behavior, Animal |
| 4 | Zinc (analysis) |
| 4 | Water |
| 4 | Water Quality |
| 4 | Viral Proteins (genetics) |
| 4 | Ultraviolet Rays |
| 4 | USSR |
| 4 | Triiodothyronine (blood) |
| 4 | Trematode Infections (parasitology) |
| 4 | Transcription Factors (metabolism) |
| 4 | Thyroxine (blood) |
| 4 | Survival Rate |
| 4 | Spinal Cord (metabolism) |
| 4 | Sodium Chloride (pharmacology) |
| 4 | Sex Characteristics |
| 4 | Sequence Analysis |
| 4 | Sensory Receptor Cells (ultrastructure) |
| 4 | Semen Analysis |
| 4 | Seafood (analysis) |
| 4 | Russia (epidemiology) |
| 4 | Reverse Transcriptase Polymerase Chain Reaction (veterinary) |
| 4 | Receptors, Aryl Hydrocarbon (genetics) |
| 4 | RNA, Ribosomal, 16S (genetics) |
| 4 | Protein Structure, Tertiary |
| 4 | Protein Conformation |
| 4 | Polymerase Chain Reaction (methods) |
| 4 | Polychlorinated Biphenyls (toxicity) |
| 4 | Pituitary Gland, Posterior (cytology) |
| 4 | Pituitary Gland (analysis) |
| 4 | Oxygen (metabolism) |
| 4 | Oxygen (blood) |
| 4 | Ovum (ultrastructure) |
| 4 | Ovum (metabolism) |
| 4 | Ovum (cytology) |
| 4 | Ovarian Follicle (cytology) |
| 4 | Osmoregulation (physiology) |
| 4 | Open Reading Frames |
| 4 | North America |
| 4 | Neurosecretory Systems (cytology) |
| 4 | Neurons (ultrastructure) |
| 4 | Myocardium (cytology) |
| 4 | Morphogenesis |
| 4 | Mitochondria (ultrastructure) |
| 4 | Metals, Heavy (toxicity) |
| 4 | Meiosis |
| 4 | Liver (pathology) |
| 4 | Lipid Peroxidation (drug effects) |
| 4 | Larva (drug effects) |
| 4 | Lakes |
| 4 | Lactic Acid (blood) |
| 4 | Kidney (chemistry) |
| 4 | Isoelectric Focusing |
| 4 | Intestines (drug effects) |
| 4 | Immunoenzyme Techniques |
| 4 | Hypothalamo-Hypophyseal System (cytology) |
| 4 | Hypercapnia (physiopathology) |
| 4 | Horseradish Peroxidase |
| 4 | High-Throughput Nucleotide Sequencing |
| 4 | Herpesviridae (isolation & purification) |
| 4 | Hematologic Tests (veterinary) |
| 4 | Hematocrit |
| 4 | Heart (physiology) |
| 4 | Growth Hormone (metabolism) |
| 4 | Gonads (chemistry) |
| 4 | Gonadotropins, Pituitary (pharmacology) |
| 4 | Gonadotropins, Pituitary (isolation & purification) |
| 4 | Gonadotropin-Releasing Hormone (pharmacology) |
| 4 | Gonadal Steroid Hormones (blood) |
| 4 | Glycosylation |
| 4 | Gills (ultrastructure) |
| 4 | Gills (physiology) |
| 4 | Gene Expression Regulation (physiology) |
| 4 | Food Microbiology |
| 4 | Fluorescent Dyes |
| 4 | Flagella (ultrastructure) |
| 4 | Fishes (virology) |
| 4 | Fertilization (physiology) |
| 4 | Expressed Sequence Tags |
| 4 | Erythrocytes (metabolism) |
| 4 | Ependyma (cytology) |
| 4 | Enzyme Inhibitors (pharmacology) |
| 4 | Environmental Monitoring (methods) |
| 4 | Energy Metabolism |
| 4 | Embryo, Nonmammalian (physiology) |
| 4 | Egtazic Acid (pharmacology) |
| 4 | Eggs (analysis) |
| 4 | Diploidy |
| 4 | Dioxins (toxicity) |
| 4 | Diencephalon (anatomy & histology) |
| 4 | DNA, Ribosomal (genetics) |
| 4 | DNA Virus Infections (pathology) |
| 4 | Cytochrome P-450 CYP1A1 (metabolism) |
| 4 | Copper (analysis) |
| 4 | Chromosome Mapping |
| 4 | Chromatography, Ion Exchange |
| 4 | Chlorides (metabolism) |
| 4 | Cell Proliferation (drug effects) |
| 4 | Cell Nucleus (ultrastructure) |
| 4 | Cell Membrane (metabolism) |
| 4 | Cell Division |
| 4 | Cell Count |
| 4 | Carbon Dioxide (blood) |
| 4 | Calcium (physiology) |
| 4 | Calcium (pharmacology) |
| 4 | Cadmium (analysis) |
| 4 | Brain Chemistry (physiology) |
| 4 | Brain (physiology) |
| 4 | Blotting, Western |
| 4 | Blood Protein Electrophoresis |
| 4 | Blood Glucose |
| 4 | Blood Chemical Analysis (veterinary) |
| 4 | Behavior, Animal (physiology) |
| 4 | Azerbaijan |
| 4 | Aquaculture (methods) |
| 4 | Animal Migration |
| 4 | Administration, Oral |
| 4 | Adaptation, Physiological (physiology) |
| 4 | Acrosome (ultrastructure) |
| 4 | Acrosome (physiology) |
| 4 | Acid-Base Equilibrium |
| 4 | Acclimatization |
| 3 | Xenopus laevis (genetics) |
| 3 | Wisconsin |
| 3 | Water Pollution, Chemical (statistics & numerical data) |
| 3 | Water Pollutants, Chemical (chemistry) |
| 3 | Water Pollutants, Chemical (adverse effects) |
| 3 | Water Pollutants (toxicity) |
| 3 | Water (analysis) |
| 3 | Washington |
| 3 | Vitellogenins (chemistry) |
| 3 | Visual Pathways (physiology) |
| 3 | Virulence |
| 3 | Video Recording |
| 3 | Veins (anatomy & histology) |
| 3 | Tyrosine 3-Monooxygenase (metabolism) |
| 3 | Trout (metabolism) |
| 3 | Tritium |
| 3 | Triiodothyronine (metabolism) |
| 3 | Trematoda (anatomy & histology) |
| 3 | Transfection |
| 3 | Toxicity Tests |
| 3 | Thyroxine (metabolism) |
| 3 | Thyroid Hormones (metabolism) |
| 3 | Thyroid Gland (physiology) |
| 3 | Thyroid Gland (growth & development) |
| 3 | Thyroid Gland (cytology) |
| 3 | Thiobarbituric Acid Reactive Substances (metabolism) |
| 3 | Testosterone (pharmacology) |
| 3 | Testosterone (metabolism) |
| 3 | Testosterone (analogs & derivatives) |
| 3 | Superior Colliculi (anatomy & histology) |
| 3 | Stress, Physiological (physiology) |
| 3 | Statistics, Nonparametric |
| 3 | Spinal Cord (anatomy & histology) |
| 3 | Spermatozoa (radiation effects) |
| 3 | Sperm Tail (physiology) |
| 3 | Spectrophotometry, Atomic |
| 3 | Somatostatin (isolation & purification) |
| 3 | Skin (pathology) |
| 3 | Skin (chemistry) |
| 3 | Sexual Maturation |
| 3 | Sex Factors |
| 3 | Sex Determination Processes |
| 3 | Sensory Receptor Cells (physiology) |
| 3 | Selenomethionine (toxicity) |
| 3 | Selenomethionine (metabolism) |
| 3 | Selenomethionine (administration & dosage) |
| 3 | Risk Assessment |
| 3 | Retina (metabolism) |
| 3 | Respiration (physiology) |
| 3 | Reproduction (genetics) |
| 3 | Repetitive Sequences, Nucleic Acid (genetics) |
| 3 | Regression Analysis |
| 3 | Reference Standards |
| 3 | Receptor, Insulin (metabolism) |
| 3 | Random Amplified Polymorphic DNA Technique (methods) |
| 3 | Random Allocation |
| 3 | Rabbits |
| 3 | RNA-Binding Proteins (genetics) |
| 3 | RNA, Ribosomal, 18S (genetics) |
| 3 | RNA, Messenger (analysis) |
| 3 | Proteomics (methods) |
| 3 | Proteins (metabolism) |
| 3 | Proteins (genetics) |
| 3 | Protein Binding |
| 3 | Protease Inhibitors (pharmacology) |
| 3 | Protamines (pharmacology) |
| 3 | Preoptic Area (anatomy & histology) |
| 3 | Potassium (pharmacology) |
| 3 | Potassium (blood) |
| 3 | Polymerase Chain Reaction (veterinary) |
| 3 | Polychlorinated Dibenzodioxins (toxicity) |
| 3 | Polychlorinated Biphenyls (analysis) |
| 3 | Pituitary Gland, Posterior (ultrastructure) |
| 3 | Periodicity |
| 3 | Perciformes (genetics) |
| 3 | Oxygen (physiology) |
| 3 | Ovum (parasitology) |
| 3 | Ovum (growth & development) |
| 3 | Ovum (chemistry) |
| 3 | Ovulation Induction |
| 3 | Ovary (ultrastructure) |
| 3 | Ovary (physiology) |
