| 759 | Animals |
| 227 | Pisces |
| 202 | Fishes (physiology) |
| 189 | Female |
| 185 | Male |
| 149 | Fishes (genetics) |
| 143 | Fishes |
| 140 | Acipenser transmontanus |
| 127 | Fishes (metabolism) |
| 121 | Freshwater environment |
| 103 | Molecular Sequence Data |
| 102 | Phylogeny |
| 100 | Stream |
| 89 | Fishes (anatomy & histology) |
| 86 | Fishes (growth & development) |
| 82 | Marine environment |
| 76 | Species Specificity |
| 76 | Aquaculture |
| 70 | Temperature |
| 68 | Acipenser sturio |
| 67 | Base Sequence |
| 65 | Endangered species |
| 65 | Amino Acid Sequence |
| 58 | Young animal |
| 56 | Pisciculture |
| 54 | Diet |
| 52 | Growth |
| 46 | Larva |
| 44 | Rivers |
| 43 | fish |
| 41 | Water Pollutants, Chemical (toxicity) |
| 40 | Development |
| 40 | Aquatic environment |
| 39 | Reproduction |
| 39 | Morphology |
| 38 | Toxicity |
| 38 | Interspecific comparison |
| 38 | Immunohistochemistry |
| 38 | Habitat |
| 38 | Feeding |
| 38 | Acipenser baeri |
| 36 | Sequence Analysis, DNA |
| 35 | United States |
| 34 | Time Factors |
| 34 | Fishes (blood) |
| 33 | Sturgeon |
| 33 | Salinity |
| 33 | Metabolism |
| 31 | growth |
| 31 | Animal conservation |
| 30 | Environment |
| 30 | Cloning, Molecular |
| 29 | conservation |
| 29 | Fishes (embryology) |
| 29 | China |
| 29 | Acipenser ruthenus |
| 28 | Spermatozoa (physiology) |
| 28 | Microscopy, Electron, Scanning |
| 28 | Huso huso |
| 27 | Liver (metabolism) |
| 27 | Fishes (classification) |
| 27 | Ecotoxicology |
| 26 | Life history |
| 25 | Swimming |
| 25 | Geographic distribution |
| 25 | Fresh Water |
| 25 | Estuaries |
| 25 | Ecosystem |
| 24 | Tissue Distribution |
| 24 | Spawning |
| 24 | Parasite |
| 24 | Hydrogen-Ion Concentration |
| 24 | Fishes (immunology) |
| 24 | Comparative study |
| 24 | Biological Evolution |
| 23 | Water Pollutants, Chemical (analysis) |
| 23 | Vitellogenin |
| 23 | Evolution, Molecular |
| 23 | Environmental Monitoring |
| 23 | Age |
| 22 | Survival |
| 22 | Seasonal variation |
| 22 | Humans |
| 22 | Habitat selection |
| 22 | Endangered Species |
| 22 | California |
| 22 | Biological accumulation |
| 21 | sturgeon |
| 21 | Ultrastructure |
| 21 | Polyploidy |
| 21 | Mortality |
| 21 | Lakes |
| 21 | Fish Proteins (genetics) |
| 21 | Canada |
| 21 | Body size |
| 21 | Animal migration |
| 21 | Acipenser stellatus |
| 20 | Sequence Homology, Amino Acid |
| 20 | Sequence Alignment |
| 20 | Population decline |
| 20 | Oncorhynchus mykiss |
| 20 | North America |
| 20 | Edible fish |
| 20 | DNA, Mitochondrial (genetics) |
| 19 | Spermatozoa |
| 19 | Scanning electron microscopy |
| 19 | Pollutant |
| 19 | Osmolar Concentration |
| 19 | Genetic Variation |
| 19 | Fishing |
| 19 | Caviar |
| 18 | Water Pollutants, Chemical (metabolism) |
| 18 | Proteins |
| 18 | Liver (drug effects) |
| 18 | France |
| 18 | Fatty acids |
| 18 | Caspian Sea |
| 17 | Status |
| 17 | Population management |
| 17 | Mitochondrial DNA |
| 17 | Microscopy, Electron |
| 17 | Fish Diseases (parasitology) |
| 17 | Enzymatic activity |
| 17 | Dam |
| 17 | DNA |
| 17 | Behavior |
| 16 | aquaculture |
| 16 | Water pollution |
| 16 | Taxonomy |
| 16 | Stock |
| 16 | Seawater |
| 16 | Russia |
| 16 | Population structure |
| 16 | Models |
| 16 | Migratory |
| 16 | Liver |
| 16 | Hydrocortisone (blood) |
| 16 | Fish Diseases (virology) |
| 16 | Farming animal |
| 15 | evolution |
| 15 | Spatial distribution |
| 15 | Sex steroid hormone |
| 15 | Lipids |
| 15 | In Vitro Techniques |
| 15 | Histology |
| 15 | Fish Proteins (metabolism) |
| 15 | Europe |
| 15 | Environmental factor |
| 15 | Dose-Response Relationship, Drug |
| 15 | Conservation of Natural Resources |
| 15 | Chemical composition |
| 14 | phylogeny |
| 14 | microsatellites |
| 14 | Spermatozoa (cytology) |
| 14 | Polymorphism, Genetic |
| 14 | Method |
| 14 | Laboratory study |
| 14 | Iran |
| 14 | Intraspecific comparison |
| 14 | Fish |
| 14 | Enzyme |
| 14 | Egg |
| 14 | Chromatography, High Pressure Liquid |
| 14 | Brain (metabolism) |
| 14 | Brackish water environment |
| 14 | Blood plasma |
| 14 | Biological evolution |
| 13 | reproduction |
| 13 | migration |
| 13 | Spermatozoa (drug effects) |
| 13 | Sperm Motility (drug effects) |
| 13 | Siberia |
| 13 | Restocking |
| 13 | Range finding |
| 13 | Polymerase Chain Reaction |
| 13 | Modeling |
| 13 | Microsatellite Repeats |
| 13 | Larva (growth & development) |
| 13 | Hypoxia |
| 13 | Fry |
| 13 | Fishes (parasitology) |
| 13 | Fish Diseases (pathology) |
| 13 | Fish Diseases (epidemiology) |
| 13 | Embryo |
| 13 | Developmental stage |
| 12 | Wisconsin |
| 12 | Sperm Motility (physiology) |
| 12 | Seasons |
| 12 | Rivers (chemistry) |
| 12 | Oxygen consumption |
| 12 | Oocyte |
| 12 | Microscopy, Electron, Transmission |
| 12 | Growth rate |
| 12 | Fishery |
| 12 | DNA, Complementary (genetics) |
| 12 | Body weight |
| 12 | Biology |
| 12 | Adaptation |
| 11 | Yangtze River |
| 11 | Transmission electron microscopy |
| 11 | Sodium-Potassium-Exchanging ATPase (metabolism) |
| 11 | Sex |
| 11 | Selenium |
| 11 | Reverse Transcriptase Polymerase Chain Reaction |
| 11 | Quebec |
| 11 | Ovum (physiology) |
| 11 | Osmoregulation |
| 11 | Iridovirus |
| 11 | Hybridization, Genetic |
| 11 | Genotype |
| 11 | Genome |
| 11 | Genetic variability |
| 11 | Florida |
| 11 | Fisheries |
| 11 | Fish Proteins (chemistry) |
| 11 | Experimental study |
| 11 | DNA Primers |
| 11 | Conservation |
| 11 | Characterization |
| 11 | Anatomy |
| 10 | mtDNA |
| 10 | growth performance |
| 10 | Substrate |
| 10 | Stress |
| 10 | Sperm Motility |
| 10 | Reproduction (physiology) |
| 10 | Rearing |
| 10 | RNA, Messenger (metabolism) |
| 10 | RNA, Messenger (genetics) |
| 10 | Pollution |
| 10 | Ovary (metabolism) |
| 10 | Oocytes (drug effects) |
| 10 | Nucleotide sequence |
| 10 | Muscle |
| 10 | Microsatellite Repeats (genetics) |
| 10 | Localization |
| 10 | Liver (enzymology) |
| 10 | Genetics, Population |
| 10 | Gene Expression Profiling |
| 10 | Environmental protection |
| 10 | Embryonic development |
| 10 | Dispersion |
| 10 | Cryopreservation |
| 10 | Central nervous system |
| 10 | British Columbia |
| 10 | Brain (anatomy & histology) |
| 10 | Blood |
| 10 | Atlantic Ocean |
| 10 | Animal active movement |
| 10 | Anadromy |
| 10 | Age Factors |
| 9 | teleost |
| 9 | phylogeography |
| 9 | morphology |
| 9 | mitochondrial DNA |
| 9 | immunohistochemistry |
| 9 | Zoogeography |
| 9 | Tissue |
| 9 | Reproductive cycle |
| 9 | Population recruitment |
| 9 | Pituitary Gland (chemistry) |
| 9 | Performance |
| 9 | Oxygen Consumption |
| 9 | Ontario |
| 9 | Oceans and Seas |
| 9 | Molecular Weight |
| 9 | Migration |
| 9 | Kidney (metabolism) |
| 9 | Karyotyping |
| 9 | Intestines (metabolism) |
| 9 | Hybrid |
| 9 | Gene Expression Regulation |
| 9 | Fishes (microbiology) |
| 9 | Fish Diseases (microbiology) |
| 9 | Electrophoresis, Polyacrylamide Gel |
| 9 | Copper (toxicity) |
| 9 | Cell Differentiation |
| 9 | Carbohydrate |
| 9 | Breeding site |
| 9 | Body composition |
| 9 | Amino Acids (analysis) |
| 9 | Adaptation, Physiological |
| 8 | endemic |
| 8 | digestibility |
| 8 | development |
| 8 | caviar |
| 8 | amphibians |
| 8 | Xenopus laevis |
| 8 | Water Pollutants, Chemical (pharmacokinetics) |
| 8 | Washington |
| 8 | Vitellogenesis |
| 8 | Swimming (physiology) |
| 8 | Spermatozoa (ultrastructure) |
| 8 | Spermatozoa (metabolism) |
| 8 | Spain |
| 8 | Sequence Homology, Nucleic Acid |
| 8 | Review |
| 8 | Respiration |
| 8 | Repetitive Sequences, Nucleic Acid |
| 8 | Radioimmunoassay |
| 8 | Prevalence |
| 8 | Population survey |
| 8 | Population recovery |
| 8 | Population number |
| 8 | Population genetics |
| 8 | Population exploitation |
| 8 | Population density |
| 8 | Polymorphism |
| 8 | Polymerase chain reaction |
| 8 | Polychlorobiphenyl |
| 8 | Pituitary gland |
| 8 | Pectoral fin |
| 8 | Oxygen |
| 8 | Organochlorine compounds |
| 8 | Oocytes (metabolism) |
| 8 | Oocytes (growth & development) |
| 8 | Nutrition |
| 8 | Muscles (metabolism) |
| 8 | Kinetics |
| 8 | Kidney |
| 8 | Kidney (drug effects) |
| 8 | Induction |
| 8 | In vitro |
| 8 | Hatchery |
| 8 | Gills (metabolism) |
| 8 | Gills (drug effects) |
| 8 | Gill |
| 8 | Genetic diversity |
| 8 | Gene Expression |
| 8 | Fish Diseases (mortality) |
| 8 | Ecology |
| 8 | DNA Virus Infections (veterinary) |
| 8 | DNA (analysis) |
| 8 | Cyprinus carpio |
| 8 | Cryopreservation (methods) |
| 8 | Commercial use |
| 8 | Cell Line |
| 8 | Cadmium (toxicity) |
| 8 | Body Weight |
| 8 | Black Sea |
| 8 | Biological marker |
| 8 | Biogeography |
| 7 | vitellogenin |
| 7 | temperature |
| 7 | paddlefish |
| 7 | nutrition |
| 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 | Quantitative analysis |
| 7 | Purification |
| 7 | Population Dynamics |
| 7 | Pituitary Gland (metabolism) |
| 7 | Pituitary Gland (cytology) |
| 7 | Ovary (cytology) |
| 7 | Oocyte maturation |
| 7 | Nutrient requirement |
| 7 | Nucleic Acid Conformation |
| 7 | Nitrogen |
| 7 | Muscle, Skeletal (metabolism) |
| 7 | Liver (chemistry) |
| 7 | Ictalurus punctatus |
| 7 | Hot Temperature |
| 7 | Histopathology |
| 7 | Histocytochemistry |
| 7 | Gonads (metabolism) |
| 7 | Genome, Mitochondrial |
| 7 | Gas Chromatography-Mass Spectrometry |
| 7 | Feeding Behavior (physiology) |
| 7 | Feed |
| 7 | Excretion |
| 7 | Estradiol |
| 7 | Embryo, Nonmammalian |
| 7 | Ecological abundance |
| 7 | Digestive system |
| 7 | Cytochrome P450 |
| 7 | Columbia River |
| 7 | Chemotaxonomy |
| 7 | Body Size |
| 7 | Blood Glucose (analysis) |
| 7 | Biological Assay |
| 7 | Antioxidants (metabolism) |
| 7 | Antioxidant |
| 7 | Anthropogenic factor |
| 7 | Animal population |
| 7 | Animal Feed |
| 7 | Ammonia |
| 7 | Aminoacid |
| 7 | Aminoacid sequence |
| 7 | Alleles |
| 7 | Absorption |
| 6 | teleosts |
| 6 | survival |
| 6 | starvation |
| 6 | sperm motility |
| 6 | rainbow trout |
| 6 | pH |
| 6 | ontogeny |
| 6 | larvae |
| 6 | immunocytochemistry |
| 6 | histology |
| 6 | glucose |
| 6 | fisheries |
| 6 | fatty acids |
| 6 | enzymes |
| 6 | cytochrome b |
| 6 | cortisol |
| 6 | brain |
| 6 | amino acids |
| 6 | acetylcholine |
| 6 | Wild animal |
| 6 | Vitellogenins (biosynthesis) |
| 6 | USSR |
| 6 | Transcription Factors (genetics) |
| 6 | Testis (metabolism) |
| 6 | Testis (cytology) |
| 6 | Survival Analysis |
| 6 | Superoxide Dismutase (metabolism) |
| 6 | Spermatozoa (enzymology) |
| 6 | Sodium (blood) |
| 6 | Siberian sturgeon |
| 6 | Sexual maturity |
| 6 | Serotonin (metabolism) |
| 6 | Sequence Homology |
| 6 | Semen Preservation (methods) |
| 6 | Salmonidae |
| 6 | Restriction fragment length polymorphism |
| 6 | Rats |
| 6 | Rana temporaria |
| 6 | Principal Component Analysis |
| 6 | Population Density |
| 6 | Polymorphism, Single Nucleotide |
| 6 | Ploidies |
| 6 | Plasma |
| 6 | Photoreceptor |
| 6 | Oxidative Stress |
| 6 | Oxidative Stress (drug effects) |
| 6 | Ovulation |
| 6 | Ovary |
| 6 | Oocytes (ultrastructure) |
| 6 | Oocytes (cytology) |
| 6 | North Atlantic |
| 6 | New species |
| 6 | Muscles (chemistry) |
| 6 | Models, Biological |
| 6 | Mitosis |
| 6 | Mitochondria |
| 6 | Microscopy, Electron, Scanning (veterinary) |
| 6 | Microsatellite DNA |
| 6 | Metals, Heavy (analysis) |
| 6 | Mercury |
| 6 | Locomotion |
| 6 | Lethal Dose 50 |
| 6 | Larva (metabolism) |
| 6 | Inhibition |
| 6 | Immunity, Innate |
| 6 | Hemoglobins (metabolism) |
| 6 | Hemoglobins (chemistry) |
| 6 | Hemoglobins (analysis) |
| 6 | Haplotypes |
| 6 | Gonadotropin RH |
| 6 | Gills (enzymology) |
| 6 | Gills (cytology) |
| 6 | Genetic Markers |
| 6 | Freezing |
| 6 | Fish Proteins |
| 6 | Fecundation |
| 6 | Faunal survey |
| 6 | Fatty Acids (analysis) |
| 6 | Estrogen |
| 6 | Distribution |
| 6 | Diploidy |
| 6 | Digestion |
| 6 | Diet (veterinary) |
| 6 | Diencephalon (cytology) |
| 6 | DNA, Complementary |
| 6 | DNA, Complementary (chemistry) |
| 6 | DNA Virus Infections (virology) |
| 6 | DNA (chemistry) |
| 6 | Cytoplasm |
| 6 | Concentration measurement |
| 6 | Color |
| 6 | Cluster Analysis |
| 6 | Chromatography, Gel |
| 6 | Cells, Cultured |
| 6 | Carps (metabolism) |
| 6 | Calcium |
| 6 | Brain Mapping |
| 6 | Brain (Vertebrata) |
| 6 | Biomarkers (metabolism) |
| 6 | Biological monitoring |
| 6 | Behavioral ontogeny |
| 6 | Atlantic cod |
| 6 | Animal |
| 6 | Animal activity |