Length |
Few centimeters to several meters. |
Weight |
Varies by species, from a few grams to hundreds of kilograms. |
Body Shape |
Typically streamlined for swimming. Some have flat or elongated bodies. |
Fins |
Two pairs of fins (dorsal, pelvic, pectoral, and anal fins), and caudal (tail) fin. |
Mouth |
Varies by species; can be terminal, superior, or inferior. |
Gills |
Used for breathing and extracting oxygen from water. |
Eyes |
Vary in size and position on the head. |
Coloration |
Varied, often camouflaging to surroundings; may change for display. |
Reproduction |
Most lay eggs, while some give birth to live young. |
Senses |
Good sense of smell, lateral line system for detecting vibrations, and vision adapted to water. |
Habitat |
Found in oceans, rivers, lakes, and ponds. |
Diet |
Carnivorous, herbivorous, or omnivorous, depending on the species. |
Lifespan |
Few years to several decades. |