fishs

Fishs is not a standard English plural. The usual plural forms are fish and fishes; “fish” is used for a group of individuals of the same species, while “fishes” is used when referring to multiple species. Fish are aquatic, gill-bearing vertebrates that live in freshwater and saltwater environments. They range in size from tiny gobies to the whale shark and occupy a variety of ecological niches, including herbivores, omnivores, and carnivores.

Most fish have fins that aid in swimming, a lateral line system that detects movement and vibration in water, and scales that protect the body. Their skeletons may be made of bone or cartilage. Respiration is through gills; blood is generally cold-blooded (ectothermic). The typical heart structure varies, but most species have a two-chambered heart.

Classification among living fish divides them into major groups: jawless (agnatha) such as lampreys; cartilaginous (chondrichthyes) such as sharks and rays; and bony (osteichthyes) including ray-finned and lobe-finned fishes. The largest group today is the ray-finned fishes (Actinopterygii), which encompasses the majority of freshwater and marine species.

Reproduction and development also vary. Many species lay eggs (oviparous); others give birth to live young (viviparous) or produce eggs that hatch inside the mother (ovoviviparous). Fertilization can be external or internal, with parental care ranging from none to extensive.

Humans rely on fish for food, sport, and ecosystem roles. Fisheries and aquaculture supply substantial portions of the world’s protein but face challenges from overfishing, bycatch, and habitat destruction. Conservation efforts seek to protect vulnerable species and sustain healthy aquatic ecosystems.