colorful betta fish swimming in blackwater with graceful fins

action animal aquarium aquatic aquaticecology aquaticenvironment aquaticlife aquaticspecies beauty betta biology closeup colorful colorfulfins delicate dynamic ecosystem elegant exotic fauna fins finsspread fish freshwater graceful habitat ichthyology illustrations lifestyle marine movement natural nature pet portraits serene surreal swimming tranquility tropical tropicalfish underwater unique vibrant wildlife zoology