underwater ecosystems, close-up view of a marine environment

underwater coral invertebrate animal organism leaf nature sea flower aquarium blue wildlife close-up marine environment likely scene multiple urchins black spines attached rock surface encrusted small organisms water appears clear greenish hue indicating shallow sunlight filtering particles captures rich biodiversity life biology ecology environmental studies sri lanka ecosystems ocean urchin sea spines spiny aquatic underwater purple animal closeup shellfish water nature wildlife marine echinoderms costa rica scuba diving healthy mediterranean cuisine