Nembrotha purpureolineolata nudibranch close up crawling over tropical coral reef

nembrotha purpureolineolata nudibranch saltwater species sea slug marine animal marine gastropod scuba scuba diving mollusca underwater reef sealife coral reef mollusc undersea mollusk aquatic oceanic underwater coral muck diving sea indian ocean saltwater small ocean tiny colorful native macro nature close up natural aqua travel adventure water