blue velvet headshield slug, chelidonura varians, is a species of small sea slug, a marine opisthobranch gastropod mollusc in the

animal background beautiful biodiversity biology blue bunaken chelidonura closeup coral diving ecology environment headshield indonesia invertebrate lens life location macro marine mollusc natural nature nudibranch ocean pacific pattern philippines photography reef romblon scuba sea slug slugs snail sulawesi tropical underwater underwaterphotography varians water wild wildlife