The Chromodoris loch is a species of sea slug found in tropical waters of the central Indo-Pacific region and is known to range from Malaysia, Indonesia, the Philippines to Fiji and the northern coast of Australia.
Chromodoris lochi is blue or bluish-white with a white margin and typically dark or black lines running down the mantle and the foot. On the mantle, a continuous line runs around the border passing on the outside of the rhinophore and a second median one can be discontinuous. Individuals can reach at least 4 cm in length.
There is some variation between individuals in this species, and the gills and rhinophores range in color from a translucent straw-color, through to pink and light orange. This species is very similar in appearance to Chromodoris willani, Chromodoris boucheti and Chromodoris dianae and can be difficult to tell apart. Its most distinguishing feature is the uniform coloring of the mantle and the lack of white specks which are present in some of the other species.
Chromodoris lochi, like many other nudibranchs, feeds on sponges. It has been reported to eat Cacospongia mycofijiensis and Semitaspongia, both in the family Thorectidae.