Loch's Chromodoris

Overview

Loch's Chromodoris is a small, colourful sea slug (a dorid nudibranch) in the family Chromodorididae. It was described by William Rudman in 1982. It is easy to confuse with a few close relatives, so careful identification helps.

Distribution & habitat

It lives in the tropical central Indo-Pacific. Its range runs from Malaysia, Indonesia and the Philippines to Fiji and the northern coast of Australia. It has also been recorded in New Caledonia and French Polynesia. In a study in Mo'orea's Cook's Bay it was among the most abundant nudibranchs, and it was more active by day than at night.

Appearance

The body is blue or bluish-white with a white edge and dark blue or black lines along the mantle and foot. A continuous line runs around the mantle border, and a second line down the middle may be broken. The gills and rhinophores vary from translucent straw-coloured to pink or light orange. The mantle is a uniform colour and lacks the white specks seen on some look-alikes. Those look-alikes include Chromodoris willani, C. dianae and C. boucheti. Individuals are small, and an average length of around 2.5 cm was recorded in Mo'orea.

Feeding

Like many dorid nudibranchs, it eats sponges. Reports mention sponges in the family Thorectidae, including Cacospongia mycofijiensis and Semitaspongia.

Reproduction

Nudibranchs are simultaneous hermaphrodites, with both male and female organs. When mating, two individuals line up side by side, facing opposite directions, so that their right sides meet.