Goniobranchus geometricus is a small nudibranch which may grow to a total length of 35mm. It is variably coloured, with the ground colour ranging from a creamy brown to purple, The mantle has numerous cream-coloured bumps and has a white margin. The gills and rhinophores are white to greenish.[5] It is very similar to Goniobranchus conchyliatus but has green-grey rhinophores and gills whilst G. conchyliatus has red ones.[4][6][7]
^ abKing, D. & Fraser, V. 2001. More Reef Fishes and Nudibranchs Struik, Cape Town. ISBN1-86872-686-X
^Debelius, H. & Kuiter, R.H. (2007) Nudibranchs of the world. ConchBooks, Frankfurt, 360 pp. ISBN978-3-939767-06-0 page(s): 164
^Gosliner, T.M., Behrens, D.W. & Valdés, Á. (2008) Indo-Pacific Nudibranchs and seaslugs. A field guide to the world's most diverse fauna. Sea Challengers Natural History Books, Washington, 426 pp. page(s): 220
^Rudman, W. B. & Bergquist, P. R. (2007) A review of feeding specificity in the sponge-feeding Chromodorididae (Nudibranchia: Mollusca). Molluscan Research, 27(2): 60-88