The genus Tambja is a member of Nembrothinae and constitutes the largest genus in the group. Several recent studies have been published by Marta Pola and her co-researchers but have concluded that more work is needed to better understand the higher systematics of the group.

As these spectacular images demonstrate, this is a very flamboyant species. Like other members of this genus, T. affinis is large, reaching 50 mm in length. The body is indigo to dark bluish black with a series of longitudinal yellow-green lines on the notum and sides. There is a lighter spot between the rhinophores, on the rhinophoral sheaths, and at the anterior base of the gill. The rhinophores and gill are black and the gill is outlined in green.

Previous documented observations set its geographic territory as Red Sea and Indian Ocean Gordan's fantastic photos here add Aniloa, Batangas, Philippines to its range.

Reference:

Pola, Marta & Valles, Yvonne & Cervera, Juan Lucas & Medina, Monica & Gosliner, Terrence. (2006). Taxonomic status of Tambja abdere and Tambja fusca based on morphological and molecular evidence, with comments on the phylogeny of the subfamily Nembrothinae (Nudibranchia, Polyceridae). Annales Zoologici Fennici. 43. 52-64.