Click the thumbnail photos to enhance!
The head has a broad brownish band from the eyes to the mouth, and their is a second brown patch from the rhinophores back towards the pericardium. The lower half of the rhinophores is white and the upper half is black. The ceratal wall is transparent, the digestive glands are green, and there are traces of a pinkish-red spot near the tips of the cerata. I have never seen a specimen larger than 6 mm.
It differs from Costasiella kuroshimae by the colour of the head, white in Costasiella kuroshimae, by the broad brownish band on the head, in Costasiella kuroshimae a thin brownish yellow, median line from the eyes to the front of the head, by the rhinophores, in Costasiella kuroshimae white with a black tip. The cerata of Costasiella kuroshimae were described as 'generally green with white tips'.
This picture with a ruler in the background gives an idea how it looks like in the field on its food plant. Costasiella cf. kuroshimae is almost always found on this kind of algae, a species of Avrainvillea, which the sacoglossa-expert Kathe R. Jensen says is the normal food plant of the genus Costasiella.
In IPN are pictures of two different species as Costasiella kuroshimae, the left one is my Costasiella cf. kuroshimae, the upper right one might be Costasiella kuroshimae, its rhinophores are white with a black tip.
The Sea-Slug Forum changed its name from Costasiella cf. kuroshimae into Costasiella sp. 3.
More information on Costasiella cf. kuroshimae as Costasiella sp. 3 are on Bill Rudman's Sea-Slug Forum!
How to cite:
Köhler, E. (2016), published 16 August 2016, Costasiella cf. kuroshimae Ichikawa, 1993
available from http://www.Philippine-Sea-Slugs.com/Sacoglossa/Costasiella_kuroshimae_cf.htm