Fig. 4From: Measurement of refractive indices of tunicates’ tunics: light reflection of the transparent integuments in an ascidian Rhopalaea sp. and a salp Thetys vagina Fine surface structure of Thetys vagina tunic (a TEM; b model for the simulation of light reflectance) and Rhopalaea sp. tunic (c TEM). Arrowheads in a indicate cuticular protuberances, and facing arrowheads in c indicate the cuticular layer. cu, cuticular layer; tm, tunic matrix. Scale bars in a and c indicate 0.2 μmBack to article page