Fig. 1
From: Photoreceptor genes in a trechine beetle, Trechiama kuznetsovi, living in the upper hypogean zone
The habitat and morphology of T. kuznetsovi. A A v-shaped valley of a mountain area at Yûbari City in Hokkaido. B The upper hypogean zone under the slope of a v-shaped valley. It consists of small rocks and clay. C Dorsal view of T. kuznetsovi. Scale bar indicates 3 mm. D Lateral view of T. kuznetsovi head. The bracket indicates the vestigial compound eye. The black part is the pigmentation of the cuticle behind a compound eye (ocular ridge). The arrowhead indicates a hole on the ocular ridge, through which the nerve bundle is presumed to pass. There is no pigmentation in cells inside the compound eye structure. Scale bar indicates 0.2 mm