Fig. 5

Photo micrographs of the silk fibers in the caddisworm H. nigrovittatus.a, b Each silk fiber (Sk) shows peculiar banding pattern as alternating dark (arrowheads) and light bands. c, d The alignment of fibers in the silken case causes the entire silk ribbon to appear striated (arrowheads). Scale bars indicate 50 μm (a), 25 μm (b), 10 μm (c), and 5 μm (d), respectively