Fig 1.
External morphology of compound eyes of adult Panorpa dubia, SEM.
(A) Adult head viewed from the front, showing compound eyes on either side of the head. (B) Right compound eye, lateral view. (C) Ommatidia. Arrows indicate interfacetal hairs. Ant, antenna; ATP, anterior tentorial pit; CE, compound eye; LO, lateral ocellus; MO, median ocellus; O, ommatidium. Scale bars: (A) and (B) = 150 μm; (C) = 10 μm.
Table 1.
Measurements on the compound eyes of male Panorpa dubia.
Fig 2.
Histological sections of compound eyes of adult Panorpa dubia, LM.
(A) Longitudinal section showing rhabdom (arrow) formed by photoreceptors in one ommatidium. (B) Transverse-oblique section of greater part of compound eye showing ommatidia cut at various levels; four cone cells are marked in one ommatidium (1–4); arrows indicate nuclei of interommatidial secondary pigment cells. Ax, axon; BM, basal matrix; C, cornea; CC, crystalline cone; PPC, primary pigment cell; R, photoreceptor; SPC, secondary pigment cell. Scale bars: (A) = 25 μm; (B) = 10 μm.
Fig 3.
Ultramorphology of compound eyes of adult Panorpa dubia, SEM.
(A) Longitudinal profile through compound eye. (B) Longitudinal profile through cornea showing approximately 60 lamellae. (C) Crystalline cones connected to rod-like photoreceptors. Inset shows that the internal surface of cornea bears numerous micropapillae (arrows) along its edge. BM, basal matrix; C, cornea; CC, crystalline cone; R, photoreceptor. Scale bars: (A) = 40 μm; (B) = 2 μm; (C) = 15 μm.
Fig 4.
Ultramorphology of photoreceptors and basal matrix of adult Panorpa dubia, SEM.
(A) Longitudinal profile through crystalline cones and photoreceptors showing that primary pigment cells surround the junction between crystalline cone and photoreceptors. (B) Transverse profile through two primary pigment cells. Arrows indicate the boundaries of primary pigment cells. (C) Seven photoreceptors (R1–R7) are identifiable. R7 has an inflated nuclear zone (asterisk) and tapers sharply toward the centre of the cluster (arrowhead). (D) Basal matrix, showing numerous round perforations for axon bundles to pass through (arrows). Ax, axon; BM, basal matrix; CC, crystalline cone; PPC, primary pigment cell; R, photoreceptor; T, tracheole. Scale bars: (A) and (D) = 6 μm; (B) = 5 μm; (C) = 4 μm.
Fig 5.
Transverse sections through rhabdom of adult Panorpa dubia, TEM.
(A) The photoreceptor cluster showing that seven photoreceptors (R1–R7) form a fused rhabdom at the depth of roughly 68–88 μm. (B) At the depth of about 20 μm below the tips of photoreceptors R7 rapidly diminishes in size and becomes much smaller than other photoreceptors (R1–R6). (C) At the depth of approximately 123–128 μm the rhabdom is formed by the rhabdomeres of R1–R8. (D) Below about 128 μm depth the rhabdom is composed of the rhabdomeres of R1–R6 and R8. Arrowhead indicates a desmosome connecting two adjacent photoreceptors. EC, endoplasmic cistern; MB, multivesicular body; Mt, mitochondrion; N, nucleus; R, photoreceptor; Rh, rhabdom; SPC, secondary pigment cell; T, tracheole. Scale bars = 1 μm.
Fig 6.
Diagram of the ommatidium of adult Panorpa dubia in a longitudinal and four transverse sections.
Ax, axon; BM, basal matrix; C, cornea; CC, crystalline cone; N, nucleus; PPC, primary pigment cell; R, photoreceptor; Rh, rhabdom; SPC, secondary pigment cell.