Insects (Feb 2024)

Functional Anatomy of Split Compound Eyes of the Whirligig Beetles <i>Dineutus mellyi</i> (Coleoptera: Gyrinidae)

  • Jacob Muinde,
  • Tian-Hao Zhang,
  • Zu-Long Liang,
  • Si-Pei Liu,
  • Esther Kioko,
  • Zheng-Zhong Huang,
  • Si-Qin Ge

DOI
https://doi.org/10.3390/insects15020122
Journal volume & issue
Vol. 15, no. 2
p. 122

Abstract

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The functional anatomy of the split compound eyes of whirligig beetles Dineutus mellyi (Coleoptera: Gyrinidae) was examined by advanced microscopy and microcomputed tomography. We report the first 3D visualization and analysis of the split compound eyes. On average, the dorsal and ventral eyes contain 1913 ± 44.5 facets and 3099 ± 86.2 facets, respectively. The larger area of ventral eyes ensures a higher field of vision underwater. The ommatidium of the split compound eyes is made up of laminated cornea lenses that offer protection against mechanical injuries, bullet-shaped crystalline cones that guide light to the photoreceptive regions, and screening pigments that ensure directional light passage. The photoreceptive elements, made up of eight retinular cells, exhibit a tri-tiered rhabdom structure, including the upper distal rhabdom, a clear zone that ensures maximum light passage, and an enlarged lower distal rhabdom that ensures optimal photon capture.

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