Meeting Abstract
Bioluminescence, the biological production of light, is a common communication strategy in many mesopelagic and bathypelagic fishes. Bioluminescence in fishes takes place inside specialized glandular cutaneous organs called photophores. The number, size, placement, and structure of photophores varies greatly across fishes and likely has evolved independently multiple times. In this study, the ultrastructure and microstructure of photophores in Vinciguerria mahabiss, a species of Phosichthyidae endemic to the Red Sea, is described. The volume of each of the 144 photophores from 5 juvenile V. mahabiss was measured. The size-corrected volumes, standardized by head length, show clear differences in photophore size across body regions with the post-orbital, lateral, and post-anal photophores the smallest and the sub-orbital photophore the largest. Photophores were sectioned at 5 microns and double stained with eosin/hematoxylin to examine their microstructure. The microscopic photophore structure shows a standard Stomiiformes arrangement with a rounded photogenic chamber and a thick outer lens. The possible functional significance of photophore arrangement and structure in V. mahabiss are discussed.
