The eyestalk photophore of Northern krill Meganyctiphanes norvegica (M. Sars) (Euphausiacea) re-investigated: Innervation by specialized ommatidia of the compound eye
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引用次数: 0
Abstract
Members of the Euphausiacea (“krill”) generate bioluminescence using light organs, the so-called photophores, including one pair associated with the eyestalks, two pairs on the thoracic segments, and four unpaired photophores on the pleon. The photophores generate light via a luciferin–luciferase type of biochemical reaction in light-emitting cells comprised in a photophore compartment called “lantern”. The behavioral significance of bioluminescence in krill is discussed controversially, and possible functions include a defensive function, camouflage by counter-shading, and intra-specific communication. Light production of all krill photophores is controlled by hormonal and neuronal pathways but our knowledge about the nature of these pathways is still rudimentary. Here, we provide a detailed description of the eyestalk photophore's histology in Northern krill Meganyctiphanes norvegica, and used immunohistochemistry combined with confocal laser-scan microscopy to explore this organ's serotonergic innervation. Furthermore, we provide evidence that the photophore is innervated by a distinct photophore nerve that originates from a specialized cluster of ca. 30 highly modified ommatidia at the dorsal rim of the compound eye that are optically isolated from the other ommatidia. Our findings suggest the compound eye – photophore link as a major anatomical axis to adjust the photophore activity.
期刊介绍:
Arthropod Structure & Development is a Journal of Arthropod Structural Biology, Development, and Functional Morphology; it considers manuscripts that deal with micro- and neuroanatomy, development, biomechanics, organogenesis in particular under comparative and evolutionary aspects but not merely taxonomic papers. The aim of the journal is to publish papers in the areas of functional and comparative anatomy and development, with an emphasis on the role of cellular organization in organ function. The journal will also publish papers on organogenisis, embryonic and postembryonic development, and organ or tissue regeneration and repair. Manuscripts dealing with comparative and evolutionary aspects of microanatomy and development are encouraged.