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Only a few studies have examined the central visual system of Solifugae until now. To get new insights suitable for phylogenetic analysis we studied the R-cell (or retinula cell) projections and visual neuropils of Galeodes granti using various methods. G. granti possesses large median eyes and rudimentary lateral eyes. In this study, only the R-cells and neuropils of the median eyes were successfully stained. The R-cells terminate in two distinct visual neuropils. The first neuropil is located externally to the protocerebrum directly below the retina, the second neuropil lies in the cell body rind of the protocerebrum, and immediately adjacent is the arcuate body. This layout of the median eye visual system differs from Arachnopulmonata (Scorpiones + Tetrapulmonata). However, there are several similarities with Opiliones. In both, (1) the R-cells are connected to a first and second visual neuropil and not to any other region of the brain, (2) the first neuropil is not embedded in the cell body rind of the protocerebrum, it is rather external to the protocerebrum, (3) the second visual neuropil is embedded in the cell body rind, and (4) the second neuropil abuts the arcuate body. These findings may provide important new characters for the discussion on arachnid phylogeny.
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http://dx.doi.org/10.1016/j.asd.2020.101024 | DOI Listing |
Nat Commun
August 2025
Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 9RT, UK.
Cambrian fossils from the Chengjiang biota demonstrate that over half a billion years ago early stem euarthropods existed coevally with representatives of already recognizable crown groups. Prominent stem taxa were Fuxianhuia protensa and Alalcomenaeus whose cerebral and ganglionic traits identify them as, respectively, stem mandibulates and stem chelicerates. Here we report on the visual systems and brain of the enigmatic lower Cambrian euarthropod Jianfengia multisegmentalis, which reveals neural traits suggestive of Pancrustacea despite its possession of 'great appendages'.
View Article and Find Full Text PDFIntegr Zool
August 2025
School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia.
The social brain hypothesis predicts that the relative size of specific brain regions is driven by the cognitive capacity required to manage complex (social) situations. Spiders are intriguing models to test this hypothesis, as sociality is rare in this usually solitary and aggressive group. Here, we used microCT to compare the central nervous system and brain volumes between social and solitary females of the species in two taxonomic groups, huntsman and crab spiders.
View Article and Find Full Text PDFJ Comp Neurol
June 2025
Queensland Brain Institute, University of Queensland, Brisbane, Australia.
The lamina is the first optic neuropil and visual information integration station in crustaceans and insects, containing synaptic connections between photoreceptors and first-order interneurons. The lamina circuitry in mantis shrimp (stomatopods) is both interesting and complex, as there are 16 different types of photoreceptors contained within the mid-band region of the eye. Using serial block-face scanning electron microscopy, we have reconstructed photoreceptor terminals and lamina interneurons in two major superfamilies with different visual ecologies.
View Article and Find Full Text PDFSci Adv
May 2025
Engineering Research Center of Optical Instrument and System, the Ministry of Education, Shanghai Key Laboratory of Modern Optical System, University of Shanghai for Science and Technology, Shanghai 200093, China.
Arthropods have intricate compound eyes and optic neuropils, exhibiting exceptional visual capabilities. Combining the strengths of digital imaging with the features of natural arthropod visual systems offers a promising approach to harness wide-angle vision and depth perception while addressing limitations like low resolving power. Here, we present an artificial intelligence-assisted biomimetic system modeled after arthropod vision.
View Article and Find Full Text PDFCell Tissue Res
July 2025
Department of Cytology and Evolutionary Biology, Zoological Institute and Museum, University of Greifswald, Soldmannstrasse 23, D.-17489, Greifswald, Germany.
Our current understanding of brain organization in malacostracan crustaceans is strongly biased towards representatives of the Decapoda ("ten legged" crustaceans) such as crayfish, crabs, clawed lobsters and spiny lobsters. However, to understand aspects of brain evolution in crustaceans, a broader taxonomic sampling is essential. The peracarid crustaceans are a species-rich group that embraces representatives of, e.
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