Differential investment in brain regions for a diurnal and nocturnal lifestyle in Australian Myrmecia ants

Zachary B. V. Sheehan, J. Frances Kamhi, Marc A. Seid, Ajay Narendra*

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    20 Citations (Scopus)
    4 Downloads (Pure)


    Animals are active at different times of the day. Each temporal niche offers a unique light environment, which affects the quality of the available visual information. To access reliable visual signals in dim-light environments, insects have evolved several visual adaptations to enhance their optical sensitivity. The extent to which these adaptations reflect on the sensory processing and integration capabilities within the brain of a nocturnal insect is unknown. To address this, we analyzed brain organization in congeneric species of the Australian bull ant, Myrmecia, that rely predominantly on visual information and range from being strictly diurnal to strictly nocturnal. Weighing brains and optic lobes of seven Myrmecia species, showed that after controlling for body mass, the brain mass was not significantly different between diurnal and nocturnal ants. However, the optic lobe mass, after controlling for central brain mass, differed between day- and night-active ants. Detailed volumetric analyses showed that the nocturnal ants invested relatively less in the primary visual processing regions but relatively more in both the primary olfactory processing regions and in the integration centers of visual and olfactory sensory information. We discuss how the temporal niche occupied by each species may affect cognitive demands, thus shaping brain organization among insects active in dim-light conditions.

    Original languageEnglish
    Pages (from-to)1261-1277
    Number of pages17
    JournalJournal of Comparative Neurology
    Issue number7
    Early online date27 Dec 2018
    Publication statusPublished - 1 May 2019


    • allometric scaling
    • ants
    • brain
    • Myrmecia
    • neuropil
    • RRID:AB_2315424
    • RRID:AB_2535771
    • RRID:SCR_002285
    • RRID:SCR_007353
    • temporal niche


    Dive into the research topics of 'Differential investment in brain regions for a diurnal and nocturnal lifestyle in Australian Myrmecia ants'. Together they form a unique fingerprint.

    Cite this