Abstract
The ability to share and store food is paramount in group-living animals, allowing a finely tuned distribution of resources over time and individuals and an enhanced survival over periods of food scarcity. Ants have several ways to store food: one of them is their gastral crop, also known as a “social stomach.” Nutrients in the crop can be regurgitated to nestmates through oral trophallaxis (mouth-to-mouth) or proceed to the midgut by opening the proventriculus, a valve connecting the crop to the midgut. However, some ants are also known to have a so-called “thoracic crop,” an extension of the esophagus that allows for additional storage space. In this study, we provide the first evidence of a thoracic crop in the genus Carebara, in reproductive (queen) and sterile (soldier and worker) castes. We discuss how the ant body plan allowed for the evolution of a novel food storage structure in the mesothorax.
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Acknowledgements
We are grateful to the late Christian Peeters for stimulating conversations on food storage in ants and suggesting the potential interest of Carebara perpusilla’s esophagus. We thank the Okinawa Institute of Science and Technology Graduate University (OIST) Imaging Section for providing access to the micro-CT scanner. We also acknowledge the assistance of An Vandoren in producing the histological sections.
Funding
This work was supported by subsidy funding to OIST and Japanese Society for the Promotion of Science (JSPS) grants (KAKENHI grant-in-aid 22F22761 for AK and 17K15180 for EPE).
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Adam Khalife: methodology, investigation (microCT and behavior), visualization, and writing—original draft; Johan Billen: investigation (histology), visualization, and writing—review and editing; Evan P. Economo: supervision, conceptualization, resources, and writing—review and editing.
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Communicated by: Matthias Waltert
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Khalife, A., Billen, J. & Economo, E.P. Evidence of a thoracic crop in workers, soldiers, and queens of Carebara perpusilla ants (Formicidae: Myrmicinae). Sci Nat 110, 36 (2023). https://doi.org/10.1007/s00114-023-01866-5
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DOI: https://doi.org/10.1007/s00114-023-01866-5