Novel morphological and physiological scaling relationships in the southern red wood ant

Perl, Craig Darren (2018) Novel morphological and physiological scaling relationships in the southern red wood ant. Doctoral thesis (PhD), University of Sussex.

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Abstract

Red wood ants (Formica rufa) are visual navigators whose colonies contain workers that differ substantially in size. By investigating the allometry of the ants’ compound eyes, and the regions within them, I showed that facets in particular regions scaled differently: both grade and slope shifts occurred. Facets in some eye regions were absolutely larger than others, while other facet regions scaled at different rates with body size.
I next compared eye scaling between nests from the same population. Nevertheless, the method by which ants increased their eye size differed between nests. I found that ants from some nests primarily increased eye size through facet number and others through facet diameter. This showed that scaling rules at the cellular levels can differ even within a single population.
Comparisons among Formica species revealed that differential eye scaling was not restricted to just F. rufa. Differential scaling was found in F. sanguinea but not F. lugubris or F. fusca. Surprisingly, scaling between facet diameter and number was conserved across all four species, demonstrating that whole-organ scaling among species can be conservative whilst differing vastly between organ-regions.
Moving beyond morphology, I next investigated whether physiological scaling was equally as variable among nests. Metabolic rate scaling was negatively allometric and the same among four nests. Respiratory water loss was found to be determined solely by metabolic rate. Metabolic rate co-varies with different ventilation types, however, switches in ventilation type are driven by movement. This demonstrates that increases in metabolic rate are not sufficient to explain changes in ventilation type but are sufficient to explain respiratory water loss.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Life Sciences > Biology and Environmental Science
Subjects: Q Science > QL Zoology > QL0360 Invertebrates > QL0434 Arthropoda > QL0463 Insects > QL0563 Hymenoptera > QL0568.A-Z Systematic divisions. By family, A-Z > QL0568.F7 Formicidae (Ants)
Q Science > QL Zoology > QL0799 Morphology
Depositing User: Library Cataloguing
Date Deposited: 25 Apr 2018 10:14
Last Modified: 26 May 2020 06:03
URI: http://sro.sussex.ac.uk/id/eprint/75440

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