Browsing by Author "Fernandes, Ana Sofia David, 1990-"
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- The influence of nutrition on the morphology of the adult body and the eye of the blowfly, Calliphora vicinaPublication . Fernandes, Ana Sofia David, 1990-; Fonseca, Paulo Jorge Quintais Cancela da, 1958-; Niven, JeremyOrganisms can have relatively larger or smaller morphological structures depending on their total body size, and this variation is called allometry. By selecting blowflies Caliphora vicina that varied in size depending on the amount of food during larval stage, it was possible to generate adult males and females with a broad range of body sizes and use them to access the scaling relationships of several external and internal morphological structures. The external characters wing, leg, and genital length, head width, eye length and width and thorax mass all showed negative allometry, genitals having the lowest slope. Males showed a higher slope for wings compared with females and so this character may be sexually selected on males. To relate the scaling relationships to a specific behavioural task as the chasing behaviour of the males, several characters that influence the visual performance and consequently this behaviour were measured. The facets diameter showed negative allometry in all regions of the eye and no differences in slope between males and females. However, the intercept was higher for some regions of the males’ eye compared with the females’, and so males are investing more on these traits in an absolute way. The internal characters rhabdom diameter and length and focal length showed much less predictable variation. The results show that it is possible that the scaling relationships of the external characters might be compensated by a larger investment of the smaller flies on the internal characters, and it is not possible to conclude if the chasing behaviour is responsible for sexual selective pressures acting on these traits. The Resting Metabolic Rate of the adult flies was also measured but no differences were found between sexes and so the investment of males on visual system is not determinant to the overall RMR.