Comparison of the tracheal systems ofAnopheles sinensisandAedes togoilarvae using synchrotron X-ray microscopic computed tomography (respiratory system of mosquito larvae using SR-μCT)

Abstract

Mosquito-borne diseases, such as malaria, dengue fever, and Zika virus, are serious global health issues. Vector control may be an important strategy in reducing the mortality caused by these diseases. The respiratory system of mosquito larvae in the water has to inhale atmospheric oxygen as aquatic organisms. In this study, the three-dimensional (3D) structures of the dorsal longitudinal trunks (DLTs) of the tracheal systems of Anopheles sinensis and Aedes togoi were compared using synchrotron X-ray microscopic computed tomography. DLT respiratory frequencies were also investigated. Interestingly, the larvae of the two mosquito species exhibit tracheal systems that are both morphologically and functionally distinct. A. sinensis hangs horizontally under the water surface, and has a smaller DLT volume than A. togoi. In contrast, A. togoi hangs upside down using a siphon by fixing its tip to the water surface. The frequency of peristaltic movement in A. togoi is higher than that of A. sinensis. These differences in the structures and breathing behaviors of the respiratory systems of mosquito larvae provide new insights into the tracheal systems of mosquito larvae, which should help develop novel effective control strategies targeting mosquito larvae.

Acoustic tracheal rupture provides insights into larval mosquito respiration

“…In order to maintain their buoyant condition, the volume proportions of the gas filled tracheal system to body volume must fall within a precise range. As reported by Ha, this percentage for Anopheles sinensis larvae was.34% 16 . The results of our observations and calculations using 37 A. aegypti samples was.33%.…”

“…Our anatomical findings complement a recent revival of interest in mosquito respiratory physiology. However, some conflicts still exist [12][13][14][15][16] . Accordingly, it is important to define some terms used herein.…”

Aquatic Insects Are Dramatically Underrepresented in Genomic Research

“…We then determined the life history strategy (aquatic or terrestrial) for each species with a sequenced genome by defining an aquatic insect as any species that spends at least a portion of its larval or adult life stage living and respiring underwater. For our purposes, we chose to exclude the ~3500 described species of mosquitoes [ 11 ] from our analyses due to their semi-aquatic life cycle, where they develop, but do not breathe, underwater [ 12 ], and long history in human biomedical research. If we elected to include mosquitoes, they would comprise 61% of all aquatic insect genomes and, a single mosquito genus, Anopheles , would account for 51% of the data on its own.…”

Aquatic insects are dramatically underrepresented in genomic research

“…We then determined the life history strategy (aquatic or terrestrial) for each species with a sequenced genome by defining an aquatic insect as any species that spends at least a portion of its larval or adult life stage living and respiring underwater. For our purposes, we chose to exclude the ~3,500 described species of mosquitoes [9] from our analyses due to their semi-aquatic life cycle where they develop, but do not breathe, underwater [10] and long history in human biomedical research. If we elected to include mosquitoes, they would comprise 61% of all aquatic insect genomes and, a single mosquito genus, Anopheles, would account for 51% of the data on its own.…”