Neuroanatomy of the complex tibial organ of Stenopelmatus (Orthoptera: Ensifera : Stenopelmatidae)
JOURNAL OF COMPARATIVE NEUROLOGY, 511 (1):
81-91 (2008)Abstract
Stenopelmatidae (or "Jerusalem crickets") belong to the atympanate
Ensifera, lacking hearing organs in the foreleg tibiae. Their
phylogenetic position is controversial, either as a taxon in
Tettigonioidea or within the clade of Gryllacridoidea. Similarly, the
origin of tibial auditory systems in Ensifera is controversial.
Therefore, we investigated the neuronal structures of the proximal
tibiae of Stenopelmatus spec. with the hypothesis that internal sensory
structures are similar to those in tympanate Ensifera. In Stenopelmatus
the complex tibial organ consists of three neuronal parts: the
subgenual organ, the intermediate organ, and a third part with linearly
arranged neurons. This tripartite organization is also found in
tympanate Ensifera, verifying our hypothesis. The third part of the
sense organ found in Stenopelmatus can be regarded by the criterion of
position as homologous to auditory receptors of hearing Tettigonioidea.
This crista acustica homolog is found serially in all