TY - JOUR
T1 - Possible atavisms of genitalia in two species of earwig (Dermaptera), Proreus simulans (Chelisochidae) and Euborellia plebeja (Anisolabididae)
AU - Kamimura, Y.
N1 - Funding Information:
I thank K. Kohno and M. Yamada for help in sample collection, K. Amano for providing useful information on mutant honeybees produced by gamma irradiation, and the staff of the Takasaki Establishment of the Radiation Application Development Association for their assistance in gamma-ray irradiation. F. Haas and an anonymous referee provided valuable suggestions for improvement. This research was supported by a Grant-in-Aid for Scientific Research (No. 16770017) and the Open Research Center Project to Rissho University from the Japan Ministry of Education, Culture, Sports, Science, and Technology.
PY - 2007/9
Y1 - 2007/9
N2 - Male and female genitalia generally show a rapid evolutionary rate, which raises the problems related to homologization and the determination of the polarities of evolutionary changes. In earwigs (Dermaptera), multiple or branched female sperm-storage organs (spermathecae) have been reported for members of the Karschiellidae, Pygidicranidae, and Diplatyidae, collectively termed the "basal" Dermaptera. Whether the complicated spermathecae represent a plesiomorphy or an apomorphy has not been resolved. Here I report the occurrence of multiple or branched spermathecae in gamma-irradiated samples of two earwig species, Euborellia plebeja (Dohrn, 1863) (Anisolabididae) and Proreus simulans (Stål, 1860) (Chelisochidae), which belong to the "higher" Dermaptera (Apachyidae, Labiduridae, Anisolabididae, Spongiphoridae, Chelisochidae, and Forficulidae). Females belonging to the higher Dermaptera normally have a single-unbranched spermatheca. I discuss examples of possible atavisms in relation to the evolutionary pathways of spermathecal morphology. Possible atavisms in the number of male organs for sperm transfer (virgae) are also reported.
AB - Male and female genitalia generally show a rapid evolutionary rate, which raises the problems related to homologization and the determination of the polarities of evolutionary changes. In earwigs (Dermaptera), multiple or branched female sperm-storage organs (spermathecae) have been reported for members of the Karschiellidae, Pygidicranidae, and Diplatyidae, collectively termed the "basal" Dermaptera. Whether the complicated spermathecae represent a plesiomorphy or an apomorphy has not been resolved. Here I report the occurrence of multiple or branched spermathecae in gamma-irradiated samples of two earwig species, Euborellia plebeja (Dohrn, 1863) (Anisolabididae) and Proreus simulans (Stål, 1860) (Chelisochidae), which belong to the "higher" Dermaptera (Apachyidae, Labiduridae, Anisolabididae, Spongiphoridae, Chelisochidae, and Forficulidae). Females belonging to the higher Dermaptera normally have a single-unbranched spermatheca. I discuss examples of possible atavisms in relation to the evolutionary pathways of spermathecal morphology. Possible atavisms in the number of male organs for sperm transfer (virgae) are also reported.
KW - Branching morphogenesis
KW - Character reversion
KW - Dermaptera
KW - Gamma-ray irradiation
KW - Genital morphology
KW - Organ-number evolution
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U2 - 10.1016/j.asd.2007.03.003
DO - 10.1016/j.asd.2007.03.003
M3 - Article
C2 - 18089114
AN - SCOPUS:34548383829
SN - 1467-8039
VL - 36
SP - 361
EP - 368
JO - Arthropod Structure and Development
JF - Arthropod Structure and Development
IS - 3
ER -