A gonopore, sometimes called a gonadopore, is a genital pore in many invertebrates. Hexapods, including insects, have a single common gonopore, except mayflies, which have a pair of gonopores.[1] More specifically, in the unmodified female, it is the opening of the common oviduct, and in the male, it is the opening of the ejaculatory duct.
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The position of the gonopore varies considerably between groups, but is generally constant within groups, allowing its position to be used as a "segmental marker". In Malacostraca, it is on the sixth thoracic segment; in Symphyla, it is on the fourth trunk segment; in arachnids, it is on the second segment of the opisthosoma.[2] In insects and centipedes, the gonopores are close to the animal's tail,[2] while in millipedes, they are on the third body segment behind the head, near the second pair of legs.[3]
See also
editReferences
edit- ^ Nikita Kluge (2004). "Morphology of mayflies". The Phylogenetic System of Ephemeroptera. Springer. pp. 21–54. ISBN 978-1-4020-1974-6.
- ^ a b Alessandro Minelli, Giuseppe Risco & Nigel Hughes (2003). "Tagmata and segment specification in trilobites". In Richard A. Fortey (ed.). Trilobites and their Relatives: Contributions from the Third International Conference, Oxford 2001. Issue 70 of Special Papers in Palaeontology. Wiley-Blackwell. pp. 31–43. ISBN 978-0-901702-81-4.
- ^ Hopkin, Stephen P.; Read, Helen J. (1992). The Biology of Millipedes. Oxford: Oxford University Press. ISBN 0198576994.