Gonopore
Agonopore,sometimes called agonadopore,is agenitalpore in manyinvertebrates.Hexapods,includinginsects,have a single common gonopore, exceptmayflies,which have a pair of gonopores.[1]More specifically, in the unmodified female, it is the opening of the commonoviduct,and in the male, it is the opening of theejaculatory duct.
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". InMalacostraca,it is on the sixth thoracic segment; inSymphyla,it is on the fourth trunk segment; inarachnids,it is on the second segment of theopisthosoma.[2]Ininsectsandcentipedes,the gonopores are close to the animal's tail,[2]while inmillipedes,they are on the thirdbody segmentbehind the head, near the second pair of legs.[3]
See also
[edit]References
[edit]- ^Nikita Kluge (2004)."Morphology of mayflies".The Phylogenetic System of Ephemeroptera.Springer.pp. 21–54.ISBN978-1-4020-1974-6.
- ^abAlessandro 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 ofSpecial Papers in Palaeontology.Wiley-Blackwell.pp. 31–43.ISBN978-0-901702-81-4.
- ^Hopkin, Stephen P.; Read, Helen J. (1992).The Biology of Millipedes.Oxford: Oxford University Press.ISBN0198576994.