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Fully female spider (Drassodes saccatus) with left male pedipalp, an example of mosaic gynandromorphism.

File:Heteropteryx dilatata 0034b L.D.jpg

Heteropteryx dilatata gynandromorph

A gynandromorph is an organism that contains both male and female characteristics. The term gynandromorph, from Greek "gyne" female and "andro" male, is mainly used in the field of Lepidopterology (butterfly/moth study) or entomology (all insects). These characteristics can be seen in butterflies, where both male and female characteristics can be seen physically because of sexual dimorphism. Cases of gynandromorphism have also been reported in crustaceans, especially lobsters, sometimes crabs and even in birds.[1][2][3][4] A clear example in birds is the gynandromorphic Zebra Finch. These birds have lateralised brain structures in the face of a common steroid signal, providing strong evidence for a non-hormonal primary sex mechanism regulating brain differentiation.[5]

A gynandromorph can have bilateral asymmetry, one side female and one side male,[6] or they can be mosaic, a case in which the two sexes aren't defined as clearly.[citation needed] Bilateral gynandromorphy arises very early in development, typically when the organism has between 8 and 64 cells.[7]

Chickens can also be gynandromorphous.[8]



  1. ^ Chen, Xuqi; Agate, Robert J.; Itoh, Yuichiro; Arnold, Arthur P. (2005). "Sexually dimorphic expression of trkB, a Z-linked gene, in early posthatch zebra finch brain". Proceedings of the National Academy of Sciences. 102 (21): 7730–5. PMC 1140405Freely accessible. PMID 15894627. doi:10.1073/pnas.0408350102. Lay summaryScientific American (March 25, 2003). 
  2. ^ Gouldian Finch Erythrura gouldiae Gynandromorph
  3. ^ Powderhill Banding Fall 2004
  4. ^ A Gender-bender Colored Cardinal, by Tim Wall, Discovery News, 31 May 2011 [1]
  5. ^ Arnold, Arthur P. (2004). "Sex chromosomes and brain gender". Nature Reviews Neuroscience. 5 (9): 701–8. PMID 15322528. doi:10.1038/nrn1494. 
  6. ^ Ian Sample, science correspondent (Tuesday 12 July 2011). "Half male, half female butterfly steals the show at Natural History Museum". The Guardian. Retrieved August 06, 2011.  Check date values in: |access-date=, |date= (help)
  7. ^ Malmquist, David (June 15, 2005). "Rare crab may hold genetic secrets". Virginia Institute of Marine Science. 
  8. ^

External links

Anatomy of an amiotic egg.svg This article is part of Project Glossary, a All Birds project that aims to write comprehensive articles on each term related to animals.