Acorn Barnacle
Balanus glandula
9.2 mm
Relaxed (not inflated) penis length of thawed, extracted soma; the 'standard length' to which the field-survey analyses were standardised (Barkley Sound, BC)
Relative champion
On wave-battered shores these barnacles have shorter, stouter penises than in sheltered bays, and barnacles transplanted from one to the other grew penises to suit their new shore.
Margin note: On these shores the weather does the tailoring, cutting them shorter and stouter wherever the waves are rough.
Sources
- Neufeld C.J., Palmer A.R. (2008) Precisely proportioned: intertidal barnacles alter penis form to suit coastal wave action. Proceedings of the Royal Society B 275(1638):1081–1087 doi:10.1098/rspb.2007.1760
- Neufeld C.J. (2011) Morphological plasticity of barnacle feeding legs and penises. PhD thesis, University of Alberta (Chapter 2 = Neufeld & Palmer 2008) link
- Darwin C. (1854) A Monograph on the Sub-class Cirripedia. Vol. 2: The Balanidae, the Verrucidae, etc. London: Ray Society link
Drawn from
- Neufeld 2011 thesis Fig. 2-4b (= Neufeld & Palmer 2008 Fig. 3b): Lateral photo of a relaxed, extracted penis (exposed-shore animal, basal width 8.9 mm), 2 mm scale bar: tapering, gently S-curved tube
- Neufeld & Palmer 2008 Fig. 3a: Protected-shore penis: longer and more slender, same view
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