|Life history parameters calculated from growth rings in parasitic barnacles of the Family Peltogastridae (Crustacea: Cirripedia: Rhizocephala)|
Lützen, J. (1987). Life history parameters calculated from growth rings in parasitic barnacles of the Family Peltogastridae (Crustacea: Cirripedia: Rhizocephala). J. Crust. Biol. 7(3): 493-506
In: Journal of Crustacean Biology. Crustacean Society: Washington. ISSN 0278-0372, more
Growth rings; Life history; Peltogaster curvatus Kossmann, 1874 [WoRMS]; Peltogaster paguri Rathke, 1842 [WoRMS]; Peltogastridae Lilljeborg, 1861 [WoRMS]; Marine
In 12 species within 8 genera of Peltogastridae the stalk base is surrounded by concentric, circular to fusiform annuli that mark the line along which the mantle cuticle splits at molts. The cuticle outside the annulus is shed, but that within each of the annuli is retained; by successive molts, these accumulate to a solid cuticular shield. Molting of the external cuticle occurs just before egg laying, but the first four molts probably occur when the parasite is immature, except in and Peltogasterella. In Peltogaster paguri and P. curvatus closely packed annuli alternate with more widely spaced ones, suggesting annual rings. Counts of annuli provide insight into the number of broods an externa may produce during its life and can help to estimate the age of individual externae as well as host crabs, or to analyze the age distribution of a rhizocephalan population. Such counts show that the growth rate in two species of Peltogaster varies greatly and is positively correlated with host size at the time of externa emergence.