|The reproductive periods and condition of the penis in several species of common cirripedes|
Barnes, M. (1992). The reproductive periods and condition of the penis in several species of common cirripedes. Oceanogr. Mar. Biol. Ann. Rev. 30: 483-525
In: Oceanography and Marine Biology: An Annual Review. Aberdeen University Press/Allen & Unwin: London. ISSN 0078-3218; e-ISSN 2154-9125, meer
The largest and most diverse order of the Cirripedia is the Thoracica which contains three living sub-orders, the Lepadomorpha, Verrucomorpha, and Balanomorpha. There is only limited information about the first two as regards the state of the penis during and after the reproductive period; this information has been summarised. Within the Balanomorpha more details are available and the regression and/or loss of the penis after the reproductive period has been discussed. The amount of regression seems to depend on how frequently the animals breed within a season. In those species producing only one brood a year or with a synchronised first brood of the year, it is easier to find complete loss of penis during the long non-breeding period. In other cases the loss appears to be masked by the variable reproductive state of the population and the lack of very frequent sampling. The connection between antenniformy, the reproductive state of the animals and the penis has been discussed. In animals having antenniform cirri the penis is usually much reduced or absent.