Examination of the tree, which provides independent data for evaluating the evolution of reproductive strategies, leads us to suggest that hermaphroditism or gonochorism
evolved once within studied Ophryotrocha taxa and that sequential hermaphroditism evolved from simultaneous hermaphroditism.
discreta (Ehlers, 1890; Oka, 1895; Marcus, 1939; Mukai and Makioka, 1980; Emschermann, 1985) contains conflicting reports of both comprehensive gonochorism (GgG) and colony hermaphroditism (HhG).
Comprehensive gonochorism (mode GgG): common in the genus Barentsia?
The data for Barentsia hildegardae represent the first compelling demonstration of colony and genet gonochorism (mode GgG) in a kamptozoan.
hildegardae provided unambiguous evidence for comprehensive gonochorism, the samples of colonies growing on ascidians [ILLUSTRATION FOR FIGURE 3A OMITTED] did not.
Field sampling was more strongly suggestive of colony gonochorism for B.
This contradicts earlier reports (Oka, 1895; Marcus, 1939) of colony gonochorism, but supports the findings of one older report (Ehlers, 1890, on B.
However, the data presented here demonstrate that three sexual modes (GgG, HhG, and HhH) are expressed by species of Barentsia, and that comprehensive gonochorism (mode GgG) may be at least as common as HhG.
Comprehensive gonochorism (GgG), as in Barentsia hildegardae, prevents the self-fertilization that might occur if calyces or colonies were hermaphroditic.