Abstract
We found the two morphological types (corallite-wall separate type and corallite-wall fusion type) in Montastraea valenciennesi in Wakayama, southern Honshu, Japan. In this study, we investigated whether these types are the morphological variations within a single species or between separate species, using cross breeding experiments. The results clearly showed that these two types were reproductively isolated, suggesting that these two types should be treated as different species, respectively. However, we could not determine which of the morph-types is true M. valenciennesi, in absence of the examination of type specimen.
