ðə θˈɪk stɹˈɔŋ ʃˈɛl ʌvðə ɹˈɑːpə wˈɛlk ɪz ˈɑːɹɡjuːəbli ɪts stɹˈɔŋɡɪst ɐdvˈæntɪdʒ ˌoʊvɚ nˈeɪɾɪv wˈɛlks, bɪkˈʌz ɹˈɑːpəz kæn ˈiːzili pɹˈeɪ ˌɔn lˈoʊkəl wˈɛlks, wˈɛɹæz lˈoʊkəl wˈɛlks ɑːɹ ʌnˈeɪbəl tə səksˈɛsfəli ɐtˈæk ɹˈɑːpəz.
The thick strong shell of the rapa whelk is arguably its strongest advantage over native whelks, because rapas can easily prey on local whelks, whereas local whelks are unable to successfully attack rapas.