Other invertebrates may have no rigid structures but the epidermis may secrete a variety of surface coatings such as the pinacoderm of sponges, the gelatinous cuticle of cnidarians (polyps, sea anemones, jellyfish) and the collagenous cuticle of annelids.
ˈʌðɚɹ ɪnvˈɜːɾɪbɹˌeɪts mˌeɪhɐv nˈoʊ ɹˈɪdʒɪd stɹˈʌktʃɚz bˌʌt ðɪ ˌɛpɪdˈɜːmɪs mˈeɪ sᵻkɹˈiːt ɐ vɚɹˈaɪəɾi ʌv sˈɜːfɪs kˈoʊɾɪŋz sˈʌtʃ ɐz ðə pˈɪnɐkˌoʊdɜːm ʌv spˈʌndʒᵻz, ðə dʒɛlˈætɪnəs kjˈuːɾɪkəl ʌv sˈiːnɪdˈɛɹiənz pˈɑːlɪps, sˈiː ɐnˈɛməniz, dʒˈɛlɪfɪʃ ænd ðə kˈɑːleɪdʒnəs kjˈuːɾɪkəl ʌv ˈænɪlˌɪdz.