Nudibranchia
Among the very large group of marine, so-called
'naked' slugs few species have developed the ability of a holo-planktonic life,
whereas the majority of the species has a benthic way of life, using their foot
for locomotion on more or less firm substrates. As none of these nudibranchs
has a shell it is impossible to find them as fossils. To give an idea about the
beauty of these animals I reproduce here the front cover of Lalli & Gilmer's (1989)
book, showing two mating individuals of Glaucus
atlanticus Forster, 1777. Further info on these creatures can be found
concentrated in this book (pp. 214-236).
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