Identification of small species with high levels of intra-specific
polymorphism within groups of inter-specific morphologically-conservative
taxa, presents numerous obstacles for biodiversity and ecological studies.
This is particularly true for deep-sea studies that often reveal a great number
of species but only few numbers of specimens. It is here proposed to deal
with such cases by extrapolating information obtained from highly detailed
baseline studies. Such baseline studies should include information about
sexual and ontogenetic variation and should include a combination of both
morphological and molecular techniques.