The dominant group Coleoidea (with one extant subdivision--Neocolioidea) includes species with an internal shell, such as squid (Teuthida), bobtail squid (Sepiolida), cuttlefish (Sepiida), octopus (Octopoda), and Vampyromorpha
. Cephalopod fisheries are widespread and their relatively short life spans and high stock fluctuations make these dynamic fisheries a challenge to manage.
Combined phylogenetic analysis of both molecular and morphological data, Vampyromorpha
has been inferred to be the sister group to Octopoda (Lindgren et al., 2004).
Comparative morphology, variability, and systematic applications of cephalopod spermatophores (Teuthoidea and Vampyromorpha
1) is the lone occupant of the cephalopod order Vampyromorpha. Its unique morphological characteristics, combining features of both the octopodiformes and decapodiformes, suggest that it represents an evolutionary position intermediate between the two groups (Young, 1977; Healy, 1989); and it may be a relic from an ancestral cephalopod line (Pickford, 1946).
The bioluminescent organs of the deep-sea cephalopod Vampyroteuthis infernalis (Cephalopoda: Vampyromorpha).
Flight of the vampire: ontogenetic gait-transition in Vampyroteuthis infernalis (Cephalopoda: Vampyromorpha) J.
Members of the sister taxon, the suborder Ciffata, lack posterior salivary glands in the mantle cavity, the glands of the outgroup, the order Vampyromorpha
, are very small (Young, 1964).