New Zealand Octopoda (Mollusca: Cephalopoda) : systematics

Abstract

The New Zealand octopod fauna (Mollusca: Cephalopoda: Octopoda) is revised, with 39 species in 2 suborders, the Cirrata and Incirrata, described. Several changes to established classifications of the cirrata and the incirrate family octopodidae are proposed. The recognized distribution of 6 octopod families (including 2 proposed new families), 14 genera (including 2 proposed new genera) and 3 species are expanded to include New Zealand waters. Nine records of species from New Zealand are synonymised, and 2 species are removed from earlier synonymy and redescribed as distinct species.The New Zealand finned (cirrate) octopod fauna as herein recognized comprises 4 families, 7 genera and 9 species; 2 new families are proposed, 7 new species are described, with 2 additional species identified only to genus (Cirroteuthis sp. and Cirrothauma sp.). One new family is described to accommodate a single new genus, the Luteuthididae fam. nov. and Luteuthis gen. nov., respectively. The second new family, the Grimpoteuthididae, is proposed to accommodate 2 genera, a revised Grimpoteuthis and one new genus, Enigmatiteuthis gen. nov. The genus Cirroctopus Naef, 1923, is removed from synonymy of Grimpoteuthis, and accommodated with Opisthoteuthis in a revised family Opisthoteuthididae. The fourth cirrate family represented in New Zealand waters, the Cirroteuthididae, is recorded for those two species identified only to genus, Cirroteuthis sp. and Cirrothauma sp. The New Zealand non-finned (incirrate) fauna comprises 7 families, 3 subfamilies, 17 genera and 30 species, including 12 proposed new species. Species previously admitted into the New Zealand fauna based solely on identifications of beak or tissue remains from gut contents of long distance foraging bird and whale species are critically evaluated: a family, genus and species are excluded from the New Zealand fauna. No changes are proposed to the classification of any of the 7 incirrate families, although new records and minor nomenclatural changes are made for many species, and the classification of the Octopodidae is re-evaluated on the basis of apparent relationships between species with and without ink sacs. Three nominal subfamilies of the Octopodidae are recognized in New Zealand waters, the octopodinae, Bathypolypodinae and Graneledoninae. Notable changes to previous classifications of the Octopodinae include removal of Pinnoctopus d’Orbigny from synonymy of Octopus, and recognition of 4 discrete types of Octopus (sensu lato) morphology. Within the Bathypolypodinae, 3 species of Benthoctopus (s.l.) are described, and within the Graneledoninae one new species and 1 subspecies of Graneledone are described, 1 is redescribed, and 2 new species of Thaumeledone are proposed. After excluding several Octopus (s.l.) species common to both New Zealand and Australia, for which the distribution could be attributed to larval dispersal, there are clear biogeographic relationships between New Zealand and Australia, the central Pacific Islands, South Africa, South America and Japan. No newly designated type of Octopus (s.l.) morphology is endemic to New Zealand. Deep-sea octopod biogeography remains obscure.