title: The study of deep-sea cephalopods.
abstract: "Deep-sea" cephalopods are here defined as cephalopods that spend a significant part of their life cycles outside the euphotic zone. In this chapter, the state of knowledge in several aspects of deep-sea cephalopod research are summarized, including information sources for these animals, diversity and general biogeography and life cycles, including reproduction. Recommendations are made for addressing some of the remaining knowledge deficiencies using a variety of traditional and more recently developed methods. The types of oceanic gear that are suitable for collecting cephalopod specimens and images are reviewed. Many groups of deep-sea cephalopods require taxonomic reviews, ideally based on both morphological and molecular characters. Museum collections play a vital role in these revisions, and novel (molecular) techniques may facilitate new use of old museum specimens. Fundamental life-cycle parameters remain unknown for many species; techniques developed for neritic species that could potentially be applied to deep-sea cephalopods are discussed. Reproductive tactics and strategies in deep-sea cephalopods are very diverse and call for comparative evolutionary and experimental studies, but even in the twenty-first century, mature individuals are still unknown for many species. New insights into diet and trophic position have begun to reveal a more diverse range of feeding strategies than the typically voracious predatory lifestyle known for many cephalopods. Regular standardized deep-sea cephalopod surveys are necessary to provide insight into temporal changes in oceanic cephalopod populations and to forecast, verify and monitor the impacts of global marine changes and human impacts on these populations.
authors.affiliation: GEOMAR, Helmholtz Centre for Ocean Research Kiel, Kiel, Germany. Electronic address: hhoving@geomar.de.
authors.forename: Henk-Jan T
authors.initials: HJ
authors.lastname: Hoving
authors.affiliation: Centro de Ciências Tecnológicas da Terra e do Mar Universidade do Vale do Itajaí, Itajaí, Santa Catarina, Brazil.
authors.forename: Jose Angel A
authors.initials: JA
authors.lastname: Perez
authors.affiliation: Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Kathrin S R
authors.initials: KS
authors.lastname: Bolstad
authors.affiliation: Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Heather E
authors.initials: HE
authors.lastname: Braid
authors.affiliation: Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Evans
authors.affiliation: Freie Universität Berlin, Institute of Geological Sciences, Branch Paleontology, Berlin, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Fuchs
authors.affiliation: Department of Biological Sciences, University of South Florida St. Petersburg, St. Petersburg, Florida, USA.
authors.forename: Heather
authors.initials: H
authors.lastname: Judkins
authors.affiliation: Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Jesse T
authors.initials: JT
authors.lastname: Kelly
authors.affiliation: Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Sao Paulo, Brazil.
authors.forename: José E A R
authors.initials: JE
authors.lastname: Marian
authors.affiliation: Department of Art and Design, University of Minnesota Duluth, Duluth, Minnesota, USA.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Nakajima
authors.affiliation: GEOMAR, Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Piatkowski
authors.affiliation: Australian Museum Research Institute, Sydney, New South Wales, Australia.
authors.forename: Amanda
authors.initials: A
authors.lastname: Reid
authors.affiliation: NMFS National Systematics Laboratory, National Museum of Natural History, Washington, DC, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Vecchione
authors.affiliation: Institute of Marine Research, Department of Life Sciences, University of Coimbra, Coimbra, Portugal; British Antarctic Survey, NERC, Cambridge, United Kingdom.
authors.forename: José C C
authors.initials: JC
authors.lastname: Xavier
mesh_terms: D000818:Animals; D005075:Biological Evolution; D049830:Cephalopoda / Q000235:genetics / Q000502:physiology*; D003710:Demography; D017753:Ecosystem; D009792:Oceans and Seas
keywords: Biogeography; Cephalopoda; Collection methods; Deep sea; Diversity; Evolution; Longevity; Reproduction; Trophic ecology