3D chemoecology and chemotaxonomy of corals using fatty acid biomarkers: Latitude, longitude and depth C  atia Figueiredo a, 1 , Miguel Baptista a, 1 , In ^ es C. Rosa a , Ana Rita Lopes a , Gisela Dionísio a, b , Rui J.M. Rocha b , Igor C.S. Cruz c , Ruy K.P. Kikuchi d , Nuno Sim ~ oes e , Miguel Costa Leal b , In ^ es Tojeira f , Narcisa Bandarra g , Ricardo Calado b , Rui Rosa a, * a MARE - Marine Environmental Science Centre, Laborat orio Marítimo da Guia, Faculdade de Ci^ encias da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal b Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universit ario de Santiago, 3810-193 Aveiro, Portugal c Laborat orio de Ecologia Marinha, Instituto de Biologia Roberto Alc^ antara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil d Departamento de Oceanograﬁa, Instituto de Geoci^ encias, Universidade Federal da Bahia, Rua Adhemar de Barros, Campus Ondina, CEP 40170-110, Salvador, Bahia, Brazil e Unidad Multidisciplinaria de Docencia e Investigaci oneSisal, Facultad de Ciencias, Universidad Nacional Autonoma de M exico (UMDI-Sisal, FC, UNAM), Mexico f Portuguese Task Group for the Extension of the Continental Shelf (EMEPC), Rua Costa Pinto 165, 2770-047 Paço de Arcos, Portugal g Instituto Portugu^ es do Mar e da Atmosfera (IPMA), Avenida de Brasília, 1449-006 Lisbon, Portugal article info Article history: Received 29 July 2016 Received in revised form 18 October 2016 Accepted 22 October 2016 Keywords: Chemoecology Chemotaxonomy Hexacorals Octocorals Zooxanthellate Azooxanthellate Deep-sea abstract With the objective of uncovering differences in the fatty acid (FA) composition of hexa- and octocorals from different climatic zones (equatorial, subtropical and tropical) and distinct habitats (e.g. rock and coral reefs; intertidal to deep-sea environments), the FA composition of 36 hexa- and octocoral species (132 specimens) was analysed (including the ﬁrst characterization of organisms from the order Zoantharia and deep-sea gorgo- nians). PCA was applied in a FA matrix of the ten major PUFAs to detect differences among coral groups. Fatty acid proﬁle analysis conﬁrmed that C24 polyunsaturated FAs are suit- able chemotaxonomic biomarkers to separate hexa- and octocorals. The polyunsaturated FA 22:6n-3 was identiﬁed as a useful biomarker to distinguish between zoantharians and scleractinians. Also, we discuss the role of food availability (type of phytoplankton assemblage) in relation to autotrophic carbon signiﬁcance and in the establishment of FA proﬁles of octocorals from the West and East coasts of the Atlantic Ocean. Furthermore, we show that the occurrence of high levels of primary productivity hinder the use of FA proﬁles to distinguish between zooxanthellate and azooxanthellate octocorals. Finally, we present and discuss the particular traits of the FA proﬁle of deep-sea gorgonians while comparing it with that of shallow species. © 2016 Elsevier Ltd. All rights reserved. * Corresponding author. E-mail address: rrosa@fc.ul.pt (R. Rosa). 1 Authors equally contributed to the work. Contents lists available at ScienceDirect Biochemical Systematics and Ecology journal homepage: www.elsevier.com/locate/biochemsyseco http://dx.doi.org/10.1016/j.bse.2016.10.016 0305-1978/© 2016 Elsevier Ltd. All rights reserved. Biochemical Systematics and Ecology 70 (2017) 35e42