Taxonomic assessment of species of the genus Octopus from the northeastern Pacific via morphological, molecular and morphometric analyses

Mariana Díaz-Santana-Iturrios; César Augusto Salinas-Zavala; Francisco Javier García-Rodríguez; Jasmín Granados-Amores

doi:10.7717/peerj.8118

Taxonomic assessment of species of the genus Octopus from the northeastern Pacific via morphological, molecular and morphometric analyses

PeerJ. 2019 Nov 29:7:e8118. doi: 10.7717/peerj.8118. eCollection 2019.

Authors

Mariana Díaz-Santana-Iturrios¹, César Augusto Salinas-Zavala², Francisco Javier García-Rodríguez³, Jasmín Granados-Amores⁴

Affiliations

¹ Programa de Doctorado en Ciencias Biológico Agropecuarias, Universidad Autónoma de Nayarit, Xalisco, Nayarit, Mexico.
² Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz, Baja California Sur, Mexico.
³ Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas (IPN-CICIMAR), La Paz, Baja California Sur, Mexico.
⁴ Escuela Nacional de Ingeniería Pesquera, Universidad Autónoma de Nayarit, San Blas, Nayarit, Mexico.

Abstract

Species of the genus Octopus from the northeastern Pacific are ecologically and economically important; however, their taxonomy is confusing and has not been comprehensively assessed. In this study, we performed a taxonomic evaluation of these species considering the morphological characteristics of the original descriptions, a molecular analysis of partial COI-gene sequences, and a traditional morphometry analysis of nine body measurements. Several interesting findings were obtained with our results: for instance, we updated the diagnoses of some species by including characters such as the number of lamellae per demibranch and the presence of chromatophores in the visceral sac; we deposited partial COI-gene sequences of species that had not been incorporated into the GenBank repository; and according to the morphometric analysis, we confirmed that the lengths of arms I-IV are relevant to discriminate the species under study. The taxa evaluated were morphologically, molecularly and morphometrically well-delimited; however, features such as funnel organ shape and arm length proportions in regard to dorsal mantle length are either not included in the diagnosis of the genus Octopus or overlap with other genera. Hence, this information, combined with the results obtained from the molecular analysis, supports the generic re-assignation of two of the species evaluated.

Keywords: Octopod; Octopodidae; Octopuses; Species discrimination; Taxonomic problems; Taxonomic tools; Taxonomy.

Grants and funding

This work derived from the project 253315 funded by CONACyT. Mariana Díaz-Santana-Iturrios was supported by CONACyT grant number: 415133. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.