Cryptic species are common in the ocean, particularly among marine invertebrates such as octopuses. Delineating cryptic species is particularly problematic in octopus taxonomy where the plasticity recorded among taxonomic characters often results in low resolution at the species level. This study investigated the morphological relationships among seven phylogenetic clades (identified using cytochrome c oxidase subunit I) of the broadly distributed Octopus vulgaris species complex and close relatives. Morphological analyses in this study were successful in delimiting O. sinensis, Brazilian O. vulgaris and O. vulgaris sensu stricto, which was congruent with the molecular findings of this study. Analyses based on male morphology were successful in distinguishing 14 of 15 total pairwise comparisons and proved to be a more reliable indicator of species‐level relationships in comparison with female morphology. The majority of characters with the greatest discriminatory power were male sexual traits. Significant morphological differences were also recorded among sampling localities of conspecifics, with phenotype showing correlation with local environmental data. The findings of this study support the hypothesis that multiple O. vulgaris‐like species are currently being incorrectly treated under a single species name, O. vulgaris. Octopuses being exported globally under the name O. vulgaris are of extremely high fisheries market value and profile. Our findings have potentially significant implications for the naming and conservation of commercially harvested members of this species complex throughout their ranges.

Despite extensive revisions over recent decades, the taxonomy of benthic octopuses (Family Octopodidae) remains in a considerable flux. Among groups of unresolved status is a species complex of morphologically similar shallow-water octopods from subtropical Australasia, including: Allopatric populations of Octopus tetricus on the eastern and western coasts of Australia, of which the Western Australian form is speculated to be a distinct or sub-species; and Octopus gibbsi from New Zealand, a proposed synonym of Australian forms. This study employed a combination of molecular and morphological techniques to resolve the taxonomic status of the ‘tetricus complex’. Phylogenetic analyses (based on five mitochondrial genes: 12S rRNA, 16S rRNA, COI, COIII and Cytb) and Generalised Mixed Yule Coalescent (GMYC) analysis (based on COI, COIII and Cytb) distinguished eastern and Western Australian O. tetricus as distinct species, while O. gibbsi was found to be synonymous with the east Australian form (BS = >97, PP = 1; GMYC p = 0.01). Discrete morphological differences in mature male octopuses (based on sixteen morphological traits) provided further evidence of cryptic speciation between east (including New Zealand) and west coast populations; although females proved less useful in morphological distinction among members of the tetricus complex. In addition, phylogenetic analyses suggested populations of octopuses currently treated under the name Octopus vulgaris are paraphyletic; providing evidence of cryptic speciation among global populations of O. vulgaris, the most commercially valuable octopus species worldwide.

Cephalopod paralarval richness was 2x higher in Moroccan than Iberian waters 2. Three planktonic dispersal patterns were identified in the Iberian-Canary current upwelling system 3. The interaction between vertical behaviour and oceanography led to these 3 dispersal patterns 4. Each planktonic pattern had different haplotype and nucleotide genetic signatures 5. Octopus vulgaris paralarvae shift within upwelling filaments from coast to ocean Oceanographic processes shape genetic signatures of planktonic cephalopod paralarvae 2 in two upwelling regions

Recent molecular studies have proved beneficial in providing taxonomic resolution within the Octopus vulgaris species complex, therefore aiding in the appropriate management of this high value global fisheries resource. This study used the mito-

Many marine species once considered to be cosmopolitan are now recognised as cryptic species complexes. Mitochondrial markers are ubiquitously used to address phylogeographic questions, and have been used to identify some cryptic species complexes; however, their efficacy in inference of evolutionary processes in the nuclear genome has not been thoroughly investigated. We used double digest restriction siteassociated DNA sequencing (ddRADseq) markers to quantify species boundaries in the widely distributed and high value common octopus, Octopus vulgaris, comparing genome-wide phylogenetic signal to that obtained from mitochondrial markers.Phylogenetic analyses, genome-wide concordance and species tree estimation based on 604 genome-wide ddRADseq loci revealed six species within the O. vulgaris group.Divergence time estimates suggested modern-day species evolved over the last 2.5 ma, during a period of global cooling. Importantly, our study identified significant phylogenetic discordance between mitochondrial and nuclear markers; genome-wide nuclear loci supported O. vulgaris sensu stricto and Type III (South Africa) as distinct species, which mtDNA failed to recognise. Our finding of conflicting phylogenetic signal between mitochondrial and nuclear markers has broad implications for many taxa.Improved phylogenetic resolution of O. vulgaris has significant implications for appropriate management of the group and will allow greater accuracy in global fisheries catch statistics.

No abstract

Anthropogenic climate change is causing a world-wide reduction of alpine habitat, leaving many high-elevation species restricted to sky-islands and vulnerable to extinction. Understanding the genetic parameters of these populations provides key insight into species diversity, dispersal capacity and vulnerability to disturbance. We examined the impact of past climatic variation on a threatened alpine endemic lizard, the Guthega skink, Liopholis guthega. We analysed SNP and mtDNA data to determine the population structure and phylogeny within this species, providing an understanding of the species' relatedness, dispersal and viability. We identified significant genetic structure, with the split between populations in Koscuiszko National Park, New South Wales (NSW) and the Bogong High Plains, Victoria (VIC) consistent with Plio-Pleistocene divergence. However, we also detected evidence of possible historical introgressive hybridization between some NSW populations and the VIC populations. Marked within-site population structure and significant population differentiation among sites within each state were found, indicating a limited dispersal capacity. Higher levels of genetic diversity within NSW support the correlation between elevation and diversity and implicate Kosciuszko National Park as a historic refugia. Low contemporary habitat availability, little to no capacity for elevational progression and low genetic diversity, particularly in VIC, leaves L. guthega highly vulnerable to threatening processes associated with climate change. Conservation management should consider genetic rescue as a potential method to enhance genetic diversity across this species' range.

A new Octopus Cuvier, 1797 species, Octopus djinda Amor, 2021 (previously treated as O. cf. tetricus and O. aff. tetricus), is described from the shallow waters off southwest Australia. This species was classified as conspecific with O. tetricus Gould, 1852 from Australia’s east coast and New Zealand but is shown here to be morphologically and genetically distinct. This description is based on 25 individuals across three localities in southwest Australia, encompassing most of its distribution. Greater and non-overlapping sucker counts on the males hectocotylised arm delimit east and west coast forms. DNA barcoding using cytochrome c oxidase subunit I also successfully differentiates between these taxa; 13 polymorphisms along a 349 bp partial fragment (3.7% sequence divergence). A close relative of the O. vulgaris Cuvier, 1797 species-group, O. djinda, sp. nov. supports a highly productive fishery and is currently one of two octopod fisheries worldwide to have received sustainable certification from the Marine Stewardship Council. The taxonomic description presented here provides formal recognition of the taxonomic status of southwest Australia’s common octopus, O. djinda, sp. nov. and facilitates appropriate fisheries catch reporting and management.