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Oceanic islands are hotspots of marine biodiversity, and biogeographic and evolutionary studies can provide important knowledge about the origin and diversification of the species that inhabit them. In the South Pacific, the Juan Fernández Archipelago (JFA) stands out for its high endemic biota, most of them endangered by human activities. Currently, two octopus species are recognized in JFA, but their taxonomic identity is not conclusive. In the present study, we performed morphometric and molecular analyses of both species inhabiting the JFA and contrast them with other species worldwide. Morphological, phylogenetic analysis, genetic diversity, and divergence times between species were estimated. Morphometric analysis did not show significant differences in body shape of males between/within Octopus species from JFA, only between females from different localities. However, phylogenetic and species delimitation analyses support the presence of two species in the JFA, namely Octopus mimus and Octopus vulgaris. In addition, both species show evidence of different divergence and colonization histories into the JFA during the Pleistocene. These findings do not only shed light on the identity, origin, and colonization time of the species, but also provide the basis to generate informed decisions on management and conservation. The recent colonization time and low genetic diversity observed in both species suggest that these populations are vulnerable to drastic changes, such as those caused by anthropic effects. [ABSTRACT FROM AUTHOR]

Two non-sulfated steroidal glycosides, cistoindosides A-B were isolated from organic extract of the marine 'old woman octopus' Cistopus indicus (family Octopodidae). Their structures were characterized as 3β-acteoxy-23β-hydroxy-cholesta-9-ene-β-D-xylopyranoside (cistoindoside A) and 22,23-epoxy-3β-hydroxy-cholesta-5-ene-β-D-4'-O-acetoxy-xylopyranoside (cistoindoside B). Cistoindoside B, glycosylated with β-D-4'-O-acetoxy-xylopyranoside in conjunction with epoxy moieties displayed superior anti-inflammatory properties as acknowledged by its promising 5-lipoxygenase attenuation potential (IC50 2.11 µM) than the 5-lipoxygenase inhibitor drug zileuton (IC50 3.76 µM). The anti-inflammatory properties were corroborated by the promising antioxidant activities (IC50 ∼ 1.0–1.5 mM) of these steroid glycosides. Sizeably greater electronic properties, balanced hydrophobic-lipophilic properties (log POW ∼ 4.0) and comparatively lower steric factors were directly proportional to their bioactivities. Molecular simulation studies in the active sites of 5-lipoxygenase displaying lesser binding energies and inhibition constant (Ki) of cistoindoside B could be correlated with anti-inflammatory properties. Cistoindosides could be projected for their utilization as potential bioactive leads in functional food and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Chemical evaluation of specialised metabolites from the old-lady marine octopus Cistopus indicus (family Octopodidae) led to the isolation of an undescribed 14-membered bislactonic macrodiolide cistobislactone, which was characterized as 12-(4'-ethyl-6'-methoxy-3'-methyl-hex-1-enyl)-5,11-dihydroxy-6-methyl-1,7-dioxacyclotetradeca-3,9-diene-2,8-dione. Cistobislactone exhibited noticeably greater inhibitory potential against 5-lipoxygenase (IC50 2.06 mM) compared to standard anti-inflammatory agent ibuprofen (IC50 4.61 mM, p < 0.05). Superior antioxidant properties of cistobislactone against the oxidants (IC50 ∼1.8 mM) also reinforced its promising anti-inflammatory activity. Higher electronic properties (topological polar surface area of 102.3) and balanced hydrophobicity (logarithm of octanol-water coefficient ∼3) could recognize its higher interaction at the enzyme active site resulting in an effective attenuation of 5-lipoxygenase and efficient inter-membrane permeability. Comparatively lesser binding energy (-6.5 kcal mol−1) and docking score (-7.5 kcal mol−1) of cistobislactone with the aminoacyl residues of 5-lipoxygenase could further recognize its anti-inflammatory potential. [ABSTRACT FROM AUTHOR]

Biochemical analysis of secondary metabolites of marine old-woman octopus Cistopus indicus (family Octopodidae) led to the identification of two sixteen-membered spiro-linked macrocyclic bislactones, named as cistobislactone A and cistobislactone B with unprecedented feature of henicos framework, based on extensive spectroscopic analyses. Cistobislactone B exhibited potential inhibition property against arachidonate 5-lipoxygenase (IC50 2.18 mM) than that demonstrated by cistobislactone A (IC50 2.54 mM) and standard non-steroidal anti-inflammatory agent ibuprofen (IC50 4.50 mM) thus signifying the higher anti-inflammatory activity of the cistobislactone B analogue. The studied macrocyclic bislactones exhibited promising antioxidant potential, in which cistobislactone B exhibited potential radical quenching (IC50 2.33 mM) and hydrogen peroxide scavenging (IC50 1.81 mM) activities that were proximal to the commercial anti-oxidant α-tocopherol (IC50 ~ 1.60 mM). This further reinforced its attenuation property against arachidonate 5-lipoxygenase. Considerably greater electronic properties coupled with balanced hydrophobicity of cistobislactone B could ascribe the superior ligand-receptor interfaces leading to its anti-inflammatory activity. Molecular docking analysis of cistobislactone B with 5-lipoxygenase recorded lesser docking score (−12.24 kcal mol−1) and binding energy (−11.24 kcal mol−1), which further supported its anti-inflammatory activity. Cistobislactone B, with six fold lesser value of inhibition constant (Ki 5.76 nM) towards 5-lipoxygenase than that displayed by cistobislactone A, could describe the superior protein-ligand interactions of the former. The undescribed cistobislactone B might be a potential natural anti-inflammatory lead to moderate the odds of inflammatory pathologies. [ABSTRACT FROM AUTHOR]

The present study identifies one species of the genus Octopus in the order: Octopoda (Cephalopoda: Mollusca), recorded for the first time in the Iraqi coastal waters and Arabian-Persian Gulf. The study extended from January 2019 to December of the same year. The Octopus specimens were seasonally obtained from the fishing trawlers operating in the Iraqi coastal waters in the South of Al-Fao District, Basrah-Iraq, NW Arabian Gulf. The Octopus was identified as O. vulgaris in Iraqi coastal waters depending on morphological features. The habitats of living specimens are briefly described. Some observations were reported on the occurrence of this species and the measurement of some environmental factors. The species was identified up to species level using standard literature. This species looks similar morphologically to the species which is already identified from the other areas around the world. The present study records significant expansion in the distribution range of this species. [ABSTRACT FROM AUTHOR]

The East Asian common octopus Octopus sinensis is a bottom-dwelling species, but goes through a planktonic phase as 'paralarvae' during the first several weeks of life. As the swimming performance of the paralarvae is relatively poor, their dispersion relies primarily on ocean currents; however, vertical swimming may play an important role in their horizontal dispersion by controlling their buoyancy in the current. Within this context, ontogenic changes in vertical swimming in relation to the ambient water flow are key to understanding the dispersion properties of the paralarvae and the subsequent onset of settlement, yet this information remains largely unknown. Here, we investigated the effects of different water flows (downward × 4 velocities, stagnant and upward × 5 velocities) on the vertical swimming position in test columns using laboratory-raised O. sinensis paralarvae aged 0, 5, 10 and 15 days during the day and at night. Paralarvae younger than 10 days (< 3 mg in dry weight) tended to swim upwards regardless of the water flow conditions, but their swimming was disrupted under downward water flows, while they exhibited repeating upward swimming and downward pushing-back movements. Thus, for early paralarvae, an upward water flow may have a positive effect on dispersion by supporting their innate upward swimming, while a downward water flow may impact paralarvae negatively due to exhaustion through excess swimming activities. Paralarvae aged 15 days (> 5 mg) commenced short clinging behaviour, and their swimming positions dispersed downwards during daytime regardless of the water flow, indicating the onset of the transition to settlement. In contrast, their position shifted to near the upper limit at night by swimming upwards, even under downward water flows. Our results suggest that O. sinensis exhibits characteristic behaviour that alternates between diurnal descent dispersion with clinging (hyperbenthic trait) and nocturnal upward swimming (planktonic trait) during the transition to permanent benthic life. [ABSTRACT FROM AUTHOR]

The population genetic structure of a species is frequently shaped by biogeographic barriers that prevent the movement of individuals from one genetic population to another. Although Octopus mimus Gould, 1852 was reported to inhabit the shallow marine waters of the Peruvian province, recent studies suggest its synonymy with O. hubbsorum Berry, 1953 from the Panamanian and the Cortez provinces where it is the main octopus species caught in the artisanal fishery. The aim of the present study was to assess the genetic variability of O. mimus and to determine the presence of population structure across three sampled regions of the eastern Pacific Ocean using the mitochondrial marker cytochrome c oxidase subunit I. The hypothesis that the biogeographic boundary between the Panamanian and Peruvian provinces acts as a genetic break was further tested and recognized by the conformation of two phylogenetic clades and two haplogroups. Results indicate that these lineages are demographically independent populations of O. mimus and do not represent different species as evidenced by the Generalized Mixed Yule Coalescent method. The oceanographic processes have apparently allowed enough genetic flow along the Pacific coast yielding low but significant levels of genetic structure (FST = 0.16, p < 0.05) as seen in some fish populations. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The octopus fauna from the southern Caribbean is an understudied field. However, recent taxonomic work in the Colombian Caribbean has led to the discovery of several new species in the family Octopodidae. To provide molecular evidence for recent descriptions in the area (i.e., Octopus taganga, O. tayrona and Macrotritopus beatrixi) and contribute to the systematics of the family, we reconstructed the first molecular phylogenies of the family including Colombian Caribbean octopus species. Using cytochrome c oxidase subunit I and rhodopsin sequences from specimens collected in three sites (Santa Marta, Old Providence and San Andrés Islands) we inferred maximum-likelihood trees and delimited species with PTP. Our mitochondrial analysis supported the monophyly of species found in the area (i.e., O. taganga, O. hummelincki and O. briareus). The genetic distinction of the species O. tayrona and O. insularis was not resolved, as these were found in one clade together with Caribbean O. vulgaris and O. aff. tayrona species (O. spB) and delimited as a single species. Additionally, our results suggest a distant relationship of the Type I O. vulgaris group (Caribbean region) from the other forms of the species complex (Old World and Brazil). Lastly, the third newly described species M. beatrixi emerged as an independent lineage and was delimited as a single species. However, its relationship to other species of its genus remains unknown due to the lack of sequences in databases. Altogether, our molecular approach to the octopus fauna from the southern Caribbean adds on information to the relationship of Octopodidae species world-wide by providing sequences from recently described species from an understudied region. Further studies employing higher taxon sampling and more molecular information are needed to fill taxonomic gaps in the area and account for single-locus resolution on the systematics of this group. [ABSTRACT FROM AUTHOR]

Several Octopodidae species have a great potential for the diversification of worldwide aquaculture. Unfortunately, the lack of stress-related biomarkers in this taxon results an obstacle for its maintenance in conditions where animal welfare is of paramount relevance. In this study, we made a first approach to uncover physiological responses related to fishing capture in Eledone moschata , Eledone cirrhosa , and Octopus vulgaris. Captured octopus from all three species were individually maintained in an aquaculture system onboard of oceanographic vessel in south-western waters of Europe. Haemolymph plasma and muscle were collected in animals at the moment of capture, and recovery was evaluated along a time-course of 48 h in Eledone spp., and 24 h for O. vulgaris. Survival rates of these species captured in spring and autumn were evaluated. Physiological parameters such as plasma pH, total CO2, peroxidase activity, lysozyme, hemocyanin, proteases, pro-phenoloxidase, anti-proteases, free amino acids, lactate and glucose levels, as well as muscle water percentage, free amino acids, lactate, glycogen and glucose values were analyzed. The immune system appears to be compromised in these species due to capture processes, while energy metabolites were mobilized to face the acute-stress situation, but recovery of all described parameters occurs within the first 24 h after capture. Moreover, this situation exerts hydric balance changes, as observed in the muscle water, being these responses depending on the species assessed. In conclusion, three Octopodidae species from south-western waters of Europe have been evaluated for stress-related biomarkers resulting in differentiated mechanisms between species. This study may pave the way to further study the physiology of stress in adult octopuses and develop new methodologies for their growth in aquaculture conditions. [ABSTRACT FROM AUTHOR]

The mitogenome of the winged argonaut Argonauta hians (Argonautidae) was decoded using next generation sequencing. The de novo assembled mitogenome consists of 16,130 bp, including 13 protein coding genes, 2 ribosomal RNAs and 22 transfer RNA genes. The gene arrangement is identical to the other available Octopodidae octopus sequences submitted to NCBI. The overall base composition of the A. hians mitogenome is 29.1% A, 6.9% C, 13.2% G and 40.9% T. The phylogenetic analysis of the A. hians mitogenome suggests an ancestral position in the order Octopoda, compared to species in the Amphioctopus, Cistopus and Octopus (Octopodidae) genera. The decoding of the A. hians mitogenome provides insight into the evolutionary history and rises the concern of conservation on this uncommon and ancestral Octopoda species. [ABSTRACT FROM AUTHOR]

In this study, the complete mitochondrial genome of Amphioctopus marginatus (Cephalopoda: Octopodidae) was sequenced. The length of A. marginatus was 15,719 base pairs (bp) and the composition of genome is A (41.74%), T (33.53%), C (16.77%), and G (7.96%). The whole mitogenome was composed of 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA genes, and a major non-coding region. The overall A+T content of A. marginatus showed remarkable similarity to other Octopodidae species reported before, with the characteristic of extremely richer than G+C. The gene order of the protein-coding genes was identical to other octopodids, but the tRNA genes were rearranged, making the gene order unique. The phylogenetic analysis showed relationships between A. marginatus and Amphioctopus aegina is close. The new mtDNA data enriched the database, which was beneficial to refine the phylogenetic relationships within Octopodidae further. ND5 gene could become an optimal DNA barcoding in taxon identification of the family. [ABSTRACT FROM AUTHOR]

The article discusses a study which reported the first fossil evidence of a drill hole in a barnacle that can be attributed to an octopod. Topics covered include the method used in calculating the percentage of octopod drill holes in barnacles, a total of two scuta and 365 wall plates of acorn barnacles used as study samples, and discussion on encrusting foraminifer. Also explored is the morphology of the drill hole.

This study combined morphological and morphometric information on egg clutches, egg capsules and paralarvae of two sympatric coastal octopuses from New Zealand waters, Octopus huttoni and Pinnoctopus cordiformis, to provide species-specific traits to identify their early life stages obtained from field surveys. Eggs of O. huttoni (2.5 mm length; 1 mm width) were entwined with one another forming strings that ranged from 11 to 25.8 mm in length. Eggs of P. cordiformis (6.4 mm length; 1.5 mm width) were significantly bigger than those of O. huttoni and were grouped in small clusters of about seven eggs. Paralarvae O. huttoni and P. cordiformis differed in hatching size (1.4 mm versus 3.1 mm mantle length), number of suckers per arm (four versus eight), number of lamellae per outer demibranch (five versus ten) and arrangements of chromatophores in the body surface (29 to 59 versus 91 to 179), respectively. The morphological traits described in hatchlings from the laboratory allowed comparisons with field-collected paralarvae, suggesting that such characters were reliable species-specific patterns to enable a consistent differentiation between the early life stages of these two sympatric species, even in the absence of the brooding female. [ABSTRACT FROM AUTHOR]

Octopuses of the family Octopodidae are singular among cephalopods in their reproductive behavior, showing two major reproductive strategies: the first is the production of few and large eggs resulting in well-developed benthic hatchlings (holobenthic life history); the second strategy is the production of numerous small eggs resulting in free-swimming planktonic hatchlings (pelago-benthic life history). Here, we utilize a Bayesian-based phylogenetic comparative method using a robust molecular phylogeny of 59 octopus species to reconstruct the ancestral states of development type in benthic octopuses, through the estimation of the most recent common ancestors and the rate of gain and loss in complexity (i.e., planktonic larvae) during the evolution. We found a high probability that a free-swimming hatchling was the ancestral state in benthic octopuses, and a similar rate of gain and loss of planktonic larvae through evolution. These results suggest that in benthic octopuses the holobenthic strategy has evolved from an ancestral pelago-benthic life history. During evolution, the paralarval stage was reduced to well-developed benthic hatchlings, which supports a 'larva-first' hypothesis. We propose that the origin of the holobenthic life history in benthic octopuses is associated with colonization of cold and deep sea waters. [ABSTRACT FROM AUTHOR]

Octopodids are a globally distributed group of marine molluscs. Despite this, our knowledge of their reproductive biology rests heavily on inference, as all phases of copulation, beginning with sperm transfer, occur within the mantle cavity. Male octopuses insert a spermatophore into the female's oviduct, which is predicted to release a sperm-filled sac that either bursts to release sperm for storage or to itself be stored in a gland in the middle of the oviduct. To test whether female octopuses use sperm from multiple males to fertilize their eggs, as may be predicted from anatomy and anecdotal accounts, we apply microsatellite analysis to a partial clutch of Graneledone boreopacifica collected at 1600-m depth to test for multiple paternity. At least two genetically distinct sires contributed sperm to the hatchlings analyzed, demonstrating for the first time multiple paternity in octopodids. [ABSTRACT FROM AUTHOR]

The genus Robsonella Adam, 1938 belongs to the family Octopodidae and can only be identified by some characters present in males. In this work the species Robsonella fontaniana is redescribed from morphological and morphometric characters of 33 specimens (21 males and 12 females) collected on the central-south coast of Chile, during the years 2003 and 2004, and of 11 specimens (three males and eight females) obtained from the Zoological Museum of Hamburg. New diagnoses for the genus Robsonella and the species R. fontaniana are provided. Sexual dimorphism in R. fontaniana is evident by adult males having enlarged suckers and a shorter third right arm compared to the females. Some morphological characters such as ligula, radula and terminal organ diverticulum make it possible to distinguish this genus clearly from other genera. The ligula of the hectocotylized arm in Robsonella is characterized by a longitudinal groove, rounded tip, large calamus and seven copulatory lamellae. In addition, the first lateral tooth in the radula is crescent-shaped; this allows the identification of Robsonella regardless of sex. [ABSTRACT FROM PUBLISHER]

During recent cruises aboard RV Polarstern in the Antarctic Peninsula region, a new species of benthic octopodid was discovered whose generic affinities based on morphological characteristics were uncertain. Molecular sequence analysis of six mitochondrial and nuclear genes allows this species to be placed with confidence within the genus Pareledone. The species is described herein and morphological diagnostic characters are provided for its identification. [ABSTRACT FROM AUTHOR]

Wunderpus photogenicus n. gen. and n. sp. is a spectacular long-armed species that occurs on soft sediment habitats in shallow waters (typically less than 20 m deep) in Indo-Malayan waters. It is characterized by small eyes on elongate stalks, a long, conical papilla over each eye and a dramatic and fixed color pattern of white bars and spots over a brown-red background. The distribution of the species is centered in the Indo-Malayan Archipelago and extends from Vanuatu to Papua New Guinea, Indonesia and Malaysia, north to the Philippines. Animals typically emerge at dusk and dawn to forage in the twilight, primarily catching small crustaceans and fishes by flaring the arms and webs over patches of sand or coral rubble to trap enclosed (and typically buried) prey. The species also extends its arms into holes to probe for potential prey. The distinctive color pattern of this species is most pronounced when the octopus is disturbed or threatened by real or perceived attackers. It appears to be a warning display and may represent one of two scenarios: either 1) it warns that the octopus is directly toxic or venomous by nature or; 2) it represents impersonations of toxic or venomous creatures with similar color patterns which cooccur in the same habitat. The new genus and species is compared with, and distinguished from, other long-armed octopuses. [ABSTRACT FROM AUTHOR]

The syntypes of the endemic Southern Ocean octopodid Pareledone polymorpha (Robson, 1930) were re-examined and measurements, counts and indices are presented. The two forms described by Robson, namely oblonga and affinis, are determined to have no taxonomic validity. The species polymorpha shows morphological similarities with Pareledone adelieana (Berry, 1917) but differs in relative arm lengths, sucker counts, external colouration and size at maturity. Both species are transferred to the new genus Adelieledone, which is separated from the genus Pareledone s.s. by the transverse ridges in the ligula groove of the hectocotylus, the sharp tip of the lower beak, the enlarged posterior salivary glands, the absence of stylets and by skin sculpture, especially by the presence of two longitudinal integumentary ridges on the dorsal mantle. A new species, Adelieledone piatkowski, is described from the Antarctic Peninsula. Beak morphology can discriminate the genera in predator studies. [ABSTRACT FROM AUTHOR]

In this paper, the circular mitochondrial genome ofAmphioctopus aegina(Cephalopoda: Octopodidae) was sequenced. The whole mitogenome ofA. aeginawas 15 545 base pairs (bp) in length with a base composition of 42.53% A, 33.26% T, 16.70% C, and 7.51% G. The complete mitogenome contained 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA genes, and a major non-coding region. The gene arrangements ofA. aeginashowed remarkable similarity to other Octopodidae species reported. The phylogenetic relationships were reconstructed with the concatenated sequences of the 13 PCGs of the mitochondrial genome, and illustrated thatA. aeginahad the closest genetic relatives toA. fangsiao. [ABSTRACT FROM PUBLISHER]