Recent papers

Analysis of bacterial community and bacterial nutritional enzyme activity associated with the digestive tract of wild Chilean octopus (Octopus mimus Gould, 1852)
  1. Shunpei Iehata, Fernando Valenzuela, Carlos Riquelme
Article first published online: 14 JUL 2013
Abstract
Information on the bacterial community associated with octopus is very scarce, unlike fish and other molluscs. This study revealed the bacterial community associated with digestive tract of wild Chilean octopus Octopus mimus using a culture-dependent method and 16S rDNA clone library. Moreover, we analysed the bacterial nutritional enzyme activity of culturable bacteria. A culture-dependent method showed that the composition of the culturable bacterial community was substantially different between female and male octopus. The predominant species in female octopus were Vibrionaceae and Streptococcaceae, whereas only Vibrionaceae was dominated in male octopus. Bacterial nutritional enzyme activities of culturable bacteria from male octopus were much higher than female octopus. The 16S rDNA clone library analysis showed that the bacterial community of male octopus exhibited a higher diversity than that of female octopus. The genus Mycoplasma was the predominant bacteria in the digestive tract of all octopus samples. The results obtained in this study raise the possibility that each octopus has different food consumption due to different bacterial community and nutritional enzyme activity, although Mycoplasma sp. is one of the predominant bacteria in the digestive tract. Moreover, our results are useful for the future of microbiological investigation associated with the octopus and for probiotics in the octopus aquaculture.
 
Beak measurements of octopus (Octopus variabilis) in Jiaozhou Bay and their use in size and biomass estimation

Ying Xue,Yiping Ren,Wenrong Meng,Long Li,Xia Mao,Dongyan Han,Qiuyun Ma

September 2013
Abstract

Cephalopods play key roles in global marine ecosystems as both predators and preys. Regressive estimation of original size and weight of cephalopod from beak measurements is a powerful tool of interrogating the feeding ecology of predators at higher trophic levels. In this study, regressive relationships among beak measurements and body length and weight were determined for an octopus species (Octopus variabilis), an important endemic cephalopod species in the northwest Pacific Ocean. A total of 193 individuals (63 males and 130 females) were collected at a monthly interval from Jiaozhou Bay, China. Regressive relationships among 6 beak measurements (upper hood length, UHL; upper crest length, UCL; lower hood length, LHL; lower crest length, LCL; and upper and lower beak weights) and mantle length (ML), total length (TL) and body weight (W) were determined. Results showed that the relationships between beak size and TL and beak size and ML were linearly regressive, while those between beak size and W fitted a power function model. LHL and UCL were the most useful measurements for estimating the size and biomass of O. variabilis. The relationships among beak measurements and body length (either ML or TL) were not significantly different between two sexes; while those among several beak measurements (UHL, LHL and LBW) and body weight (W) were sexually different. Since male individuals of this species have a slightly greater body weight distribution than female individuals, the body weight was not an appropriate measurement for estimating size and biomass, especially when the sex of individuals in the stomachs of predators was unknown. These relationships provided essential information for future use in size and biomass estimation of O. variabilis, as well as the estimation of predator/prey size ratios in the diet of top predators.
 
Numerous papers this week from Science Direct. I have posted several to specific topics but am copying the full list here:

Micro-CT in cephalopod research: Investigating the internal anatomy of a sepiolid squid using a non-destructive technique with special focus on the ganglionic systemA Kerbl, S Handschuh, MT Nödl, B Metscher, M Walzl… - Journal of Experimental …, 2013
Abstract Most investigations on the internal organization of soft-bodied animals such as
cephalopods are based on classical serial sectioning (ie histological). Here, we demonstrate
a state-of-the-art-technique of X-ray microtomography (micro-CT) for 3D imaging of soft- ...



[h=3]Cephalopod research and EU Directive 2010/63/EU: Requirements, impacts and ethical review[/h] JA Smith, PLR Andrews, P Hawkins, S Louhimies… - Journal of Experimental …, 2013
Abstract For the first time, European Union legislation on animal research and testing has
extended its scope to include invertebrate species—the Class Cephalopoda. EU Directive
2010/63/EU, which was due to be implemented in Member States 1 January 2013, covers ...



[h=3]Video analyses of chromatophore activity in the European cuttlefish,< i> Sepia officinalis[/h] E Goodwin, N Tublitz - Journal of Experimental Marine Biology and Ecology, 2013
... Volume 447, September 2013, Pages 156–159. Cephalopod Biology a special issue compiled
under the auspices of no-profit research organization CephRes. Edited By Graziano Fiorito and
Giovanna Ponte. Cover image Cover image. Special issue: Cephalopod Biology. ...



[h=3]Immune responses of< i> Octopus vulgaris(Mollusca: Cephalopoda) exposed to titanium dioxide nanoparticles[/h] AM Grimaldi, P Belcari, E Pagano, F Cacialli… - Journal of Experimental …, 2013
... Volume 447, September 2013, Pages 123–127. Cephalopod Biology a special issue compiled
under the auspices of no-profit research organization CephRes. Edited By Graziano Fiorito and
Giovanna Ponte. Cover image Cover image. Special issue: Cephalopod Biology. ...



[h=3]Preliminary in vitro functional evidence for reflex responses to noxious stimuli in the arms of< i> Octopus vulgaris[/h] T Hague, M Florini, PLR Andrews - Journal of Experimental Marine Biology and …, 2013
... Volume 447, September 2013, Pages 100–105. Cephalopod Biology a special issue compiled
under the auspices of no-profit research organization CephRes. Edited By Graziano Fiorito and
Giovanna Ponte. Cover image Cover image. Special issue: Cephalopod Biology. ...



[h=3]Octopus arm regeneration: Role of acetylcholinesterase during morphological modification[/h] SM Fossati, F Carella, G De Vico, F Benfenati, L Zullo - Journal of Experimental …, 2013
... Volume 447, September 2013, Pages 93–99. Cephalopod Biology a special issue compiled
under the auspices of no-profit research organization CephRes. Edited By Graziano Fiorito and
Giovanna Ponte. Cover image Cover image. Special issue: Cephalopod Biology. ...



[h=3]< i> Sepia officinalis: A new biological model for eco-evo-devo studies[/h] Y Bassaglia, A Buresi, D Franko, A Andouche… - Journal of Experimental …, 2013
... Volume 447, September 2013, Pages 4–13. Cephalopod Biology a special issue compiled
under the auspices of no-profit research organization CephRes. Edited By Graziano Fiorito
and Giovanna Ponte. ... 5.1. Coloured components of cephalopod skin. ...



[h=3]The effect of predatory presence on the temporal organization of activity in< i> Octopus vulgaris[/h] DV Meisel, M Kuba, RA Byrne, J Mather - Journal of Experimental Marine Biology and …, 2013
... Volume 447, September 2013, Pages 75–79. Cephalopod Biology a special issue compiled
under the auspices of no-profit research organization CephRes. Edited By Graziano Fiorito and
Giovanna Ponte. Cover image Cover image. Special issue: Cephalopod Biology. ...



[h=3]Pathogens and immune response of cephalopods[/h] S Castellanos-Martínez, C Gestal - Journal of Experimental Marine Biology and …, 2013
Cephalopod mollusks are an important marine resource for fisheries, and have received
marked attention for studies on organismal biology; they are also good can. ... 4. Response
to diseases: overview on the cephalopod immune system. ...



[h=3]Early visual experience of background contrast affects the expression of NMDA-like glutamate receptors in the optic lobe of cuttlefish,< i> Sepia pharaonis[/h] YH Lee, YC Chang, HY Yan, CC Chiao - Journal of Experimental Marine Biology and …, 2013
... Volume 447, September 2013, Pages 86–92. Cephalopod Biology a special issue compiled
under the auspices of no-profit research organization CephRes. Edited By Graziano Fiorito and
Giovanna Ponte. Cover image Cover image. Special issue: Cephalopod Biology. ...
 
An alternative approach for improving freshness indices for squid (loligo plei) J. Lapa-Guimarães, P.E. Felício, E. Contreras Guzmán[SUP] 2013[/SUP]

[h=2]Abstract[/h] The leaching of soluble compounds reduces the efficiency of chemical indices for freshness when fish is stored in ice. The objective of this study was to evaluate whether chemical indices for freshness evaluation of squid (Loligo plei) could be improved by expressing their contents as percentages of the non-protein nitrogen (NPN). The contents of NPN, free amino groups (FAG), trimethylamine oxide (TMA-O), trimethylamine (TMA), volatile basic nitrogen (VBN), ammonia (AMM), urea and free tryptophan (FT) were periodically determined in squid muscle during 16 days of storage in ice. The VBN, AMM, TMA, urea and FT contents in squids, when expressed as mg/100 g, did not distinguish between squids stored in ice for 1 or 2 weeks. However, when the contents of VBN and AMM were expressed as percentages of the NPN, it was possible to distinguish between squids stored for 1, 4 and 7 days. Free tryptophan was the most efficient quality index for L. plei, allowing accurate discrimination of squids stored in ice for 02-2, 4, 7–10, 13 and 16 days.
 
[h=2]Methods in Brain Development of Molluscs Andreas Wanninger, Tim Wollesen - subscription or individual purchase[/h] [h=2]Abstract[/h] Representatives of the phylum Mollusca have long been important models in neurobiological research. Recently, the routine application of immunocytochemistry in combination with confocal laser scanning microscopy has allowed fast generation of highly detailed reconstructions of neural structures of even the smallest multicellular animals, including early developmental stages. As a consequence, large-scale comparative analyses of neurogenesis—an important prerequisite for inferences concerning the evolution of animal nervous systems—are now possible in a reasonable amount of time. Herein, we describe immunocytochemical staining protocols for both whole-mount preparations of developmental stages—usually 70–300 μm in size—as well as for vibratome sections of complex brains. Although our procedures have been optimized for marine molluscs, they may easily be adapted for other (marine) organisms by the creative neurobiologist.
 
New Technique for aging an octopus Today, 3:24am
Age validation in Octopus maya (Voss and Solís, 1966) by counting increments in the beak rostrum sagittal sections of known age individuals

Guadalupe Villegas Bárcenas,Catalina Perales-Raya,Aurora Bartolomé,Eduardo Almansa,Carlos Rosas - subscription or individual purchase, some graphs available with abstract

Abstract

The present study was carried out to validate the daily deposition and age estimation by using beak rostrum sagittal sections increments of cultivated Octopus maya (Voss and Solís, 1966). This study validates for first time the periodicity of beak increments by using animals of known age. We analyzed the rostrum sagittal sections (RSS) of upper and lower beaks in 40 juveniles of O. maya divided into four age groups (63, 87, 105 and 122 days) with 10 individuals per group. The animals were fed with a soft diet allowing obtaining age estimations not affected by the beak erosion. At the same time 50 animals were sampled every 20 days until 120 days old to obtain an age-body wet weight (BW) curve which could be compared with the age-BW curve obtained using age estimations from beaks. Co-variance analysis showed no statistical differences between both curves. The number of increments present in the beaks corresponded with the number of days from hatchling. Therefore, it was possible to validate that a growth increment corresponds to a day of life in O. maya, confirming that, up to 122 days old, the beaks counts can be used to determine the age of O. maya.
 
Five new species of dicyemid mesozoans (Dicyemida: Dicyemidae) from two Australian cuttlefish species, with comments on dicyemid fauna composition - Sarah R. Catalano 2013 subscription or individual purchase

[h=2]Abstract[/h] Five new species of dicyemid mesozoans in two genera are described from two Australian cuttlefish species, Sepia apama Gray (giant Australian cuttlefish) and S. novaehollandiae Hoyle (nova cuttlefish): Dicyema coffinense n. sp. from S. apama collected from Coffin Bay, South Australia (SA), Australia; D. koinonum n. sp. from S. apama and S. novaehollandiae collected from Gulf St Vincent (GSV) and Spencer Gulf (SG), SA, Australia; D. multimegalum n. sp. from S. apama collected from Cronulla and North Bondi, New South Wales, Australia; D. vincentense n. sp. from S. novaehollandiae collected from GSV, SA, Australia; and Dicyemennea spencerense n. sp. from S. novaehollandiae and S. apama collected from SG, SA, Australia. Totals of 51 S. apama and 27 S. novaehollandiae individuals were examined, of which all except for four S. apama were infected by at least one dicyemid species. Dicyemid parasites were also observed in host individuals that were held in tanks for 2–3 months prior to examination, including nematogen-exclusive infections, leading to questions about persistence of dicyemids after host death and the mechanism responsible for the switch between a nematogen phase and a rhombogen phase. Variations in host size, calotte shape and collection locality are explored as predictors of differences in observed composition of the parasite fauna. In particular, dicyemid parasite fauna varied with host collection locality. As these parasites are highly host-species specific, their use as biological tags to assess cephalopod population structure using a combined morphological and molecular approach is discussed. This study increases the number of dicyemid species described from Australian cephalopods from five to ten, and from 117 to 122 species described worldwide.
 
Crystallographic Orientation of Cuttlebone Shield Determined by Electron Backscatter Diffraction
Maggie Cusack, Peter Chung 2013 (subscription)

Abstract
In common with many cephalopod mollusks, cuttlefish produce an internal biomineral buoyancy device. This cuttlebone is analogous to a surf board in shape and structure, providing rigidity and a means of controlling buoyancy. The cuttlebone is composed of calcium carbonate in the form of aragonite and comprises an upper dorsal shield and a lower lamellar matrix. The lamellar matrix comprises layers of chambers with highly corrugated walls. The dorsal shield comprises bundles of aragonite needles stacked on top of each other. Electron backscatter diffraction analyses of the dorsal shield reveal that the c-axis of aragonite is parallel with the long axis of the needles in the bundles such that any spread in crystallographic orientation is consistent with the spread in orientation of the fibers as they radiate to form the overall structure of the dorsal shield. This arrangement of c-axis coincident with the long axis of the biomineral structure is similar to the arrangement in corals and in contrast to the situation in the molluskan aragonite nacre of brachiopod calcite where the c-axis is perpendicular to the aragonite tablet or calcite fiber, respectively.
 
Parasites as biological tags to assess host population structure: Guidelines, recent genetic advances and comments on a holistic approach
Sarah R. Catalano, Ian D. Whittington, Stephen C. Donnellan, Bronwyn M. Gillanders 2013 (full PDF)

Abstract
We review the use of parasites as biological tags of marine fishes and cephalopods in host population structure studies. The majority of the work published has focused on marine fish and either single parasite species or more recently, whole parasite assemblages, as biological tags. There is representation of host organisms and parasites from a diverse range of taxonomic groups, although focus has primarily been on host species of commercial importance. In contrast, few studies have used parasites as tags to assess cephalopod population structure, even though records of parasites infecting cephalopods are well-documented. Squid species are the only cephalopod hosts for which parasites as biological tags have been applied, with anisakid nematode larvae and metacestodes being the parasite taxa most frequently used. Following a brief insight into the importance of accurate parasite identification, the population studies that have used parasites as biological tags for marine fish and cephalopods are reviewed, including comments on the dicyemid mesozoans. The advancement of molecular genetic techniques is discussed in regards to the new ways parasite genetic data can be incorporated into population structure studies, alongside host population genetic analyses, followed by an update on the guidelines for selecting a parasite species as a reliable tag candidate. As multiple techniques and methods can be used to assess population structure of marine organism (e.g. artificial tags, phenotypic characters, biometrics, life history, genetics, otolith microchemistry and parasitological data), we conclude by commenting on a holistic approach to allow for a deeper insight into population structuring
 
D, I thought the same thing about squid until I was out with MBARI and I don't think we saw a single squid swimming the way I thought all squid swam (i.e., plain old horizontally). The histioteuthids were somewhere between vertical and 45 degrees, many others had the mantle at about 45 and then the head/arms bent around to more horizontal, Taonius often swam straight up and down, and Galiteuthis liked to sit with the mantle horizontal and the arms all gathered vertically into the cockatoo pose. That was one of my main take-home messages from the trip: few squid (at least in the deep sea in Monterey) swim the way I had previously envisioned most/all squid to swim.
 
The Complete Mitochondrial Genomes of Two Octopods Cistopus chinensis andCistopus taiwanicus: Revealing the Phylogenetic Position of the Genus Cistopuswithin the Order Octopoda
Rubin Cheng,Xiaodong Zheng mail,Yuanyuan Ma, Qi Li 2013 (full text)

Abstract
In the present study, we determined the complete mitochondrial DNA (mtDNA) sequences of two species of Cistopus, namely C. chinensis and C. taiwanicus, and conducted a comparative mt genome analysis across the class Cephalopoda. The mtDNA length of C. chinensis and C. taiwanicus are 15706 and 15793 nucleotides with an AT content of 76.21% and 76.5%, respectively. The sequence identity of mtDNA between C. chinensis and C. taiwanicus was 88%, suggesting a close relationship. Compared with C. taiwanicus and other octopods, C. chinensis encoded two additional tRNA genes, showing a novel gene arrangement. In addition, an unusual 23 poly (A) signal structure is found in the ATP8 coding region of C. chinensis. The entire genome and each protein coding gene of the two Cistopus species displayed notable levels of AT and GC skews. Based on sliding window analysis among Octopodiformes, ND1 and DN5 were considered to be more reliable molecular beacons. Phylogenetic analyses based on the 13 protein-coding genes revealed that C. chinensis and C. taiwanicus form a monophyletic group with high statistical support, consistent with previous studies based on morphological characteristics. Our results also indicated that the phylogenetic position of the genus Cistopus is closer to Octopus than to Amphioctopus and Callistoctopus. The complete mtDNA sequence of C. chinensis and C. taiwanicus represent the first whole mt genomes in the genus Cistopus. These novel mtDNA data will be important in refining the phylogenetic relationships within Octopodiformes and enriching the resource of markers for systematic, population genetic and evolutionary biological studies of Cephalopoda
 
Proteomic characterization of the hemolymph of Octopus vulgaris infected by the protozoan parasite Aggregata octopiana
Sheila Castellanos-Martínez, Angel P. Diz, Paula Álvarez-Chaver, Camino Gestal 2013 (subscription)

The immune system of cephalopods is poorly known to date. The lack of genomic information makes difficult to understand vital processes like immune defense mechanisms and their interaction with pathogens at molecular level. The common octopus Octopus vulgaris has a high economic relevance and potential for aquaculture. However, disease outbreaks provoke serious reductions in production with potentially severe economic losses. In this study, a proteomic approach is used to analyze the immune response of O.vulgarisagainst the coccidia Aggregata octopiana, a gastrointestinal parasite which impairs the cephalopod nutritional status. The hemocytes and plasma proteomes were compared by 2-DE between sick and healthy octopus. The identities of 12 differentially expressed spots and other 27 spots without significant alteration from hemocytes, and 5 spots from plasma, were determined by mass spectrometry analysis aided by a six reading-frames translation of an octopus hemocytes RNA-seq database and also public databases. Principal component analysis pointed to 7 proteins from hemocytes as the major contributors to the overall difference between levels of infection and so could be considered as potential biomarkers. Particularly, filamin, fascin and peroxiredoxin are highlighted because of their implication in octopus immune defense activity. From the octopus plasma, hemocyanin was identified. This work represents a first step forward in order to characterize the protein profile of O.vulgaris hemolymph, providing important information for subsequent studies of the octopus immune system at molecular level and also to the understanding of the basis of octopus tolerance-resistance to Aoctopiana.

Another immune system paper - S. Officinalis
Hemocyte morphology and phagocytic activity in the common cuttlefish (Sepia officinalis) Charles Le Pabic, Didier Goux, Maryline Guillamin, Georges Safi, Jean-Marc, Noussithé, Antoine Serpentini 2014 (subscription)

Abstract
Little is known about the immune system of cephalopods, in spite of their many highly derived characters within the molluscan clade, including a vertebrate-like high-pressure closed circulatory system. Further the economic importance of cephalopod fisheries, potential for aquaculture, and use as ecotoxicology models demand a thorough understanding of their immune system. In this study, we present a comprehensive characterization of hemocytes in the common cuttlefish Sepia officinalis. Cytological stainings, electron microscopy- and flow cytometry-observations highlight a single granulocyte population with various densities of eosinophilic granules and unstained vesicles. These hemocytes contain acid phosphatase-, lysozyme- and proPO system enzymes, and have high activity in bead phagocytosis assays. Interestingly, bead pre-incubation in plasma results in timedependent aggregation perhaps resulting from hemocyanin-coating, and decrease in phagocytosis. This study provides the basis for understanding hemocyte-mediated immunity in the common cuttlefish, and essential background for future studies on cephalopod immunity.
 
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Defensive Responses of Cuttlefish to Different Teleost Predators
Michelle D. Staudingera,Kendra C. Buresch, Lydia M. Mäthger,Charlie Fry, Sarah Mcanulty, Kimberly M. Ulmer, Roger T. Hanlon
2014 (subscription)

Abstract
We evaluated cuttlefish (Sepia officinalis) responses to three teleost predators: bluefish (Pomatomus saltatrix), summer flounder (Paralichthys dentatus), and black seabass (Centropristis striata). We hypothesized that the distinct body shapes, swimming behaviors, and predation tactics exhibited by the three fishes would elicit markedly different antipredator responses by cuttlefish. Over the course of 25 predator-prey behavioral trials, 3 primary and 15 secondary defense behaviors of cuttlefish were shown to predators. In contrast, secondary defenses were not shown during control trials in which predators were absent. With seabass—a benthic, sit-and-pursue predator—cuttlefish used flight and spent more time swimming in the water column than with other predators. With bluefish—an active, pelagic searching predator—cuttlefish remained closely associated with the substrate and relied more on cryptic behaviors. Startle (deimatic) displays were the most frequent secondary defense shown to seabass and bluefish, particularly the Dark eye ring and Deimatic spot displays. We were unable to evaluate secondary defenses by cuttlefish to flounder—a lie-and-wait predator—because flounder did not pursue cuttlefish or make attacks. Nonetheless, cuttlefish used primary defense during flounder trials, alternating between cryptic still and moving behaviors. Overall, our results suggest that cuttlefish may vary their behavior in the presence of different teleost predators: cryptic behaviors may be more important in the presence of active searching predators (e.g., bluefish), while conspicuous movements such as swimming in the water column and startle displays may be more prevalent with relatively sedentary, bottom-associated predators (e.g., seabass).
 
Ink From Longfin Inshore Squid,Doryteuthis pealeii, as a Chemical and Visual Defense Against Two Predatory Fishes, Summer Flounder, Paralichthys dentatus, and Sea Catfish, Ariopsis felis
Charles D. Derby, Mihika Tottempudi, Tiffany Love-Chezem, Lanna S. Wolfe
2014 (subscription)

Abstract
Chemical and visual defenses are used by many organisms to avoid being approached or eaten by predators. An example is inking molluscs—including gastropods such as sea hares and cephalopods such as squid, cuttlefish, and octopus—which release a colored ink upon approach or attack. Previous work showed that ink can protect molluscs through a combination of chemical, visual, and other effects. In this study, we examined the effects of ink from longfin inshore squid, Doryteuthis pealeii, on the behavior of two species of predatory fishes, summer flounder, Paralichthys dentatus, and sea catfish, Ariopsis felis. Using a cloud assay, we found that ink from longfin inshore squid affected the approach phase of predation by summer flounder, primarily through its visual effects. Using a food assay, we found that the ink affected the consummatory and ingestive phase of predation of both sea catfish and summer flounder, through the ink's chemical properties. Fractionation of ink showed that most of its deterrent chemical activity is associated with melanin granules, suggesting that either compounds adhering to these granules or melanin itself are the most biologically active. This work provides the basis for a comparative approach to identify deterrent molecules from inking cephalopods and to examine neural mechanisms whereby these chemicals affect behavior of fish, using the sea catfish as a chemosensory model.
 
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