Ommastrephes Research Articles

Age, growth, and population structure of the red flying squid (Ommastrephes bartramii) in the North Pacific Ocean, determined from beak microstructure

1 College of Marine Sciences Shanghai Ocean University 999 Hucheng Ring Road Shanghai 201306, China 2 National Engineering Research Center for Oceanic Fisheries Shanghai Ocean University 999 Hucheng Ring Road Shanghai 201306, China 3 Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources Ministry of Education Shanghai Ocean University 999 Hucheng Ring Road Shanghai 201306, China

Spatio-temporal distributions and habitat hotspots of the winter–spring cohort of neon flying squid Ommastrephes bartramii in relation to oceanographic conditions in the Northwest Pacific Ocean

ABSTRACT The spatio-temporal distribution and habitat hotspots of western winter–spring cohort of neon flying squid Ommastrephes bartramii in the Northwest Pacific Ocean were examined using Chinese squid-jigging fishery data and relevant environmental data during 1998–2009. An empirical cumulative distribution function approach was employed for evaluating squid’s preference of biophysical environments. The following environmental variables were included because of their identified importance in influencing squid habitat: sea surface temperature (SST), sea surface height anomaly (SSHA), sea surface salinity (SSS), chlorophyll-a (Chl-a) concentration, mixed layer depth (MLD) and eddy kinetic energy (EKE). Integrated environmental probability maps were generated for identifying the squid habitat hotspots. The distribution and abundance of O. bartramii exhibited interannual and seasonal variability. Annual latitudinal and longitudinal gravity centers were mainly located in the waters between 41.7° and 43.4°N and between 154.2° and 160.4°E, respectively. The nominal catch-per-unit-effort (CPUE) was high in 2003–2005, 2007 and 2008, but was relatively low in 2001, 2002 and 2009. The highest CPUE occurred in August. The inferred optimal ranges for SST, SSHA, SSS, Chl-a, MLD and EKE, determined from the cumulative distribution curves, were 17.6–18.6 °C, −5–1.5 cm, 33.58–33.79 psu, 0.41–0.55 mg m −3 , 15.5–18.5 m and 28–35.5 cm 2 s −2 , respectively. Potential habitat hotspots identified for O. bartramii coincided with locations of subarctic front zone (SAFZ). Approximately 72% of the average O. bartramii CPUE observations were found in the regions with probability indices higher than 0.6. The O. bartramii CPUEs tended to increase with the increasing integrated environmental probability values over 1998–2007. The predicted areas of high CPUEs corresponded well with the fishery observation data in 2008 and 2009. This study improves our understanding of spatio-temporal variability in the habitat hotspots of O. bartramii . Similar approach may also be used to predict habitat hotspots distributions of other pelagic species.

Application of a continuous time delay-difference model for the population dynamics of winter-spring cohort of neon flying squid (Ommastrephes bartramii, Lesueur 1821) in the North-west Pacific Ocean

A continuous time delay-difference model (CD-DM) was applied to the Chinese neon flying squid (Ommastrephes bartramii) jigging fisheries data (2001–2004) in the north-west Pacific Ocean. The continuous time delay-difference model (CD-DM) was modified from the discrete-time delay-difference model (D-DM), in which recruitment, growth and mortality rates are treated as varying continuously over time. Some commercially important stocks, such as shrimp andO. bartramiwith recruitment, growth and mortality rates all varying continuously over time, may be better analysed by a continuous delay-difference model. We estimated the growth and recruitment ofO. bartramiion the basis of the CD-DM, and biological reference points (BRPs) and accuracy of estimates are discussed in this study. We obtained population sizes of 183.9–201.8 million squid during early September 2004. The status of the stock was not in a sustainable state at this time with the available data, which suggests that measures should be taken for the sustainable utilization of this stock. The ability to calculate reference points without need of a full age-structured data makes CD-DM an attractive option for data-poor fisheries. We provided an alternative method for assessingO. bartramiistock and bridged the gap between simple surplus production models and complex fully age-structured models.

Identifying Pelagic Habitat Hotspots of Neon Flying Squid in the Temperate Waters of the Central North Pacific.

We identified the pelagic habitat hotspots of the neon flying squid (Ommastrephes bartramii) in the central North Pacific from May to July and characterized the spatial patterns of squid aggregations in relation to oceanographic features such as mesoscale oceanic eddies and the Transition Zone Chlorophyll-a Front (TZCF). The data used for the habitat model construction and analyses were squid fishery information, remotely-sensed and numerical model-derived environmental data from May to July 1999–2010. Squid habitat hotspots were deduced from the monthly Maximum Entropy (MaxEnt) models and were identified as regions of persistent high suitable habitat across the 12-year period. The distribution of predicted squid habitat hotspots in central North Pacific revealed interesting spatial and temporal patterns likely linked with the presence and dynamics of oceanographic features in squid’s putative foraging grounds from late spring to summer. From May to June, the inferred patches of squid habitat hotspots developed within the Kuroshio-Oyashio transition zone (KOTZ; 37–40°N) and further expanded north towards the subarctic frontal zone (SAFZ; 40–44°N) in July. The squid habitat hotspots within the KOTZ and areas west of the dateline (160°W-180°) were likely influenced and associated with the highly dynamic and transient oceanic eddies and could possibly account for lower squid suitable habitat persistence obtained from these regions. However, predicted squid habitat hotspots located in regions east of the dateline (180°-160°W) from June to July, showed predominantly higher squid habitat persistence presumably due to their proximity to the mean position of the seasonally-shifting TZCF and consequent utilization of the highly productive waters of the SAFZ.

Future projected impacts of ocean warming to potential squid habitat in western and central North Pacific

Abstract Climate-driven changes in the marine ecosystem largely influence the distribution, abundance, and the consequent availability of marine resources to the fishery. In this study, we examined the potential habitat distributions of the neon flying squid (Ommastrephes bartramii) under the projected impacts of ocean warming. We used the sea surface temperature (SST) from the three CMIP5 climate scenarios (RCP4.5, RCP6.0, and RCP8.5) with the low to high future emissions. Based on the squid habitat models, SST showed the highest effect on the present potential squid habitat distribution that accounted for at least 60% of the predicted spatial patterns from May to July 2000–2010. This result underpinned the species' high sensitivity to the temperature changes in its feeding environments. Moreover, the projected future potential squid habitats revealed pronounced differences in the spatial and temporal patterns relative to the present habitat distributions across the different regions of the western and central North Pacific. The future squid habitat predictions revealed a net reduction in the suitable squid habitat coupled with the corresponding northward habitat retreat. Moreover, the magnitude of the predicted habitat changes was proportional to the levels of warming for the representative periods from May to July 2025, 2050, and 2100. The highest decrease in the spatial extent and poleward retreat of the potential squid habitat were observed from May to July 2100 under the RCP 8.5 scenario. These trends could translate to shorter squid fishing periods and offshore shifts of the squid fishing grounds. Thus, insights into the future spatio-temporal patterns and trajectories of the potential squid habitats could lend important implications on the availability of squid resources to the fishery and subsequent evaluation of squid fishery management options under climate change.

Stable isotope analysis of the gladius to investigate migration and trophic patterns of the neon flying squid (Ommastrephes bartramii)

The neon flying squid, Ommastrephes bartramii is broadly distributed in subtropical and temperate regions of the world’s oceans. The North Pacific population is comprised of two spawning cohorts; the autumn cohort and winter-spring cohort, which despite their apparent contiguous hatching periods, have marked differences in the mantle length between the two cohorts, indicating differences in behavior. Especially, females of the autumn cohort after remaining in the subtropical zone for spring, in the first half of the summer migrate close to the vicinity of the southern boundary of the transition area. Subsequently they migrate into the subarctic waters to feed. However, for males details are less clear and it is considered that they remain in the subtropical zone without migrating to the subarctic feeding area. However little is known about the migration strategy of O. bartramii.Stable isotope profiles along the gladius (internal chitinous shell) have been recently analyzed and form a promising tool to back-calculate a chronological record of changes in the diet and habitat. In this study, δ13C and δ15N values were measured along the gladius to reconstruct the feeding variations and habitat of the autumn cohort during ontogeny. The results of δ13C values support previous studies which inferred differences in migratory behavior between males and females. These differences occurred from 260mm mantle length.

Effects of environmental variations on the abundance of western winter-spring cohort of neon flying squid (Ommastrephes bartramii) in the Northwest Pacific Ocean

During 1995–2011, annual production of winter-spring cohort of Ommastrephes bartramii for Chinese squidjigging fishery has greatly fluctuated, which is closely related to the environmental conditions on the spawning and fishing grounds. To better understand how squid recruitment and abundance were influenced by ocean environmental conditions, biological and physical environmental variables including sea surface temperature (SST), SST anomaly (SSTA), chlorophyll a (Chl a) concentration and the Kuroshio Current were examined during years with the highest (1999), intermediate (2005), and lowest (2009) catches. Catch per unit effort (CPUE) of the squid-jigging vessels was used as an indicator of squid abundance. The results indicated that high SST and Chl a concentration on the spawning ground in 1999 resulted in favorable incubation and feeding conditions for squid recruitment. Whereas the suitable spawning zone (SSZ) in 2009 shifted southward and coincided with low SST and Chl a concentration, resulting in a reduction in the squid recruitment. The small difference of SSZ area in the three years suggested the SSZ provided limited influences on the variability in squid recruitment. Furthermore, high squid abundance in 1999 and 2005 was associated with warm SSTA on the fishing ground. While the cool SSTA on the fishing ground in 2009 contributed to adverse habitat for the squid, leading to extremely low abundance. It was inferred that strengthened intensity of the Kuroshio force generally yielded favorable environmental conditions for O. bartramii. Future research are suggested to focus on the fundamental research on the early life stage of O. bartramii and mechanism of how the ocean-climate variability affects the squid abundance and spatial distribution by coupling physical model with squid biological process to explore transport path and abundance distribution.

Determination of squid age using upper beak rostrum sections: technique improvement and comparison with the statolith

Analysis of growth increments in beak rostrum sagittal sections (RSSs) has been increasingly used for estimating octopus age. In this study, we develop an effective method to process and read the RSS of four oceanic ommastrephid squid species (Dosidicus gigas, Ommastrephes bartramii, Illex argentinus and Sthenoteuthis oualaniensis) and validate the daily deposition of the increments by comparing to corresponding statolith-determined ages. The proposed method of processing yielded readable rates ranging from 42.9 % in I. argentinus to 71.7 % in D. gigas for samples from I. argentinus to D. gigas. The high precision of the increment readings with low independent counting coefficient of variation indicates that the processing and counting methods used are reliable. This study suggests that the RSS of the upper beak is an appropriate tool for estimating the age of D. gigas, O. bartramii and perhaps S. oualaniensis, although erosion of the rostral region may result in an underestimation of squid ages.

A review of interaction between neon flying squid (Ommastrephes bartramii) and oceanographic variability in the North Pacific Ocean

The neon flying squid (Ommastrephes bartramii) is a short-lived opportunistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic eggs to nektonic adults is closely linked to oceanographic conditions. The fluctuations in O. bartramii abundance and distribution tend to increase and widen continuously due to the heavy influences of ocean-climate events on various spatio-temporal scales. In this study, we reviewed the interaction between O. bartramii and oceanography variability in the North Pacific with respect to large-scale climatic-oceanic phenomena including El Nino, La Nina, Kuroshio, Oyashio and Pacific Decadal Oscillation (PDO), as well as regional environmental variables such as sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS), chlorophyll-a (Chl-a) concentration, and plankton density. The population dynamics of O. bartramii is mediated mainly by meso- and large-scale climatic-oceanic events (e.g., Kuroshio and Oyashio Currents) rather than other local environmental conditions (e.g., SST and Chl-a concentration), because all of the oceanographic influences are imposed on the context of large-scale climate changes (e.g., PDO). An unstructured-grid finite-volume coastal ocean model coupled with an individual-based model is proposed to simulate relevant physical-biological oceanographic processes for identifying ocean-climate influence and predicting O. bartramii distribution and abundance in the North Pacific. Future research needs to be focused on improving the knowledge about early life history of O. bartramii and evaluating the relationship between marine physical environment and two separate passive drifting life stages of O. bartramii including free-floating eggs and planktonic paralarvae.

Detection of potential fishing zones for neon flying squid based on remote-sensing data in the Northwest Pacific Ocean using an artificial neural network

Ommastrephes bartramii is a short-lived species of squid and reacts rapidly to changes in the regional environmental conditions of the fishing ground. Understanding the preferred range of key environmental variables and predicting potential resource distributions are critical to conserve and manage its resources. Commercial fishery data for the western winter–spring cohort of O. bartramii from Chinese squid-jigging vessels during 2003–2013 were used to evaluate a suitable range of three key environmental variables, sea surface temperature (SST), sea surface height (SSH), and chlorophyll-a (chl-a) concentration, and to explore potential fishing zones (PFZs) using an artificial neural network. The neural interpretation diagram and independent variable relevance analysis indicate that month, latitude, and SST had significant influences on the PFZ distribution of O. bartramii, yielding 21.78%, 23.91%, and 26.04% of contribution rates, respectively. Based on the sensitivity analyses, a high abundance of O. bartramii mainly occurred in the waters between 150°–165° E and 37°–42° N during July to August. Suitable ranges of environmental variables for O. bartramii were 11–18°C for SST, −10 to 60 cm for SSH, and 0.1–1.7 mg/m3 for chl-a concentration, respectively. The back-propagation network model was well developed and could be used to predict the PFZ with 80% accuracy. The actual fishing grounds coincided with the predicted PFZ, suggesting that the established model of PFZ is effective in forecasting the potential habitat of O. bartramii in the Northwest Pacific Ocean.

Detection of Squid and Pacific Saury fishing vessels around Japan using VIIRS Day/Night Band image

The Suomi National Polar-orbiting Partnership (S-NPP) satellite, which carries a new Day/Night Band (DNB) radiometer, has very high sensitivity to observe anthropogenic light emission sources, especially on the activity of maritime vessels. This study applied DNB images to detect fishing vessel by three case species in Northwest Pacific ocean (Neon flying squid (Ommastrephes bartramii), Japanese common squid (Todarodes pacificus), and Pacific saury (Cololabis saira)). The results of fishing positions and distribution were well validated using location reported data by fisherman. The more application of DNB data could be used to estimate the numbers of fishing vessels, vessel speed from Vessel Monitoring System (VMS), and combined traditional fishing grounds, season time, habits and water temperature to distinguish the fishing species. The DNB data could form the basis for future fisheries management and information system.

Effects of temperature on embryonic development and paralarval behavior of the neon flying squid Ommastrephes bartramii

Studies on the relationships between the early life stages of the neon flying squid Ommastrephes bartramii and oceanographic conditions are essential for understanding the spatial and temporal distribution patterns of this ecologically and economically important species. In this study, O. bartramii eggs were artificially fertilized and incubated at temperatures found in its known distribution range (16−26°C). Complete organogenesis with normal successive cleavage and the distinct continuity of morphological features was limited to between 18 and 25°C. Experimental rearing, cruise-collected specimens, and oceanographic data confirmed that the optimal temperature range for paralarval survival around Hawaii is 18 to 25°C. Embryos reared at 16°C showed abnormal organogenesis; however, normal development resumed when the embryos were transferred to 22 or 24°C after blastoderm formation. Hatchlings showed a variety of swimming behaviors, which may allow squid to regulate their thermal distribution in the wild. Furthermore, ball formation and associated chromatophore expansion might represent an apo sematic adaptation to imitate unpalatable prey. This study highlights the flexible strategy of O. bartramii embryo development and illustrates how information on paralarval behavior and oceanographic data (sea surface temperature) may be combined to improve our understanding of the factors that influence the survival of this species.

Wind‐induced stock variation of the neon flying squid (Ommastrephes bartramii) winter–spring cohort in the subtropical North Pacific Ocean

AbstractOur examination of the neon flying squid (Ommastrephes bartramii) winter–spring cohort catch per unit effort (CPUE, an index of stock) revealed significant positive correlations with the interannual variations of observed chlorophyll‐a (Chl‐a) concentration and autumn–winter mixed layer depth (MLD) in the winter–spring feeding grounds of paralarvae and juveniles (130–170°E, 20–27°N). These correlations suggest the importance of integrated bottom‐up effects by the autumn–winter MLD for the neon flying squid stocks. However, the influence of autumn–winter MLD interannual variation in the forage availability for paralarvae and juveniles, i.e., particulate organic matter and zooplankton, has still been unclear. In this study, we use the lower trophic ecosystem model NEMURO, which uses the physical environmental data from the ocean reanalysis dataset obtained by the four‐dimensional variational (4DVAR) data assimilation method. The model‐based investigation enables us to clarify how the autumn–winter MLD controls the particulate organic matter and zooplankton abundance in the feeding grounds. Further, our investigation of the autumn–winter MLD interannual variation demonstrates that the stronger autumn wind in the feeding grounds develops a deeper mixed layer. Therefore, the deep mixed layer entrains nutrient‐rich water and enhances photosynthesis, which results in good feeding conditions for paralarvae and juveniles. Our results underline that the wind system interannual variation has critical roles on the winter–spring cohort of the neon flying squid stock.

Variability of Suitable Habitat of Western Winter-Spring Cohort for Neon Flying Squid in the Northwest Pacific under Anomalous Environments.

We developed a habitat suitability index (HSI) model to evaluate the variability of suitable habitat for neon flying squid (Ommastrephes bartramii) under anomalous environments in the Northwest Pacific Ocean. Commercial fisheries data from the Chinese squid-jigging vessels on the traditional fishing ground bounded by 35°-45°N and 150°-175°E from July to November during 1998-2009 were used for analyses, as well as the environmental variables including sea surface temperature (SST), chlorophyll-a (Chl-a) concentration, sea surface height anomaly (SSHA) and sea surface salinity (SSS). Two empirical HSI models (arithmetic mean model, AMM; geometric mean model, GMM) were established according to the frequency distribution of fishing efforts. The AMM model was found to perform better than the GMM model. The AMM-based HSI model was further validated by the fishery and environmental data in 2010. The predicted HSI values in 1998 (high catch), 2008 (average catch) and 2009 (low catch) indicated that the squid habitat quality was strongly associated with the ENSO-induced variability in the oceanic conditions on the fishing ground. The La Niña events in 1998 tended to yield warm SST and favorable range of Chl-a concentration and SSHA, resulting in high-quality habitats for O. bartramii. While the fishing ground in the El Niño year of 2009 experienced anomalous cool waters and unfavorable range of Chl-a concentration and SSHA, leading to relatively low-quality squid habitats. Our findings suggest that the La Niña event in 1998 tended to result in more favorable habitats for O. bartramii in the Northwest Pacific with the gravity centers of fishing efforts falling within the defined suitable habitat and yielding high squid catch; whereas the El Niño event in 2009 yielded less favorable habitat areas with the fishing effort distribution mismatching the suitable habitat and a dramatic decline of the catch of O. bartramii. This study might provide some potentially valuable insights into exploring the relationship between the underlying squid habitat and the inter-annual environmental change.

Possible link between interannual variation of neon flying squid (Ommastrephes bartramii) abundance in the North Pacific and the climate phase shift in 1998/1999

The relationship between interannual variation in abundance of the autumn cohort of the neon flying squid (Ommastrephes bartramii) and ocean environmental changes in the central North Pacific was examined. We focused on the change in subsurface ocean state during the 1998/1999 climate shift. Changes in catch per unit effort (CPUE) of the neon flying squid derived from long-term driftnet survey was compared to that in ocean environments related to the feeding conditions of the squid. A four-dimensional variational (4D-VAR) ocean data assimilation product was used as an accurate estimate of the dynamic state in the North Pacific. Correlation analysis indicated that the squid CPUE was highly related with the Pacific Decadal Oscillation (PDO) in winter. In January, the correlation field with the entrainment rate (ENT), the proxy for the nutrient-rich water supply entering the mixed layer, showed a good agreement with the main spawning and nursery ground of the autumn cohort (MSNGAC). The nutrient-rich water supply in the MSNGAC in early winter was mainly induced by the deepening of the mixed layer forced by surface latent heat cooling and turbulent mixing, while the basin-scale wind stress curl and the horizontal advection were less affected. These results suggest that the amount of newly supplied nutrient-rich water mass in early winter could affect the primary productivity throughout the winter and the resultant feeding conditions of the juvenile squid. We assumed that this process would determine the stock levels of the neon flying squid in the following summer. We further attempted to reconstruct the changes in neon flying squid CPUE during 1994–2006 by applying regression analysis to several parameters. The result showed that ENT, surface and subsurface temperatures, and the PDO index in February were good predictors for estimating the squid CPUE time series. In addition, the subsurface temperature in the MSNGAC in the preceding autumn was also a good predictor. This indicates that the squid CPUE could be predicted four months earlier than its nursery period, as the same accuracy as that using February data. The accurate prediction in early period could be useful for the squid stock management in the future.

Embryonic and paralarval development following artificial fertilization in the neon flying squid Ommastrephes bartramii

Ommastrephidae are the most important commercial fishery group among cephalopods. However, little is known about their embryonic development. This article provides details of embryonic development observed in three ommastrephids: Ommastrephes bartramii, Sthenoteuthis oualaniensis, and Eucleoteuthis luminosa. All embryos were obtained through artificial fertilization conducted onboard the research vessel Kaiyo Maru during a cruise around the Hawaiian Islands in December 2013. The embryonic and paralarval stages of O. bartramii are explained in detail. The hatchling stages were compared between all three species, as well as with information on Illex argentinus hatchlings from the literature. The species-specific effects of the oviducal gland powder on chorion expansion were analyzed. The results indicated that the overall chemical nature of the oviducal gland was species specific, although the inducer of chorion expansion was the same across species. In addition, treatment with oviducal gland jelly induced partial parthenogenesis in the early stages of embryonic development through the expansion of the perivitelline space and blastodisc formation.

Seasonal potential fishing ground prediction of neon flying squid (Ommastrephes bartramii) in the western and central North Pacific

AbstractWe explored the seasonal potential fishing grounds of neon flying squid (Ommastrephes bartramii) in the western and central North Pacific using maximum entropy (MaxEnt) models fitted with squid fishery data as response and environmental factors from remotely sensed [sea surface temperature (SST), sea surface height (SSH), eddy kinetic energy (EKE), wind stress curl (WSC) and numerical model‐derived sea surface salinity (SSS)] covariates. The potential squid fishing grounds from January–February (winter) and June–July (summer) 2001–2004 were simulated separately and covered the near‐coast (winter) and offshore (summer) forage areas off the Kuroshio–Oyashio transition and subarctic frontal zones. The oceanographic conditions differed between regions and were regulated by the inherent seasonal variability and prevailing basin dynamics. The seasonal and spatial extents of potential squid fishing grounds were largely explained by SST (7–17°C in the winter and 11–18°C in the summer) and SSS (33.8–34.8 in the winter and 33.7–34.3 in the summer). These ocean properties are water mass tracers and define the boundaries of the North Pacific hydrographic provinces. Mesoscale variability in the upper ocean inferred from SSH and EKE were also influential to squid potential fishing grounds and are presumably linked to the augmented primary productivity from nutrient enhancement and entrainment of passive plankton. WSC, however, has the least model contribution to squid potential fishing habitat relative to the other environmental factors examined. Findings of this work underpin the importance of SST and SSS as robust predictors of the seasonal squid potential fishing grounds in the western and central North Pacific and highlight MaxEnt's potential for operational fishery application.

The Squid Ink Polysaccharides Protect Tight Junctions and Adherens Junctions from Chemotherapeutic Injury in the Small Intestinal Epithelium of Mice

Gastrointestinal mucositis and infection by chemotherapy treatment are associated with alterations in the functioning of the intestinal barrier, due to the potential damage induced by anticancer drugs on the epithelial tight junctions and adheren junction. We aimed to study the protective effect of dietary polysaccharides on chemotherapy-induced injury in the epithelial cells. In the current study, using mice that were intraperitoneally injected with 50 mg/kg cyclophosphamide for 2 days, we reveal that polysaccharides from the ink of Ommastrephes bartrami (OBP) enhanced the mRNA and protein expression levels of Occludin, zonulae occluden (ZO)-1, and E-cadherin. Immunohistochemistry staining of ZO-1 and E-cadherin confirmed the increase in the mRNA and protein levels. OBP also remarkably enhanced the mRNA expression of other tight junction proteins, ZO-2, ZO-3, claudin-2, and cingulin. Our results may have important implications in host defense, especially the immunopotentiation function of OBP on the cyclophosphamide-induced epithelial cell injury, as well as intestinal disorders involving inflammation and infection.

Dietary squid ink polysaccharide induces goblet cells to protect small intestine from chemotherapy induced injury.

Gastrointestinal mucositis induced by chemotherapy is associated with alterations of intestinal barrier function due to the potential damage induced by anti-cancer drugs on the epithelial cells. Goblet cells, an important epithelial lining in the intestine, contribute to innate immunity by secreting mucin glycoproteins. Employing a mouse model of chemotherapy induced intestinal mucosal immunity injury by cyclophosphamide, we demonstrated for the first time that polysaccharide from the ink of Ommastrephes bartramii (OBP) enhanced Cyto18, which is a mucin expression in goblet cells. The up-regulation of mucins by OBP relied on the augmented quantity of goblet cells, but not on the changes in the ultrastructure of endoplasmic reticulum (ER). Our results may have important implications for enhanced immunopotentiation function of functional OBP on intestinal mucosal immunity against intestinal disorders involving inflammation and infection.

The dietary polysaccharide from Ommastrephes bartrami prevents chemotherapeutic mucositis by promoting the gene expression of antimicrobial peptides in Paneth cells

Gastrointestinal mucositis (GIM), induced by chemotherapy, is associated with alterations in the function of the intestinal barrier due to the potential damage induced by anti-cancer drugs on the epithelial cells. The Paneth cells, an important epithelial lineage in the intestine, contribute to the innate immunity by releasing antimicrobial proteins onto the mucosal surfaces. Polysaccharide, as a widely used immunomodulatory nutrient, was reported to have an effect of modulating the intestinal immune system. However, the effect of dietary polysaccharides in protecting the Paneth cells from injuries induced by chemotherapy was poorly investigated. In the current study, with a mouse model of cyclophosphamide (Cy)-induced gastrointestinal injury, the polysaccharide extracted from the ink of Ommastrephes bartrami (OBP) were found to protect the mouse Paneth cells from chemotherapeutic injury. Ommastrephes bartrami polysaccharide (OBP) treatment could enhance the mRNA expression of antimicrobial proteins in the Paneth cells, such as lysozyme, Ang4, Defa-5, and sPLA2. The increased production of the microbicidal proteins in the Paneth cells was dependent on the relatively highly developed endoplasmic reticulum (ER) structure but was not dependent on the increase in the quantity of the ER. The Ommastrephes bartrami polysaccharide (OBP) activated the IRE-1 mediated XBP-1s pathway to cope with antimicrobial protein secretion. Our results may have important implications with regard to the role of OBP in chemotherapy-induced Paneth cell injury in intestinal disorders involving inflammation and infection.