Corbicula Fluminea Research Articles

The effects of food quantity, light, and temperature on clearance rates in freshwater bivalves (Cyrenidae and Unionidae)

Assessing the environmental variables that influence freshwater bivalve filtration activity is key to better understand the functioning of stream ecosystems. In the present study, the effects of light (0 ± 0 µmol m−2 s−1 and 19 ± 2 µmol m−2 s−1) and temperature (10, 15, 20 and 25°C) on the clearance rates of two bivalve species: the Asian clam Corbicula fluminea (Cyrenidae) and pocketbook Lampsilis ovata (Unionidae) were assessed under controlled laboratory conditions at two different concentrations of algal food (i.e., 10,000 cells ml−1 and 100,000 cells ml−1). Clearance rates for C. fluminea varied from 0 to 491 ml g−1 h−1, while the observed range for L. ovata was 0 to 905 ml g−1 h−1. We found that the relative contribution of the tested variables was species-dependent. While temperature plays a major role in the clearance rates of C. fluminea, food concentration was the most significant variable in the clearance rate of L. ovata. Our results confirm the complex interactions between abiotic and biotic factors in freshwater bivalve filtration activity. Overall, clearance rates are highly variable especially in C. fluminea and presumably regulated by other untested factors suggesting high plasticity in filtration.

Toxic effects of zinc and cadium on the benthic organisms in sediments of Lake Poyang and verification of quality guideline

以泥鳅（Misgurnus anguillicaudatus）、铜锈环棱螺（Bellamya aeruginosa）、河蚬（Corbicula fluminea）为受试生物，以死亡率、渗血率、体质量变化、行动迟钝率、挖洞率为测试指标，探究沉积物中Zn和Cd对底栖生物的21 d慢性毒性效应，并对鄱阳湖Zn和Cd的沉积物基准值进行了验证.结果表明，沉积物中Cd对底栖生物的毒性效应强于Zn，沉积物中Zn、Cd对泥鳅、铜锈环棱螺、河蚬的LC₅₀（半数致死浓度）分别为644和61 mg/kg、751和54 mg/kg、652和81 mg/kg，EC₅₀（半数效应浓度）值分别为526和49 mg/kg、589和35 mg/kg、474和45 mg/kg.经验证，沉积物Zn和Cd的TEL（临界效应浓度）、PEL（必然效应浓度）值比较合理，具有一定适用性，即当Zn、Cd的加标含量低于TEL值时，Q_TEL<1，不具有毒性；当加标含量高于PEL值时，Q_PEL>1，毒性明显.;The 21d chronic toxic effects of Zn and Cd in sediments on benthic organisms were investigated by using Misgurnus anguillicaudatus, Bellamya aeruginosa and Corbicula fluminea as the testing organisms, using mortality rate, bleeding rate, average body weight change, sluggishness rate and burrowing rate as the testing indexes, and verified by the sediment reference values of Zn and Cd in Lake Poyang. The results showed that the toxicity of Cd to benthic organisms in sediments was stronger than that of Zn, and the LC₅₀(50% lethal concentration) of Zn and Cd to Misgurnus anguillicaudatus, Bellamya aeruginosa and Corbicula fluminea were 644 and 61 mg/kg, 751 and 54 mg/kg, 652 and 81 mg/kg, and the EC₅₀(50% effective concentration) values were 526 and 49 mg/kg, 589 and 35 mg/kg, 474 and 45 mg/kg, respectively. It has been verified that the TEL (threshold effect level) and PEL (probable effect level) values of the sediments Zn and Cd are reasonable and have certain applicability. When the additive concentration of Zn and Cd is lower than the TEL value, Q_TEL<1 is not toxic. When the additive concentration was higher than PEL value, Q_PEL>1 showed obvious toxicity.

Synchrony between Reproductive Phase and Flood Period: A Dispersion Mechanism for the Freshwater Clam Corbicula fluminea (Bivalvia: Corbiculidae) in a Brazilian Neotropical Floodplain.

This study evaluates the gonadal histology of Corbicula fluminea present in the upper Paraná River floodplain and samples of limnological variables to understand its reproductive cycle. Corbicula fluminea was monitored monthly from December 2013 to February 2015. Spermatogonia, primary and secondary spermatocytes, spermatids and spermatozoa were identified in the male follicles of the hermaphrodites. Oogonia, oogonial nests, previtellogenic oocytes, early vitellogenic oocytes, middle vitellogenic oocytes and full-grown vitellogenic oocytes were identified in the female follicles of the hermaphrodites and females. The reproductive phases were described as developing, active spawning/sperm releasing, regression and regeneration. Higher values of temperature, dissolved oxygen, total nitrogen and total phosphorous were identified during flood periods, while higher values of pH and conductivity were obtained during dry periods. The species either does not reproduce or reduces the intensity of reproduction in cold months, with the sex ratio not differing significantly between hermaphrodites and females with regard to month and reproductive phase. Thus, reproduction is synchronized with the flood period and its limnological characteristics and when the increase in connectivity between floodplain environments facilitates the larval dispersion of this non-native species into other environments.

Bioaccumulation, Elimination, Biotransformation Products and Structural Damage of Legacy and Novel Brominated Flame Retardants in Asian Freshwater Clams ( &lt;i&gt;Corbicula Fluminea&lt;/i&gt;)

Bioaccumulation, Elimination, Biotransformation Products and Structural Damage of Legacy and Novel Brominated Flame Retardants in Asian Freshwater Clams ( &lt;i&gt;Corbicula Fluminea&lt;/i&gt;)

Morphological and Genetic Traits of the First Invasive Population of the Asiatic Clam Corbicula fluminea (O.F. Müller, 1774) Naturalized in the Volga River Basin

Variability of the first invasive population of C. fluminea (O.F. Muller, 1774) from the Volga basin is studied using the mitochondrial cytochrome c oxidase subunit I gene fragment (COI mtDNA), and morphological features of the shells are characterized. A comparison with C. fluminalis (O.F. Muller, 1774) from the Kura River basin is made in order to avoid errors in species identification. All analyzed individuals belong to the most widespread R morphological type. The only nucleotide sequence haplotype we found is identical to the widespread variant prevailing in the populations of Corbicula with R morphological type in Europe and also in America. There were mollusks of different shell size groups in the sample. Corbicula larvae were detected in qualitative zooplankton samples and in the gills of adults. Therefore, the studied population reproduces independently and may possibly become a source for further species expansion.

Evidence of a Dietary Shift in Female Barbour's Map Turtle (Graptemys barbouri) to Exploit an Exotic Mollusk

Barbour's map turtle (Graptemys barbouri) is the species of map turtle with the highest degree of sexual dimorphism, with females attaining larger body sizes and having much greater head widths than males. Accordingly, females and males also feed on different riverine prey, with females historically feeding on native gastropods and bivalves and males predominantly feeding on soft-bodied macroinvertebrates. Here, we report on a diet shift in female Barbour's map turtle from native prey to an invasive mollusk, the Asian clam (Corbicula fluminea), in southwestern Georgia.

Comparative Evaluation of Volatile Profiles of Asian Hard Clams (Meretrix meretrix) with Different Shell Colors by Electronic Nose and GC-MS

ABSTRACT Odor is an important factor influencing the acceptance of clams by the consumer. In order to better understand the flavor characteristics of different clams, the volatiles in raw and cooked Meretrix meretrix with three shell colors (mottled shell, red shell, and yellow shell) were investigated by electronic nose and gas chromatography-mass spectrometry (GC-MS). A total of 69 volatiles, dominated by alcohols (32.10–41.02%) and 25 odor-active compounds, were identified in the raw samples, while 73 volatiles, dominated by aldehydes (55.18–58.22%) and 27 odor-active compounds, were determined in the cooked samples. Compared to raw samples, cooked samples had higher concentrations and odor activity values (OAVs) of volatiles. Among the raw clams, OAVs of volatiles in red shell clams were significantly higher than yellow shell clams. According to both electronic nose and GC-MS, all the samples could be distinguished, and 3-octanone, (Z)-1,5-octadien-3-ol, linalool, 1-octen-3-one, 1-octen-3-ol, 2-nonanone, (E,E)-2,4-heptadienal, and undecanal were the key volatiles to distinguish the odor profile of Meretrix meretrix with different shell colors.

Abundance of an invasive bivalve, Corbicula fluminea, is negatively related to growth of freshwater mussels in the wild

Abstract Causes of worldwide freshwater mussel declines are poorly understood, and the potential role of the invasive Asian Clam, Corbicula fluminea, has received little attention. We measured survival and growth of captively‐reared juveniles of four native mussel species during 84‐day in situ exposures at 17 sites in the Rockcastle River system, Kentucky, U.S.A., where mussel declines are attributed to coal mining. We measured water temperature, a comprehensive array of water chemistry variables, and Corbicula abundance at each site during mussel exposures. Mussel survival was high (mean = 85.4%), did not differ among species, and was not related to any measured factor. In contrast, growth varied among sites by an order of magnitude, but growth responses were nearly identical for all four species. We found little evidence of water pollution from coal mining or other sources, and pollution did not explain variation in mussel growth. Growth was best explained by a model including only temperature (positive effect) and Corbicula abundance (negative effect) without interaction. Our model predicts 46% lower mass gain over 84 days for every 10‐fold increase in Corbicula abundance regardless of temperature, but growth may be reduced to unsustainably low levels in cooler streams. Previous ideas about water pollution as a cause of low growth and mussel declines were not supported by our data. Instead, the predicted strong effects of Corbicula, combined with similar responses of four mussel species, suggest that Corbicula may be an important, but overlooked, factor in widespread mussel declines.

First records of Sinanodonta woodiana (Lea, 1834) and Corbicula fluminea (O. F. Müller, 1774) (Mollusca, Bivalvia) from the Adriatic part of Croatia

Sinanodonta woodiana (Lea) and Corbicula fluminea (O. F. Müller) are among the most invasive aquatic molluscs found in Europe. Both species were recorded in the Adriatic part of Croatia for the first time in 2019 although in the Danubian Croatia they were more common. An abundant population of S. woodiana was found in an oxbow of the Cetina River; mussels with shell length of ca. 12–17 cm dominated. A population of C. fluminea was recorded in the freshwater section of the Zrmanja River above the Jankovića Buk waterfall which forms the border between the brackish and the freshwater sections of the river. Possible pathways of their introduction and reasons for their rare occurrence in contrast to the Danubian Croatia are discussed.

New evidence on the relationships between Hypnophila Bourguignat, 1859 and Gomphroa Westerlund, 1902 (Gastropoda: Eupulmonata: Azecidae)

Sinanodonta woodiana (Lea) and Corbicula fluminea (O. F. Müller) are among the most invasive aquatic molluscs found in Europe. Both species were recorded in the Adriatic part of Croatia for the first time in 2019 although in the Danubian Croatia they were more common. An abundant population of S. woodiana was found in an oxbow of the Cetina River; mussels with shell length of ca. 12–17 cm dominated. A population of C. fluminea was recorded in the freshwater section of the Zrmanja River above the Jankovića Buk waterfall which forms the border between the brackish and the freshwater sections of the river. Possible pathways of their introduction and reasons for their rare occurrence in contrast to the Danubian Croatia are discussed.

Modeling the trophic impacts of invasive zooplankton in a highly invaded river.

The lower Columbia River (Washington and Oregon, USA) has been heavily invaded by a large number of planktonic organisms including the invasive copepod Pseudodiaptomus forbesi and the planktonic juveniles of the invasive clam, Corbicula fluminea. In order to assess the ecological impacts of these highly abundant invaders, we developed a multivariate auto-regressive (MAR) model of food web dynamics based upon a 12-year time-series of plankton community and environmental data from the Columbia River. Our model results indicate that plankton communities in the lower Columbia River are strongly impacted by the copepod P. forbesi at multiple trophic levels. We observed different ecological effects across different life stages of P. forbesi, with nauplii negatively impacting ciliates and autotrophs, and copepodite stages negatively impacting Daphnia and cyclopoid copepods. Although juvenile C. fluminea were highly abundant in the summer and autumn of each year, our best fit MAR model did not show significant C. fluminea impacts. Our results illustrate the strong ecological impact that some zooplankton invaders may cause within rivers and estuarine systems, and highlight the need for further research on the feeding ecology of the planktonic life-stage of C. fluminea. Overall, our study demonstrates the manner in which long-term, high resolution data sets can be used to better understand the ecological impacts of invasive species among complex and highly dynamic communities.

Traditional Processing Method of Smoked Corbicula fluminea (Etak): Case of Etak Vendor in Kelantan, Malaysia

Traditional knowledge is very synonymous with communities and tribes around the world, especially indigenous peoples or in Malaysia known as Orang Asli. This knowledge is borne out of the constraints faced by society in daily life and often passed down from generation to generation. All aspects of life in the community such as traditional medicines, pest and disease control, farming method, tools used in the preparation of soil and roads, methods of food preparation and so on are assisted by the traditional knowledge created by the community itself. Asian clams (Corbicula fluminea), locally known as “etak” in Kelantan dialect, Malaysia, has been consumed by the local community as a snack for a years. Smoked “etak” is prepared traditionally using freshly harvested “etak” from the river or natural habitat. Freshly harvested “etak” is then washed thoroughly and soak overnight to remove sand and dirt. Followed by, marinating with the previously prepared spices and soak for about 2 hours. The last process is to smoke the “etak” on the fire with medium heat. “Etaks” are placed on a platform made of bamboo with height of about one meter above the ground. Beneath it was lighted with firewood and before “etak” can be placed on a bamboo platform, it was necessary to make sure that the firewood is burned to the coals. This is to ensure that the “etak” shell is not opened as it is considered to be damaged and should not be eaten as a snack. “Etak” with shell open will dry and lose its juiciness and flavor. “Etak” should be stirred all the time when it is on a platform with medium heat fire. “Etak” is usually smoked for about 45 minutes and left to cool down before eating or selling. Based on an interview and observation conducted, it can be concluded that smoked “etak” which is prepared using traditional method is preferred by consumers, as it has a unique aroma and flavor. Hence, the current study aims to document this knowledge through informal conversational interview with “etak” smokers and consumers in Kelantan as well as observing the working mechanism of this method.

Interaction between curcumin and a peptide and their protective effects against hepatic steatosis in mice

Curcumin is antioxidative, liver protective and it has lipid regulatory effects. However, its in vivo efficiency is limited because of the low absorption rate and bioavailability. LVYP (Leu-Val-Tyr-Pro) is a tetrapeptide isolated, purified and identified from Corbicula fluminea with strong antioxidant activity. The interaction mechanisms between curcumin and LVYP were investigated using UV–vis absorption and fluorescence spectra. The results showed that the interaction between curcumin and LVYP was hydrophobic. When the temperature was increased from 25 to 37 °C, ΔG decreased and the number of ligand molecules increased, the interaction was quenched statically explained the formation of some compounds. On the other hand, dynamic quenching occurred when the temperature reached 60 °C, ΔG increased and the number of ligand molecules decreased, which indicated that temperature affected the interaction between curcumin and LVYP. This study also showed that LVYP could promote intestinal absorption of curcumin, predominantly in the ileum, which was explored using a non-everted intestinal sac model. In vivo experiments showed that the liver's protective effect with the combined administration of LVYP and curcumin was better than the curcumin alone, and LVYP could promote the hepatoprotective function of curcumin. It was hypothesized that the interaction of LVYP and curcumin enhanced the intestinal absorption rate of curcumin, thereby increasing its liver protection effect.

Integrating expert opinion and traditional ecological knowledge in invasive alien species management: Corbicula in Eastern Europe as a model

The rate of alien species introduction is on the rise and seems unstoppable at a global scale. Once an alien species has been introduced to a new system, early detection and rapid eradication is the only cost-effective alternative to containment and long-term control. Here, we provide an integrative approach combining three sources of information to assist the management of invasive alien species. We used the Asian clam Corbicula sp. invasion in the Lower Danube as a model. First, the reference distribution data for the species was obtained through a crowdsourcing campaign, including a bibliographic review, public repositories and unpublished data. Next, we weighted the importance of different introduction pathways and dispersal vectors, focusing on the opinion and experience of an expert panel. Finally, information retrieved with semi-structured interviews was contrasted against the present distribution of the species. The expert panel highlighted the opening of the Rhine–Main–Danube Canal in 1992 as the most probable pathway of Corbicula introduction in the Lower Danube. However, the bibliographic review and interviews pointed to an earlier introduction event throughout the Danube Delta. In the subsequent spread phase, all three sources of information refer to zoochory, but also human mediated activities, as the vectors responsible for Corbicula dispersal to Danube tributaries. Our study presents a methodology on how expert opinion and traditional ecological knowledge can be effectively integrated to identify introduction pathways and dispersal vectors that facilitate the spread of invasive alien species. This approach can be used for enhancing collaboration between academic and research institutions and for raising stakeholders’ awareness to be used in management.

STATUS OF FRESHWATER MUSSELS (UNIONIDAE) OF THE RÍO CONCHOS BASIN, CHIHUAHUA, MEXICO

Before this study, researchers had not systematically surveyed the Rio Conchos, a tributary of the Rio Grande located in northern Mexico, for freshwater mussels. The Texas hornshell, Popenaias popeii, an endangered species under the United States Endangered Species Act, occurs in the main stem of the Rio Grande near its confluence with the Rio Conchos. The Texas hornshell's proximity to the Rio Conchos prompted us to survey to determine whether P. popeii also occurs within the Conchos basin. Additionally, previous researchers described the Conchos disk, Disconaias conchos, from the Rio Conchos but, to date, no one has reported live individuals of this species. The goal of this study was to determine the status of mussels within the Rio Conchos basin and to provide a baseline for future monitoring efforts. We qualitatively surveyed 11 sites within the Rio Conchos basin in May 2018. In total, we found two live individuals of the paper pondshell, Utterbackia imbecillis, at one site in the Rio San Pedro, a tributary of the Conchos River, and as shells of recently live individuals at two sites in the Rio Conchos. We found D. conchos as relict shells only at three sites, two in the Rio Conchos and one in a tributary of the river at Coyame. The lack of live or fresh-dead material suggests that D. conchos is extinct. We also found live individuals of nonnative Asian clams (Corbicula spp.) at 10 sites. Sand and gravel mining, high organic pollution, and inadequate instream flows were evident throughout the basin and might explain the general absence of mussels.

High stream flows dilute environmental DNA (eDNA) concentrations and reduce detectability

AbstractAimEnvironmental DNA (eDNA) is a rapidly emerging methodology with important applications to environmental management and conservation. However, the effects of stream flow or discharge on eDNA have been minimally investigated in lotic (stream and river) environments. In this study, we examined the role of stream flow on eDNA concentrations and detectability of an invasive clam (Corbicula fluminea), while also accounting for other abiotic and biotic variables.LocationIllinois, United States of America.MethodsWe used a longitudinal study over a year in two streams, as well as a seasonal study (summer, autumn) in eight streams, to investigate the effects of variable stream flow on eDNA concentrations and detectability. We used linear mixed‐effects models to assess the influence of various factors on eDNA concentration and occupancy models to make predictions on how seasonality can influence eDNA detection.ResultsWe found higher stream flows decreased eDNA concentrations, and floods produced false negatives or non‐detections at locations where C. fluminea was relatively common. In addition, we found concentrations and detectability of C. fluminea eDNA to be higher in summer than in autumn.Main conclusionsWe found that stream flow dilutes eDNA concentrations, which may have serious implications for the detection of low abundance organisms. Managers and practitioners applying eDNA for rare species should seek to sample at low or base stream flows when feasible, and future studies should investigate whether our findings here are consistent for other taxa and lotic ecosystems.

Using Freshwater Bivalves (Corbicula Fluminea) to Alleviate Harmful Effects of Small-Sized Crucian Carp (Carassius Carassius) on Growth of Submerged Macrophytes during Lake Restoration by Biomanipulation

Increased recruitment of small-sized fish following biomanipulation by reducing the biomass of plankti-benthivorous fish, not least in (sub)tropical lakes, may deteriorate water quality and thereby potentially hamper the recovery of submerged macrophytes. Filter-feeding bivalves remove suspended particles from the water and may, thereby, somewhat or fully counteract this negative effect of the increasing abundance of small-sized fish. So far, only few studies have investigated the interactive effects of fish and bivalves on water clarity and macrophyte growth. We conducted a 2 × 2 factorial designed outdoor mesocosm experiment with two densities of small crucian carp Carassius carassius (low 10 g m−2 and high 40 g m−2) and two densities of bivalves Corbicula fluminea (low 204 g m−2 and high 816 g m−2). We found significant interactive effect of fish and bivalves on the growth of the macrophyte Vallisneria natans. In the low density bivalve regime, the relative growth rates, root mass, root:shoot ratio and number of tubers were 30.3%, 30.8%, 21.6% and 27.8% lower in the high than in the low density fish treatments, while the decrease was less pronounced in the high density bivalve regime: 1.2%, 8.7%, 2.1% and 13.3%, respectively. Thus, bivalves reduced the negative effects of fish, not least when bivalve density was high. The weaker effects of small fish on plants in the high- than in the low-density C. fluminea regime can be attributed to lower total suspended solids (TSS) and Chl a in the first week of the experiment. Better light conditions further stimulated the growth of benthic algae, potentially increasing the removal of nutrients from the water and reducing fish-driven resuspension of the sediment. In addition, high densities of C. fluminea also enriched the sediment total nitrogen (TN) and total phosphorus (TP) content, favouring plant growth as indicated by an increase in leaf tissue TN and TP contents. Our results demonstrate that filter-feeding bivalves can alleviate harmful effects of small fish by prolonging a clear-water state that facilitates submerged macrophyte growth. Addition of the bivalve C. fluminea can be a promising tool for the restoration of submerged macrophytes in shallow eutrophic lakes, in particular lakes containing small, rapidly reproducing fish that due to their small sizes are not capable of controlling the bivalves.

Comparative acute toxicity of benzophenone derivatives and bisphenol analogues in the Asian clam Corbicula fluminea.

Among UV-filters, benzophenones are one of the most abundantly used and detected groups in the environment. Bisphenols are also one of the most widely used chemicals in plastics, but their demonstrated deleterious effects on several organisms and humans have led to the production of alternative analogues. However, few comparative studies on the ecotoxicological effects of these derivatives or analogues have been carried out. The present study aimed to investigate the effects of two benzophenones (BP-3 and BP-4) and two bisphenols (BPA and BPS) in a short-term exposure of the freshwater endobenthic bivalve Corbicula fluminea. Clams were exposed for 96 h to several concentrations of the four pollutants: BP-3 (0.63; 1.25; 2.5; 5 mg l-1), BP-4 (4.75; 9.5; 19; 38 mg l-1), BPA (3.75; 7.5; 15; 30 mg l-1), and BPS (2.5; 5; 10; 20 mg l-1). The comparative acute toxicity of these pollutants was evaluated by the analysis of the post-exposure filtering capacity of clams, lipid peroxidation (LP) levels and the activity of the antioxidant enzymes catalase (CAT) and glutathione reductase (GR). After the exposure period, except for BP-4, the chemicals tested seemed to be detected by clams and provoked valve closure, decreasing filter-feeding in a concentration-dependent manner. Furthermore, C. fluminea exposed to the highest concentrations of BP-3, BP-4 and BPA showed a significant increase in LP, CAT and GR activities with respect to their controls. BP-3 and BPA were the most toxic compounds showing significant differences in all the parameters analysed at the highest concentrations assayed. However, clams exposed to BPS showed only significant alterations in filtration parameters and in GR activity, in the two highest concentrations tested, indicating that this compound was the least toxic to clams. Obtained results highlight the importance of investigating the effects that emerging pollutants have on aquatic organisms.

Parasitism and fitness of invaders: oligochaete Chaetogaster limnaei produces gill damage and increased respiration rates in freshwater Asian clams

Biological interactions between invasive and resident species are perceived as a key factor mediating impacts in invaded ecosystems, although symbiotic interactions have received relatively little attention. To evaluate the association between the invasive clam Corbicula fluminea and its oligochaete symbiont Chaetogaster limnaei, we conducted laboratory assessments of prevalence and intensity of infection, external and internal macroscopic alterations, and histological analyses of the gills of uninfected and infected clams collected from the shores of the Rio de la Plata estuary in Argentina. To evaluate potential ramifications of physical alterations on physiological traits and host fitness, we conducted respiration experiments on the same clams. Worm prevalence was higher in smaller than large clams. While no macroscopical alterations were detected, several histopathological changes were observed in the gills of infected clams. Infected clams had significantly higher metabolic rates than uninfected conspecifics and smaller clams had higher metabolic rates than larger conspecifics. Increased host metabolic rates, even at very low infections intensities, were likely a compensatory response to the stress caused by gill damaged inflicted by the oligochaetes. The relationship between C. limnaei and invasive C. fluminea in Rio de la Plata best fits as parasitism.

Antibacterial properties and cytocompatibility of biobased nanofibers of fish scale gelatine, modified polylactide, and freshwater clam shell

We report herein new nanofibers prepared from fish scale gelatine (FSG), modified polylactide (MPLA), and a natural antibacterial agent of freshwater clam (Corbicula fluminea Estefanía) shell powder (FCSP). A preparation of FSG from Mullet scales is also described. To improve the biocompatibility and antibacterial activity of the non-woven nanofibers, MPLA/FCSP was added to enhance their antibacterial properties. FSG was then combined with MPLA/FCSP using an electrospinning technique to improve the biocompatibility of the as-fabricated 100–500-nm-diameter non-woven MPLA/FCSP/FSG nanofibers. The resulting tensile properties and morphological characteristics indicated enhanced adhesion among FSG, FCSP, and MPLA in the MPLA/FCSP/FSG nanofibers, as well as improved water resistance and tensile strength, compared with the PLA/FSG nanofibers. MTT assay, cell-cycle, and apoptosis analyses showed that both PLA/FSG and MPLA/FCSP/FSG nanofibers had good biocompatibility. Increasing the FSG content in PLA/FSG and MPLA/FCSP/FSG nanofibers enhanced cell proliferation and free-radical scavenging ability, but did not affect cell viability. Quantitative analysis of bacteria inhibition revealed that FCSP imparts antibacterial activity.