Trophic Feeding Research Articles

Feeding habits variability of Lutjanus synagris and Lutjanus griseus in the littoral of Campeche, Mexico: an approach of food web trophic interactions between two snapper species

The study of the feeding habits variability (spatial and temporal scales) allows us to evaluate the trophic interactions between species, thus, the short and long-term effects of the removal of different species by the presence of different phenomena. In this study, we carried out stable isotope (δ13C and δ15N) and stomach content analyses to infer the trophic linkages between two snapper species (Lutjanus synagris and Lutjanus griseus) captured in the littoral of Campeche, Mexico. In total, 781 specimens were collected (528 L. synagris and 253 L. griseus) and based on relative importance index [%PSIRI] both snapper species consumed based on the prey-specific index of relative importance (PSIRI), Penaeidae family (PSIRI = 23.41%) was the most important species in the diet of Lutjanus synagris, while Callinectes sapidus (PSIRI = 21.45%) was the primary prey of Lutjanus griseus. The isotopic analyses indicated that both snapper species feed in the coastal-marine (δ15N: 10.6 to 12.1‰ and δ13C: -15.7 to -12.7‰); however, according to PERMANOVA, low diet similarity was found between snapper species (R = 0.07, P < 0.01), also, significant differences was detected in the δ15N and δ13C values between L. synagris, and L. griseus. Therefore, despite both snapper species presents similar trophic positions (L. synagris: 4.2 ± 0.2; L. griseus: 3.9 ± 0.1) and feeding behavior (according to SIBER = opportunistic predators), a low trophic overlap was observed, probably associated with the differential use of habitat in the coastal zone; where L. synagris is ecologically fed in areas of seagrass, while L. griseus is probably intermittent between pasture and mangrove areas, therefore, the role of each species is crucial in the dynamics of coastal-marine ecosystems as predators and potential structuring of the populations of their prey.

The Clinical Impacts of Early Trophic Feeding Using Protein Formulas in Compared With Standard Formulas in Intolerated Enteral Nutrition Hospitalized Patients

The Clinical Impacts of Early Trophic Feeding Using Protein Formulas in Compared With Standard Formulas in Intolerated Enteral Nutrition Hospitalized Patients

What’s Your Motivation?

What’s Your Motivation?

Gastroschisis in Hospital del IESS “Manuel Ygnacio Ygnacio”. Case Report and Literature Reviview

BACKGROUND: Gastroschisis is an anomaly in which abdominal organs are exposed outside the abdominal wall. The global average prevalence is 1.36 for each 10 000 newborns. In Ecuador, according to the National Institute of Statistics and Censuses (INEC), there is evidence of an increase in the number of hospital discharges with this diagnosis, reaching 52 in 2010, 85 in 2012, and 112 patients in 2015. The aim of this publication is to describe this pathology and expose the importance of prenatal diagnosis to plan prompt surgical intervention for the newborn after birth. CASE REPORT: newborn from a 16-year-old primigravid mother, with no other prenatal history, four ultrasounds were performed during pregnancy in a private health facility, which reported no alterations. At 37.4 weeks of pregnancy, the newborn was delivered by eutocic birth, showing gastroschisis. The patient underwent laparotomy and peritoneostomy at 24 hours of age, delayed closure was scheduled. EVOLUTION: the newborn received comprehensive care in the neonatal intensive care unit. Delayed closure was performed eight days later. He remained hospitalized for 22 days, he received parenteral nutrition and started trophic feeding at 15 days of age; first-line antibiotic therapy was initiated, however due to torpid evolution, he required a change to a broad-spectrum antibiotic. CONCLUSION: gastroschisis can be detected in ultrasound from the twelve week of pregnancy to minimize complications and program the surgical procedure immediately after birth.

High frequencies of theropod bite marks provide evidence for feeding, scavenging, and possible cannibalism in a stressed Late Jurassic ecosystem.

Bite marks provide direct evidence for trophic interactions and competition in the fossil record. However, variations in paleoecological dynamics, such as trophic relationships, feeding behavior, and food availability, govern the frequency of these traces. Theropod bite marks are particularly rare, suggesting that members of this clade might not often focus on bone as a resource, instead preferentially targeting softer tissues. Here, we present an unusually large sample of theropod bite marks from the Upper Jurassic Mygatt-Moore Quarry (MMQ). We surveyed 2,368 vertebrate fossils from MMQ in this analysis, with 684 specimens (28.885% of the sample) preserving at least one theropod bite mark. This is substantially higher than in other dinosaur-dominated assemblages, including contemporaneous localities from the Morrison Formation. Observed bite marks include punctures, scores, furrows, pits, and striations. Striated marks are particularly useful, diagnostic traces generated by the denticles of ziphodont teeth, because the spacing of these features can be used to provide minimum estimates of trace maker size. In the MMQ assemblage, most of the striations are consistent with denticles of the two largest predators known from the site: Allosaurus and Ceratosaurus. One of the bite marks suggests that a substantially larger theropod was possibly present at the site and are consistent with large theropods known from other Morrison Formation assemblages (either an unusually large Allosaurus or a separate, large-bodied taxon such as Saurophaganax or Torvosaurus). The distribution of the bite marks on skeletal elements, particularly those found on other theropods, suggest that they potentially preserve evidence of scavenging, rather than active predation. Given the relative abundances of the MMQ carnivores, partnered with the size-estimates based on the striated bite marks, the feeding trace assemblage likely preserves the first evidence of cannibalism in Allosaurus.

Biogeographical comparison of terrestrial invertebrates and trophic feeding guilds in the native and invasive ranges of Carpobrotus edulis

Plant invasions impact on biodiversity by altering the composition of native communities by disrupting taxonomic and functional diversity. Non-native plants are often released from their natural enemies, which might result in a reduction of the attack of primary consumers. However, they can also be exposed to the attack of new herbivores that they might not be able to tolerate. Hence, invertebrate communities can be influenced by invasive non-native plants, which in turn modify interactions and change environmental conditions. In this study, we examined the compositional and trophic diversity of invertebrate species, comparing ecosystems with and without the plant species Carpobrotus edulis in coastal areas in its native (South Africa) and introduced (Iberian Peninsula) ranges. Results show that C. edulis has a clear impact on invertebrate communities in its non-native range, reducing their abundance in invaded areas, and particularly affecting certain trophic groups. Invasive C. edulis also alters the invertebrate diversity by not only reducing abundance but also by altering species composition. Overall, the physical dominance of C. edulis modifies the co-occurrence of invertebrate assemblages, reducing the number of trophic groups and leading to substantial effects on primary consumers. Results suggest that the lack of natural enemies might be an important driver of the expansion of C. edulis in its introduced range. Further work is needed to examine long-term changes caused by non-native plants on invertebrate assemblages and the subsequent modification of biological interactions.

Food preference determines the best suitable digestion protocol for analysing microplastic ingestion by fish

Microplastic presence in the marine environment has generated considerable concern. Many procedures for microplastics detection in fish gastrointestinal tract have been recently developed. In this study, we compared efficiencies of two common procedures applied for the digestion of organic matter (10% KOH; 15% H2O2) with a new proposal (mixture of 5% HNO3 and 15% H2O2). We considered ecological diversity among species and differences in their diet compositions as factors that could affect the efficiency and feasibility of analytical approaches. Our aim was to understand whether either one of the three protocols might be suitable for all species or it might be more advisable to select a method according to the gut content determined by different food preferences. The results showed that the trophic level and feeding habits should be considered for protocol selection. Finally, we applied the best protocols on samples from the Tyrrhenian sea.

Assessing the relationship between diet and size-at-age in Pacific halibut (Hippoglossus stenolepis) using δ13C and δ15N analysis

The ecological mechanisms driving an observed decline in the mean size-at-age of adult Pacific halibut (Hippoglossus stenolepis) in the eastern North Pacific Ocean have yet to be defined. Here, we present the results of a study designed to investigate the relationship between one potential mechanism — diet — and size-at-age using carbon and nitrogen stable isotope analysis. Our results indicate significant differences in the skeletal muscle δ13C and δ15N values between size-at-age categories for each sex, with larger-size-at-age fish consuming diets with higher δ15N values, indicating higher trophic level feeding. Analysis of Bayesian standard ellipse areas showed that for females, intermediate size-at-age categories have the largest dietary range. For males, the largest dietary range was observed in the largest size-at-age category. Our results suggest a size-based stratification in dietary strategy for Pacific halibut with implications for observed declines in size-at-age.

Assessing trophic relationships between shallow-water black corals (Antipatharia) and their symbionts using stable isotopes

Shallow-water antipatharians host many symbiotic species, which spend their adult life with their host and/or use them to have access to food. Here we determine the trophic relationships between four common macrosymbionts observed on/in Cirripathes anguina, Cirrhipathes densiflora and Stichopathes maldivensis in SW Madagascar. These include the myzostomid Eenymeenymyzostoma nigrocorallium, the gobiid fish Bryaninops yongei, and two palaemonid shrimps, Pontonides unciger and Periclimenes sp. The first is an endosymbiont living in the digestive tract, while the others are ectosymbionts. The analyses show that most likely (i) none of the symbionts uses the host as a main food source, (ii) nocturnal plankton represents a main part of the diet of antipatharians while the symbionts feed preferentially on diurnal plankton, (iii) the myzostomid has the narrowest trophic niche, (iv) the two shrimps have distinct trophic niches and feed at lower trophic level than do the other symbionts. Concerning the myzostomids, they had the same δ13C values but had significantly higher δ15N values than the hosts. TEFs (Trophic Enrichment Factors) recorded were Δ13C = 0.28 ± 0.25 ‰ and Δ15N = 0.51 ± 0.37 ‰, but these were not high enough to explain a predator-prey relationship. These worms rely on the coral diet but may also ingest host fluids explaining the slight enrichment in heavier nitrogen isotopes. On the other hand, the ectosymbionts use the coral as a pathway to have access to food from the midwater: they feed from the water passing nearby the black corals, but a kleptoparasitic behaviour cannot be excluded.

An integrated approach to the treatment of diffuse peritonitis in children

The purpose of the study . Improving the treatment of advanced peritonitis with using in therapy antihypoxant Reamberin and hepatoprotector Remaxol, nutritional support, sanitation laparoscopic abdominal cavity. Materials and methods. A total of 327 children aged 1 to 15 years with generalized purulent peritonitis treated at the children's surgical departments of Samara from 2001 to 2018. A study group comprised 241 patients who used the optimized pathogenetic therapy. In the study group was allocated two groups: 69 patients in the pathogenetic therapy that used antihypoxant Reamberin, and 110 children in the treatment of which Reamberin and hepatoprotector Remaxol. All the children of the main group received nutritional support (trophic feedings), used in the surgical treatment of abdominal laparoscopic sanitation. Comprehensive survey includes the study of the dynamics of the level of white blood cells, leukocyte index, total albumin concentration. Results. Comparison of the studied parameters in the study and control groups, showed a more rapid decrease in the symptoms and signs of intoxication (leukocytosis, LII), relief of enteric disease, recovery of protein-synthetic function of the liver, a decrease of cytolytic and mesenchymal-inflammatory syndrome in the study group, especially in the subgroup in which therapy was included Remaxol. Conclusions . Optimization of treatment involving the application of the combined drugs – antihypoxant Reamberin, hepatoprotector Remaxol, nutritional support and implementation of laparoscopic abdominal sanitation led to improved results of therapy common purulent peritonitis in children.

Feeding strategies of Euphausia superba in the eastern South Shetland Islands in austral summer

Euphausia superba is a key species in the Southern Ocean that serves as a link between primary production and higher trophic levels. To investigate the feeding strategies of E. superba from the eastern South Shetland Islands, fatty acid biomarkers, stable isotope signatures, and an incubation experiment were conducted. The results of the incubation experiment proved that adult E. superba mainly fed on 2–20 μm particles, demonstrating the importance of nanoplankton in their diet. Moreover, significant positive relationships between δ15N and body size demonstrated that size-related dietary shifts were present in E. superba. Evidence from principal component analysis and the C16:1ω7/C18:4ω3 ratio showed that juveniles preferentially fed on dinoflagellates and adults were more likely to feed on diatoms. Fatty acid profiles in adult E. superba roughly mirrored the different trophic conditions and feeding strategies between stations. Adult E. superba at Stas D2-07, D5-07, DA-01 and DA-02 exhibited elevated levels of C16:1ω7, C18:4ω3, C18:1ω9 and C18:1ω9/C18:1ω7, indicating higher levels of feeding on both phytoplankton and higher trophic diets. In contrast, adult E. superba at Stas D1-03 and D1-04 were characterized by high levels of polyunsaturated fatty acids/saturated fatty acids ratios and low levels of C16:1ω7, C18:1ω7, C18:4ω3, C18:1ω9 and total fatty acids. We inferred that adult krill at Stas D1-03 and D1-04 still suffered from difficult dietary conditions after overwintering. The different dietary conditions between stations suggest a highly plastic feeding strategy of E. superba in the eastern South Shetland Islands.

Energy Expenditure and Protein Requirements Following Burn Injury.

Severe burn injuries have long been known to have a profound effect on metabolic equilibrium that can persist after resolution of the cutaneous injuries. Following burn injury, metabolism is a dynamic state resulting in the need for frequent interval reassessment over the course of the care continuum. The acute phase of injury transitions to chronic alterations in macronutrient utilization characterized by futile energy cycling and disproportionate catabolism of skeletal muscle. Protein supplementation appears to be preferentially distributed to the burn wound rather than the skeletal muscle pool. Accurate assessment of caloric and protein requirements is extremely difficult in these patients but is an essential step in efforts to attenuate functional impairment. Indirect calorimetry should be utilized to determine caloric requirements, but trophic feeding strategies are preferred in the initial resuscitative phase to prevent overfeeding while maintaining enteric and immune function. Controversy persists regarding optimal protein targets, and weight-based estimates remain the norm. Exogenous protein and caloric provision performed in isolation is insufficient to optimize outcomes and should be incorporated within a multidisciplinary approach to include muscle loading and pharmaceutical adjuncts.

Multielemental composition and consumption risk characterization of three commercial marine fish species

Marine fish are considered a source of high quality proteins and fatty acids. However, the consumption of fish may pose a health risk as it may have potentially toxic elements in high concentrations. In this study we quantify the multielemental composition of muscle and fins for three species of commercial marine fish from Brazil: Sphyraena guachancho (Barracuda), Priacantus arenatus (Common bigeye) and Genidens genidens (Guri sea catfish). We then assessed the potential risk of fish consumption by means of a Provisional Hazard Indices. Amongst the elements detected in fish tissue were potentially toxic elements such as Ag, Ba, Cd, Cr and Hg. Concentration differences were species-specific, and affected by the species trophic level, morphological characteristics and feeding habits. Results suggest the higher the trophic level of the fish, the higher the risk of consumption. Caution is recommended for the frequent ingestion of high trophic level fish species in Brazil.

Gut rest strategy and trophic feeding in the acute phase of critical illness with acute gastrointestinal injury.

Critically ill patients frequently suffer from gastrointestinal dysfunction as the intestine is a vulnerable organ. In critically ill patients who require nutritional support, the current guidelines recommend the use of enteral nutrition within 24-48 h and advancing towards optimal nutritional goals over the next 48-72 h; however, this may be contraindicated in patients with acute gastrointestinal injury because overuse of the gut in the acute phase of critical illness may have an adverse effect on the prognosis. We propose that trophic feeding after 72 h, as a partial gut rest strategy, should be provided to critically ill patients during the acute phase of illness as an organ-protective strategy, especially for those with acute gastrointestinal injury.

Feeding Ecology and Distribution of an Invasive Apex Predator: Flathead Catfish in Subestuaries of the Chesapeake Bay, Virginia

AbstractNative to the central United States, Flathead CatfishPylodictus olivarishave invaded Atlantic coast rivers from Florida to Pennsylvania. They are now invasive in several subestuaries of the Chesapeake Bay, yet contemporary accounts of their distribution do not exist. Due to their piscivorous nature, Flathead Catfish could have deleterious impacts on native ichthyofauna, yet their feeding ecology has not been well described in these systems. We used a large‐scale, stratified random sampling effort to describe the current distribution and feeding ecology of Flathead Catfish in Virginia tidal rivers. Low‐frequency electrofishing was conducted at more than 1,500 sites in the James, Pamunkey, Mattaponi, and Rappahannock rivers in eastern Virginia, resulting in 766 Flathead Catfish being captured in the James, Pamunkey, and Mattaponi rivers. Flathead Catfish are abundant in the tidal James River from Richmond, Virginia, to the confluence of the Chickahominy River. A relatively new but established population was also observed in the Pamunkey River, where the highest observed densities of Flathead Catfish occurred near Williams Landing (37°36′21.49″N, 77°5′33.42″W) in New Kent County, Virginia. Stomachs collected from 731 Flathead Catfish revealed that they are piscivores that feed heavily on Gizzard ShadDorosoma cepedianum, White PerchMorone americana, and variousAlosaspecies. Analysis of trophic level, diet breadth, and feeding strategy demonstrated that Flathead Catfish are piscine specialists that occupy trophic positions indicative of an apex predator. Our results show that Flathead Catfish could have substantial per capita impacts on at‐risk native species including American ShadAlosa sapidissima, Blueback HerringA. aestivalis, and AlewifeA. pseudoharengusas they make seasonal migrations in and out of these river systems. Moreover, future range expansion of Flathead Catfish into the Rappahannock River is plausible, as established populations now exist in adjacent tributaries.

Stable isotope tracing of links between marine wintering and freshwater breeding habitats of Red-necked Grebes

Stable isotope analyses can detect interactions between different stages of the annual cycle in migratory animals. We used carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) isotopes to identify non-breeding environments, the strategy of nutrient allocation to eggs, and potential carry-over effects from wintering areas in Red-necked Grebes Podiceps grisegena breeding in eastern Poland. Strongly positive isotopic signatures in adult grebe feathers compared to freshwater food webs and feathers of locally fledged young suggested that most adults had moulted in marine areas. Enriched isotopic values in the breast muscles of spring-arriving grebes pointed to transfer of marine-derived nutrients to freshwater breeding sites. Isotopic mixing models revealed that egg nutrients were mainly acquired locally. Endogenous nutrients were to some extent mobilised for the formation of albumen (25–26%, 95% credible interval, three-isotope model) and lipid-free yolk (17–18%, two-isotope, δ13C and δ15N model) in early laid clutches, but were little mobilised, if at all, in clutches of females that delayed laying. The non-breeding trophic feeding level, as indexed by δ15N in feathers of grebe females, was related to laying initiation date (greater enrichment, earlier egg production), indicating cross–seasonal effects on reproduction. Both endogenous nutrient transfer to eggs and a high-quality non-breeding diet may facilitate early breeding, which is advantageous in species constrained by short breeding seasons.

Making the best of a bad situation: differential predator avoidance in a diminutive woodland salamander

Predator avoidance behaviour has been observed in many species and can strongly affect trophic interactions. Animals frequently adjust their response to predators in proportion to risk; however, when they are exposed to chronic predation risk, some animals reduce their antipredator responses in favour of resource acquisition. Animals that are subjected to predation pressure from multiple predator species may have to respond to different spatial and temporal distributions of risk; how they balance these risks will affect their choice of habitat or microhabitat patches. One species that is exposed to a wide range of predators is the pygmy salamander, Desmognathus wrighti. These miniaturized terrestrial plethodontids spend their entire life on the forest floor where they are exposed to a diversity of predators. We examined pygmy salamanders' ability to avoid potential predators based on the presence of substrate-borne chemical cues. The predator species included ground beetles (Carabidae: Pterostichus), Jordan's salamanders, Plethodon jordani, and ring-necked snakes, Diadophis punctatus. The ring-necked snake is a trophic specialist feeding on salamanders while the beetles and Jordan's salamanders are generalist predators. The pygmy salamanders were also exposed to chemical alarm cues from a congeneric salamander (Desmognathus fuscus) and odours from two unfamiliar species: corn snakes (Pantherophis gutattus) and herbivorous desert tortoises (Gopherus agassizii). We used a hierarchical Bayesian beta regression with a repeated measures design to model proportion of time spent in each treatment. Compared to controls, pygmy salamanders exhibited strong aversion to fed ring-necked snakes, a moderate avoidance of unfamiliar odours and a slight attraction to scents from the two common generalist predators. Our results suggest that pygmy salamanders accept modest risk from common generalist predators but avoid less common, specialist predators and unfamiliar species.

Benthic trophic sensitivity to on-going changes in Pacific Arctic seasonal sea ice cover – Insights from the nitrogen isotopic composition of amino acids

We studied trophic relations among benthic species collected in the northern Bering and Chukchi seas, specifically in biologically productive “hotspots” within the Distributed Biological Observatory (DBO) program. The stable nitrogen isotope composition of compound-specific amino acids (δ15NAA) was used as an approach to assess how several benthic species in this Arctic ecosystem are responding to the earlier timing of sea-ice melt and associated shifts to the onset of the annual production season. The trophic level of 16 common benthic taxa with different feeding behaviors were collected along a south-to-north latitudinal gradient extending from the northern Bering Sea, south of St. Lawrence Island, to the northern Chukchi Sea, including the Barrow Canyon undersea feature, and examined with respect to the available food sources. The δ15NAA values of source and trophic amino acids varied among studied regions and among species. δ15NAA-based trophic level estimations, using δ15N values in both source and trophic amino acids and the measure of heterotrophic resynthesis (ΣV parameter), provided new insights on trophic levels and feeding behaviors of different taxonomic groups that were not apparent from more commonly used isotopic measurements of bulk tissues. The compound-specific amino acid isotope compositions varied geographically, but not necessarily by latitude. This indicates that a simple time for space replacement perspective extending from south to north over the study area and reflecting variable persistence of seasonal sea ice, is inadequate to explain food web complexity. Highest bulk δ15N and δ15NAA values were observed in depositional zones (near and within the St. Lawrence Island Winter-Spring Polynya, in particular). The δ15NAA values also suggested high feeding plasticity in benthic species in the northern Bering and Chukchi seas hotspots. Benthic consumers most likely can change feeding behavior (e.g. suspension versus deposit feeding) in response to different environmental conditions and resulting changes in the quality of organic matter reaching the sea floor. We conclude that the sensitivity of productive arctic benthic ecosystems to climate related change, i.e. earlier sea-ice melt and related onset of primary production, might be mitigated by robust capabilities to adapt to changes in food quality and supply.

Persistent Organochlorine Compounds Levels in Selected Fish Species from Lake Victoria and Associated Human Health Risks

Nile perch (<i>L. niloticus </i>) and Nile tilapia (<i>O. niloticus</i>) are the major commercial fish species in Lake Victoria region of Tanzania. This study was conducted to assess the levels of persistent organochlorine compounds, namely PCBs and OCPs in these two fish species and the probable human health risks associated with the consumption of these two fish species from Lake Victoria. Fish samples were collected between May and August 2016 and the necessary anthropometric measurements such as length and weight were taken. The extraction was done using a modified QuEChERS method and the identification and quantification of the chemicals were done using GC/ECDs. The results of this study revealed that fish species sampled were undersize, which was an indication of overfishing and abuse of bylaws. Among the 19 OCPs which were considered, only four (β- HCH, HCB, Aldrin and Dieldrin) were detected at measurable quantities. β- HCH ranged from <0.24 to 1.19µg/kg. The mean concentrations were 0.77±0.43µg/kg and 0.56±0.16µg/kg for <i>L. niloticus</i> and <i>O. niloticus</i> respectively. HCB levels ranged from <0.18 to 0.59µg/kg in <i>L. niloticus</i> and <0.18µg/kg in <i>O. niloticus</i>. Aldrin ranged from <0.14 to 0.34µg/kg in <i>L. niloticus</i> whereas it was not detected in <i>O. niloticus</i>. Moreover, Dieldrin residues ranged from <0.17 to 1.06µg/kg in <i>O. niloticus</i> but were not detected in <i>L. niloticus</i>. Generally, there were slightly higher levels of the detected OCPs in <i>L. niloticus</i> than the corresponding levels in <i>O. niloticus</i> mainly due to their differences in trophic levels and feeding habits. The indicator PCBs were not detected in all the investigated fish samples. The levels of all the detected organochlorines were far below the MRL set for fish and fishery products suggesting that the fresh fish from Lake Victoria are safe for human consumption. Low levels of the detected residues and non- detection of many organochlorines considered indicate that contamination in Lake Victoria has not reached alarming levels. The human health risk assessment of the detected organochlorines showed cancer risk from 8.6E-06 to 3.2E-05 for children and from 7.8E-06 to 1.3E-05 for adults indicating that there is a low cancer risk for both age groups. The non- cancer risks (HI) on the other hand, were 5.7E-02 for children and 4.7E-02 for adults, which is an indication of an insignificant risk.

Effect of feeding of cyclopoid copepods (Eucyclop sp.) exposed to engineered titanium dioxide nanoparticles (nTiO2) and Lead (Pb2+) on Clarias gariepinus growth and metabolism

BackgroundThe application of Lead (Pb2+) and titanium dioxide nanoparticles (nTiO2) in commercial products is on the rise since the development of nanotechnology. The increasing usage of products containing these compounds had led to the rise of their concentration in aquatic environment, but information on the potential risk of co-exposure of these compounds in aquatic environment is still limited. In this study, the effect of feeding Clarias gariepinus with cyclopoid copepods exposed to engineered Pb2+ and nTiO2 on growth performance, and proximate composition of Clarias gariepinus was investigated.MethodologyA chronic (28 days) laboratory bioassay was carried out by feeding C. gariepinus fries with cyclopoid copepods exposed to nTiO2 (7.5, 16.5 μg L−1) and Pb2+ (6.5, 15 μg L−1) alone as well as binary mixtures through dietary uptake.ResultsOur results indicate negative allometric growth (b < 3), while the highest condition factor (1.74) was recorded in the control. A significant decreased of specific growth rate (SGR) compared to the control was observed in exposed fish. Some parameters of proximate composition (crude protein, ash, moisture, total lipid) from the fish decreased significantly (P < 0.05) with synergistic effect on binary mixture. In contrast, carbohydrate content increased significantly (P < 0.05) with synergistic effect on binary mixture.ConclusionThe present study clearly indicates that the chronic exposure of nTiO2 and Pb2+ mixtures caused the delay in the growth performance and changes in the proximate compositions of the fish. This findings raise concern regarding the fate of higher trophic level feeding on primary consumers inhabiting freshwater ecosystems contaminated with nTiO2 and Pb2+.