Bighead Carp Research Articles

Physicochemical, Structural and Antioxidant Properties of Collagens from the Swim Bladder of Four Fish Species.

This study aimed to isolate and characterize pepsin-solubilized collagen (PSC) from marine and freshwater fish swim bladders. The physicochemical properties, protein pattern, amino acid composition, structure, thermal denaturation temperature, and antioxidant activity of PSC from four different swim bladder sources were investigated and compared. The results demonstrated that the four types of collagen extracted were all type I collagen. The yield of PSC extracted from grass carp (GCSB-PSC), bighead carp (BCSB-PSC), grouper (GSB-PSC), and monkfish swim bladders (MSB-PSC) were 38.98, 27.97, 18.16, and 10.35%, respectively. Compared to the other three PSCs, BCSB-PSC has the highest thermal denaturation temperature (38.60 °C). Based on FTIR spectroscopy and circular dichroism (CD) analysis, the extracted PSCs retained the triple helix and secondary structure well. Antioxidant studies showed that in the swim bladders of four species the swim bladder PSC could scavenge DPPH and ABTS radicals. Overall, swim bladders from marine and freshwater fish can be utilized as raw materials for collagen extraction, and the extracted collagen has potential commercial applications.

A trophic cascade triggers blooms of Asterionella formosa in subtropical eutrophic Lake Taihu, China

Abstract The importance of trophic interactions for determining the distributions, abundances, and taxonomic compositions of organisms in ecosystems has long been studied and debated. Here we test the effect of a trophic cascade on diatom (Asterionella formosa) blooms in subtropical, eutrophic Lake Taihu, China. A long‐term data series (2005–2015) on planktivorous fish, zooplankton and diatoms has been analysed. Structural equation modelling is used to test our hypotheses about the influences of top‐down and bottom‐up forces on A. formosa. Since 2009, a spring bloom of A. formosa has occurred in the lake, coinciding with a reduction of Daphnia galeata biomass and of total cladoceran biomass following a marked increase in the stock of planktivorous fish (bighead carp and silver carp). Light, phosphorus (total and soluble reactive phosphate) and silica did not act as limiting factors for the growth of A. formosa. Structural equation modelling analysis showed that top‐down effects of cladocerans on A. formosa biomass were more important than bottom‐up effects (wind speed and soluble reactive phosphate). Although A. formosa was negatively correlated with total nitrogen, total with other inorganic nitrogen (NO3 and NH4) did not restrict the proliferation of diatom blooms after 2007. These results suggested that the substantial reduction of the Daphnia population caused a diatom bloom through a trophic cascade by planktivorous fish. Our study provides new insight into the effects of trophic interactions on diatom bloom formation in natural freshwater ecosystems.

Traceability and identification of fish gelatin from seven cyprinid fishes by high performance liquid chromatography and high-resolution mass spectrometry

The broad application prospect of fish gelatin makes the traceability and identification of fish gelatin imminent. High performance liquid chromatography and high-resolution mass spectrometry (HPLC-MS/MS) was used to identify fish gelatins in seven commercial cyprinid fishes, namely, black carp, grass carp, silver carp, bighead carp, common carp, crucian carp, and Wuchang bream. By comparison with theoretical mammalian collagen (bovine and porcine collagen), the common and unique theoretical peptides were found in the collagen of grass carp, silver carp, and crucian carp, respectively. HPLC-MS/MS results showed that 7 common characteristic peptides were obtained from seven cyprinid fish gelatins. Moreover, 44, 36, and 42 unique characteristic peptides were detected in the gelatins of grass carp, silver carp, and crucian carp, respectively. The combined use of common and unique characteristic peptides could improve the accuracy and authenticity of traceability and identification of fish gelatin in comparison with mammalian gelatin.

Gut microbiota and metabolic profile as affected by Maillard reaction products derived from bighead carp meat hydrolysates with galactose and galacto-oligosaccharides during in vitro pig fecal fermentation

Maillard reaction products (MRPs) play pivotal roles in gut health by affecting the microbiome-host interactions. This study aimed at investigating the effects of MRPs derived from bighead carp meat hydrolysates with galactose and galacto-oligosaccharides on intestinal microbial composition and metabolic profile by in vitro pig fecal fermentation. The pH decreased sharply in the first 12 h and the highest production of butyric acid was observed in GM (glycated BCH with galacto-oligosaccharide) treatment with 64.7 μmoL/10 mL (p < 0.05) at 48 h. Clostridium_sensu_stricto_1, Streptococcus, and Enterococcus were dominant in the GM treatment, while Escherichia-Shigella was predominant in LgM (glycated BCH with galactose) treatment at 12 h. The up-regulated metabolites indicated that GM and LgM might participate in the fatty acids synthesis and modulate lipid metabolism, respectively. Overall, GM will be more beneficial for gut health by promoting the production of butyric acid and fatty acids synthesis.

Investigation of internal organs and additive tissue of hybrid hypophthalmichthys (Hypophthalmichthys spp.) as a promising raw material for the production of dietary nutritional products

Preservation of the nutritional value of fish and the useful qualities of its rich composition is extremely important. The urgent task of the food industry is to develop and create quality food products that meet modern production trends and compete in domestic and foreign markets. This scientific paper describes studies aimed at assessing the specific weight (%) of essential nutrients (glycogen, proteins, and lipids) in particular organs and tissues of different size and mass groups of the hybrid of silver and bighead carp experimental ponds and reservoirs of Ukraine. To achieve the goal in the research process, fish farming, biochemical (study of total protein, lipids, and carbohydrates), and statistical (mathematical processing of research results) research methods were used. In all size and mass groups of the hybrid of silver and bighead carp from ponds and reservoirs in 2017, 2018, and 2019, mostly satisfactory values of general metabolism indicators were found - glycogen, proteins, and lipids in the liver, gills, and muscles of fish. In annual fish of winter ponds, total protein and glycogen content in all organs and tissues was slightly reduced. The organisms of biennial fish from feeding ponds were characterized by fluctuations in the content of glycogen in the liver (it was the highest in fish, 3.28 – 3.33%). Significant fluctuations in the total protein content of muscle, liver, and gills and a slight excess of glycogen in the liver and lipids in the gills of three-year-olds were observed in the reservoirs. The difference found in the availability of essential nutrients in the body of the studied fish indicates a change in the intensity and direction of their metabolic processes. However, their physiological condition at the time of the study was within normal limits.

Hydrological and lock operation conditions associated with paddlefish and bigheaded carp dam passage on a large and small scale in the Upper Mississippi River (Pools 14-18).

Movement and dispersal of migratory fish species is an important life-history characteristics that can be impeded by navigation dams. Although habitat fragmentation may be detrimental to native fish species, it might act as an effective and economical barrier for controlling the spread of invasive species in riverine systems. Various technologies have been proposed as potential fish deterrents at locks and dams to reduce bigheaded carp (i.e., silver carp and bighead carp (Hypophthalmichthys spp.)) range expansion in the Upper Mississippi River (UMR). Lock and Dam (LD) 15 is infrequently at open-river condition (spillway gates completely open; hydraulic head across the dam <0.4 m) and has been identified as a potential location for fish deterrent implementation. We used acoustic telemetry to evaluate paddlefish passage at UMR dams and to evaluate seasonal and diel movement of paddlefish and bigheaded carp relative to environmental conditions and lock operations at LD 15. We observed successful paddlefish passage at all dams, with the highest number of passages occurring at LDs 17 and 16. Paddlefish residency events in the downstream lock approach of LD 15 occurred more frequently and for longer durations than residency events of bigheaded carp. We documented upstream passages completed by two individual paddlefish through the lock chamber at LD 15, and a single bighead carp completed upstream passage through the lock chamber during two separate years of this study. We identified four bigheaded carp and 19 paddlefish that made upstream passages through the spillway gates at LD 15 during this study. The majority of the upstream passages through the spillway gates for both species occurred during open river conditions. When hydraulic head was approximately 1-m or greater, we observed these taxa opt for upstream passage through the lock chamber more often than the dam gates. In years with infrequent open-river condition, a deterrent placed in the downstream lock approach may assist in meeting the management goal of reducing upstream passage of bigheaded carps but could also potentially affect paddlefish residency and passage. Continued study to understand the effects of deterrents on native fish could be beneficial for implementing an integrated bigheaded carp control strategy. Understanding fish behavior at UMR dams is a critical information need for river managers as they evaluate potential tools or technologies to control upstream expansion of bigheaded carp in the UMR.

Effects of High-Pressure Treatments (Ultra-High Hydrostatic Pressure and High-Pressure Homogenization) on Bighead Carp (Aristichthys nobilis) Myofibrillar Protein Native State and Its Hydrolysate

The impacts of four treatments, ultra-high hydrostatic pressure (UHP), high-pressure homogenization (HPH), combined UHP + HPH (U-H), and HPH + UHP (H-U), on bighead carp (Aristichthys nobilis) myofibrillar protein (BMP) structure, functional hydrolysis property to pepsin, and antioxidant activity of hydrolysates were investigated. All treatments led to increase in low-molecular-weight BMP, the BMP stability, and hydrophobic group exposure, but decrease in total sulfhydryl content and BMP particle size, thus resulting in increased hydrolysis and antioxidant capacity of enzymatic hydrolysates. U-H treated BMP exhibited the highest surface hydrophobicity (924.5 ± 1.0), zeta potential absolute value (18.88 ± 0.11 mV), hydrolysis degree (54.5 ± 1.6%), and antioxidant activity, but the lowest α-helix (21.84 ± 2.61%), intrinsic fluorescence spectrum intensity, total sulfhydryl (7.24 ± 0.07 μmol/g), and mean particle size (182.57 ± 2.23 nm). Therefore, U-H might be a promising pretreatment to prepare bioactive peptide.

Using Pectoral Fin Ridges to Assign Sex to Bighead Carp

Bighead Carp Hypophthalmichthys nobilis are native to eastern Asia, have been introduced throughout the world, and are subjected to immense management where they persist. Identifying sex of Bighead Carp during monitoring efforts could provide additional data to enhance fishery management schemes, thereby facilitating better management. A sex-assignment method needs to be accurate, straightforward, and rapid if it is to be used consistently. We assessed the presence (male) or absence (female) of bony ctenoid serrations on the upper edge of the foremost pectoral fin ray to noninvasively and nonlethally determine the sex of 745 Bighead Carp collected from March to December. Bighead Carp sex was correctly assigned 93% of the time by three readers, with males correctly identified 94% of the time and females 92% of the time. A generalized linear model indicated that total length and water temperature influence sex-assignment success. Overall effects of water temperature and size were relatively low, as the pectoral fin method was highly accurate (93%) and precise (88% agreement among readers). Thus, the pectoral fin method provides reliable Bighead Carp sex assignment that can be used on wild-caught fish to non-invasively and rapidly assign sex in the field or lab.

Effects of Spray Drying and Freeze Drying on Physicochemical Properties, Antioxidant and ACE Inhibitory Activities of Bighead Carp (Aristichthys nobilis) Skin Hydrolysates.

The physicochemical, structural properties, antioxidant, and angiotensin I-converting enzyme (ACE) inhibitory activities of fish skin protein hydrolysate (SPH) that were freeze-dried (SPH-FD) and spray-dried (SPH-SD) were investigated. SPH-SD showed abundant volatile compounds, higher DPPH radical scavenging activity and ferrous iron chelating activity than SPH-FD, while the ABTS radical scavenging activity and ACE inhibitory activity were not influenced by the drying method. Amino acid compositions showed a higher proportion of proline and hydroxyproline residues in SPH-FD. The major molecular weights were both distributed below 1000 Da. SPH-SD had spherical structures, while SPH-FD had glass shard-like structures. The results indicated that the drying method could affect the physicochemical properties of hydrolysates, and SPH-SD showed potential prospects in developing functional fortified foods.

Analysis of Movements and Behavior of Bighead Carps (Hypophthalmichthys nobilis) Considering Fish Passage Energetics in an Experimental Vertical Slot Fishway.

Simple SummaryHydraulic structures have modified the natural waterways, and they have inevitably blocked fish migration routes and reduced fish habitat. To mitigate the impact on fish, fish passages have been developed as an effective way to restore riverine connectivity. The design of fish passage facilities refers to both hydrodynamics and fish behavior, and the information on the energetic expenditure of fish can be used to identify movement zones that are suitable for fish migration. Thus, this paper intended to identify fish movement behavior in response to water flow field information by means of estimating the energetic expenditure using an IBM approach. The results demonstrated that the fish required more energy in high TKE zones, and they were therefore likely to utilize the low TKE zones. This study provides a reference for optimizing the design of fish passages, and the method can be applied to assess the efficiency of fish passages and other fish bypass structures.An understanding of fish movement behavior in response to flow field variables is important for exploring the hydrodynamic strategies of fish in fish passages. In this paper, bighead carps were taken as an example. The fish movement behavior response to water flow field information by means of estimating the energetic expenditure using an IBM approach in an experimental fishway was investigated. Fish swimming velocity, drag force, and energy expenditure were analyzed in varied flow conditions related to hydraulic variables, including velocity (V), turbulent kinetic energy (TKE), and strain rate (SR). The result indicated that the fish will require more energy in high TKE zones. This study provides a reference for optimizing the design of fish passages and fisheries management. This method can be applied to assess the efficiency of fish bypass structures and conduct fish survival studies.

Analysis of the Ecological Carrying Capacity of Fish Resources in Shengjin Lake, Anhui Province, China.

The carrying capacity of fish is related to the sustainability of fisheries’ activities in water bodies. The fish carrying capacity of a water body is the maximum fish yield that can be carried by the natural bait organisms in the water body under the ideal natural conditions without feeding and fertilization. The evaluation of fish productivity is an important basis for rational stocking, rational fishing, and the scientific utilization of natural bait resources in a water area. This paper adopts the background data of the Shengjin Lake fishery ecosystem and uses the bait-based estimation method. The results show that (1) the annual yield of silver carp fed on phytoplankton is 1.5 million kg; (2) the annual yield of bighead carp fed on zooplankton is 1.295 million kg; (3) the annual yield of benthos is 310,000 kg; (4) the annual yield of organic detritus is 280,000 kg; and (5) as the coverage of water grass in Shengjin Lake is less than 10%, it should be protected and restored rather than used by fish. In general, the annual maximum carrying capacity of fish in Shengjin Lake is 3.385 million kg, except for water and grass.

Nutrient dynamics and balance of zero–water exchange ponds of grass carp, crucian carp and bighead carp

This study aimed to investigate the nutrient dynamics and balance of zero–water exchange ponds of grass carp Ctenopharyngodon idella, crucian carp Carassius auratus and bighead carp Aristichthys nobilis, and explain advantages of the zero–water exchange mode from the perspective of material flow. This study was conducted for two years. The polyculture ponds of grass carp, crucian carp and bighead carp were grouped into the treatment group using the zero–water exchange mode, while the ordinary polyculture ponds of grass carp, bighead carp, and crucian carp were grouped into the control group. The results showed that 1) the treatment group reduced water conductivity, dissolved solids and sediment organic carbon significantly (P < 0.05), and improved water transparency significantly (P < 0.05); 2) the carbon, nitrogen, and phosphorus accumulation amount and rate in the water of the treatment group were significantly lower (P < 0.05) than those in the control group, so was the sediment accumulation rate of organic carbon and nitrogen (P < 0.05); 3) the carbon, nitrogen, and phosphorus utilization efficiency of stocked fish in the treatment group were significantly higher (P < 0.05) than those in the control group, with an increase of 29.49%, 21.72%, and 20.65%, respectively. Therefore, the zero–water exchange pond was a green and efficient aquaculture mode, which could improve water quality, reduce nutrient accumulation, and improve the utilization efficiency of nutrients effectively. Considering the nutrient emissions from aquaculture in China, the zero–water exchange mode has a good value for promotion.

Determining β-lactam antibiotics in aquaculture products by modified QuECHERS combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)

In this study, a multi-residue determination method of QuECHERS combined with UHPLC-MS/MS was developed to determine nine β-lactam antibiotics (penicillin G, amoxicillin, ampicillin, cephalexin, cefquinome, ceftiofur, cefazolin, cephapirin, cefuroxime) in aquaculture products. All the nine β-lactam antibiotics exhibited excellent linearity within the range of 2.0–200 ng/mL (cefuroxime: 5.0–200 ng/mL, r greater than 0.999), while the limits of detection (LODs) and quantification (LOQs) were 2.0–5.0 μg/kg and 5.0–10.0 μg/kg, respectively. The recoveries of this method in five aquaculture products ( Penaeus Orientalis , Cyprinus Carpio , Channa Argus, Aristichthys Nobilis, and Ctenopharyngodon Idella ) ranged from 85.4% to 113.3% and the intra-day and inter-day precisions (%RSDs) were less than 15%. The results suggested the feasibility of this method as a rapid, simple, and accurate approach for determining the residues of the β-lactam antibiotics in aquaculture products.

Структурні показники популяції окуня (Perca fluviatilis Linnaeus, 1758) Кременчуцького водосховища

Objective. Analysis of the structural parameters of the perch (Perca fluviatilis L.) population in the Kremenchuk Reservoir in the world of the development of the program of stocking large flat reservoirs of the Dnipro with juveniles of Far Eastern herbivorous fish, there was a need for methodical approaches to reduce the negative impact of small predators on the efficiency of planned stocking. Methodology. Primary materials related to the biology and fishing of perch were collected at the monitoring points of the Institute of Fisheries of the National Academy of Sciences. The basis of this article is the results of our own field research, which was carried out in the entire water area of the Kremenchuk Reservoir during 2016–2021. To determine the composition of catches in nets with different mesh sizes, the refined coefficient of annual commercial mortality was used. Results. The article establishes the general basic population indices of the perch (Perca fluviatilis L.) population in the Kremenchuk Reservoir. Acceptable indices of the perch population and the probability of its negative impact on the stocking of big-headed Chinese carps this year have been established. The scientific novelty of the work is due to the fact that effective stocking is currently possible only in the presence of scientifically based data, which can significantly affect the cost of planting material, and, as a result, the volume of work carried out. These basic principles are able to ensure the sustainable use of aquatic biological resources in natural reservoirs. Practical significance: the biological indices of the P. fluviatilis population presented in this work can be used to calculate the limits for perch commercial fishing in Kremenchuk Reservoir and to assess its negative impact on the stocked young fishes. Key words: perch, Kremenchuk Reservoir, length structure, catch per unit effort, commercial harvest.

Особенности раскрытия ростовой и адаптогенной потенции у двух- и трехлеток растительноядных рыб в условиях Калининградской области

This article reviews the experiment of growing two-year old three-year old carp, grass carp, silver and bighead carp in experimental ponds of EEF KSTU from May to October 2021 in order to determine their growth and adaptagenic potency. According to the results of the evaluation of growth potential disclosure of herbivorous fish, we observed similar dynamics of the rate of mass accumulation at two and three years of age. Maximum values were observed in summer (July-August) and minimum values in autumn (September-October). Close resolution of growth potency was observed for three-year-old silver and bighead carp. According to the results of the assessment of the disclosure of adaptogenic potency, the highest value of the ecological coefficient was observed for bigheaded carp (70% of the influence on growth from ecological factors). In other groups of two-year-olds, the disclosure of this factor was at an average level (39-56 %), and in three-year-olds it was at a low level (33 %). The survival rate of the study groups did not exceed 80-92%. According to the results of the study, the disclosure of growth and adaptogenic potency for two-year old three-year-old fish in ponds of EEF in 2021 was disclosed at the average level of values, the growing season corresponded to IV fish farming zone.

Assessment of Biophysical Properties of Faecal Pellets from Channel Catfish (Ictalurus punctatus) and Bighead Carp (Aristichthys nobilis)

Fish faeces are a crucial component of solid wastes from cage culture systems. In order to investigate the environmental impacts of faeces from channel catfish (Ictalurus punctatus) and bighead carp (Aristichthys nobilis), certain biophysical characteristics during faecal sinking at three temperatures (10, 20 and 30 °C for winter, spring-autumn and summer conditions, respectively) were assessed in the present study. Settling velocities of faeces from channel catfish (1.72–13.33 cm/s) and bighead carp (4.16–13.83 cm/s) accelerated with an increase in water temperature. For channel catfish faeces, there were positive correlations between settling velocity and physical properties, i.e., weight, volume, length and diameter; however, for bighead carp faeces, no linear relationship between settling velocity and length was found. The main faecal water absorption period for these two species occurred after 2.5 min of immersion. The main leaching period of faecal carbon and nitrogen was 0–2.5 min, and the leaching period of faecal phosphorus was 0–10 min. The nutrient contents in channel catfish faeces were significantly higher than those in bighead carp faeces. These results suggest that co-culturing channel catfish with bighead carp can effectively reduce the discharge of nutrients from aquaculture. The biophysical properties of these two types of fish faeces can also provide guidance in particle waste collection.

A three-dimensional Lagrangian particle tracking model for predicting transport of eggs of rheophilic-spawning carps in turbulent rivers

Grass carp, bighead carp, and silver carp spawn in flowing water. Their eggs, and then larvae, develop while drifting. Hydraulic conditions and water temperature control spawning locations, egg survival, and the downstream distance traveled before the hatched larvae can swim for low velocity nursery habitats. Existing egg drift models simulate the fluvial transport of carp eggs but have limitations in capturing the effect of localized turbulence on egg transport due to inadequate dimensions of hydrodynamics and/or empirical parameterization of river dispersion. We present a three-dimensional Lagrangian particle tracking model that uses fully resolved river hydrodynamics and a continuous random walk algorithm driven by local turbulent kinetic energy and its dissipation rate. We incorporate a new set of equations to compute evolving egg characteristics with fully resolved 3-D hydrodynamics. To demonstrate the performance of the model, we conducted a case study in an eight-kilometer reach of the Missouri River at the discharge of approximately 25% daily flow exceedance. Three-dimensional river hydrodynamics was modeled, calibrated, and evaluated with measurement data. Egg drift was modeled and compared using fully three-dimensional, depth-averaged two-dimensional, and zone-averaged one-dimensional hydrodynamics. The comparison shows a generally good agreement among models of downstream egg transport due to advection but a different dispersion pattern of eggs in the river, as a result of turbulent diffusion and shear induced dispersion.

Nondestructive determination of the freshness change in bighead carp heads under variable temperatures by using excitation-emission matrix fluorescence and back-propagation neural networks

This study established back-propagation neural networks (BPNNs) for evaluating the freshness of bighead carp ( Hypophthalmichthys nobilis ) heads during chilled storage via fluorescence spectroscopy using an excitation-emission matrix (EEM). The total volatile basic nitrogen (TVB-N) and total aerobic count (TAC) of fish increased obviously during storage at 0, 4, 8, 12, and 16 °C, while sensory scores decreased with increasing storage time. The EEM fluorescence intensity was measured, and its change was correlated with the freshness indicators of the samples. Three characteristic components of EEM data were extracted by parallel factor analysis, and two freshness indicators were used to construct the EEM-BPNNs model. The results demonstrated that the relative errors of the EEM-BPNNs model for TVB-N and TAC were less than 14%. This result indicated that the EEM-BPNNs model could determine the freshness of fish in cold chains in a rapid and nondestructive way.

Production of a diploid hybrid with fast growth performance derived from the distant hybridization of Hypophthalmichthys nobilis (female) × Megalobrama amblycephala (male)

Based on the distant hybridization derived from Hypophthalmichthys nobilis (bighead carp, BIC, 2n ​= ​48) (♀) ​× ​Megalobrama amblycephala (blunt snout bream, BSB, 2n ​= ​48) (♂), we obtained a novel hybrid (BB) in this study. We comparatively investigated the morphological traits, chromosome numbers, DNA contents, microsatellite patterns, and DNA variations in 5S rDNA and Hox genes. The chromosome and flow cytometer results indicated that BB was a diploid hybrid with 48 chromosomes. We confirmed successful hybridization with microsatellite DNA markers and analyzed the Hox gene family in the parental and hybrid lines. The sequences of 5S rDNA in BB mapped to those in BIC and BSB, indicating that the genetic materials of BB were derived from BIC and BSB. The breeding experiment showed that BB had the characteristics of herbivore and fast growth. This diploid hybrid is of great significance for fish genetic breeding and applied research.

Effect of the Degree of Hydrolysis on Nutritional, Functional, and Morphological Characteristics of Protein Hydrolysate Produced from Bighead Carp (Hypophthalmichthys nobilis) Using Ficin Enzyme.

The production of fish protein hydrolysates from bighead carp (Hypophthalmichthys nobilis) using ficin enzymes was achieved in optimal conditions of 3% enzyme/substrate ratio, 40 °C temperature, and pH 6. Three different hydrolysis times, 1, 3, and 6 h, were investigated, and their degree of hydrolysis (DH) values were 13.36%, 17.09%, and 20.15%, respectively. The hydrolysate yield values increased with DH increase, and the highest yield was obtained at DH 20.15%. The crude protein content increased from 80.58% to 85.27%, and amino acid compositions increased from 78.33% to 83.07%. The peptides formed during hydrolysis indicated low molecular weight that might improve functional characteristics of fish protein hydrolysates, including protein solubility, which ranged from 84.88% to 95.48% for all hydrolysates. The thermal degradation of hydrolysates occurred from 160 to 168 °C with intensive endothermic peaks. Results revealed that oil holding capacity was higher at DH 13.36%; water holding capacity was higher when DH increased. Hence, fish protein hydrolysates (FPH) from bighead carp have improved functional properties, and can be utilized as supplements and excellent protein sources in various uses in food applications.