Study for the Forming Principle of Logix Gear Tooth Profile and Its Mesh Performance

In recent years, a new type of gear named Logix gea r was developed. Actually, the tooth profile of this new type of gear is composed of lots of micro-segment involute curves, and on the profile, there exist lots of points, which their relative curvatures are equal to zero. This can result in the sliding coefficient smaller between two meshed Logix gears, and the mesh ch aracteristic becomes almost rolling transmission from sliding transmission accor dingly. So, this new type of gear has lots of advantages such as higher contact intensity, longer useful life and can easily realize power transfer of bigger tr ansmission ratio than standard involute gear. Study results showed that the cont act fatigue strength is 3 times larger, the bend fatigue strength is 2.5 times l arger, and the minimum tooth number can be decreased to 3, much smaller than tha t of standard involute gear. In this paper, following studies had been done: 1) The formation principle of Logix gear tooth profile was studied. The theoreti cal models describing the geometrical formations of this type of gear and its re lative Logix rack had been deduced. 2) While cutting a Logix gear, its tooth profile is decided by its normal tooth profile of Logix rack. Besides the basic parameters of standard involute gear, L ogix rack has its own specific parameters such as preliminary pressure angle, re lative pressure angle, and preliminary referential circle radius etc. So, the in fluence of connatural parameters of Logix rack on the tooth profile of Logix gea r had been farther studied. Reasonable selection for these parameters had been d iscussed. 3) Several kinds of transition curves for gear’s tooth profile had been introdu ced, its selection used by Logix gear had been described, and also its mathemati cal description model had been deduced. 4) The mesh theories of Logix gears had been developed. It had been proved that the transmission performance between Logix gears coincides with E-W theorem as that of ordinary standard involute gears. The formula calculating superposition coefficient was deduced according to its definition. Different from standard inv olute gears, the parameter of gear number has no effect on the superposition coe fficient of the Logix gears. Accordingly, bigger ratio transmission can be acqui red by means of decreasing the gear number, and its minimum gear number can be r eached to 3, much smaller than the minimum gear number of ordinary standard invo lute gear: 14～17. This is very important to realize the miniaturization of prod uction design. 5) The CAD special software was developed to design all kinds of Logix gears, an d a solid design example was offered. To sum up, by means of above study, the system info about Logix gear had been de veloped and enriched. This has most significant impact on its widely promotion a nd practical application, on the improvement of carrying capacity, miniaturizati on, and life of kinetic transmission products.

Effect of Fish Meal Replacement with Maggot Meal on the Growth Performance of Misgurnus anguillicaudatus

Maggot meal was used to replace 0, 20% , 40% , 60% , 80% , 100% of the fish meal in the hasal feed, getting 6 kinds of feed with the same nitrogen content and equal energy （marked as group H0, H20, H40, H60, H80, H100）, which were used to feed the Misgurnus anguillicaudatus （loach） for60 d. The effects of the fish meal replacement by maggot meal on the growth performance of M. anguiUicaudatus were studied by comparing the growth performances and body indica- tors of M. anguillicaudatus fed with different feed groups. The results showed that the final weight, weight gain rate, specific growth rate of the M. anguillicaudatus in group H40 showed no significant difference with the control P 〉0.05 ）, but was significantly higher than that of other groups P 〈0.05 ）. Moreover, except group H40, the feed coefficients of all other groups were significantly higher than that in control group （P 〈0.05 ）. The M. anguillicaudatus in group 1-140 had the highest condition factor and COR and the lowest viscera index, all of which showed significant differences with the other replacement groups （P 〈0.05） but the difference with the control group was not significant （P 〉 0.05）. Thus, a proportion of 40% of the fish meal replaced with maggot meal in the mixed feed for the M. anguilli- caudatus could improve the growth performance and physique indexes of M. anguillicaudatus.

Numerical Study of the Hydrodynamic Performance of Two Wiggling Hydrofoils in Diagonal Arrangement

The hydrodynamics in fish school are studied through simulating the flow over two wiggling hydrofoils in diagonal arrangement by using the immersed boundary method, both in-phase and anti-phase wiggling motions are considered in this study, the effect of the longitudinal spacing on the hydrodynamic performance has been investigated. It is revealed that, when the longitudinal spacing is smaller than body length, the diagonal formation is helpful to the follower but harmful to the leader;when the longitudinal spacing is larger than body length, the opposite effect is occurring;and a significant enhancement of the propulsive performance is obtained when the longitudinal spacing is optimized.

Assessment of the curving performance of heavy haul trains under braking conditions

To study the curving performance of trains, 1D and 3D dynamic models of trains were built using nu- merical methods. The 1D model was composed of 210 simple wagons, each allowed only longitudinal motion; whereas the 3D model included three complicated wagons for which longitudinal, lateral, and vertical degrees of freedom were considered. Combined with the calculated results from the 1D model under braking conditions, the behavior of draft gears and brake shoes were added to the 3D model. The assessment of the curving performance of trains was focused on making comparisons between idling and braking conditions. The results indicated the following： when a train brakes on a curved track, the wheel-rail lateral force and derailment factor are greater than under idling conditions. Because the yawing movement of the wheelset is limited by brake shoes, the zone of wheel contact along the wheel tread is wider than under idling conditions. Furthermore, as the curvature becomes tighter, the traction ratio shows a nonlinear increasing trend, whether under idling or braking conditions. By increasing the brake shoe pressure, train steering becomes more difficult.

Evaluation of the suitability of a partially defatted black soldier fly (Hermetia illucens L.) larvae meal as ingredient for rainbow trout (Oncorhynchus mykiss Walbaum) diets

Background: Two trials were performed to evaluate a partially defatted Hermetia illucens(HI) larvae meal as potential feed ingredient in rainbow trout(Oncorhynchus mykiss Walbaum) diets. In the first trial, 360 trout(178.9 ± 9.8 g of mean initial body weight) were randomly divided into three experimental groups(4 tanks/treatment, 30 fish/tank). The fish were fed for 78 days with isonitrogenous, isolipidic and isoenergetic diets containing increasing levels of HI, on as fed basis: 0%(HI0, control diet), 25%(HI25) and 50%(HI50) of fish meal substitution, corresponding to dietary inclusion levels of 0, 20% and 40%. In the second trial, 36 trout(4 tanks/treatment, 3 fish/tank) were used to evaluate the in vivo apparent digestibility coefficients(ADC) of the same diets used in the first trial.Results: Survival, growth performance, condition factor, somatic indexes, and dorsal fillet physical quality parameters were not affected by diet. The highest dietary inclusion of HI larvae meal increased dry matter and ether extract contents of trout dorsal fillet. The use of HI larvae meal induced a decrease of valuable polyunsaturated fatty acids(PUFA) even if differences were only reported at the highest level of HI inclusion. The insect meal worsened the lipids health indexes of the same muscle. Dietary inclusion of insect meal did not alter the villus height of the fish. No differences were found among treatments in relation to ADC of ether extract and gross energy, while ADC of dry matter and crude protein were higher in HI25 if compared to HI50.Conclusions: The obtained results showed that a partially defatted HI larvae meal can be used as feed ingredient in trout diets up to 40% of inclusion level without impacting survival, growth performance, condition factor, somatic indexes, dorsal fillet physical quality parameters, and intestinal morphology of the fish. However, further investigations on specific feeding strategies and diet formulations are needed to limit the observed negative effects of the insect meal on the FA composition of dorsal muscle.

Significant Effects of Fishing Gear Selectivity on Fish Life History

Over the past few decades, extreme changes have occurred in the characters of exploited fish populations. The majority of these changes have affected the growth traits of fish life history, which include a smaller size-at-age, an earlier age-at-maturation and among others. Currently, the causes of these life history traits changes still require systematic analyses and empirical studies. The explanations that have been cited are merely expressed in terms of fish phenotypic adaptation. It has been claimed that the original traits of fish can be recovered once the intensity of exploitation of the fish is controlled. Sustained environmental and fishing pressure will change the life history traits of most fish species, so the fish individual's traits are still in small size-at-age and at earlier age-at-maturation in exploited fish populations. In this paper, we expressed our view of points that fishing gear has imposed selectivity on fish populations and individuals as various other environmental factors have done and such changes are unrecoverable. According to the existing tend of exploited fish individual's life history traits, we suggested further researches in this field and provided better methods of fishery management and thereby fishery resources protection than those available early.

Analysis of lubrication performance for internal meshing gear pair considering vibration

The thermal elasto-hydrodynamic lubrication characteristics of the internal meshing gears in a planetary gear train under vibrations were examined considering the influence of the modification coefficient and time-varying meshing stiffness.Based on dynamic theory of the gear system,a dynamic model of the planetary gear train was established.The lubrication performances of modified gear systems under vibrations and static loads were analyzed.Compared with other transmission types,the best lubrication effect could be produced by the positive transmission.A thicker lubricating oil film could be formed,and the friction coefficient and oil film flash temperature are the smallest.Increasing modification coefficient improves the lubrication performance continuously but intensifies the engage-in and tooth-change impact.For the planetary and inner gears,the increase in the modification coefficient also leads a decrease in the oil film stiffness.

Study and Performance Test of Full Complement Cycloidal Ball Reducer with Ceramic Balls as its Gear Teeth

To improve the transmission accuracy and stiffness of the ball cycloid reducer, the authors developed a novel cycloid ball reducer, which uses a full complement ball as its gear teeth. Ceramic balls are used to get better performance in severe working conditions. A simple synthesis method was also found to determine the raceway forms and compute the contact forces among the balls and raceways. The Contact Stress Analysis (CSA) computer program was used to optimize the design of the reducer. In this paper, the following topics are covered: (1) Study of the geometry of the raceways. (2) Analyses of the principal curvature of the raceways are also accomplished. In addition, the modification of the raceway is put forward. (3) The contact forces and the reducer efficiency are evaluated. (4) Study of the performance of ceramic balls used in the CBR. A reducer using the above design technique was tested and the performances show that the reducer has high precision and rigidity. An increase of more than 50 percent transmission power was realized in the new gearing.

A Study on the Meat and Bone Meal and Poultry By-product Meal as Protein Substitutes of Fish Meal in Practical Diets for Litopenaeus vannamei Juveniles

A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fish meal in the diets on the growth performance, survival and apparent digestibility coefficients (ADC) of Litopenaeus vannamei. The basal diets were formulated with 22% fish meal and other ingredients which provided about 40% protein and 9% lipid in the diet. The experimental diets included MBM or PBM to replace 0, 20%, 40%, 60% and 80% of total fish meal respectively. All diets were iso-nitrogenous and isocaloric in gross terms. The results showed that there were no significant differences (P>0.05) in growth performance and ADC among the treatments fed with the diets in which 0-60% fish meal had been replaced with MBM, while the percent weight gain (WG, %), body length gain (BLG, %) and ADC significantly decreased when the MBM was up to 80% of the fish meal. There were no significant differences (P>0.05) in growth performance and ADC among all the treatments fed with the diets in which 0-80% fish meal had been replaced with PBM.

Application and dynamical performance simulation of tooth surface measured data of hypoid gear

The tooth surface shape of hypoid gear is very complicated, and tooth surface accuracy of hypoid gear can be measured by using the latticed measurement and scanning measurement. Advantages and disadvantages of the two measurement patterns are compared and application of their measurement data on hypoid gear＇s quality management is analyzed. How to use these measurement data to simulate the dynamical performance of hypoid gear is researched, and the intelligent predicton of the dynamical performance indexes of contact spot, root stress, vibration exciting forces and load distribution and hertz contact stress on the tooth surface are carried out. This research work has an important guiding sense to design and ma- chine hypoid gear with low vibration and noise.

Fishery and the Tourism Potential of Agbokum Waterfalls, Nigeria

Species richness and human activities in natural environments are among the most important recreational needs. Monthly studies of aquatic fauna, artisanal fisheries and tourism characteristics was conducted during wet and dry seasons, over a two year period in the three landscapes along the 6817.7 m length of Agbokum waterfalls by using a close-ended pre-coded survey instrument. Through MANOVA analysis of the 1780 respondents we found strong positive association between peoples visits to the recreational areas and the type of landscape in which the respondents felt happy. People who felt happier in landscape dominated by waterfalls, visit the middle reaches of the river for outdoor recreation more often while people who feel happy in landscapes dominated by slow water current with an extensive wide area and floodplains, visit downstream reaches of the waterfalls more often. Activities performed more often along downstream reaches include fishing, bathing/swimming, boating and hunting while more frequent activities in the middle reaches (waterfalls) include taking photographs, picnics, enjoying nature, outing with family and friends, looking at view, resting and relaxing. A total of 5484 fish representing 22 species belonging to 16 genera from 9 families were sampled with 10 species being restricted to wet season and only 1 in the dry. The number of taxa and individuals present at upstream, midstream and downstream reaches were 16 (2003), 13 (1034), 17 (2447), respectively. Tilapia zillii, Clarias gariepinus and Labeo coubie dominated overall catch constituting 35.5%. Twenty five operational boats counted during the period of study, were only used downstream by 25 full-time fishermen, 87 part-time, 44 shoreline fishermen and 36 assistant fishermen. Common gears were the hook and line constituting 45.8%, cast and dip net (10.1%) bailing (8.7%), gill nets (7.3%), seine net (6.4%) Traps (5.5%), lift net (4.7%) Dip nets (0.9%), poisoning (2.8%), cutlass (3.3%) and spear (1%). Seasonally occurring aquatic fauna include crustaceans (Atya gaboneensis and Palaemon paucidens) (23.5%) oysters (Etheria elliptica) (15.4%), clams (Galacea paradoxa) (20.8%), Manatee (Trichechus senegalensis) (2.5), Hippopotamus amphibious (1.8%), Otter (Lutra macullicolis) (0.5%), Crocodyles (Crocodylus niloticus, Crocodylus cataphractus (Aligata) and Osteolaemus tetraspsis) (18.8%). The nile monitor (Varanus nilaticus), aquatic snake (Anoscopus sp), and three species of water turtle (Kimxys erosa, Pelumedusa sp and Peliosus sp) (21.6%). Relatively higher faunal densities and species richness in the upstream and downstream reaches coupled with waterfalls in middle reaches can makes Agbokum waterfalls a tourism destination if only management strategies include Legislation to conserve these natural resources.

Influence of cutter diameter on meshing performance in spiral bevel gears

Playing a critical role in transmitting movement and power, the meshing performance of spiral bevel gears has a significant effect on products' operational performance. To evaluate the meshing performance, the accurate three-dimensional(3D) spiral bevel gear models are established through the Pro/E and MATLAB softwares, and the finite element analysis(FEA) methods are applied to the theoretical investigation of the influence of cutter diameter on meshing performance in spiral bevel gears. The results obtained show that the cutter diameter has a significant influence on spiral bevel gears' meshing performance, such as the contact area, contact pressure, bending stress, torsional stiffness and transmission error.

Effect of Bioactive Peptides(BPs) on the Development of Pacific White Shrimp(Litopenaeus vannamei Boone, 1931)

The present study was conducted to evaluate the feasibility of replacing fish meal(FM) with bioactive peptides(BPs) in diet of white shrimp(Litopenaeus vannamei). The changes in growth performance, body composition, non-specific immunity, and water quality were examined after the shrimp were fed four diets, in which 0%(control), 33.3%, 66.7% and 100% of FM was replaced by BPs, respectively. The groups were designated as Con, 1/3BPs, 2/3BPs, and 3/3BPs. A total of 720 shrimp with an initial body weight of 1.46 ± 0.78 g were fed the experimental diets for 56 days. The results revealed that: 1) the weight gain rate(WGR) in 1/3BPs, 2/3BPs, and 3/3BPs was significantly higher than that in Con(P < 0.05), while no significant difference was found on survival rate and feed conversion ratio(FCR); 2) the whole-body crude protein(CP) and crude lipids(CL) were significantly different among groups, while there was no significant difference between crude ash and phosphorus contents; 3) the levels of acid phosphatase(ACP), lysozyme(LZM), superoxide dismutase(SOD), phenol oxidase(PO) and bactericidal activity increased significantly with the inclusion of BPs; 4) in terms of water quality, no significant difference was found in p H and dissolved oxygen among diets during the whole experimental period. Moreover, even though nitrite and ammonium levels tended to increase with time, there was no significant difference among groups. The results indicated that BPs is an applicable alternative of protein source, which can substitute FM in the diets of L. vannamei; it is able to effectively promote growth performance and improve immunity. Moreover, BPs in the diets had no negative impact on water quality.

Ichthyofaunic Inventory and Fish Landings of Lom Pangar Hydropower Dam Reservoir in the Eastern Region of Cameroon

The Lom Pangar hydroelectric dam project located in the eastern region of Cameroon was implemented by Electricity Development Corporation (EDC). The impoundment of the Lom Pangar dam created a large reservoir with an area ~590 km2 and a useful storage capacity ~6 billion m3. Thereby, this impoundment has created favourable conditions for the proliferation of fishery resources. However, a fisheries assessment study based on fishing activities is essential to attain reliable information for implementing a management plan to achieve rational and sustainable exploitation. This study was carried out on the ichtyofaunic inventory and the assessment of fish landings in Lom Pangar hydroelectric dam reservoir from April 2016 to September 30, 2016. Three main groups of fishing gear have been identified, among which gillnets, traps and longlines occupy major fishing activities. Indeed, the spatial and landing sites surveies were conducted on species composition, size composition, and quantities of fish landed during the study period. Moreover, 37 species of fish divided into 16 families were found in seven different selected fish landing sites. Carp (Cyprinus carpio) was the major fish species abundantly caught by these fishing gears which accounted for 81.60% of the total catch, and the least species was sardine (Sardinella aurita). A total of 623,229 Kg of fish were landed which were dominated by those of the Wami landing site with 480,773 Kg representing 76.96% of the total landed catches. The smallest species caught was the white carp (7 cm) while the longest one was the catfish (71 cm). In addition, the species of fish in the breeding season are carp, catfish, viper fish and red tail.

The Effects of Size-fractionated Fish Hydrolysate in the Diet on Growth, and Feed Utilization of Turbot （Scophthalmus maximus）

Four experimental diets were fed to turbet to examine the effect of fish bydrolyside and ultra filtered fish hydrolysafe on growth performate feed utilization and growth regulation using diets low in dietary fish meal inclusion. Diets A, B contained 3.7%,1.2% fish hydrolysate to replace fish meal respectively and the fish hydrolysate in two diets was ultra filtered to keep low molecular weight compounds. The diets A,

Comparative Analysis of Three Types of Fishing Gear Marking for Anchored Fish Aggregating Devices in Purse Seine Fishery in Thai Waters

Anchored fish aggregating devices(AFADs)have been widely used for fishing in Thai waters.However,abandoned,lost,and discarded fishing gears(ALDFGs),including lost AFADs,may cause environmental impacts.Fishing gear marking(FGM)is considered as a tool to help identification of ALDFGs.The main objective of this study is to compare the durability represented by the percentage of remaining condition(R-value)of three material types of FGM applied for AFADs,i.e.,stainless steel(SS),colored acrylic(CA),and polypropylene(PP).This study was carried out using 50 AFADs deployed in the Gulf of Thailand(GOT)and the Andaman Sea(ANS)between July and October 2020 in cooperation with 10 fishers.The AFADs were deployed in similar habitat(bottom depth and type)between the GOT and the ANS.The three material types of FGM were assumed to be sufficiently durable to last for the lifespan of the AFADs in both the GOT and the ANS(within 2 months and 3.5 months,respectively)though some FGMs in the ANS were detached from cable ties or broken before AFADs were lost.The loss of AFADs and FGMs was mainly caused by adverse weather condition(rough sea).Only data from the ANS was included in comparative analysis due to the insufficient variance data obtained from the GOT.The analysis revealed that SS had the higher durability than CA and PP when the AFADs lasted for less than 3.5 months.As a result of our study,some recommendations were made.For example,the cable ties can be replaced by ropes or threads to improve the installation method.This study serves as a basis to develop FGM and to support responsible fisheries.Beneficiaries of the study include fisheries policy makers,managers,and fishers.

A comparison between benthic gillnet and bottom trawl for assessing fish assemblages in a shallow eutrophic lake near the Changjiang River estuary

Two fishing methods including gillnetting and trawling to estimate attributes of fish assemblage were compared in Dianshan Lake from August 2009 to July 2010. Species composition dif fered significantly between the gears, with four significant contributors in gillnet catches and one in trawl catches. Trawling collected more proportions of benthic species by number and biomass than gillnetting. Size distribution was significantly influenced by fishing technique; gillnetting captured relatively less small-sized fishes and trawling captured less large-sized individuals. Trawling produced species richness closer to the one expected than gillnetting. On the whole, trawl catch was a quadratic polynomial function of gillnet catch and a significantly negative correlation was found between them, both of which varied as dif ferent polynomial functions of temperature. However, trawl and gillnet catches were significantly correlated only in one of five month groups. It is concluded that single-gear-based surveys can be misleading in assessments of attributes of fish assemblages, bottom trawling is a more ef fective gear for assessing fish diversity than benthic gillnetting, and using gillnet catches as an indicator of fish density depends on fishing season in the lake.

Determination of Steroid Hormone Residues in Fish Tissues Using Gel Permeation Chromatography and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A highly sensitive method was developed for the simultaneous determination of 8 steroid hormones in high-fat fish tissues using ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The 8 steroid hormones were extracted from the tissues with diethyl ether.Differing from other common purification methods,the extract solutions were cleaned by gel permeation chromatography(GPC) using ethyl acetate-cyclohexane solution(1:1,v/v) as the mobile phase.The separation of target compounds was carried out by a BEH C18 column and a gradient elution consisting of acetonitrile and 0.2% aqueous formic acid(v/v).The compounds were detected under the multiple reaction monitoring(MRM) mode and quantified with external standard method.This method was validated with respect to linearity,specificity,accuracy and precision.A linearity with correlation coefficient larger than 0.995 was achieved in the range of 0.5 to 50 ng m L^(-1).The average recoveries at the spiked levels of 1.0,5.0,and 10.0 μg kg^(–1) varied between 81.7% and 90.8%,with the relative standard deviations(n=5) ranged from 3.50% to 10.0%.The limit of quantification(LOQ) for 8 steroid hormones ranged from 0.2 to 1.5 μg kg^(-1).It was concluded that this method can be successfully applied for the determination of 8 steroid hormones in complicated matrices including high-fat fish tissues.

Effects of fish meal and sodium butyrate on growth performance, gut development and glucagon-like peptide-2 secretion in weanling piglets

The experiment was conducted to study the effects of fish meal and sodium butyrate on growth performance, gut development and GLP-2 secretion in weanling piglets. A 2×2 factorial design was used with two fish meal levels （0, 5%）, and two sodium butyrate levels （0, 0.3%）. There were 4 dietary treatments： control diet （CD）; control diet supplemented with fish meal （CF）, control diet supplemented with sodium butyrate （CB）, control diet supplemented with fish meal and sodium butyrate （FB）. A total of 44 28-days-old Large White×Landrace weanling piglets were randomly allotted into 4 treatment averagely. The experiment period was 14 days. The results showed that sodium butyrate＇s addition increased average diary gain （ADG）, average diary feed intake （ADFI） and gain to feed intake ratio （G：F） of weanling piglets （all P〈0,05）, improved gut morphology （mucosa thickness, ratio of villous height to crypt depth） and sucrase activity, and fish meal＇s addition increased maltase activity （all P〈0.05）. Either sodium butyrate or fish meal addition decreased cecum colibacillus quantity, sodium butyrate increaded ratio of cecum lactobacilli to colibacillus （P〈0.05）. Consequently, diarrhea was reduced in diet supplemented with fish meal （P=-0.08） and diet supplemented with sodium butyrate （P=0.15） through 14 days of experiment, significant reduction of diarrhea rate was observed in diet supplemented with fish meal through the first 7 days （P〈0.05）. In addition, sodium butyrate and fish meal addition in diets tended to increase plasma GLP-2 concentration, however, GLP-2 concentration on the 4th day was consistently decreased in diet supplemented with fish meal relative to that on day 0 （P=0.08）. Overall, it could be concluded that both sodium butyrate and fish meal addition improve intestinal development and sodium butyrate addition significantly increase growth performance. The gut trophic response to sodium butyrate or may be in agreement with development. peptide GLP-2 increases in fish meal addition in diet and the alteration of intestinal

Effects of fish protein hydrolysate on growth performance and humoral immune response in large yellow croaker (Pseudosciaena crocea R.)

We investigated the effects of fish protein hydrolysate (FPH) on growth performance and humoral immune response of the large yellow croaker (Pseudosciaena crocea R.). One thousand and two hundred large yellow croakers [initial average weight: (162.75±23.85) g] were divided into four groups and reared in floating sea cages (3 m×3 m×3 m). The animals were fed with 4 diets: basal diet only (control) or diets supplemented with 5%, 10% and 15% (w/w) FPH. The results show that dietary FPH levels significantly influenced the growth and immunity of the large yellow croaker. Compared with the control group, total weight gain (TWG) in all treatment groups, relative weight gain (RWG) and specific growth rate (SGR) in fish fed with diets supplemented with 10% and 15% FPH were significantly increased (P<0.05). Similar results were observed in immune parameters [lysozyme activity, serum complements, immunoglobulin M (IgM)]. Lysozyme activity, complement C4 and IgM were also significantly increased (P<0.05) in fish fed with diets supplemented with 10% and 15% FPH, while complement C3 level was significantly increased (P<0.05) in all treatment groups. In general, with the supplementation of FPH, particularly at dose of 10%, the growth performance and immunity of the large yellow croaker can be improved effectively.