Abstract:To research the characteristics and structural features of BPI1 gene from channel catfish (Ictalurus punctatus), total RNA was extracted from channel catfish kidney tissue and reversely transcribed into cDNA. Specific primers were designed to clone the BPI1 gene. Then BPI1 gene was inserted into the prokaryotic expression vector pTWIN1. The successfully constructed vector pTWIN1-BPI1 was transformed into BL21 (DE3) competent cells for prokaryotic expression. According to the analysis of SDS-PAGE, the recombinant expression vector pTWIN1-BPI1 successfully expressed a 50 kDa fusion protein, which conformed to the expected size. BPI1 gene sequence was studied by means of bioinformatics software. The results showed that BPI1 nucleotide sequence encoded 223 aa, with an isoelectric point (pI) of 9.07, and belonged to BPI superfamily. It was a stable and soluble protein. Subcellular localization of BPI1 was in the mitochondria (43.5%), cytoplasm (30.4%) and nucleus (26.1%), hence BPI1 may play a role in signal transducer or promote growth, especially in the energy metabolism and cofactor biosynthesis like purines and thymine. The secondary structure of BPI1 mainly consists of α-helices and beta-pleated sheet, besides, the tertiary structure of BPI1 was a rod-like structure. The amino acid sequence was highly conserved and shared the highest homology with BPI of channel catfish, along with sequences identities 99.1% and the same branch in the phylogenetic tree. Thus BPI1 gene sequence had lower mutation rate in the same species and had a strong conservative property that may have little impact on the bioactivity among individuals.

Abstract:Myostatin (MSTN) is a negative regulatory factor in animal muscle development and growth. In order to identify the sequence information and the function of Carassius auratus MSTN in the process of muscle development, rapid amplification of cDNA ends (RACE) and real time PCR were used to clone the full length cDNA sequence and analyse the expression level of MSTN in embryonic development stages and different tissues. The results showed that the full length cDNA of MSTN was 2094 bp (no. KC851952.1), including 86bp at 5'-UTR, 880 bp at 3'-UTR, and a 1128 bp open reading frame encoded a peptide of 375 amino acids. The putative peptide contained a 22 amino acids signal peptide, a TGF-β propeptide domain (34-256), a TGF-β domain (281-375), a conserved RIRR proteolytic processing site and 9 conserved cysteine residues in the C-terminal of the protein. Multiple sequence comparison indicated that the MSTN of Carassius auratus has high similarity with cypriniformes species, while has low similarity with mammalian and bird. The phylogenetic analysis also showed that the crucian carp MSTN has close relationship with cypriniformes species like Carassius carassius, Cyprinus carpio and Labeo rohita. Real time PCR results showed that MSTN mRNA was checked in eight different tissues of crucian carp, among which the maximum level was detected in brain, followed by muscle and liver, the minimum level was displayed in intestine. In addition, the MSTN was also confirmed to express at every stage of embryogenesis, in which the highest level was found at fertilized eggs, followed by blastula and the lowest level was detected at neurula. Thus, the MSTN gene was speculated to have relation with crucian carp muscle development and growth, and might play an important role in the "double dorsal muscle" formation.

Abstract:To carry out genetic evaluation on growth traits in redfin puffer (Takifugu rubripes) by using molecular marker-assisted family selection and breeding, in this study, the mature 11 females and 11 males chosen from the selection and breeding founder were used to produce 11 full-sib families of redfin puffer. 10 individuals from each family separately raised were random selected to construct the family population. About 400 larger individuals from the families raised together were random selected to construct the mixed breeding population. A set of 44 microsatellite DNA markers distributed evenly in 22 linkage groups were selected from the genetic linkage maps of redfin puffer, furthermore, 2 markers were located in each linkage group. According to the Excl 1 and Excl 2 probabilities based on the results of genetic analysis in full-sib family population, high probability values of 10 markers ranged from 0.58 to 0.662 and 0.736 to 0.797, low probability values of 14 markers were from 0.054 to 0.43and 0.177 to 0.608, and intermediate probability values of the remainder 20 markers showed 0.467 to 0.575 and 0.641 to 0.732. The results of parentage determination of mixed breeding population by using these markers with higher parental probabilities demonstrated that there were differences in the number of offspring from the combination of different parents. Male M2 and female F4 generated 124 offspring, whose percentage of all the individuals attained to 32.89%. Estimating the genetic parameters of growth traits with the marker-based pedigree according to the results of parentage determination, the heritabilities of body weight and body length were from 0.17 to 0.21 and 0.15 to 0.18 at different days of age, respectively. The research results verified that the microsatellite DNA markers selected with higher parental probabilities of exclusion can effectively construct the pedigree in redfin puffer to perform the estimation of genetic parameters for growth traits, therefore, molecular marker-assisted family selection is an efficient approach to genetically improve objective traits in this species.

Abstract:In order to study the genetic diversity of Collichthys lucidus of Chinese coastal areas, microsatellite markers were used to analyze genetic diversity of seven wild C. lucidus populations (Lianyungang, Dafeng, Chongming, Zhoushan, Wenzhou, Ningde, Xiamen). The results showed that the number of total alleles was 63 in the seven populations by nine microsatellite loci, and the mean number of alleles of every locus was 3 to 13. The average effect alleles ranged from 1.7510 to 8.0317. The average observed heterozygosity (H_o) ranged from 0.3596 to 0.7854, and the average expected heterozygosity (H_e) ranged from 0.4300 to 0.8780, and the average polymorphic information content (PIC) ranged from 0.3604-0.8631. Among them, 2 loci showed moderate polymorphic, 7 loci showed highly polymorphic. This showed that seven populations had high levels of genetic diversity. Most loci did not deviate from Hardy-Weinberg equilibrium (P>0.05). The UPGMA phylogenetic tree of the seven populations was constructed based on Nei's genetic distance. The result showed that the relationship between WZ and ND was the closest while the relationship between ZS and WZ was the farthest, WZ and ND clustered into one group, while there was no significant genetic differentiation as a whole.

Abstract:In order to explore the function of IGF1R during the process of the growth and development in Tegillarca granosa, Tg-IGF1R cDNA was cloned by SMART RACE (Rapid Amplification of cDNA Ends) techniques on the basis of cDNA library of T.granosa. The full length cDNA of Tg-IGF1R was 5793 bp, and its complete ORF (Open Reading Frame) was 4638 bp encoding 1546 amino acids. Bioinformatics analysis showed that the sequence of Tg-IGF1R contains a 5'-untranslated region (UTR) of 810 bp, and a 3'-UTR of 345 bp. The predicted molecular mass of the deduced amino acid of Tg-IGF1R was 176.01 ku, and the theoretical isoelectric point was 6.04. Tg-IGF1R protein consists of four fibronectin type Ⅲ(FN3) domains, one furin like cysteine-rich (FU) domain and Tyrosine kinase (TyrKc) domain, belonging to transmembrane and hydrophilic protein. Homologous analysis on the amino acids showed that IGF1R of T. granosa shared more than 40% similarity with the most species of IGF1R, including Homo sapiens, Xenopus laevis, and Danio rerio. qRT-PCR (Real-time quantitative PCR) results indicated that Tg-IGF1R gene was expressed in 6 tissues (blood, adductor muscle, foot, gill, visceral mass and mantle.), and the expression of blood was significantly higher than other tissues, which implied that Tg-IGF1R plays various biological roles. The results of relative expression in 9 development stages revealed that the expression of Tg-IGF1R gene showed the highest expression in the gastrulae stage, and followed by trochophore and juvenile clams stages. Therefore, Tg-IGF1R may be involved in the formation of certain organs in early developmental stages.

Abstract:The study was designed to know the characteristics of reproductive biology and embryonic development regularity of Sebastes hubbsi, to accumulate basic data for further study on protection and sustainable utilization of this fish resources. The reproductive biology and embryonic development of S. hubbsi were studied based on 283 samples of breeding stocks caught in spring in Jiaozhou Bay, Qingdao, from April to May 2015. After obtaining fertilized eggs from female fish, we observed the embryonic development using the microscope and examined the morphological characteristics of each development stage. The collected samples had a body length ranging from 62 to 137 mm, a body weight ranging from 9.4 to 126.8 g, and an age range of 2 to 4 years. The female-male sex ratio was 1.85:1 and the first sexual maturity age was 2 years. The body length of the species at the first sexual maturity age was 70.6 mm. The individual absolute fecundity F ranged from 656 to 9235 (mean 3176) eggs. The individual length-specific fecundity to body length F_L ranged from 12 to 67 (mean 29) eggs per mm and the individual weight-specific fecundity F_W ranged from 72 to 140 (mean 108) eggs per gram. The egg of S. hubbsi was globular with a light yellow color and had multiple oil globules of varied size. The sterilized eggs would sink in the water with an average diameter of (1.50±0.03) mm. With the embryonic development, all oil globules of the egg gradually merged into a single one until at about the late gastrula stage, and the eggs gradually changed to pear-shaped from the heart beat stage. The newly hatched larvae were still in the ovarian cavity and had a total length of (5.57±0.06) mm. The embryonic development of ovoviviparous teleost Sebastes hubbsi seems to be similar to most of the marine teleost fishes, but there were still some characteristics different from others such as in pigmentation, oil globule variation, morphological change of eggs, etc.

Abstract:The effects of salinity (15, 20, 25, 30, 35) and body weight[(2.11±0.60) g, (6.31±0.85) g and (8.80±1.40) g] on oxygen consumption rate (OR) and ammonia excretion rate (AR) of Sipunculus nudus Linnaeus were studied using experimental ecology methods. The results indicated that salinity had significant effect on OR and AR, and their interaction also had significant influence on OR and AR. Both OR and AR increased with salinity increment, and reached its peak at salinity 25, then decreased rapidly with salinity increasing. The relationship between OR and salinity can be represented by the quadratic equation y=-ax²+bx-c, where a ranges from 0.030 to 0.044, b ranges from 1.525 to 2.252, c ranges from 11.824 to 20.132. The relationship between AR and salinity was similar with OR and salinity, however, a ranges from 0.009 to 0.012, b ranges from 0.455 to 0.593, c ranges from 4.369 to 5.275. The O/N value ranged from 4.06 to 14.28. The study showed that S. nudus Linnaeus can adapt to the low salinity and high salinity environment by adjusting physiological metabolism, and the salinity 25 might be the optimum for the growth.

Abstract:The energy sourcing for reproduction in short-life cephalopod species is vitally important for the successful development of reproductive organs, in which the energy acquisition and allocation to gamete production would be greatly in relation to their reproductive strategies. Therefore, by using the technology of energy density determination combined with residuals analysis, we investigated the energy accumulation and allocation in both soma and reproductive organs of Argentinean short-fin squid Illex argentinus, an important cephalopod species, to provide further evidence whether the reproductive investment comes from food intake or diverts from the somatic growth. The tissue energy density was determined for the arms, mantle, ovary, nidamental gland and oviducal complex, where it had an average value of (22.75±0.60), (23.42±0.68), (25.15±2.08), (21.49±1.46) and (25.12±3.02) kJ/g, separately. There was no statistically significant difference in the energy density between different sexual maturity stages for the tissue of arms, mantle, and nidamental glands separately. However, the energy density was significantly different between sexual maturity stages for ovary and oviducal complex separately. Both arms and mantle attained their maximum tissue energy at maturity stage III. In the reproductive system, ovary attained its maximum tissue energy at maturity stage V, whereas both the tissue energy of nidamental gland and oviducal complex were gently increasing with maturity and attained their maximum value at maturity stage VI. Specifically, the tissue energy of oviducal complex had a burst increase after maturity stage IV onwards. At the same maturity stage, the somatic tissue energy, calculated as the sum of mantle and arms tissue energy, was always in the larger proportion, while the tissue energy of reproductive organs, calculated as the sum of tissue energy of ovary, nidamental gland and oviducal compex, accounted for a smaller percentage. However, the proportion occupied by somatic tissue energy was decreasing gradually, while that by reproductive organ was increasing with maturation. The soma energy was partly remobilized for reproduction from maturity stages III to V, but this process of remobilization did not impact the integrity of somatic tissues. These findings confirm that the reproductive investment in I. argentinus is mainly from food intake, but along with some energy remobilization from soma during the sexual maturation.

Abstract:The paper studied the effects of dry storage and wet storage on biochemical metabolism of live scallop Patinopecten yessoensis during post-harvest process, and discussed the influences of stressors (exposure, mechanical shock and temperature). Dry storage is stored with ice for 4 days. Wet storage is stored with circulating seawater, including three groups:5℃, 10℃ and 10℃ with mechanical shock, for 7 days. We analyzed the biochemical index of ATP related compounds, glycogen, AEC value, pH value and water soluble protein. The results showed that under dry storage, the ATP content, AEC and pH value in the adductor muscle of scallop decreased rapidly, eventually leading death. Under wet storage of 5 and 10℃, the scallop kept higher ATP content, AEC and pH value, and wet storage of 5℃ could maintain higher glycogen content than 10℃. Also at 10℃, adding mechanical shock will lead to the decrease of ATP content, AEC value and the increase of the consumption of glycogen. Therefore, the biochemical metabolism of live scallops is closely related to the post-harvest handling. Exposure is the most harmful stressor, the mechanical shock and temperature could also affect the physiological status.

Abstract:To study the effects of ecological floating beds on the quality of aquatic products, three species of fish (Sparu latus, Oreochromis niloticus and Mugil cephalus) and two species of mollusk (Crassostrea rivularis and Tegillarca granosa) were collected from the polyculture pond with floating bed and traditional monoculture ponds. Concentrations of heavy metals including Ni, Cu, Zn, Cd and Pb were measured in muscles, gills and viscera of fish and in the edible part of mollusk for health risk assessment. Nutritional quality of S. latus and O. niloticus was analyzed in terms of their muscle nutrition, amino acids and fatty acids composition. The results showed that the concentrations of five heavy metals of all products from the experimental pond conformed to the criteria values for aquatic food in China. However, the concentrations of Cu (57.113 mg/kg wet wt) and Cd (1.163 mg/kg wet wt) in C. rivularis and the concentration of Cd in T. granosa from the control ponds were all beyond the criteria values. According to the Hazard Quotient, there will be no potential risks resulting from ingestion of fish from two kinds of ponds. Content of umami amino acid of S. latus from the experimental pond was significantly higher than that of the control pond. O. niloticus from the experimental pond had notably higher contents of TAA, EAA and DAA than those from control pond. Contents of polyunsaturated fatty acids of S. latus and O. niloticus from the testing pond were all higher than those in the control ponds, while opposite results were observed for the contents of saturated fatty acids. Generally, polyculture mode with in-situ ecological floating beds system demonstrated superiorities to the traditional monoculture mode according to the health risk assessment and nutritional quality of aquatic products.

Abstract:The bioflocs can be used as an addition of high value feed by fish or shrimp. Water quality can be improved, and pathogenic bacteria can be controlled, thereby reducing the potential spread of diseases, and feed conversion ratio can be reduced in biofloc technology systems. Mirror carp, Cyprinus carpio, as a bottom fish, are popular with culturists because of its ease of breeding, fast growth, and tolerance to wide range of environmental conditions and resistance to diseases. The species is also ideal for use in polyculture systems because of its mild behavior and broad diet. Similarly, silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis), are the typical filter-feeding fish, which have drawn much attention worldwide because of their importance as aquaculture species as well as their potential for the biomanipulation of plankton communities. The multitrophic approach of combining species with different specific feeding niches maximizes resource utilization more efficiently than monoculture. However, there is little documentation on practicability of using biofloc technology for bottom and filter feeding carp in minimum water exchange pond polyculture systems. Therefore, a 90-day experiment was conducted to examine the effects of carbon source addition on water quality and growth performance of fish in different carp stocking modes land-based experimental mesocosm biofloc systems. Three stocking modes with mirror carp monoculture, mirror carp + bighead carp polyculture, and mirror carp + bighead carp + silver carp polyculture were arranged in three replicate enclosures. The results showed survival rates (SR) of mirror carp in polyculture mode were significantly higher than that in monoculture mode, and protein efficiency ratios (PER) of fish in two species and three species polyculture modes were 30.1% and 36.1% higher than that in monoculture mode, while the total feed conversion rates (TFCR) of fish were 22.7% and 26.3% lower than that in monoculture mode. The crude protein and ash of the muscle composition of mirror carp in three species polyculture mode were significantly higher than those in monoculture mode. The results showed a significant positive correlation between bioflocs volumes and experimental water temperatures at the temperatures of 19.3-28.5℃ in different stocking modes. The total ammonia nitrogen (TAN), nitrite nitrogen (NO₂-N), total inorganic nitrogen (TIN), orthophosphate (PO₄-P) and total suspended solidities (TSS) in two species and three species polyculture modes were lower than those in monoculture mode, while the nitrate nitrogen (NO₃-N), total alkalinity, total suspended organics (TSO) and Chlorophyll a were higher than those in monoculture mode, and there were no significant differences in these parameters except for the Chlorophyll a between different stocking modes. The present study revealed that polyculture modes can effectively perform the ecological function and increase aquaculture efficiency in biofloc systems.

Abstract:This study was designed to investigate gonadosomatic index (GSI), hepatosomatic index (HSI), meat yield (MY), total edible yield (TEY) and relative fatness (RF), and then, their proximate composition, fatty acids and amino acids composition and essential amino acid score were further detected and compared for the three edible parts (gonad, hepatopancreas and muscle) of pond-cultured female Eriocheir sinensis among Yangtze, Huang and Liao River populations. The results are shown as follows:(1) There were significant differences in the speed of ovarian development and GSI among three populations; the Liao River population had the highest GSI while Yangtze population had the lowest GSI during the period of August to end of September among three populations; however, the similar GSI was found between Liao River and Huang River populations in late October. (2) When the females had the similar GSI and body weight, no significant differences were found in HSI, MY, TEY and RF among three populations. (3) Female from three populations had the similar proximate composition for each edible part, while the Yangtze population had the significantly higher ash content in hepatopancreas and muscle than the other two populations. (4) For the fatty acid compositions in the ovaries, Yangtze population had the highest percentage of C22:6n3 (DHA) among three populations; except for C20:1n9 and C20:4n6 in the hepatopancreas, three populations females had the similar fatty acid composition in hepatopancreas and muscle. (5) The ovaries of Yangtze population had the significantly higher contents of phenylalanine, tyrosine, tryptophan, aspartic acid and serine than Liao River population; for the amino acid contents in the muscle, Huang River population had the highest contents for most amino acids, leading to the significantly higher total amino acid (TAA) than that of the other two populations. (6) No restrictive amino acids were found in the ovaries or muscle of three populations; the ovaries of Yangtze population had the highest mean essential amino acid score (EAAS) while the muscle of Huang River population had the highest mean EAAS among the three populations; despite of populations, the mean EAAS of ovaries was higher than that of muscle. In conclusion, Yangtze population had the slowest speed of ovarian development among three populations, while the fastest ovarian development was found in Liao River population. Females from three populations had the similar proximate composition and fatty acids levels in the three edible parts. Although the significant differences were detected for the contents of many amino acid in the muscle among three populations, no restrictive amino acids were found in ovaries and muscle.

Abstract:Dietary conjugated linoleic acids (CLA) have been shown to alter growth rates, improve antioxidant capacity and modulate lipid metabolism in higher animals including some species of fish, but have not been evaluated in economic crustaceans. An 8-weeks feeding trial was conducted to evaluate the effects of dietary CLA on growth, antioxidant capacity and lipid metabolism of oriental river prawn, Macrobrachium nipponense. Five semi-purified diets were supplemented with different levels of CLA (CLA1, 0%; CLA2, 1.5%; CLA3, 3%; CLA4, 4.5%; CLA5, 6%). Each diet was fed to juvenile prawns (mean weight, 0.102±0.0024 g) twice daily to apparent satiation in five replicates. The survival rate was influenced by dietary CLA content, and the survival rate of CLA5 significantly decreased compared with that of CLA1 (P<0.05). No significant difference was observed on weight gain among all groups. Activity of superoxide dismutase (SOD), total antioxidant activity competence (T-AOC) and malondialdehyde (MDA) level in hepatopancreas decreased first, and then increased as CLA level was increased. The SOD activity in prawns fed CLA1 was significantly higher than that of other treatments (P<0.05). The hepatopancreas MDA content was significantly increased when the CLA inclusion was above 4.5% (P<0.05). The total cholesterol concentration (TC) and total triacylglycerol concentration (TG) in plasma were also significantly affected by dietary CLA levels. Gradually decreased TG and TC were observed with the increase of CLA level (P<0.05). The mRNA expressions of carnitine palmityltransferase-1 (CPT1), Acetyl CoA carboxylase (ACC) and scavenger receptor class B type Ⅰ (SR-BI) in hepatopancreas were highly sensitive to dietary CLA. The 4.5% CLA level induced the highest CPT1 and SR-BI mRNA expression levels. Similarly, ACC mRNA expression was also the highest in prawns fed the CLA4 diet, which was significantly higher than that of other groups (P<0.05). These findings demonstrated that (1) CLA inclusion could improve the antioxidant capacity and modulate lipid metabolism; (2) Dietary CLA had little potential for improving growth responses of M. nipponense, and a high proportion (6%) of CLA would reduce the survival rate of prawns.

Abstract:Aeromonas hydrophila is a Gram-negative bacterium, which is widely distributed in the water environment. Pathogenic strains can cause sepsis in a variety of aquatic animals. In Sept. 2015, crucian carp (Carassius carassius) in one farm of Nanjing showed symptoms of haemorrhagic septicaemia. Samples from diseased fish in three ponds were collected and the pathogenic bacteria were isolated. Three A. hydrophila isolates were identified based on sequencing of the housekeeping gene gyrB, and named GL-15, GL-17 and GL-18, respectively. Then the three A. hydrophila strains were typed using multilocus sequence typing (MLST) based on six housekeeping genes. Also, all the three isolates were analyzed for hemolytic and proteolytic characterizations and pathogenicity in zebrafish. The results showed that all the three strains presented hemolytic and proteolytic activities, and the abilities of biofilm formation in which OD₅₉₅ is more than 0.5 and also had swarming and swimming motility. And they were highly virulent strains, with the LD₅₀ values of 1.4×10³ to 3.9×10³ CFU. This study provided a basis for control of MAS caused by A. hydrophila in Nanjing area.

Abstract:In order to develop an immunological method for detection of the antibody against grass carp reovirus HZ08, using the cell culture plate which infected with the the GCRV HZ08 as the antigen, and serum collected from the vaccine immune grass carp used as the antibody, an immunoperoxidase monolayer assay (IPMA) was developed to detect antibody against grass carp reovirus HZ08 based on the optimized reaction condition.The specificity, sensitivity, reproducibility and using for clinical application of IPMA were evaluated, and compared with that of ELISA.The results showed that in the optimized IPMA, the virus was diluted at 1×10³ copies/μL after 72 hours, HRP-IgG was diluted at 1:1000, and grass carp serum samples were diluted at 1:100, there was no cross-reaction with serum from grass carp against other pathogeny. The sensitivity test showed that the positive serum could be detected at 1:800. Reproducibility tests proved that the established IPMA had good reproducibility. The IPMA method had 95.7% positive coincident rate and 87.5% negative coincident rate with ELISA method. The results of the IPMA for detection of the immunized grass carp serum showed that the antibody titer reached peak value in the 2nd week post-inoculation.A total of 126 field serum samples were examined using this method, the average positive rate was 72.2%. The IPMA is a highly specific, sensitive, and stable method with high repeatability, and it offered a convenient tool for the epidemiological investigation, vaccine immunization effect assessment, and antigen and antibody detection.

Abstract:The order Decapoda, with most species and high economic value in crustaceans, was divided to two sub-orders:Dendrobranchiata (Penaeidea etc.) and Pleocyemata (Caridea, Astacidea, Palinura, and Brachyura etc.). The full length of vitellogenin cDNA in Decapoda is about 8 kilobases (kb) in size, and encoded 2500-2600 amino acid residues. Vg gene organization and expression pattern in Decapods is highly conserved. But the site and model of vitellogenesis is obviously different. In the artificial control conditions, there is a distinguished different exhibition between the Penaeidea shrimps and Caridea or Brachyura, etc.. The ovary of Penaeid shrimps is difficult to mature, and usually people have to remove their eye-stalk to promote the gonad (ovary) development, however, the species in Pleocyemata like Caridea or Brachyura are very easy to mature, even people need to inhibit their ovary to develop early with control temperature and nutrition. Vg in Penaeidea shrimps is synthesized in ovary and hepatopancreas coordinately, and ovary contributes more than hepatopancreas usually, especially during the early stage of the gonadal development. So penaeid shrimps may constitute a unique model for vitellogenesis, showing intra-ovarian gene expression and synthesis of yolk protein. However, in Pleocyemata such as Caredea, Brachyura etc., the ovary also joins the vitellogenesis, but the hepatopancreas plays the major role and its contribution rate accounts for more than 90%. Why so big difference of vitellogenesis mechanism and gonad maturation in captive condition exists in these two groups of crustacean is discussed in this paper.