• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Impact of Different Diets on Adult Tri-Spine Horseshoe Crab, Tachypleus tridentatus

    2022-06-14 06:53:38YINGZiweiBAOYuyuanLIYinkangYEGuolingZHANGShuhuanXUPengZHUJunhuaandXIEXiaoyong
    Journal of Ocean University of China 2022年3期

    YING Ziwei, BAO Yuyuan, LI Yinkang, YE Guoling, ZHANG Shuhuan,XU Peng, ZHU Junhua, and XIE Xiaoyong, 3), *

    Impact of Different Diets on Adult Tri-Spine Horseshoe Crab,

    YING Ziwei1), 2), 3), #, BAO Yuyuan4), #, LI Yinkang1), 2), YE Guoling1), ZHANG Shuhuan5),XU Peng6), ZHU Junhua6), and XIE Xiaoyong1), 2), 3), *

    1);,,510300,2),201306,3),511458,4),510322,5),550025,6),,535011,

    Effective culture and management of adult tri-spine horseshoe crab,can ensure that stock enhancement programs and aquaculture systems are maintained. To explore suitable feed for animalsduring the breeding season, Pacific oyster () (oyster group; OG) and frozen sharpbelly fish () (frozen fish group; FG) were selected to feed 20male and female pairs, respectively. At the end of the experiment, intestinal samples were obtained to measure digestive enzymes activities. The intestinal flora were determined by 16S rDNA sequencing. No eggs were observed in the FG and oneadult died. No animals died in the OG, and 9.7×104eggs were obtained. These results show that oysters are more suitable for the development and reproduction of adultthan frozen fish. Additionally, the digestive enzyme activity analysis revealed that animals in the OG exhibited higher protein digestibility than those in the FG, but no significant differences in lipid and carbohydrate uptake were observed between the groups. Furthermore, the intestinal flora analysis showed that operational taxonomic units (OTUs) and the Chao1 index were significantly higher in the OG than in the FG, but no significant difference was observed in the Shannon or Simpson indices between the groups. Our data indicate that the oyster diet improved the intestinal microbial diversity ofWe hypothesize that nutrients, such as oyster-based taurine, proteins, and highly unsaturated fatty acids, improve protease activity in thedigestive tract,alter the intestinal floral structure, and improve the reproductive performance of.

    ; diet; reproductive performance; digestive enzyme activity; intestinal flora

    1 Introduction

    Horseshoe crabs are known as ancient ‘living fossils’ as they have survived for 400 million years on the Earth(Van Roy., 2010; Kwan., 2018). The hemolymphfromcan be used to produceamebocyte lysate; therefore,is of uni- que value for national public health security (Xie., 2021). Human disturbance and environmental pollution have caused a sharp decline of theresource (Cai., 2021). In 2019, the International Union for Conser- vation of Nature Red List updatedto endangered status (Laurie., 2019), and the animal was listed as a Grade II protected species in the National Key Wildlife List of China in 2021. Due to the ongoing CO- VID-19 pandemic, the large-scale production of vaccines has led to increasing demand foramebocyte lysate and increased pressure on horseshoe crab conser- vation. Large-scale artificial breeding, larval culture, and field release measures are vital and reliableconser- vation modalities forresource management (Hong, 2011). Therefore, cultivation and management of adult horseshoe crab are of great importance to ensure en- hanced release and culture of. Food sources are crucial to the physiological activities of aquatic animals (Doxa., 2013). Mastering feeding demands and beha- viors are key to successful artificial breeding programs,such as improving growth performance (Tacon., 2002), reducing mortality (Espinosa and Allam, 2006), enhanc- ing adult fecundity (Pan., 2009), and replacing natu- ral diets with artificial compound feed (Millamena, 2002).

    Horseshoe crabs have different dietary habits at differ- ent life stages. Mollusks, crustaceans, and polychaetes have been observed in gut samples from adultin India (Chatterji., 1992) and adultin Malaysia (John., 2012). How- ever, studies on the diet ofhave only been reported for juvenile and sub-adult animals. Hu(2013) studied the diet of juvenileat the third instar. Kwan(2014) investigated the health status of juve- nilefed with different diets at the eighth in- star, and Gao(2003) conducted preliminary research on the diet of juvenilewith a prosomal width of 10–20cm. There is a need for research on the diet of adultduring the breeding season, which has not been studied.

    Different diets can lead to differences in intestinal microbial community structure, with intestinal microbiota af- fecting the host immune defense, digestion and absorption, nutritional metabolism, and other physiological functions (Chen., 2018). Little information is available on the intestinal microbiota diversity ofMiao(2020) analyzed the gut microbiota diversity of first and second instar, and reported that initial molt- ing rather than feeding has a significant effect on the in- testinal flora of juvenile. The effects of diet on intestinal microflora diversity in adultre- main unclear.

    Based on the finding that major food sources for adultandare bivalves and fish (Guo, 2021; Halim, 2021), oysters and frozen fish were selected as diets for adultin this study. Oys- ters have more moisture, crude protein, crude fat, and ash content than frozen fish (Li, 2021). Moreover, oys- ters are rich in high-quality protein, glycogen, n-3 poly- unsaturated fatty acids, essential amino acids, trace ele- ments, and other nutrients (Li, 2021). We then ana- lyzed the dietary effects on reproductive performance and intestinal flora of adultto provide a scien- tific and theoretical basis for selecting an artificial breed- ing diet for these animals

    2 Materials and Methods

    2.1 Selection and Culture Management of Adult T. tridentatus

    Horseshoe crabs (female, 4.21kg±0.68kg; male, 1.70kg±0.22kg) were obtained from the South China SeaFisheries Research Institute, Chinese Academy of FisheriesSciences in March 2019. Twentymale and female pairswere randomly selected for breeding studies (May–August). The average prosomal width of the females was 35.28cm±4.62cm, while that of males was 27.19cm±2.37cm.

    Culture studies were conducted in two indoor cement ponds (4m×4m×0.8m) containing filter-disinfected seawater at 28–32℃, with 26%–30% salinity, pH of 7.4–7.8, and dissolved oxygen ≥4.0mgL?1. Ten animal pairs were randomly selected and placed in each pond, which was also equipped with a water circulating system, and a sand covered bottom (depth, 20–40cm; grain size, 0.5–2.0mm). The animals were fed once daily at 18:00 during culture. In one pond, animals were fed 20mm (length)×8mm(width)×5mm (height) oysters () (oyster group; OG), while the other pond was fed an equal portion of frozen fish () (frozen fish group; FG) with the same particle size, and both groups were fed at 3% of overall body mass. About 80% of the seawater in each pond was renewed daily. The sandy bottom and pondwalls were cleaned once every 15 days. Health parameters, including final body weight, mortality, weight gain rate, and specific growth rate, were observed in all animals du- ring the study. All horseshoe crabs were weighed at the beginning and the end of the experiment. Additionally, breeding activities were recorded in the groups, including egg number and hatching rate. Eggs were obtained by na- tural spawning. The total number of eggs spawned by the 10 pairs of horseshoe crabs was counted at the end of the experiment.

    2.2 Sampling and Experimental Manipulation

    After 120 days of feeding experiment, threemale and female pairs were randomly sampled from each pond. The digestive tract was dissected and stored at ?80℃. Intestinal tissues (0.5g per sample) were ground twice in an automatic freezing grinding instrument (JXFSTPRP-32L, Shanghai Jingxin Industrial Development Co., Ltd., Shang- hai, China), and the supernatant was centrifuged at 4℃ (Thermo ST16, Shanghai, China) and stored to determine enzyme activities. Pepsin, trypsin, lipase, and α-amylase levels were determined using kits provided by Nanjing Jian- cheng Bioengineering Institute (Shanghai, China).

    Intestinal samples (0.5g per sample) were also ground. Total intestinal bacterial DNA was extracted using the Tian-gen DNA extraction kit (DP308, Tiangen Biotech Co., Ltd., Beijing, China), and the V3 and V4 regions of 16S rRNA were amplified. The polymerase chain reaction (PCR) was carried out in a 30μL reaction system with 15μL of Phusion? High-Fidelity PCR Master Mix (New England Bio- labs, Ipswich, MA, USA), 0.2μmolL?1of the forward and reverse primers, and about 10ng of template DNA. The PCR conditions were initial denaturation at 98℃ for 1min,followed by 30 cycles of denaturation at 98℃ for 10s, annealing at 50℃ for 30s, and elongation at 72℃ for 60s, followed by a final elongation step at 72℃ for 5min. Oncesuccessful amplification was indicated using 1% agarose gel electrophoresis, high throughput sequencing of the 16S rRNA gene was entrusted to Mingke Biotechnology Co., Ltd. (Hangzhou, China). The PCR primers were: 515F (5’- GTGCCAGCMGCCCGG-3’) and 907R (5’-CCGTCAAT TCMTTTRAGTTT-3’) DNA was amplified using Trans- Start Fastpfu DNA Polymerase (TransGen AP221-02, Bei- jing, China) with a PCR instrument (ABI GeneAmp? 9700,ABI, Foster City, CA, USA). Three replicates of each sam- ple were mixed, and the PCR products from the same sam- ple were recovered by 2% agarose gel electrophoresis. The PCR products were purified using the AxyPrepDNA Gel Recovery Kit (Axygen?, Tewkesbury, MA, USA) and eluted in Tris-HCl (pH 7.4).

    2.3 Intestinal Microbiome Analysis Determination of Taurine Content in Two Diets

    Based on the Illumina PE250 sequencing tool, fast length adjustment of short reads and paired-end reads were fil- tered and spliced according to the overlapped relation- ships to generate good quality data. Operational taxono- mic units (OTUs) were clustered to analyze differences in species abundance and the α- and β-diversity indices between the groups. Linear discriminant analysis effect size (LEfSe) was used to identify significant differences in the relative abundance of the bacterial taxa.

    Muscle samples were collected randomly and locally fromand(six sam- ples for each). Taurine concentrations in muscle samples were measured using taurine assay kit (Cell Biolabs, San Jose, CA, USA).

    2.4 Data Analysis

    Data were tested for normality and homogeneity of va- riance using the Shapiro-Wilk test, and the-test was used to analyze differences between groups. The results are ex- pressed as mean±standard deviation (SD). Duncan’s mul- tiple comparison test was used to analyze differences between groups, and<0.05 was considered significant. Prin- cipal component analysis (PCA) was performed in R soft- ware (Version 4.0.5; The R Foundation for Statistical Com- puting, Vienna, Austria) to identify differences in the mi- crobial structure between the groups.

    3 Results

    3.1 Effects of Different Diets on Adult T. tridentatus Growth and Reproductive Performance

    No eggs were observed in the FG, and one adultdied. No horseshoe crabs died in the OG, and 9.7×104eggs were obtained. These eggs were pale yellow spherical, with diameters of 2.98mm±0.15mm, and a hat- ching rate of 89%. The final body weight, weight gain rate,and specific growth rate of the OG group were higher than those of the FG group (Table 1).

    Table 1 Influence of the different diets on growth of adult Tachypleus tridentatus

    Notes: IBW, initial body weight; FBW, final body weight; WGR, weight gain rate; SGR, specific growth rate. Different superscript letters indicate a significant difference between the treatment groups (0.05).

    3.2 Effects of the Different Diets on Adult T. tridentatus Intestinal Enzyme Activity

    As shown (Table 2), pepsin activity was significantly higher in the OG crabs than in the FG crabs (<0.01,=?3.038), while lipase, α-amylase, and trypsin activities were not significantly different (>0.05).

    Table 2 Influence of different diets on intestinal enzyme activities of adult Tachypleus tridentatus

    Note: Different superscript letters indicate a significant difference between the treatment groups (0.01).

    3.3 Effects of the Different Diets on the Adult T. tridentatus Intestinal Flora

    3.3.1 OTU cluster and species diversity analyses

    In total, 237969 valid sequences were identified across the sample groups, including 114155 from the FG and 123814 from the OG. The OTUs belonged to 11 phyla, 17 classes, 32 orders, 50 families, 57 genera, and 55 species. OTU similarity and overlap between the groups were in- vestigated using a Venn diagram (Fig.1A). In total, 1487 OTUs were identified in both groups, of which the num- bers of OTUs in the FG and OG were 775 and 1272, re-spectively. A total of 560 OTUs were common between the groups, while there were 215 (FG) and 712 (OG) unique OTUs. These data indicate that oysters improved the in- testinal microbial diversity of

    Fig.1 (A)Venn diagram used to count the number of shared and unique OTUs in different samples; the red circle represents the FG group, the green circle represents the OG group, and the overlap represents the number of shared OTUs between the two groups; (B) PCA of adult Tachypleus tridentatus intestinal flora. FG, frozen fish group; OG, oyster group.

    The Chao1 index was used to evaluate the richness of the intestinal flora. The Shannon and Simpson indices have been commonly used to assess intestinal flora diversity; a higher Shannon index and a lower Simpson index indicate higher diversity in bacterial communities (Liu and Peng, 2021). Our results show that the coverage value of both groups was >0.99, suggesting that the results were reliable. The abundance (OTUs and Chao1 index) and diversity (Shannon index) of the intestinal flora were higher in the OG than those in the FG (Table 3). The OTUs and Chao1 indices were significantly different between the groups (<0.05), while the Shannon and Simpson indices were not significantly different (>0.05) (Fig.2).

    PCA showed that diet (59.3%) was the main factor responsible for the difference of the intestinal content samples fromin the FG and OG groups (Fig.1B).

    Table 3 Influence of the different diets on the intestinal microbial diversity index of Tachypleus tridentatus

    Fig.2 α-Diversity of the bacterial communities: The Chao1 index estimates richness; the Shannon and Simpson indi- ces estimate diversity. FG, frozen fish group; OG, oyster group.

    3.3.2 Community composition and intestinal flora abundance

    The dominant phyla and genera in thein- testinal samplesare shown in Fig.3. Proteobacteria (FG: 37.59% and OG: 20.59%), Tenericutes (FG: 34.89% and OG: 22.64%), Firmicutes (FG: 14.76% and OG: 21.62%), and Bacteroidetes (FG: 9.81% and OG: 16.85%) were the common dominant phyla. In addition, Fusobacteria (6.35%)was a unique dominant phylum in the OG, and the remain- ing abundances were<3% (Fig.3A).(14.02%),(5.73%),(5.49%),(4.25%),(3.96%), and(3.93%) were the dominant genera in the FG, while(7.08%),(6.34%),(5.99%), and(5.68%) were the dominant genera in the OG (Fig.3B).

    Fig.3 Dominant phyla (A) and genera (B) of intestinal florain the different dietary groups. FG, frozen fish group; OG, oyster group.

    3.3.3 Species differences among the intestinal flora groups and taurine content in two diets

    The results of the LEfSe analysis showed that Fuso- bacteria was a phylum-level biomarker and,,,, andwere genus-level biomarkers between FG and OG (Fig.4).

    The taurine content of two diets was significantly dif- ferent (<0.05). Taurine content in oysters was 362.19±13.46mg(100g)?1, whilewas 236.78±19.75mg(100g)?1.

    Fig.4 LEfSe results of intestinal microbial composition between the frozen fish group (FG) and oyster group (OG). A, LDAscores of the bacterial clades identified by the LEfSe analysis; B, Phylogenetic relationships of the bacterial clades revealed by LEfSe. The single characters before the underlines are abbreviations: p, phylum; c, class; o, order; f, family; g, genus.

    4 Discussion

    Our data show that adultfed frozen fish (FG) did not spawn during the experiment (120d), while animals fed oysters (OG) laid eggs, suggesting that the nu- trients in oysters were more suitable for adultgrowth and development than frozen fish. Thefro- zen fish ()had a high fat content (Zeng, 2012). The different particle sizes and hardness of the diets may also be a reason for the results. Oysters are highly palatable with a soft meat quality, which are conducive to feeding horseshoe crabs. Frozen fish are difficult to chew and swallow. In addition, the width and thickness of the frozen fish pieces may have affected feeding ofA previous study showed that the feed intake of ju- veniledecreases with increasing particle size of the diet (Gao, 2003). Considering these dietary factors, both diets were cut into small size pieces before feeding. Oyster soft tissues are rich in amino acids, with taurine levels accounting for almost half of all free amino acids (Fuentes., 2010). Taurine levels in oysters from the southwestern South China Sea are 16.81–19.83mgg?1(Gao., 2013), which are 5–30 times higher than those of other marine fishes, such as, Chelido- nichthys kumu,and(Tan., 2000). Previous studies reported that taurine improves growth andreproduction (Xu., 2020; Yu., 2021). Oysters also contain highly unsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid) that promote vitellogenesis and gonadal and embryonic development in aquatic ani- mals and are key nutrients affecting the reproductive performance of adult fish (Bell and Sargent, 2003; Watanabeand Vassalloagius, 2003; Callan., 2014). Similarly, these molecules enhance the reproductive performance of aqua- tic animals, including(Xu., 2016),(R?jbek., 2014), and(Luo., 2015).

    Pepsin activity was significantly higher in the OG than in the FG, but no significant difference was observed in in- testinal α-amylase activity. This may be because oysters are rich in protein, glycogen, and taurine (Wang., 2011). Taurine increases protease activity and the feeding rate (Li., 2017; Wang., 2018). Similar to our data, Yu(2021) reported that the protease activity ofwas significantly higher in a taurine-treated group than that in a control group, whereas α-amy- lase activity was not significantly different. He(2017) showed that feed containing 1.3% taurine enhances pro- tease activity in the stomach, liver, and intestine of. Other studies have reported that the in- testinal protease activities of(Liang, 2018),(Wang., 2017), and juvenile(Dong., 2017) in- crease with dietary protein level. Thus, taurine could be supplemented infeed to observe its specific effect on the digestive enzyme activity ofPepsin activity in the OG was significantly higher com-pared to the FG. Therefore, adultof OG group had stronger ability to digest and absorb protein. Among the total fat of oyster, omega-3 highly unsaturated fatty acids (-3 HUFAs) such as eicosapentaenoic acid (EPA) and do-cosahexaenoic acid (DHA) accounted for 28% (Wang., 2003). Ma. (2005) found that turbotfed high-protein and high-3 HUFAs diet had highest spawning-stock biomass. This finding is in agree- ment with the results found in our study.

    Bacteria have a strong capacity to metabolize taurine, which can be directly broken down into carbon, nitrogen, and sulfur for growth (Cook., 2006). Ma(2021) reported that taurine levels in feed affect the structure, rich- ness, and diversity of the intestinal flora. Our data show that Proteobacteria, Tenericutes, Firmicutes, and Bacteroi- detes were the common dominant phyla in the horseshoe crab groups, and Fusobacteria was the unique dominant phy-lum in the OG. Proteobacteria are Gram-positive bacilli that produce spores in harsh environments. Bacteroidetes are the largest Gram-negative bacilli group in the animal in- testine and are involved in metabolic processes, such as di- gestion of nutrients and absorption (Francois., 2011). Fusobacteria are Gram-negative bacilli with a higher de- tection rate in human colorectal tumors than surrounding normal tissues (Kelly., 2018). Studies have shown that high-protein diets enrichFlavobacteria and Fusobac- teriain male,and a low-protein diet benefits the growth of Bacteroidetes, Rikenellaceae, and Tannerellaceae(Wang., 2021).

    Oysters are high in protein and low in fat, and our re- sults were consistent with previous studies. The quantity ofwas higher in the OG (5.99%) than in the FG (5.49%). These bacteria produce butyric acid, a short-chain fatty acid that can be produced by intestinal bacteria from cellulose fermentation (Tang., 2018). Butyrate-producing probiotics can reduce non- alcoholic fatty liver disease (NAFLD) progression in rats (Endo., 2013). Zhou. (2017) also confirmed that sodium butyrate attenuates high-fat diet (HFD)-induced steatohepatitis in mice by improving the gut microbiota and gastrointestinal battier. Short-chain fatty acids maintain ho- meostasis in the intestinal environment and regulate the im- mune response (Serino, 2019).is a pathogen that causes bacteriemia and infections in wounds, the uri- nary tract, and other body regions (Rihs., 1993). Pa- thogens were detected in the intestines of the OG, which may have been due to remnant, undigested oysters.

    Horseshoe crabs have a wide variety of food sources in the natural environment, where nutrients are highly abun- dant, whereas a single diet is usually fed to animals under artificial culture conditions. The differences in intestinal flo-ra between wildand artificially cultured ani- malsmust be comprehensively characterized in terms of differences in nutrient digestion and absorption to deve- lop compound feeds that promotegrowth, development, and reproductive performance.

    5 Conclusions

    Adultfed oysters had higher weight gain rate (WGR), specific growth rate (SGR), spawning-stock biomass. These results showed that oysters were more suit-able for enhancing the growth and reproduction perfor- mance of adultthan frozen fish,which is of great significance for the recovery of there- source. However, a high-protein diet can also provide nu- trients for pathogens to breed while promoting animal growth and reproduction. Thus, it is advisable to change the culture water frequently to remove the residual food and prevent replication of pathogens.

    Acknowledgements

    This research was supported by the fund of the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (No. GML2019ZD0605), the Guangdong Pro- vincial Key Laboratory of Fishery Ecology and Environ- ment (No. FEEL-2020-2), the Science and Technology Plan- ning Project of Guangdong Province (No. 2019B12120 1001), the Special Fund for Basic Scientific Research of Central Public Research Institutes of South China Sea Fisheries Research Institute, the Chinese Academy ofFishery (No. 2019TS21), and the National Natural Science Foundation of China (No. 42067038).

    Bell, J. G., and Sargent, J. R., 2003. Arachidonic acid in aqua- culture feeds: Current status and future opportunities., 218 (1-4): 491-499, DOI: 10.1016/S0044-8486(02)00 370-8.

    Cai, L., Chen, X., Fu, S., Yang, D., and Zhao, X., 2021. Popula- tion dynamics and benthic environment ofin the intertidal zone of Eyu Islet in Xiamen., 17 (1): 14-18, DOI: 10.3969/j.issn. 1673-3290.2021.01.03(in Chinese with English abstract).

    Callan, C. K., Laidley, C. W., Kling, L. J., Breen, N. E., and Rhyne, A. L., 2014. The effects of dietary HUFA level on flame angelfish () spawning, egg quality and early larval characterstics., 45 (7): 1176-1186, DOI: 10.1111/are.12063.

    Chen, H., Yan, H., Zhao, Y., Xiao, H., and Chen, S., 2018. Metagenomics and its advances in research of fish gut microbiome., 37 (5): 699-706, DOI: 10.16378/j. cnki.1003-1111.2018.05.020 (in Chinese with English abstract).

    Cook, A. M., and Denger, K., 2006. Metabolism of taurine in microorganisms: A primer in molecular biodiversity., 583: 3-13, DOI: 10. 1007/978-0-387-33504-9_1.

    Dong, L., Tong, T., Zhang, Q., Xu, M., Su, Q., Nie, Z.,., 2017. Effect of dietary protein level on growth performance, body composition, and digestive enzyme activities in green mud crab () juveniles., 24 (3): 524-532, DOI: 10.3724/SP.J. 1118.2017.16289 (in Chinese with English abstract).

    Doxa, C. K., Divanach, P., and Kentouri, M., 2013. Consumption rates and digestibility of four food items by the marine gastropod(Aradas & Benoit, 1870)., 446: 10-16, DOI: 10.1016/j.jembe.2013.04.019.

    Endo, H., Niioka, M., Kobayashi, N., Tanaka, M., and Watanabe, T., 2013. Butyrate-producing probiotics reduce nonalcoholic fatty liver disease progression in rats: New insight into the pro- biotics for the gut-liver axis., 8 (5): e63388, DOI: 10.1371/journal.pone.0063388.

    Espinosa, E. P., and Allam, B., 2006. Comparative growth and survival of juvenile hard clams,, fed commercially available diets., 25 (6): 513-525, DOI: 10.1002/zoo.20113.

    Francois, T., Jan-Hendrik, H., Etienne, R., Mirjam, C., and Gur- van, M., 2011. Environmental and gut bacteroidetes: The food connection., 2: 93, DOI: 10.3389/ FMICB.2011.00093.

    Fuentes, A., Fernández-Segovia, I., Serra, J. A., and Barat, J. M., 2010. Comparison of wild and cultured sea bass () quality., 119 (4): 1514-1518, DOI: 10.1016/j.foodchem.2009.09.036.

    Gao, F., Liao, Y., and Ye, F., 2003. Feed study of thejuvenile., 22 (4): 92-96 (in Chinese with English abstract).

    Gao, J., Zhang, C., Qiu, W., Cao, W., and Qin, X., 2013. Deter- mination of taurine infrom different parts of the South China Sea., 34 (10): 164-168, DOI: 10.7506/spkx1002-6630-201310035 (in Chinese with English abstract).

    Guo, Q., Gu, Y., Bao, Y., Li, Y., Zhou, C., and Xie, X., 2021. Dietary composition and trophic position of, 17 (4): 35-40, DOI: 10.12131/20200234 (in Chinese with English abstract).

    Halim, A. S. A., Mohamad, F., Ahmad, F., Ismail, N., Chilek, T. Z. T., Ahmad, A. R.,., 2021. Possible predation on com- mercial bivalves by: An assessment of horse- shoe crab reintroduction in Setiu Lagoon of Terengganu, Malaysia., 848 (4): 841-855, DOI: 10.1007/s10750- 020-04493-7.

    He, M., Liu, L., Qu, H., Zhang, X., and Gao, J., 2017. Effects of dietary taurine on growth performance and digestive enzyme activity of., 26 (2): 227-234, DOI: 10.12024/jsou.20151201609 (in Chinese with English abstract).

    Hong, S., 2011.. Xiamen University Press, Xiamen, 77-79.

    Hu, M., Wang, Y., Cheung, S. G., and Shin, P. K. S., 2011. Com- parison of different frozen natural foods on survival and growth of juvenile Chinese horseshoe crab, (Leach, 1819): Implications on laboratory culture., 44 (4): 567-573, DOI: 10.1111/j.1365-2109.2011. 03059.x.

    Kelly, D., Yang, L., and Pei, Z., 2018. Gut microbiota,, and colorectal cancer., 6 (4): 1-10, DOI: 10. 3390/diseases6040109.

    Kwan, B. K. Y., Chan, A. K. Y., Cheung, S. G., and Shin, P. K. S., 2014. Hemolymph quality as indicator of health status in ju- venile Chinese horseshoe crab(Xipho- sura) under laboratory culture., 457: 135-142, DOI: 10.1016/j.jembe. 2014.04.011.

    Kwan, K. Y., Virginia, K. Y., Cheung, S. G., and Paul, K. S., 2018.Horseshoe crabs as potential sentinel species for coastal health: Juvenile haemolymph quality and relationship to habitat con- ditions., 69 (6): 894-905, DOI: 10.1071/MF17210.

    Laurie, K., Chen, C. P., Cheung, S. G., Do, V., Hsieh, H. L., John, A.,, 2019.(Errata Version Pub- lished in 2019). e.T21309A149768986. IUCN, Gland, Switzerland, 60pp, DOI: 10.2305/IUCN.UK.2019-1.RLTS.T2130 9A149768986.en.

    Li, H., Huang, X., Wang, X., Yan, M., and Zheng, X., 2017. Ef- fect of dietary taurine supplementation on the growth, body composition, digestive enzyme activity and anti-stress ability ofin freshwater culture., 26 (5): 706-715, DOI: 10.12024/ jsou.20170101950 (in Chinese with English abstract).

    Li, X. D., Peng, J. X., Wu, H. Y., Zheng, G. C., Guo, M. M., Zhao, X. N.,., 2021. Review on nutrition, taste and functional components in oysters., DOI: 10. 16378/j.cnki.1003-1111.20245.

    Liang, P., Qin, Z., Lin, J., Wu, G., Zhu, Q., and Qiu, M., 2018. Effect of feed protein levels on growth performance and digestive enzyme activity of juvenile., 34 (2): 136-140 (in Chinese with English abstract).

    Liu, N., and Peng, Z., 2021. Analysis of intestinal microorganismsin(Teleostei, Cypriniformes)., 45 (1): 118-124, DOI: 10.7541/2020.2019. 169 (in Chinese with English abstract).

    Luo, L., Ai, L., Li, T., Xue, M., Wang, J., Li, W.,., 2015. The impact of dietary DHA/EPA ratio on spawning perfor-mance, egg and offspring quality in Siberian sturgeon ()., 437 (4): 140-145, DOI: 10.1016/ j.aquaculture.2014.11.036.

    Ma, A., Chen, C., Lei, J., Chen, S., and Zhuang, Z., 2005. The effect of protein and n-3 HUFA on the reproduction of turbot ()., 26 (1): 7-12 (in Chinese with English abstract).

    Ma, Q., Guo, L., Liu, B., Liu, B., Zhu, K., Guo, H.,., 2021. Effect of taurine on intestinal microbes and immune function in golden pompano ()., 17 (2): 87-96, DOI: 10.12131/202000193 (in Chinese with English abstract).

    Miao, F., Zhao, Z., Li, Q., Song, J., Wang, Y., and Hu, M., 2020. Impact of initial feeding and molting ongut microbiota., 77: 2847-2858, DOI: 10.1007/s00284-020-02108-x.

    Millamena, O. M., 2002. Replacement of fish meal by animal by- product meals in a practical diet for grow-out culture of grouper, 204 (1-2): 75-84, DOI: 10. 1016/S0044-8486(01)00629-9.

    Pan, Q., Tian, X., Ye, J., Chen, J., Zhang, J., Wang, Y.,., 2009.Effect of diets on growth and fecundity of., 33 (6): 1005-1010, DOI: 10.3724/SP.J.0000.2009.61005 (in Chinese with English abstract).

    Rihs, J. D., Brenner, D. J., Weaver, R. E., Steigerwalt, A. G., Hol- lis, D. G., and Yu, V. L., 1993., a new genus as- sociated with bacteremia and other human infections., 31 (12): 3275-3283, DOI: 10.1128/ jcm.31.12.3275-3283.1993.

    R?jbek, M. C., St?ttrup, J. G., and Jacobsen, C., 2014. Effects of dietary fatty acids on the production and quality of eggs and larvae of Atlantic cod (L.)., 20 (6): 654-666, DOI: 10.1111/anu.12124.

    Serino, M., 2019. SCFAs–The thin microbial metabolic line be- tween good and bad., 15: 318- 319, DOI: 10.1038/s41574-019-0205-7.

    Tacon, A. G. J., Cody, J. J., Conquest, L. D., Divakaran, S., For- ster, I. P., and Decamp, O. E., 2002. Effect of culture system on the nutrition and growth performance of Pacific white shrimp(Boone) fed different diets., 8 (2): 121-137, DOI: 10.1046/j.1365-2095.2002. 00199.x.

    Tan, L., Zhang, C., Xue, C., and Lin, H., 2000. Bioactivity of tau- rine and its distribution in marine organisms., 20 (3): 75-79 (in Chinesewith Eng- lish abstract).

    Tang, W., Yao, X., Xia, F., Yang, M., Chen, Z., Zhou, B.,., 2018. Modulation of the gut microbiota in rats by Hugan Qingzhi tablets during the treatment of high-fat-diet-induced nonalcoholic fatty liver disease., 2018 (4): 1-14, DOI: 10.1155/2018/7261619.

    Van Roy, P., Orr, P. J., Botting, J. P., Muir, L. A., Vinther, J., Le- febvre, B. E. L.,., 2010. Ordovician faunas of Burgess Shale type., 465: 215-218, DOI: 10.1038/NATURE 09038.

    Wang, A. R., Ran, C., Ring?, E., and Zhou, Z. G., 2018. Progress in fish gastrointestinal microbiota research., 10: 626-640, DOI: 10.1111/raq.12191.

    Wang, C., Hu, G., Sun, P., Gu, W., Wang, B., and Xu, Q., 2017. Effects of dietary protein an lipid levels on growth perfor- mance, digestive enzyme activities and serum indices ofbroodstock., 29 (2): 571-582, DOI: 10.3969/j.issn.1006-267x.2017.02.025 (in Chinesewith English abstract).

    Wang, D., Zhao, Y., Zeng, M., Liu, Z., and Dong, S., 2011. Nu- tritional components and water-extraction process ofmeat., 36 (3): 209- 212, DOI: 10.13684/j.cnki.spkj.2011.03.029 (in Chinese with English abstract).

    Wang, H., Yang, R., and Wang, Z., 2003. Nutritional components and proteolysis of oyster meat., 27 (2): 163-168 (in Chinese with English abstract).

    Wang, Y., Tian, B., Zhang, B., Fan, J., Ge, F., and Wang, G., 2021. Effects of dietary protein levels on intestinal bacterial com- munities of., 41 (13):5495-5505, DOI: 10.5846/stxb202006221621 (in Chinese with English abstract).

    Watanabe, T., and Vassalloagius, R., 2003. Broodstock nutrition research on marine finfish in Japan., 227 (1-4): 35-61, DOI: 10.1016/S0044-8486(03)00494-0.

    Xie, X., Zhong, J., Guan, J., and Jia, X., 2021. The urgency of horseshoe crab protection in China from the perspective of Tachypleus Amebocyte Lysate industry., 39 (2): 109-116 (in Chinese with English abstract).

    Xu, Y., Liu, X., Zheng, Y., Li, W., and Ding, Z., 2020. Effect and mechanism of taurine on the metabolism of aquatic animal., 41 (16): 35-40, DOI: 10.13302/j.cnki.fi.2020. 16.007(in Chinese with English abstract).

    Xu, Y. Q., Li, W. F., and Ding, Z. K., 2016. Polyunsaturated fattyacid supplements could considerably promote the breeding per- formance of carp., 119 (5): 1-8, DOI: 10.1002/ejlt.201600183.

    Yu, W., Yang, Y., Lin, H., Huang, X., Huang, Z., Li, T.,., 2021. Effects of taurine on growth performance, digestive en- zymes, antioxidant capacity and immune indices of., 17 (2): 78- 86, DOI: 10.12131/20200223 (in Chinese with English abstract).

    Zeng, G., Lv, Y., Huang, P., Yu, J., and Yang, L., 2012. Analy- sis of flesh content and nutritional component in the muscle ofBasilewsky andGunther., 33 (5): 1-7, DOI: 10.3875/j.issn.1674-3563.2012.05.001 (in Chinese with English abstract).

    Zhou, D., Pan, Q., Xin, F. Z., Zhang, R. N., He, C. X., Chen, G. Y.,., 2017. Sodium butyrate attenuates high-fat diet-in- duced steatohepatitis in mice by improving gut microbiota and gastrointestinal barrier., 23 (1): 60-75, DOI: 10.3748/wjg.v23.i1.60.

    J. Ocean Univ. China(Oceanic and Coastal Sea Research)

    https://doi.org/10.1007/s11802-022-5199-4

    ISSN 1672-5182, 2022 21 (3): 541-548

    #The two authors contributed equally to this work.

    ? Ocean University of China, Science Press and Springer-Verlag GmbH Germany 2022

    Corresponding author. E-mail: xyxie@scsfri.ac.cn

    (September 17, 2021;

    November 8, 2021;

    January 11, 2022)

    (Edited by Qiu Yantao)

    青草久久国产| 国产精品人妻久久久久久| 波野结衣二区三区在线| 欧美日本亚洲视频在线播放| 九九热线精品视视频播放| 日本 欧美在线| 久久久久性生活片| 看片在线看免费视频| 动漫黄色视频在线观看| 久久久久久久久久黄片| 久久午夜亚洲精品久久| 亚洲欧美日韩高清在线视频| 一区二区三区高清视频在线| 亚洲国产欧洲综合997久久,| 好男人在线观看高清免费视频| www.熟女人妻精品国产| 欧美日韩瑟瑟在线播放| 最新中文字幕久久久久| 观看美女的网站| 99久久精品国产亚洲精品| 可以在线观看毛片的网站| 欧美日韩黄片免| 宅男免费午夜| 男人和女人高潮做爰伦理| 高清在线国产一区| 亚洲第一区二区三区不卡| 精品一区二区免费观看| 亚洲五月婷婷丁香| 九色国产91popny在线| 一级黄色大片毛片| 丰满人妻一区二区三区视频av| 搡老妇女老女人老熟妇| 99热这里只有是精品在线观看 | 久久久精品欧美日韩精品| 简卡轻食公司| 色综合婷婷激情| 嫩草影视91久久| 精品久久国产蜜桃| 欧美xxxx性猛交bbbb| 中文字幕久久专区| 久久热精品热| 有码 亚洲区| 精品午夜福利在线看| а√天堂www在线а√下载| 欧美3d第一页| 日韩精品中文字幕看吧| 他把我摸到了高潮在线观看| 欧美日韩乱码在线| 欧美高清性xxxxhd video| 成人国产综合亚洲| 亚洲av.av天堂| 久久天躁狠狠躁夜夜2o2o| 蜜桃久久精品国产亚洲av| 欧美日韩瑟瑟在线播放| 午夜a级毛片| 精品久久国产蜜桃| 变态另类丝袜制服| 国产成年人精品一区二区| 91麻豆精品激情在线观看国产| АⅤ资源中文在线天堂| 他把我摸到了高潮在线观看| 色吧在线观看| 88av欧美| 国产黄a三级三级三级人| 欧美性猛交╳xxx乱大交人| 美女xxoo啪啪120秒动态图 | 欧美日本视频| 99久久99久久久精品蜜桃| 天堂av国产一区二区熟女人妻| 99热精品在线国产| 搡老熟女国产l中国老女人| 国产精品不卡视频一区二区 | 国产精品久久久久久人妻精品电影| 1024手机看黄色片| 国产精品永久免费网站| 九九在线视频观看精品| 国产91精品成人一区二区三区| 18禁裸乳无遮挡免费网站照片| 午夜久久久久精精品| 激情在线观看视频在线高清| 在线免费观看的www视频| 青草久久国产| 中文资源天堂在线| 精品人妻视频免费看| 乱人视频在线观看| 免费高清视频大片| 桃红色精品国产亚洲av| 可以在线观看毛片的网站| 欧美+亚洲+日韩+国产| 国产精品爽爽va在线观看网站| 美女 人体艺术 gogo| 亚洲无线观看免费| 日韩欧美一区二区三区在线观看| 毛片女人毛片| 波多野结衣巨乳人妻| 日韩欧美国产一区二区入口| 亚洲av一区综合| 又爽又黄无遮挡网站| 在线十欧美十亚洲十日本专区| 3wmmmm亚洲av在线观看| 亚洲欧美清纯卡通| 中文字幕高清在线视频| 欧美bdsm另类| 午夜精品在线福利| 中文资源天堂在线| 丰满的人妻完整版| 一进一出抽搐动态| 亚洲国产精品合色在线| 亚洲美女视频黄频| 亚洲国产色片| 免费看光身美女| 精品国产三级普通话版| 别揉我奶头~嗯~啊~动态视频| 99久久精品一区二区三区| 97碰自拍视频| 99久久无色码亚洲精品果冻| 99热精品在线国产| 3wmmmm亚洲av在线观看| 国产欧美日韩一区二区精品| 国产精品99久久久久久久久| 久久婷婷人人爽人人干人人爱| a在线观看视频网站| 夜夜躁狠狠躁天天躁| 日本免费一区二区三区高清不卡| 亚洲七黄色美女视频| 日本三级黄在线观看| 在线天堂最新版资源| 国产精品一区二区三区四区久久| 夜夜夜夜夜久久久久| 亚洲最大成人中文| 国产国拍精品亚洲av在线观看| 国产成人av教育| 好看av亚洲va欧美ⅴa在| eeuss影院久久| 18美女黄网站色大片免费观看| 天堂网av新在线| 神马国产精品三级电影在线观看| 欧美激情在线99| 直男gayav资源| 国产极品精品免费视频能看的| 丰满乱子伦码专区| 91麻豆av在线| 亚洲一区二区三区色噜噜| 琪琪午夜伦伦电影理论片6080| 亚洲欧美激情综合另类| av福利片在线观看| 国产av不卡久久| 在线看三级毛片| 少妇高潮的动态图| 亚洲国产欧美人成| 色尼玛亚洲综合影院| 精品一区二区三区人妻视频| 一夜夜www| 中文字幕人妻熟人妻熟丝袜美| 亚洲一区二区三区色噜噜| 国产精品爽爽va在线观看网站| 色综合欧美亚洲国产小说| 日本成人三级电影网站| 色综合站精品国产| 中文字幕人妻熟人妻熟丝袜美| 午夜福利高清视频| 天天躁日日操中文字幕| 少妇的逼水好多| 男女下面进入的视频免费午夜| a在线观看视频网站| 麻豆一二三区av精品| 97人妻精品一区二区三区麻豆| 亚洲五月天丁香| 亚洲欧美日韩高清在线视频| 男人舔女人下体高潮全视频| 99热6这里只有精品| 一个人看视频在线观看www免费| 久久久久久久久大av| 可以在线观看的亚洲视频| 成人高潮视频无遮挡免费网站| 香蕉av资源在线| 久99久视频精品免费| 老司机深夜福利视频在线观看| 色综合亚洲欧美另类图片| 成人av在线播放网站| 国产高清激情床上av| 国产成人影院久久av| av专区在线播放| 国产真实伦视频高清在线观看 | 中文在线观看免费www的网站| 91久久精品电影网| 性插视频无遮挡在线免费观看| 欧美一级a爱片免费观看看| 国产男靠女视频免费网站| 97热精品久久久久久| 国产伦精品一区二区三区四那| 色在线成人网| 1024手机看黄色片| .国产精品久久| 有码 亚洲区| 午夜福利成人在线免费观看| 又粗又爽又猛毛片免费看| 久久6这里有精品| 国产精品永久免费网站| 村上凉子中文字幕在线| 久久午夜亚洲精品久久| 国语自产精品视频在线第100页| 国产伦精品一区二区三区视频9| 狠狠狠狠99中文字幕| 国产美女午夜福利| 天堂网av新在线| 亚洲午夜理论影院| 一级黄色大片毛片| 免费无遮挡裸体视频| 亚洲精品乱码久久久久久按摩| 99热国产这里只有精品6| 亚洲国产欧美人成| 午夜亚洲福利在线播放| 日韩 亚洲 欧美在线| 内地一区二区视频在线| 在线播放无遮挡| 亚洲经典国产精华液单| 亚洲av国产av综合av卡| 国产一区二区在线观看日韩| 欧美国产精品一级二级三级 | 日韩av在线免费看完整版不卡| 国产一区二区亚洲精品在线观看| 国产 一区 欧美 日韩| 国产精品偷伦视频观看了| 欧美xxxx黑人xx丫x性爽| 少妇的逼水好多| 亚洲综合色惰| 在线亚洲精品国产二区图片欧美 | 久久久久久久大尺度免费视频| 国产成人精品久久久久久| 国产黄片视频在线免费观看| 国产伦精品一区二区三区四那| 搡女人真爽免费视频火全软件| 黄色视频在线播放观看不卡| 你懂的网址亚洲精品在线观看| 黄色怎么调成土黄色| 欧美一级a爱片免费观看看| av国产免费在线观看| 亚洲精品日本国产第一区| 日本熟妇午夜| 中国国产av一级| 精品亚洲乱码少妇综合久久| 欧美亚洲 丝袜 人妻 在线| 午夜老司机福利剧场| 日韩成人伦理影院| 国产成人福利小说| 在线观看一区二区三区激情| 国产成人91sexporn| 久久精品国产亚洲网站| 在线观看av片永久免费下载| 色婷婷久久久亚洲欧美| 成年版毛片免费区| 视频中文字幕在线观看| 18+在线观看网站| 亚州av有码| 美女视频免费永久观看网站| 免费高清在线观看视频在线观看| 最近手机中文字幕大全| 亚洲色图av天堂| 青春草亚洲视频在线观看| 国产 一区 欧美 日韩| 亚洲精品日韩av片在线观看| 国产视频内射| 天天躁夜夜躁狠狠久久av| 王馨瑶露胸无遮挡在线观看| 免费大片黄手机在线观看| av一本久久久久| 男女那种视频在线观看| 日本wwww免费看| 欧美3d第一页| 国产亚洲5aaaaa淫片| 高清欧美精品videossex| 一个人看视频在线观看www免费| 精品久久国产蜜桃| 成人综合一区亚洲| xxx大片免费视频| 狠狠精品人妻久久久久久综合| 日日啪夜夜撸| 欧美xxxx性猛交bbbb| 夜夜看夜夜爽夜夜摸| 欧美zozozo另类| 久久久欧美国产精品| av又黄又爽大尺度在线免费看| 在线亚洲精品国产二区图片欧美 | 极品少妇高潮喷水抽搐| 少妇人妻一区二区三区视频| 日韩一区二区三区影片| 国产免费一级a男人的天堂| 午夜福利视频精品| 伦理电影大哥的女人| 中国国产av一级| 免费人成在线观看视频色| 亚洲国产精品专区欧美| 久久精品国产a三级三级三级| 亚洲欧美日韩无卡精品| a级毛色黄片| 1000部很黄的大片| 国产亚洲精品久久久com| 女人久久www免费人成看片| 偷拍熟女少妇极品色| 久久精品熟女亚洲av麻豆精品| 少妇人妻久久综合中文| 久久久久久久久久久丰满| 成人黄色视频免费在线看| 久久人人爽人人片av| 国产成人精品久久久久久| 97热精品久久久久久| 大香蕉久久网| 在线观看免费高清a一片| 搞女人的毛片| 亚洲精品久久午夜乱码| 国产伦在线观看视频一区| 久久精品综合一区二区三区| 成人一区二区视频在线观看| 少妇的逼好多水| 亚洲天堂国产精品一区在线| 色吧在线观看| 国产色爽女视频免费观看| 国产精品av视频在线免费观看| 少妇人妻精品综合一区二区| 天天躁夜夜躁狠狠久久av| 五月天丁香电影| 在线天堂最新版资源| 嫩草影院入口| 国产高清不卡午夜福利| 亚洲精品影视一区二区三区av| 久久鲁丝午夜福利片| 听说在线观看完整版免费高清| 日韩欧美一区视频在线观看 | 精品久久久久久电影网| 亚洲图色成人| 九九久久精品国产亚洲av麻豆| 成人亚洲精品av一区二区| 亚洲欧美精品专区久久| 三级国产精品片| 久久女婷五月综合色啪小说 | 在线观看一区二区三区激情| 五月玫瑰六月丁香| 国产探花在线观看一区二区| 麻豆国产97在线/欧美| 免费少妇av软件| 97超视频在线观看视频| 国产亚洲av片在线观看秒播厂| 搡女人真爽免费视频火全软件| 在线亚洲精品国产二区图片欧美 | 在线观看一区二区三区激情| 中国三级夫妇交换| 国产成人精品一,二区| av免费在线看不卡| 一级爰片在线观看| 国产精品人妻久久久影院| 精品人妻一区二区三区麻豆| 中国三级夫妇交换| 黄色欧美视频在线观看| 色哟哟·www| 亚洲三级黄色毛片| 中文精品一卡2卡3卡4更新| 国产 一区 欧美 日韩| 国产成人免费观看mmmm| 久久久a久久爽久久v久久| 久久久久久久久大av| av在线app专区| 99久久精品热视频| 老师上课跳d突然被开到最大视频| www.色视频.com| 久久久久久久久久久丰满| 日韩制服骚丝袜av| 国产亚洲av片在线观看秒播厂| 一级毛片 在线播放| videos熟女内射| 日日撸夜夜添| 欧美一级a爱片免费观看看| 亚洲av福利一区| 亚洲人成网站高清观看| 国产男人的电影天堂91| 成人一区二区视频在线观看| av又黄又爽大尺度在线免费看| 久久久久久久大尺度免费视频| 午夜福利高清视频| 日韩成人av中文字幕在线观看| 国产日韩欧美在线精品| 免费播放大片免费观看视频在线观看| 韩国av在线不卡| 插逼视频在线观看| 午夜免费鲁丝| 联通29元200g的流量卡| 深夜a级毛片| 一个人观看的视频www高清免费观看| 欧美潮喷喷水| 国产精品av视频在线免费观看| 国产精品一二三区在线看| 国产成人精品福利久久| 国产成人福利小说| 中文字幕制服av| 日本与韩国留学比较| 亚洲国产色片| 日本黄大片高清| 一区二区三区四区激情视频| av在线app专区| 久久精品人妻少妇| 成年人午夜在线观看视频| 看免费成人av毛片| 国产高清国产精品国产三级 | 丝瓜视频免费看黄片| 哪个播放器可以免费观看大片| 亚洲精品成人av观看孕妇| 欧美激情久久久久久爽电影| 欧美性猛交╳xxx乱大交人| 国产淫语在线视频| 亚洲综合色惰| 欧美 日韩 精品 国产| 只有这里有精品99| 热99国产精品久久久久久7| 波野结衣二区三区在线| 久久精品综合一区二区三区| 涩涩av久久男人的天堂| 亚洲自拍偷在线| 日韩欧美精品免费久久| 久久精品国产亚洲av涩爱| 99九九线精品视频在线观看视频| 亚洲精品国产av蜜桃| 日韩av不卡免费在线播放| 2021少妇久久久久久久久久久| 高清午夜精品一区二区三区| 欧美激情在线99| 91精品一卡2卡3卡4卡| 国产国拍精品亚洲av在线观看| videos熟女内射| 亚洲欧美成人综合另类久久久| 麻豆乱淫一区二区| 成人毛片60女人毛片免费| 国产在视频线精品| 久热这里只有精品99| 看非洲黑人一级黄片| 国产中年淑女户外野战色| 亚洲最大成人中文| 久久人人爽人人爽人人片va| 欧美极品一区二区三区四区| 1000部很黄的大片| 天天躁日日操中文字幕| 小蜜桃在线观看免费完整版高清| 亚洲精品久久久久久婷婷小说| 婷婷色综合www| 搞女人的毛片| 久久久久久国产a免费观看| 欧美成人午夜免费资源| 亚洲电影在线观看av| 精品少妇久久久久久888优播| 日韩电影二区| 亚洲av.av天堂| 18禁动态无遮挡网站| 国产极品天堂在线| 毛片女人毛片| 白带黄色成豆腐渣| 国产精品精品国产色婷婷| 80岁老熟妇乱子伦牲交| 97超视频在线观看视频| 在线观看一区二区三区激情| 国产精品人妻久久久影院| 夜夜爽夜夜爽视频| 国产一区亚洲一区在线观看| 国产久久久一区二区三区| 亚洲欧美精品专区久久| 一级黄片播放器| 日日啪夜夜撸| 99热全是精品| 国产黄色免费在线视频| 高清欧美精品videossex| 久久女婷五月综合色啪小说 | 蜜桃亚洲精品一区二区三区| 国产黄色免费在线视频| 亚洲成人久久爱视频| 天堂中文最新版在线下载 | 欧美一级a爱片免费观看看| 99久久中文字幕三级久久日本| 久久精品国产鲁丝片午夜精品| 免费播放大片免费观看视频在线观看| 一级av片app| 深夜a级毛片| 欧美3d第一页| av播播在线观看一区| 麻豆精品久久久久久蜜桃| 亚洲av国产av综合av卡| 少妇人妻精品综合一区二区| 日韩av在线免费看完整版不卡| 乱系列少妇在线播放| 1000部很黄的大片| 亚洲精品日本国产第一区| 亚洲av日韩在线播放| av女优亚洲男人天堂| 国产高潮美女av| 国产 精品1| 亚洲一区二区三区欧美精品 | 久久99精品国语久久久| 国产乱来视频区| 男女啪啪激烈高潮av片| 日韩 亚洲 欧美在线| 天天躁夜夜躁狠狠久久av| 简卡轻食公司| 午夜福利高清视频| 人妻少妇偷人精品九色| 91久久精品电影网| 国产精品国产三级专区第一集| 亚洲精品第二区| 午夜福利在线在线| 国产乱来视频区| av在线观看视频网站免费| 少妇人妻精品综合一区二区| 亚洲激情五月婷婷啪啪| 国产黄色视频一区二区在线观看| 成人毛片a级毛片在线播放| 久久久久精品性色| 久久久久久九九精品二区国产| 在线免费十八禁| 久久久久久九九精品二区国产| 亚洲欧美中文字幕日韩二区| 亚洲精品aⅴ在线观看| 水蜜桃什么品种好| 久久精品人妻少妇| 免费在线观看成人毛片| 国产黄色免费在线视频| 午夜激情福利司机影院| 亚洲激情五月婷婷啪啪| 99热6这里只有精品| 国产精品福利在线免费观看| 亚洲美女搞黄在线观看| 一级毛片电影观看| 老司机影院毛片| 水蜜桃什么品种好| 一区二区av电影网| 午夜免费男女啪啪视频观看| 一区二区三区免费毛片| 国产极品天堂在线| 老师上课跳d突然被开到最大视频| 国产高清国产精品国产三级 | 日日撸夜夜添| 中国美白少妇内射xxxbb| 欧美日韩视频高清一区二区三区二| 精品少妇黑人巨大在线播放| 欧美激情在线99| 亚洲色图av天堂| 嫩草影院入口| 色网站视频免费| 午夜福利视频1000在线观看| 日本免费在线观看一区| 国产老妇伦熟女老妇高清| 国产免费一级a男人的天堂| 国产美女午夜福利| 久久99精品国语久久久| 美女视频免费永久观看网站| 少妇丰满av| 尤物成人国产欧美一区二区三区| 七月丁香在线播放| 免费少妇av软件| 欧美另类一区| 国产成人一区二区在线| 嫩草影院新地址| 亚洲色图av天堂| 一本久久精品| 大话2 男鬼变身卡| 久久精品夜色国产| 国产真实伦视频高清在线观看| 狠狠精品人妻久久久久久综合| 亚洲伊人久久精品综合| 精品久久久噜噜| 激情五月婷婷亚洲| 中国美白少妇内射xxxbb| 日本爱情动作片www.在线观看| 三级经典国产精品| 久久久久九九精品影院| 欧美精品一区二区大全| 国产乱来视频区| 美女主播在线视频| 亚洲天堂国产精品一区在线| 大片电影免费在线观看免费| 新久久久久国产一级毛片| 亚洲欧美日韩无卡精品| 国产欧美日韩一区二区三区在线 | www.色视频.com| 午夜精品一区二区三区免费看| 一级毛片电影观看| 亚洲在久久综合| videossex国产| 欧美精品一区二区大全| 日本黄色片子视频| 精品久久久久久电影网| 午夜精品一区二区三区免费看| 综合色av麻豆| 九草在线视频观看| 日本一二三区视频观看| 日韩av不卡免费在线播放| 亚洲精品中文字幕在线视频 | 美女高潮的动态| 国产精品无大码| 亚洲精品一区蜜桃| 在线观看三级黄色| 亚洲精华国产精华液的使用体验| 精品少妇久久久久久888优播| 亚洲经典国产精华液单| 亚洲精品日本国产第一区| 免费看a级黄色片| 别揉我奶头 嗯啊视频| 又粗又硬又长又爽又黄的视频| 亚洲欧美成人精品一区二区| 69av精品久久久久久| 制服丝袜香蕉在线| 建设人人有责人人尽责人人享有的 | 狂野欧美白嫩少妇大欣赏| 亚洲熟女精品中文字幕| 精品人妻一区二区三区麻豆| 国产亚洲午夜精品一区二区久久 | 精品少妇久久久久久888优播| 亚洲成色77777| 午夜激情福利司机影院| 国产精品人妻久久久影院|