The process of disposing of expanded polystyrene (EPS) is by burning it in municipal incinerators. This process gives off EPS microplastics, which can find their way into water, food, blood, and major organ systems. Z...The process of disposing of expanded polystyrene (EPS) is by burning it in municipal incinerators. This process gives off EPS microplastics, which can find their way into water, food, blood, and major organ systems. Zophobas morio larvae are capable of consuming and breaking down EPS within their digestive tracts by minimizing the spread of microplastics. Studies of the consumption of EPS by Z. morio larvae are typically conducted under white or no visible light treatments. This study tested whether the color of visible light influenced the consumption rate of EPS by Z. morio larvae. If Z. morio larvae consume EPS under visible light, then visible light will influence the amount of EPS consumed. If results suggest that the consumption rate is influenced by visible light colors, then Z. morio larvae could be a solution for recycling EPS. This study’s procedure placed Z. morio larvae into 25 jars under one of six visible light treatments of red, yellow, green, blue, white, and no visible light. Each jar contained a pre-weighed block of EPS and six Z. morio larvae. After two weeks, the Z. morio larvae were removed from the jars, and the difference between each pre-weighed EPS block and the weight of the same partially consumed block was recorded in three trials. The data indicates that green and blue visible light treatments resulted in the greatest amount of EPS consumed by Z. morio larvae while the red and yellow had the least amount of EPS consumed by the Z. morio larvae. In conclusion, results indicate that green and blue visible light, compared to the no visible light treatment, could be used to influence the Z. morio larvae to consume more EPS. Green and blue visible light and Z. morio larvae could make the recycling process of EPS more environmentally friendly when used in households or by local environmental organizations.展开更多
The interaction between nanoparticles (NPs) and pollutants affects their bioavailability and toxicity.However,the processes by which NPs and pollutants change in vivo have rarely been explored.Here,using laser ablatio...The interaction between nanoparticles (NPs) and pollutants affects their bioavailability and toxicity.However,the processes by which NPs and pollutants change in vivo have rarely been explored.Here,using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS),we found that both nanoplastics and ZnO NPs caused more Cd to accumulate in zebrafish larvae,but with distinct pathways.Nanoplastics could adsorb Cd^(2+) and transfer it into the larvae through the“Trojan horse”effect.The coexposure of nanoplastics and Cd^(2+) caused Cd to accumulate in the abdomen where the nanoplastics were located without dissociation,showing a lower toxic effect than Cd^(2+) exposure alone.ZnO NPs weakly adsorbed Cd^(2+),but they increased the Zn and Cd contents in larvae by enhancing the expression of metal transporters.The coexposure of ZnO and Cd^(2+) evenly distributed Cd in the larvae,revealing a more severe toxic effect than Cd^(2+) exposure alone.Our results demonstrated the changing bioavailability and toxicity of Cd induced by different NPs.This also shows the vital role LA-ICP-MS plays in revealing the relationship between toxicity and bioavailability.In addition,the long-term effect of bioavailability on heavy metal toxicity and nanosafety deserves further investigation.展开更多
Background Black soldier fly larvae meal(BSFLM)stands out as a promising nutritional resource due to its rich bioactive substances and favorable protein profile.Nonetheless,its potential to mitigate coccidia infection...Background Black soldier fly larvae meal(BSFLM)stands out as a promising nutritional resource due to its rich bioactive substances and favorable protein profile.Nonetheless,its potential to mitigate coccidia infection in broilers remains uncertain.This study aimed to evaluate the impact of partially defatted BSFLM(pBSFLM)on growth performance,nutrient utilization,and intestinal health,focusing on morphology,immunology,and cecal fermentation in coccidia-infected broilers.Methods Over the initial 13 d,480 newly-hatched Cobb 500 male birds were allocated to three diets with increasing pBSFLM concentrations(0,60,or 120 g/kg).At d 13 post hatching,chicks within each dietary group were further allotted to non-challenge or challenge subsets,generating six treatments in a 3×2 factorial arrangement.Challenged birds were orally administered oocysts of E.maxima,E.acervulina,and E.tenella(25,000:125,000:25,000).Results During the infection phase(d 13 to 19),linear interactions between Eimeria and pBSFLM were observed in gain to feed ratio(G:F)(P<0.05)and cecal interferon-γ(IFN-γ,P<0.05),with a tendency in cecal acetate concentration(P=0.06).A quadratic interaction was observed in crypt depth(CD,P<0.05).Incremental pBSFLM inclusion negatively affected G:F,CD,IFN-γ,and acetate productions in the ceca under coccidia challenge.Conversely in nonchallenged birds,the impact of pBSFLM varied from neutral(e.g.G:F)to potentially advantageous(e.g.acetate).Challenged birds exhibited decreased(P<0.01)BW,BW gain,feed intake(FI),and the apparent ileal digestibility and total tract nutrient utilization of DM,gross energy,and nitrogen(N).Eimeria challenge reduced(P<0.01)serum carotenoid concentrations,decreased the villus height to crypt depth ratio(VH:CD,P<0.01),and increased concentrations of branched-chain fatty acids,specifically isobutyrate(P=0.059)and isovalerate(P<0.05)in the cecum.Dietary pBSFLM addition linearly reduced(P<0.05)BW,FI,and N utilization.Tendencies(P<0.06)were observed where pBSFLM linearly decreased VH:CD and reduced goblet cell density.Conclusions Increasing pBSFLM supplementation,particularly at 12%,adversely affected growth,ileal morphology,cecal acetate production,and downregulated key cytokine expression in response to coccidia infection.展开更多
The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while tre...The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food chain.However,the performance of this technology in terms of its environmental impacts is still unclear,particularly with regards to global warming potential(GWP).This study used a life cycle assessment(LCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per day.The LCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,respectively.The greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more power.The main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).展开更多
[Objectives]The paper was to screen effective biocontrol strains against Meloidogyne incognita.[Methods]The effect of six bacterial strains sourced from the research group s strain library on the activity of second in...[Objectives]The paper was to screen effective biocontrol strains against Meloidogyne incognita.[Methods]The effect of six bacterial strains sourced from the research group s strain library on the activity of second instar larvae of M.incognita,as well as on egg hatching,was evaluated.[Results]The treatment of fermentation supernatant derived from the X-2 strain exhibited a pronounced lethal effect on M.incognita,with a corrected mortality rate reaching 97%within 72 h.Additionally,this treatment significantly inhibited egg hatching,achieving an inhibition rate of 94.69%at a 20-fold dilution.The strain was identified as Bacillus velezensis,belonging to the genus Bacillus,and was designated as RKN1111.[Conclusions]This study presents alternative strains and a theoretical framework for the biological control of M.incognita.展开更多
[ Objective ] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [ Method ] The heterobacteria, vibr...[ Objective ] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [ Method ] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were monitored in larvae industrialized culture system. [ Result] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were the most in fertilized eggs of shrimp but the least in nauplius, then their number would increase with growth. During whole rearing period, both boterobacteria in larvae, vibrios in water would increase by one order of magnitude, while both vibrios in larvae and heterobacteria in water would increase by two orders of magnitude. There were many heterobacteria and vibrios but few vibrio parahaemolyticus in living bait. The correlation coefficients between larvae and heterobacteria and vibrios in water were 0. 704 and 0. 840 in culture system respectively, while the correlation among heterobacteria, vibrios in living bait and larvae, water were weak or negative. [ Conclusion ] There was a dynamic relation between water and larvae in rearing period, and restrictly control of culture condition would restrain the occurrence of disease caused by vibrio parahaemolyticus, besides that bacteria number in bait was not obviously correlated with bacteria nubmer in culture system.展开更多
[Objective] The aim was to explore key technology to cultivate Holotdchia diomphalia larvae with Agaricus bisporus residues and to provide, technologicar sup- ports for processing of Agaricus bisporus residues. [Metho...[Objective] The aim was to explore key technology to cultivate Holotdchia diomphalia larvae with Agaricus bisporus residues and to provide, technologicar sup- ports for processing of Agaricus bisporus residues. [Method] In the research, fodder thickness, population density and residues under different treatments were set to re- search effects on Holotrichia diomphalia larvae. [Result] The optimal thickness of fodder was 25 cm and the optimal feeding density was 44-56 larvae per hectare. The dry residues were more suitable, compared with decomposed residues and corn bran powders, for cultivation of Holotrichia diomphalia larvae. [Conclusion] Cultivation of Holotrichia diomphalia larvae with Agaricus bisporus residues is a new method to make use of Agaricus bisporus residues and of significance for extension of agricul- tural circulation chain, increase of economic benefits and ecological benefits.展开更多
The development of methods for the efficient treatment and application of food waste digestate is an important research goal.Vermicomposting via housefly larvae is an efficient way to reduce food waste and achieve its...The development of methods for the efficient treatment and application of food waste digestate is an important research goal.Vermicomposting via housefly larvae is an efficient way to reduce food waste and achieve its valorization,however,studies on the application and performance of digestate in vermicomposting are rarely.The present study aimed to investigate the feasibility of the co-treatment of food waste and digestate as an additive via larvae.Restaurant food waste(RFW)and household food waste(HFW)were selected to assess the effects of waste type on vermicomposting performance and larval quality.Waste reduction rates of 50.9%–57.8%were observed in the vermicomposting of food waste mixed with digestate at a ratio of 25%,which were slightly lower than those for treatments without the addition of digestate(62.8%–65.9%).The addition of digestate increased the germination index,with a maximum value of 82%in the RFW treatments with 25%digestate,and decreased the respiration activity,with a minimum value of 30 mg-O_(2)/g-TS.The larval productivity of 13.9%in the RFW treatment system with a digestate rate of 25%was lower that without digestate(19.5%).Materials balance shows that larval biomass and metabolic equivalent had decreasing trends as the amount of digestate increased and HFW vermicomposting exhibited lower bioconversion efficiency than that of RFW treatment system regardless of the addition of digestate.These results suggest that mixing digestate at a low ratio(25%)during vermicomposting of foodwaste especially RFW could lead to considerable larval biomass and generate relatively stable residues.展开更多
In order to control the spawning quality and improve the economic benefit of Apostichopus japonicus Selenka, the indoor temperature and light control methods were employed for artificial maturation, spawning and hatch...In order to control the spawning quality and improve the economic benefit of Apostichopus japonicus Selenka, the indoor temperature and light control methods were employed for artificial maturation, spawning and hatching of A. japonicus, and the larval survival rate, disease incidence rate and economic benefit were analyzed. The results showed that compared with those of conventional temperature-reared larvae, the survival rate of raised temperature-reared larvae was increased by 15.8%, the disease incidence rate was reduced by 10.2%, and the economic benefit was improved by 21.6%. These results will provide theoretical basis and technical support for the artificial breeding of A. japonicus.展开更多
A chironomid larvae images recognition method based on wavelet energy feature and improved KNN is developed. Wavelet decomposition and color information entropy are selected to construct vectors for KNN that is used t...A chironomid larvae images recognition method based on wavelet energy feature and improved KNN is developed. Wavelet decomposition and color information entropy are selected to construct vectors for KNN that is used to classify of the images. The distance function is modified according to the weight determined by the correlation degree between feature and class, which effectively improves classification accuracy. The result shows the mean accuracy of classification rate is up to 95.41% for freshwater plankton images, such as chironomid larvae, cyclops and harpacticoida.展开更多
Background:The possibility of partially replacing soybean meal(SBM)with Hermetia illucens(HI)defatted larvae meal in broiler nutrition has frequently been suggested.For sustainability reasons,however,the larvae fat pr...Background:The possibility of partially replacing soybean meal(SBM)with Hermetia illucens(HI)defatted larvae meal in broiler nutrition has frequently been suggested.For sustainability reasons,however,the larvae fat produced during defatting should also be used and could be particularly beneficial regarding gut health due to its fatty acid composition.To evaluate the suitability of HI larvae as protein and fat source,a 2×3 factorial arrangement with two types of protein,i.e.SBM(S)or SBM and 15%of its crude protein replaced by HI larvae meal(L),and three levels of fat sources,namely 0(0 L),50%(50 L)or 100%HI larvae fat(100 L)at the expense of soybean oil was applied.Results:In the starter phase,an interaction showed higher body weight(BW),average daily gain(ADG)and improved feed conversion ratio(FCR)if 50%or 100%HI larvae fat was fed with HI larvae meal.Moreover,BW,ADG and FCR improved when feeding HI larvae meal as protein source.Additionally,we observed an increased average daily feed intake in the grower,finisher,and overall phase in the L groups and an improved FCR in 0 L compared to 50 L groups during the overall period.Regarding apparent ileal digestibility,HI larvae meal feeding increased dry matter,organic matter,and fat digestibility.Feeding HI larvae meal as protein source decreased the concentrations of agmatine,spermidine,spermine and ammonia in the caecal digesta,whereas fat source affected agmatine with higher concentrations in 50 L compared to 0 L in the colonic digesta.In contrast,caecal ethanolamine concentrations increased in HI larvae meal groups compared to SBM.Caecal butyric acid concentrations decreased with HI larvae meal feeding.An interaction was found for the jejunal villus area,being higher in L+100 L compared to S+100 L.Furthermore,L groups had greater villus width.Conclusions:A partial replacement of SBM with HI larvae meal and soybean oil with HI larvae fat in broiler diets without impairing animal performance or gut health seems possible.Feeding HI larvae meal affected broiler performance positively in the starter phase and improved apparent ileal digestibility.展开更多
Background: Insects, such as Hermetia illucens larvae, are rich in chitin and proteins, and represent a suitable feed ingredient replacement for animals. However, little is known about the effect of administering H. i...Background: Insects, such as Hermetia illucens larvae, are rich in chitin and proteins, and represent a suitable feed ingredient replacement for animals. However, little is known about the effect of administering H. illucens larvae on intestinal microbiota, bacterial metabolite profiles, and mucosal immune status in animals. This study aimed to investigate the effects of administering H. illucens larvae on colonic microbiota and bacterial metabolites production in finishing pigs. Seventy-two crossbred(Duroc × Landrace × Large White) female pigs(initial body weight, 76.0 ± 0.52 kg) were randomly allocated to three different dietary treatments: a control diet(Control group) and two diets corresponding to 4%(H1 group) and 8%(H2 group) H. illucens larvae inclusion levels, respectively. Each treatment consisted of eight pens(replicates), with three pigs per pen. After 46 days of feeding, eight pigs per treatment(n =8) were slaughtered, and the colonic digesta and mucosa were collected for microbial composition and microbial fermentation products, and genes expression analyses.Results: The results showed that the H1 diet significantly increased the abundance of Lactobacillus,Pseudobutyrivibrio, Roseburia, and Faecalibacterium compared with those in the control group(P < 0.05), with a decrease in the abundance of Streptococcus. The numbers of Lactobacillus, Roseburia, and Clostridium cluster XIVa were significantly greater in the H1 group than in the control group(P < 0.05). Meanwhile, H2 diet increased the number of Clostridium cluster XIVa compared with the control group(P < 0.05). For colonic metabolites, total short chain fatty acids, butyrate, and isobutyrate concentrations were significantly higher in the H1 group than those in the control group(P < 0.05);the H1 treatment caused a striking decrease in protein fermentation compared with the control group, as the concentrations of total amines, cadaverine, tryptamine, phenol, p-cresol, and skatole were significantly lower(P < 0.05). Additionally, H2 diet also increased butyrate concentration compared with control group(P < 0.05), while decreased the concentrations of phenol, p-cresol, and skatole(P < 0.05). Pigs in the H1 group down-regulated the expression of TLR-4 and pro-inflammatory cytokines(IFN-γ) compared with pigs in the control group(P < 0.05), and up-regulated anti-inflammatory cytokine(IL-10) and intestinal barrier genes(ZO-1, occludin, and mucin-1). H2 diet up-regulated the expression of ZO-1 compared with control group(P < 0.05). Furthermore, the changes in the colonic mucosal gene expression were associated with changes in the bacterial composition and their metabolites.Conclusions: Collectively, dietary inclusion of Hermetia illucens larvae may enhance mucosal immune homeostasis of pigs via altering bacterial composition and their metabolites. These findings provide a new perspective on insect meal as a sustainable protein source rich in nutrient ingredients for swine.展开更多
The microscale distribution of oxygen,the nitrogen flux and the denitrification rates in sediment inhabited by chironomid larvae（Tanypus chinensis） were measured in eutrophic Lake Taihu,China.The presence of the chi...The microscale distribution of oxygen,the nitrogen flux and the denitrification rates in sediment inhabited by chironomid larvae（Tanypus chinensis） were measured in eutrophic Lake Taihu,China.The presence of the chironomids in the sediment increased the oxygen diffusional flux from 10.4 ± 1.4 to 12.7 ± 2.5 mmol O 2 /（m 2 ·day）.The burrows of the larvae represented ＂hot spots＂ and strongly influenced the nitrogen cycles and diagenetic activity in the sediment.The results indicate that the bioturbation effects of Tanypus chinensis chironomid larvae increased the capacity of the sediment as a sink for nitrate and a source for ammonium.Nitrate influx and ammonium outflux were increased 8.8 and 1.7 times,respectively.Under bioturbation,the amount of nitrate consumed was greater than the amount of ammonium released.The total denitrification rate was also enhanced from 0.76 ± 0.34 to 5.50 ± 1.30 mmol N/（m 2 ·day）.The net effect was that the bioturbated sediments acted as a net sink for inorganic nitrogen under direct and indirect bioturbation effects compared to the control.展开更多
In order to improve production and breed new broods of bay scallop Argopecten irradians irradians, different-colored orange, purple and white lines were established by two mating methods of self-fertilization and mass...In order to improve production and breed new broods of bay scallop Argopecten irradians irradians, different-colored orange, purple and white lines were established by two mating methods of self-fertilization and mass spawning at a commercial scallop hatchery in spring, 2002. And then larval growth and survival of different lines was compared to test whether there is a relationship between shell color and growth and survival at early developmental stage. Both growth and survival have no significant differences among different experimental larvae of self-fertilization or mass spawning. Results are as following in the order of orange, purple and white shell stock. For the self-fertilization, growth rates of larvae were 6.174, 6.412, and 6.599 μm/d, respectively. Survival rates of larvae at Day 3 were 74.41%, 76.86%, and 82.05%; Day 6 were 49.14%, 65.63%, and 52.79%; and Day 9 were 25.06%, 20.80%, and 26.47%, respectively. For the mass spawning, the growth rates were 7.836, 7.941, and 7.878 μm/d, respectively. Survival rates at Day 3 were 93.05%, 91.95%, and 92.50%; Day 6 were 79.17%, 78.05%, and 82.50%; and Day 9 were 34.72%, 36.67%, and 38.33%, respectively. The absence of any relationship between shell color and growth and survival at the larval stage may be resulted from their common genetic basis.展开更多
During the First Chinese Antarctic Expedition zooplankton samples were collected at each of the oceanography stations in the waters around South Sheltland Islands (S. S. Is.) and in the northern part of the Bellinshau...During the First Chinese Antarctic Expedition zooplankton samples were collected at each of the oceanography stations in the waters around South Sheltland Islands (S. S. Is.) and in the northern part of the Bellinshausen Sea from 20 January to 12 February, 1985 by vertical tows of an 80 cm diameter conical net from 200 m to surface. Two deep tows with a closing net. were performed in slope water north of S.S. Is, and in the basin of Bransfield Strait. Eggs and larvae of Euphatisia superba Dana in zooplankton samples were identified and counted.There were four records of eggs from 27 stations. Most catches were of small number and restricted to within the nearshore area south of S.S Is.The largest number (1500/1000 cubic meters )was found in the outer side of Smith Island.No Nauplius was found . The earliest stage we found 【was Metanauplius , in two deep tows. The distribution of Calyptopis MI and Furcili I-III were quite similar. They were found mainly in three areas: 1 ) nearshore water along the展开更多
Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact ...Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact of effluents from the firms.Methods:Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry(AAS).Results:Cx.quinquefasciatus was the most abundant species followed by Cx.gelidus.The levels of lead were higher in the Cx.quinquefasciatus(1.08-47.47μg/g),than in the wastewaters surface(0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the.criteria for lead determination.Conclusions:The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination,to complemente conventional techniques.展开更多
In laboratory conditions,effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively.Data series like larval ...In laboratory conditions,effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively.Data series like larval length and density,metamorphic time,and survival rate of the larvae were recorded.Statistics showed that for A.japonicus,survival rate(from fertilized egg to late auricularia) decreased significantly with the increasing rearing temperature(P<0.05).At different temperatures SGR was statistically significant as well(P<0.05) from day 1,and maximal SGR was found on day 9 at 24℃(159.26±3.28).This study clearly indicated that at low temperature(<24℃),metamorphic rate was remarkably higher than at higher temperature(>26℃).Hatching rate was significantly different between 0.2-5 ind./ml groups and 20-50 ind./ml groups.Rearing larvae at the higher density had the smaller maximal-length,whereas needed longer time to complete metamorphosis.This study suggested that 21℃ and 0.4 ind./ml can be used as the most suitable rearing temperature and stocking density for large-scale artificial breeding of A.japonicus's larvae.展开更多
As the most widely used plasticizers in the world, phthalate esters （PAEs） are potential endocrine disruption compounds （EDCs）. In the present study, the toxicity of dimethyl phthalate （DMP）, diethyl phthalate ...As the most widely used plasticizers in the world, phthalate esters （PAEs） are potential endocrine disruption compounds （EDCs）. In the present study, the toxicity of dimethyl phthalate （DMP）, diethyl phthalate （DEP）, dibutyl phthalate （DBP）, di （2-ethylhexyl） phthalate （DEHP） on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMR DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP〉DEP〉DMP〉DEHE Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.展开更多
The major population of the veined rapa whelk Rapana venosa （Valenciennes, 1846）, which is an important fishery resource, is facing a large decline in China. We studied the effects of incubation temperature （16-34...The major population of the veined rapa whelk Rapana venosa （Valenciennes, 1846）, which is an important fishery resource, is facing a large decline in China. We studied the effects of incubation temperature （16-34℃ at salinity 30） and salinity （5-45 at 25℃） on the incubation period and subsequent larval development. In the temperature experiment, the shortest incubation period was 12 days at 34℃, the lower temperature limit was 16~C, the longest mean shell length （1 193＋17 pan） occurred at 25℃ and the highest survival rate 72.28%＋5.62% was observed at 28℃. In the salinity experiment, the shortest incubation period was 15 days at 25. The salinity tolerance range was 15-40, the longest mean shell length （855-4-9 μm） and the highest survival rate 72.93%~4.85% were both observed at 35. This study demonstrated that, during the egg-mass stage, temperature and salinity regimes influence later growth and survival of larvae. These observations deepen our understanding of the ecology and conservation of natural populations of Rapana venosa.展开更多
The activities of some digestive enzymes are studied for Takifugu rubripes larvae and juvenile from the first feeding to 27 d after hatching at selected stages of development. The homogenate of whole larvae body is us...The activities of some digestive enzymes are studied for Takifugu rubripes larvae and juvenile from the first feeding to 27 d after hatching at selected stages of development. The homogenate of whole larvae body is used for enzymatic determination. Activity of acid protease decreases notably during the beginning days after the commencement of completely exogenous feeding and the days before the beginning of the juvenile stage. Alkaline protease specific activity also decreases at metamorphosis. The activities are associated with the morphology of the developing digestive tract. Amylase activity increases before the first feeding, followed by a decreasing and then a rather constant level. Lipase activity remains low during the larvae and juvenile periods. Alkaline phosphatase activity increases gradually. This reflects the development of brush border membranes of enterocytes.展开更多
文摘The process of disposing of expanded polystyrene (EPS) is by burning it in municipal incinerators. This process gives off EPS microplastics, which can find their way into water, food, blood, and major organ systems. Zophobas morio larvae are capable of consuming and breaking down EPS within their digestive tracts by minimizing the spread of microplastics. Studies of the consumption of EPS by Z. morio larvae are typically conducted under white or no visible light treatments. This study tested whether the color of visible light influenced the consumption rate of EPS by Z. morio larvae. If Z. morio larvae consume EPS under visible light, then visible light will influence the amount of EPS consumed. If results suggest that the consumption rate is influenced by visible light colors, then Z. morio larvae could be a solution for recycling EPS. This study’s procedure placed Z. morio larvae into 25 jars under one of six visible light treatments of red, yellow, green, blue, white, and no visible light. Each jar contained a pre-weighed block of EPS and six Z. morio larvae. After two weeks, the Z. morio larvae were removed from the jars, and the difference between each pre-weighed EPS block and the weight of the same partially consumed block was recorded in three trials. The data indicates that green and blue visible light treatments resulted in the greatest amount of EPS consumed by Z. morio larvae while the red and yellow had the least amount of EPS consumed by the Z. morio larvae. In conclusion, results indicate that green and blue visible light, compared to the no visible light treatment, could be used to influence the Z. morio larvae to consume more EPS. Green and blue visible light and Z. morio larvae could make the recycling process of EPS more environmentally friendly when used in households or by local environmental organizations.
基金financially supported by the National Natural Science Foundation of China(NSFC,Nos.22174103 and 21575107)。
文摘The interaction between nanoparticles (NPs) and pollutants affects their bioavailability and toxicity.However,the processes by which NPs and pollutants change in vivo have rarely been explored.Here,using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS),we found that both nanoplastics and ZnO NPs caused more Cd to accumulate in zebrafish larvae,but with distinct pathways.Nanoplastics could adsorb Cd^(2+) and transfer it into the larvae through the“Trojan horse”effect.The coexposure of nanoplastics and Cd^(2+) caused Cd to accumulate in the abdomen where the nanoplastics were located without dissociation,showing a lower toxic effect than Cd^(2+) exposure alone.ZnO NPs weakly adsorbed Cd^(2+),but they increased the Zn and Cd contents in larvae by enhancing the expression of metal transporters.The coexposure of ZnO and Cd^(2+) evenly distributed Cd in the larvae,revealing a more severe toxic effect than Cd^(2+) exposure alone.Our results demonstrated the changing bioavailability and toxicity of Cd induced by different NPs.This also shows the vital role LA-ICP-MS plays in revealing the relationship between toxicity and bioavailability.In addition,the long-term effect of bioavailability on heavy metal toxicity and nanosafety deserves further investigation.
文摘Background Black soldier fly larvae meal(BSFLM)stands out as a promising nutritional resource due to its rich bioactive substances and favorable protein profile.Nonetheless,its potential to mitigate coccidia infection in broilers remains uncertain.This study aimed to evaluate the impact of partially defatted BSFLM(pBSFLM)on growth performance,nutrient utilization,and intestinal health,focusing on morphology,immunology,and cecal fermentation in coccidia-infected broilers.Methods Over the initial 13 d,480 newly-hatched Cobb 500 male birds were allocated to three diets with increasing pBSFLM concentrations(0,60,or 120 g/kg).At d 13 post hatching,chicks within each dietary group were further allotted to non-challenge or challenge subsets,generating six treatments in a 3×2 factorial arrangement.Challenged birds were orally administered oocysts of E.maxima,E.acervulina,and E.tenella(25,000:125,000:25,000).Results During the infection phase(d 13 to 19),linear interactions between Eimeria and pBSFLM were observed in gain to feed ratio(G:F)(P<0.05)and cecal interferon-γ(IFN-γ,P<0.05),with a tendency in cecal acetate concentration(P=0.06).A quadratic interaction was observed in crypt depth(CD,P<0.05).Incremental pBSFLM inclusion negatively affected G:F,CD,IFN-γ,and acetate productions in the ceca under coccidia challenge.Conversely in nonchallenged birds,the impact of pBSFLM varied from neutral(e.g.G:F)to potentially advantageous(e.g.acetate).Challenged birds exhibited decreased(P<0.01)BW,BW gain,feed intake(FI),and the apparent ileal digestibility and total tract nutrient utilization of DM,gross energy,and nitrogen(N).Eimeria challenge reduced(P<0.01)serum carotenoid concentrations,decreased the villus height to crypt depth ratio(VH:CD,P<0.01),and increased concentrations of branched-chain fatty acids,specifically isobutyrate(P=0.059)and isovalerate(P<0.05)in the cecum.Dietary pBSFLM addition linearly reduced(P<0.05)BW,FI,and N utilization.Tendencies(P<0.06)were observed where pBSFLM linearly decreased VH:CD and reduced goblet cell density.Conclusions Increasing pBSFLM supplementation,particularly at 12%,adversely affected growth,ileal morphology,cecal acetate production,and downregulated key cytokine expression in response to coccidia infection.
基金supported by the National Key Research and Development Program of China(No.2018YFD1100600)Shanghai Municipal Government State-Owned Assets Supervision and Administration Commission(No.2022028)。
文摘The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food chain.However,the performance of this technology in terms of its environmental impacts is still unclear,particularly with regards to global warming potential(GWP).This study used a life cycle assessment(LCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per day.The LCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,respectively.The greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more power.The main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).
基金Supported by Key R&D Project of Science&Technology Department of Ningxia Hui Autonomous Region(2021BBF02013)Post-doctoral Program of Hebei Province(2019003011)Hebei Province Innovation Ability Enhancement Plan Project(225676109H).
文摘[Objectives]The paper was to screen effective biocontrol strains against Meloidogyne incognita.[Methods]The effect of six bacterial strains sourced from the research group s strain library on the activity of second instar larvae of M.incognita,as well as on egg hatching,was evaluated.[Results]The treatment of fermentation supernatant derived from the X-2 strain exhibited a pronounced lethal effect on M.incognita,with a corrected mortality rate reaching 97%within 72 h.Additionally,this treatment significantly inhibited egg hatching,achieving an inhibition rate of 94.69%at a 20-fold dilution.The strain was identified as Bacillus velezensis,belonging to the genus Bacillus,and was designated as RKN1111.[Conclusions]This study presents alternative strains and a theoretical framework for the biological control of M.incognita.
基金the National High Technology Research and Development Program of China (863 Program) (2006AA10A406)National Key Technology Research and Development Program of China (2006BAD01A13)Public Agriculture Specific Research Program (nyhyzx07-042)~~
文摘[ Objective ] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [ Method ] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were monitored in larvae industrialized culture system. [ Result] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were the most in fertilized eggs of shrimp but the least in nauplius, then their number would increase with growth. During whole rearing period, both boterobacteria in larvae, vibrios in water would increase by one order of magnitude, while both vibrios in larvae and heterobacteria in water would increase by two orders of magnitude. There were many heterobacteria and vibrios but few vibrio parahaemolyticus in living bait. The correlation coefficients between larvae and heterobacteria and vibrios in water were 0. 704 and 0. 840 in culture system respectively, while the correlation among heterobacteria, vibrios in living bait and larvae, water were weak or negative. [ Conclusion ] There was a dynamic relation between water and larvae in rearing period, and restrictly control of culture condition would restrain the occurrence of disease caused by vibrio parahaemolyticus, besides that bacteria number in bait was not obviously correlated with bacteria nubmer in culture system.
基金Supported by the National Key Technology R&D Program (2007BAD89B09-10)National Public Service Project (200803033-A0903)~~
文摘[Objective] The aim was to explore key technology to cultivate Holotdchia diomphalia larvae with Agaricus bisporus residues and to provide, technologicar sup- ports for processing of Agaricus bisporus residues. [Method] In the research, fodder thickness, population density and residues under different treatments were set to re- search effects on Holotrichia diomphalia larvae. [Result] The optimal thickness of fodder was 25 cm and the optimal feeding density was 44-56 larvae per hectare. The dry residues were more suitable, compared with decomposed residues and corn bran powders, for cultivation of Holotrichia diomphalia larvae. [Conclusion] Cultivation of Holotrichia diomphalia larvae with Agaricus bisporus residues is a new method to make use of Agaricus bisporus residues and of significance for extension of agricul- tural circulation chain, increase of economic benefits and ecological benefits.
基金This work is supported by the National Key R&D Program of China(No.2018YFD1100600).The authors appreciate Ms.Ning Zhang,Mr.WeiWang,and Mr.Jing Guo for their assistances in analysis.
文摘The development of methods for the efficient treatment and application of food waste digestate is an important research goal.Vermicomposting via housefly larvae is an efficient way to reduce food waste and achieve its valorization,however,studies on the application and performance of digestate in vermicomposting are rarely.The present study aimed to investigate the feasibility of the co-treatment of food waste and digestate as an additive via larvae.Restaurant food waste(RFW)and household food waste(HFW)were selected to assess the effects of waste type on vermicomposting performance and larval quality.Waste reduction rates of 50.9%–57.8%were observed in the vermicomposting of food waste mixed with digestate at a ratio of 25%,which were slightly lower than those for treatments without the addition of digestate(62.8%–65.9%).The addition of digestate increased the germination index,with a maximum value of 82%in the RFW treatments with 25%digestate,and decreased the respiration activity,with a minimum value of 30 mg-O_(2)/g-TS.The larval productivity of 13.9%in the RFW treatment system with a digestate rate of 25%was lower that without digestate(19.5%).Materials balance shows that larval biomass and metabolic equivalent had decreasing trends as the amount of digestate increased and HFW vermicomposting exhibited lower bioconversion efficiency than that of RFW treatment system regardless of the addition of digestate.These results suggest that mixing digestate at a low ratio(25%)during vermicomposting of foodwaste especially RFW could lead to considerable larval biomass and generate relatively stable residues.
文摘In order to control the spawning quality and improve the economic benefit of Apostichopus japonicus Selenka, the indoor temperature and light control methods were employed for artificial maturation, spawning and hatching of A. japonicus, and the larval survival rate, disease incidence rate and economic benefit were analyzed. The results showed that compared with those of conventional temperature-reared larvae, the survival rate of raised temperature-reared larvae was increased by 15.8%, the disease incidence rate was reduced by 10.2%, and the economic benefit was improved by 21.6%. These results will provide theoretical basis and technical support for the artificial breeding of A. japonicus.
基金Supported by the National Natural Science Foundation of China(50778048)(60803096)the Natural Science Foundation of Hei-longjiang Province(E200812)China Postdoctoral ScienceFoundation Funded Project(20070420882)~~
文摘A chironomid larvae images recognition method based on wavelet energy feature and improved KNN is developed. Wavelet decomposition and color information entropy are selected to construct vectors for KNN that is used to classify of the images. The distance function is modified according to the weight determined by the correlation degree between feature and class, which effectively improves classification accuracy. The result shows the mean accuracy of classification rate is up to 95.41% for freshwater plankton images, such as chironomid larvae, cyclops and harpacticoida.
基金supported by the Federal Ministry Republic of Austria,Agriculture,Regions and Tourism(LE 14-20,Application number 16.1.1-S2-23/18 and 16.2.1.-S2-23/18),within an EIP-Project.
文摘Background:The possibility of partially replacing soybean meal(SBM)with Hermetia illucens(HI)defatted larvae meal in broiler nutrition has frequently been suggested.For sustainability reasons,however,the larvae fat produced during defatting should also be used and could be particularly beneficial regarding gut health due to its fatty acid composition.To evaluate the suitability of HI larvae as protein and fat source,a 2×3 factorial arrangement with two types of protein,i.e.SBM(S)or SBM and 15%of its crude protein replaced by HI larvae meal(L),and three levels of fat sources,namely 0(0 L),50%(50 L)or 100%HI larvae fat(100 L)at the expense of soybean oil was applied.Results:In the starter phase,an interaction showed higher body weight(BW),average daily gain(ADG)and improved feed conversion ratio(FCR)if 50%or 100%HI larvae fat was fed with HI larvae meal.Moreover,BW,ADG and FCR improved when feeding HI larvae meal as protein source.Additionally,we observed an increased average daily feed intake in the grower,finisher,and overall phase in the L groups and an improved FCR in 0 L compared to 50 L groups during the overall period.Regarding apparent ileal digestibility,HI larvae meal feeding increased dry matter,organic matter,and fat digestibility.Feeding HI larvae meal as protein source decreased the concentrations of agmatine,spermidine,spermine and ammonia in the caecal digesta,whereas fat source affected agmatine with higher concentrations in 50 L compared to 0 L in the colonic digesta.In contrast,caecal ethanolamine concentrations increased in HI larvae meal groups compared to SBM.Caecal butyric acid concentrations decreased with HI larvae meal feeding.An interaction was found for the jejunal villus area,being higher in L+100 L compared to S+100 L.Furthermore,L groups had greater villus width.Conclusions:A partial replacement of SBM with HI larvae meal and soybean oil with HI larvae fat in broiler diets without impairing animal performance or gut health seems possible.Feeding HI larvae meal affected broiler performance positively in the starter phase and improved apparent ileal digestibility.
基金supported by the Presidential Foundation of the Guangdong Academy of Agricultural Sciences(201802B,201621)Guangdong Modern Agro-industry Technology Research System(2016LM1080,2017LM1080)
文摘Background: Insects, such as Hermetia illucens larvae, are rich in chitin and proteins, and represent a suitable feed ingredient replacement for animals. However, little is known about the effect of administering H. illucens larvae on intestinal microbiota, bacterial metabolite profiles, and mucosal immune status in animals. This study aimed to investigate the effects of administering H. illucens larvae on colonic microbiota and bacterial metabolites production in finishing pigs. Seventy-two crossbred(Duroc × Landrace × Large White) female pigs(initial body weight, 76.0 ± 0.52 kg) were randomly allocated to three different dietary treatments: a control diet(Control group) and two diets corresponding to 4%(H1 group) and 8%(H2 group) H. illucens larvae inclusion levels, respectively. Each treatment consisted of eight pens(replicates), with three pigs per pen. After 46 days of feeding, eight pigs per treatment(n =8) were slaughtered, and the colonic digesta and mucosa were collected for microbial composition and microbial fermentation products, and genes expression analyses.Results: The results showed that the H1 diet significantly increased the abundance of Lactobacillus,Pseudobutyrivibrio, Roseburia, and Faecalibacterium compared with those in the control group(P < 0.05), with a decrease in the abundance of Streptococcus. The numbers of Lactobacillus, Roseburia, and Clostridium cluster XIVa were significantly greater in the H1 group than in the control group(P < 0.05). Meanwhile, H2 diet increased the number of Clostridium cluster XIVa compared with the control group(P < 0.05). For colonic metabolites, total short chain fatty acids, butyrate, and isobutyrate concentrations were significantly higher in the H1 group than those in the control group(P < 0.05);the H1 treatment caused a striking decrease in protein fermentation compared with the control group, as the concentrations of total amines, cadaverine, tryptamine, phenol, p-cresol, and skatole were significantly lower(P < 0.05). Additionally, H2 diet also increased butyrate concentration compared with control group(P < 0.05), while decreased the concentrations of phenol, p-cresol, and skatole(P < 0.05). Pigs in the H1 group down-regulated the expression of TLR-4 and pro-inflammatory cytokines(IFN-γ) compared with pigs in the control group(P < 0.05), and up-regulated anti-inflammatory cytokine(IL-10) and intestinal barrier genes(ZO-1, occludin, and mucin-1). H2 diet up-regulated the expression of ZO-1 compared with control group(P < 0.05). Furthermore, the changes in the colonic mucosal gene expression were associated with changes in the bacterial composition and their metabolites.Conclusions: Collectively, dietary inclusion of Hermetia illucens larvae may enhance mucosal immune homeostasis of pigs via altering bacterial composition and their metabolites. These findings provide a new perspective on insect meal as a sustainable protein source rich in nutrient ingredients for swine.
基金supported by the National Natural Science Foundation of China (No. 41271468,40971253,40903031)the Basic Research Program of Jiangsu Province (No. BK2011879)the Key Project of"One Three Five" Strategic Developing Plan (No. NIGLAS2012135008
文摘The microscale distribution of oxygen,the nitrogen flux and the denitrification rates in sediment inhabited by chironomid larvae（Tanypus chinensis） were measured in eutrophic Lake Taihu,China.The presence of the chironomids in the sediment increased the oxygen diffusional flux from 10.4 ± 1.4 to 12.7 ± 2.5 mmol O 2 /（m 2 ·day）.The burrows of the larvae represented ＂hot spots＂ and strongly influenced the nitrogen cycles and diagenetic activity in the sediment.The results indicate that the bioturbation effects of Tanypus chinensis chironomid larvae increased the capacity of the sediment as a sink for nitrate and a source for ammonium.Nitrate influx and ammonium outflux were increased 8.8 and 1.7 times,respectively.Under bioturbation,the amount of nitrate consumed was greater than the amount of ammonium released.The total denitrification rate was also enhanced from 0.76 ± 0.34 to 5.50 ± 1.30 mmol N/（m 2 ·day）.The net effect was that the bioturbated sediments acted as a net sink for inorganic nitrogen under direct and indirect bioturbation effects compared to the control.
基金This work was financially supported by Project of Scientific Innova-tion, Chinese Academy of Sciences (ZKCX2-211).
文摘In order to improve production and breed new broods of bay scallop Argopecten irradians irradians, different-colored orange, purple and white lines were established by two mating methods of self-fertilization and mass spawning at a commercial scallop hatchery in spring, 2002. And then larval growth and survival of different lines was compared to test whether there is a relationship between shell color and growth and survival at early developmental stage. Both growth and survival have no significant differences among different experimental larvae of self-fertilization or mass spawning. Results are as following in the order of orange, purple and white shell stock. For the self-fertilization, growth rates of larvae were 6.174, 6.412, and 6.599 μm/d, respectively. Survival rates of larvae at Day 3 were 74.41%, 76.86%, and 82.05%; Day 6 were 49.14%, 65.63%, and 52.79%; and Day 9 were 25.06%, 20.80%, and 26.47%, respectively. For the mass spawning, the growth rates were 7.836, 7.941, and 7.878 μm/d, respectively. Survival rates at Day 3 were 93.05%, 91.95%, and 92.50%; Day 6 were 79.17%, 78.05%, and 82.50%; and Day 9 were 34.72%, 36.67%, and 38.33%, respectively. The absence of any relationship between shell color and growth and survival at the larval stage may be resulted from their common genetic basis.
文摘During the First Chinese Antarctic Expedition zooplankton samples were collected at each of the oceanography stations in the waters around South Sheltland Islands (S. S. Is.) and in the northern part of the Bellinshausen Sea from 20 January to 12 February, 1985 by vertical tows of an 80 cm diameter conical net from 200 m to surface. Two deep tows with a closing net. were performed in slope water north of S.S. Is, and in the basin of Bransfield Strait. Eggs and larvae of Euphatisia superba Dana in zooplankton samples were identified and counted.There were four records of eggs from 27 stations. Most catches were of small number and restricted to within the nearshore area south of S.S Is.The largest number (1500/1000 cubic meters )was found in the outer side of Smith Island.No Nauplius was found . The earliest stage we found 【was Metanauplius , in two deep tows. The distribution of Calyptopis MI and Furcili I-III were quite similar. They were found mainly in three areas: 1 ) nearshore water along the
文摘Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact of effluents from the firms.Methods:Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry(AAS).Results:Cx.quinquefasciatus was the most abundant species followed by Cx.gelidus.The levels of lead were higher in the Cx.quinquefasciatus(1.08-47.47μg/g),than in the wastewaters surface(0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the.criteria for lead determination.Conclusions:The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination,to complemente conventional techniques.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2006AA10A411)Shandong Agriculture Seed Stock Projects
文摘In laboratory conditions,effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively.Data series like larval length and density,metamorphic time,and survival rate of the larvae were recorded.Statistics showed that for A.japonicus,survival rate(from fertilized egg to late auricularia) decreased significantly with the increasing rearing temperature(P<0.05).At different temperatures SGR was statistically significant as well(P<0.05) from day 1,and maximal SGR was found on day 9 at 24℃(159.26±3.28).This study clearly indicated that at low temperature(<24℃),metamorphic rate was remarkably higher than at higher temperature(>26℃).Hatching rate was significantly different between 0.2-5 ind./ml groups and 20-50 ind./ml groups.Rearing larvae at the higher density had the smaller maximal-length,whereas needed longer time to complete metamorphosis.This study suggested that 21℃ and 0.4 ind./ml can be used as the most suitable rearing temperature and stocking density for large-scale artificial breeding of A.japonicus's larvae.
基金Supported by National Natural Science Foundation of China (No. 40476057)
文摘As the most widely used plasticizers in the world, phthalate esters （PAEs） are potential endocrine disruption compounds （EDCs）. In the present study, the toxicity of dimethyl phthalate （DMP）, diethyl phthalate （DEP）, dibutyl phthalate （DBP）, di （2-ethylhexyl） phthalate （DEHP） on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMR DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP〉DEP〉DMP〉DEHE Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.
基金Supported by the National Key Technology Research and Development Program of China(Nos.2011BAD13B01,2011BAD45B01)the Chinese Academy of Science and Government Cooperation Program(No.Y12319101L)the National Marine Public Welfare Research Program of China(No.201305043)
文摘The major population of the veined rapa whelk Rapana venosa （Valenciennes, 1846）, which is an important fishery resource, is facing a large decline in China. We studied the effects of incubation temperature （16-34℃ at salinity 30） and salinity （5-45 at 25℃） on the incubation period and subsequent larval development. In the temperature experiment, the shortest incubation period was 12 days at 34℃, the lower temperature limit was 16~C, the longest mean shell length （1 193＋17 pan） occurred at 25℃ and the highest survival rate 72.28%＋5.62% was observed at 28℃. In the salinity experiment, the shortest incubation period was 15 days at 25. The salinity tolerance range was 15-40, the longest mean shell length （855-4-9 μm） and the highest survival rate 72.93%~4.85% were both observed at 35. This study demonstrated that, during the egg-mass stage, temperature and salinity regimes influence later growth and survival of larvae. These observations deepen our understanding of the ecology and conservation of natural populations of Rapana venosa.
基金The present research is supported by the‘948’Of-fice Project of Ministry of Agriculture(963087)
文摘The activities of some digestive enzymes are studied for Takifugu rubripes larvae and juvenile from the first feeding to 27 d after hatching at selected stages of development. The homogenate of whole larvae body is used for enzymatic determination. Activity of acid protease decreases notably during the beginning days after the commencement of completely exogenous feeding and the days before the beginning of the juvenile stage. Alkaline protease specific activity also decreases at metamorphosis. The activities are associated with the morphology of the developing digestive tract. Amylase activity increases before the first feeding, followed by a decreasing and then a rather constant level. Lipase activity remains low during the larvae and juvenile periods. Alkaline phosphatase activity increases gradually. This reflects the development of brush border membranes of enterocytes.
