The larvae of Styela canopus show the highest rates of settlement and metamorphosis when treated with 40 mM KCl-elevated seawater at 25 degreesC in temperature and 27.0 in salinity. Induced by 40 mM KCl-elevated seawa...The larvae of Styela canopus show the highest rates of settlement and metamorphosis when treated with 40 mM KCl-elevated seawater at 25 degreesC in temperature and 27.0 in salinity. Induced by 40 mM KCl-elevated seawater, it took Styela canopus larvae approximately 3 h after hatching to develop competence to settle and metamorphose. The present experiment shows that Styela canopus larvae is an ideal model organism for examining the efficiency of antifouling substance.展开更多
The genus Rhynchospio has fronto-lateral horns on prostomium,paired branchiae from chaetiger 2 to near the posterior end,capillary notochaetae only,and more than two pairs of pygidial cirri.Rhynchospio species are com...The genus Rhynchospio has fronto-lateral horns on prostomium,paired branchiae from chaetiger 2 to near the posterior end,capillary notochaetae only,and more than two pairs of pygidial cirri.Rhynchospio species are common in coastal soft bottom communities;nevertheless,many recorded Rhynchospio specimens around the world are currently undescribed.Here we described a Rhynchospio species based on specimens collected from Qingdao,China.Comparison with the reported DNA sequences of four gene markers(16S rRNA,18S rRNA,28S rRNA,and Histone H3)and brief morphological description of specimens collected from Jinhae Bay,South Korea,previously reported as Rhynchospio aff.asiatica,indicated that they are conspecific.Morphologically,specimens of R.aff.asiatica from Qingdao are characterized by having neuropodial hooded hooks from chaetigers 14–17(vs.10–23 in R.asiatica)to near pygidial chaetigers,sperm from chaetiger 11 to 14(vs.from chaetiger 11 to 21–22 in R.asiatica),oocytes from chaetigers 16–17 to 26–39(vs.from 22–24 in R.asiatica),and 4–6(vs.up to 6 in R.asiatica)pygidial cirri.Genetically,Rhynchospio aff.asiatica is most closely related to R.arenincola Hartman,1936 from California,USA with the interspecific distances of 20.02%(16S rRNA),4.50%(18S rRNA),8.44%(28S rRNA),2.74%(Histone H3),and 6.10%(concatenated sequences).Water flow across the dorsum created by ciliary beating of the branchiae and nototrochs,observed on live specimens,may help transport gametes from reproductive segments in anterior and middle parts to the posterior brooding segments.Phylogenetic trees based on concatenated sequences of four gene markers of 54 spioniform species in 25 genera revealed two clades,covering the two subfamilies Spioninae and Nerininae respectively.Two families(i.e.,Poecilochaetidae and Trochochaetidae)in the order Spionida were clustered within Spionidae,supporting a morphology-based proposal that these families bearing a pair of prehensile,grooved palps should be grouped within a more broadly defi ned family Spionidae.Mapping morphological and reproductive characteristics to the phylogenetic trees indicated that the ancestor of spionids might lack branchiae,broadcast spawn thick-envelop oocytes and ect-aquasperm,and produce planktotrophic larvae.展开更多
Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of bu...Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of burrowing clams within various substrates get less attention due to difficulty in carrying out physiological tests in buried conditions.Consequently,this study investigated the burrowing behavior,feeding physiology and energy budget of Paphia undulata,which is an important aquaculture bivalve species in south China.The clams were exposed to mud and sand substrates with variable physical properties in the laboratory,to determine the suitable substrate conditions for this species.The results showed that the percentage of burrowing clams,digging index,burrowing time,burrowing depth and scope for growth(SFG)were higher in mud substrates with≥40%water content.Likewise,burrowing percentage,digging index,and burrowing depths were higher in substrates with≤40%sand content.Moreover,the burrowing depth had significant effect on the feeding physiology and SFG of P.undulata as clams burrowed at 6.3±1.8 cm had higher clearance rates and SFG as compared to other buried depths.This study further revealed that low water content in the sediment inhibited physiological performances of P.undulata by impairing feeding or absorption,hence reducing the SFG.In conclusion,mud substrate with≥40%water content or with≤40%sand content is suitable for proper burrowing and growth of P.undulata.Our findings therefore provide fundamental knowledge that will be applicable in the improvement of bottom aquaculture and conservation of P.undulata.展开更多
Prostaglandin E2(PGE2)has been reported to be involved in reproduction as one of the most abundant and widely distributed prostaglandins in invertebrates.Regulating gonad development and gamete production in mollusks ...Prostaglandin E2(PGE2)has been reported to be involved in reproduction as one of the most abundant and widely distributed prostaglandins in invertebrates.Regulating gonad development and gamete production in mollusks can greatly assist artificial breeding,which is believed to promote the commercial benefits of various mollusk species.In the present study,the contents of PGE2 in the gonads of abalone at different developmental stages(maturing stage,ripe stage,and spawning stage)and reproduction states(before and after spawning)were measured.A higher PGE2 level was found in the gonads of abalones at the ripe stage than other stages,and the highest PGE2 level was detected in the ovaries of female H.diversicolor in the UV-stimulated group.Then the effects of PGE2 injection on the spawning efficiency were explored,and the gamete emission rates of female and male abalone were significantly increased after PGE2 injection.Through qRT-PCR and in situ hybridization assay,higher expression levels and wide distribution of phospholipase A2(PLA2),cyclooxygenase 2(COX2),prostaglandin E synthases(PGES2),and prostaglandin E2 receptor 4(EP4)in the gonads of H.diversicolor were observed after spawning.It is speculated that PGE2 may promote the reproductive cycle in both male and female H.diversicolor,although the regulation mechanism of PGE2 in female and male abalone might be different.The results will be useful for the application of PGE2 in the abalone aquaculture practices to increase the reproduction efficiency in future.展开更多
The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus ha...The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus hannai,kept in various male and female groups,were significantly higher than those of sexually mature individuals,except when kept in mixed cultures of mature males and females.After mixed-culture,sexually mature males moved significantly further and for a longer duration than mature female abalones,and even more so than mature male abalones of any other group.Examination of the LC-MS metabolomics of mature males cultured with sexually mature females(AM)and those cultured with sexually immature females(JM)showed that cyclic adenosine monophosphate(cAMP)acted as a differential metabolic biomarker.After 24-h uninterrupted sampling,the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM.After further injection of 5-HT2 and 5-HT6 receptor antagonists,the concentrations of cAMP and PKA rose again,but the cumulative movement duration and distance of male abalones decreased significantly,showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways.The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females,providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.展开更多
基金National Natural Science Foundation of China under contract No. 49976034.
文摘The larvae of Styela canopus show the highest rates of settlement and metamorphosis when treated with 40 mM KCl-elevated seawater at 25 degreesC in temperature and 27.0 in salinity. Induced by 40 mM KCl-elevated seawater, it took Styela canopus larvae approximately 3 h after hatching to develop competence to settle and metamorphose. The present experiment shows that Styela canopus larvae is an ideal model organism for examining the efficiency of antifouling substance.
基金Supported by the China Postdoctoral Science Foundation (No.2021M691866)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Nos.GML2019ZD0404,GML2019ZD0409)+2 种基金the Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.SMSEGL20SC02)the MEL Outstanding Postdoctoral Scholarshipthe Undergraduate Innovation and Entrepreneurship Training Programs at Xiamen University(No.2021103 84077)
文摘The genus Rhynchospio has fronto-lateral horns on prostomium,paired branchiae from chaetiger 2 to near the posterior end,capillary notochaetae only,and more than two pairs of pygidial cirri.Rhynchospio species are common in coastal soft bottom communities;nevertheless,many recorded Rhynchospio specimens around the world are currently undescribed.Here we described a Rhynchospio species based on specimens collected from Qingdao,China.Comparison with the reported DNA sequences of four gene markers(16S rRNA,18S rRNA,28S rRNA,and Histone H3)and brief morphological description of specimens collected from Jinhae Bay,South Korea,previously reported as Rhynchospio aff.asiatica,indicated that they are conspecific.Morphologically,specimens of R.aff.asiatica from Qingdao are characterized by having neuropodial hooded hooks from chaetigers 14–17(vs.10–23 in R.asiatica)to near pygidial chaetigers,sperm from chaetiger 11 to 14(vs.from chaetiger 11 to 21–22 in R.asiatica),oocytes from chaetigers 16–17 to 26–39(vs.from 22–24 in R.asiatica),and 4–6(vs.up to 6 in R.asiatica)pygidial cirri.Genetically,Rhynchospio aff.asiatica is most closely related to R.arenincola Hartman,1936 from California,USA with the interspecific distances of 20.02%(16S rRNA),4.50%(18S rRNA),8.44%(28S rRNA),2.74%(Histone H3),and 6.10%(concatenated sequences).Water flow across the dorsum created by ciliary beating of the branchiae and nototrochs,observed on live specimens,may help transport gametes from reproductive segments in anterior and middle parts to the posterior brooding segments.Phylogenetic trees based on concatenated sequences of four gene markers of 54 spioniform species in 25 genera revealed two clades,covering the two subfamilies Spioninae and Nerininae respectively.Two families(i.e.,Poecilochaetidae and Trochochaetidae)in the order Spionida were clustered within Spionidae,supporting a morphology-based proposal that these families bearing a pair of prehensile,grooved palps should be grouped within a more broadly defi ned family Spionidae.Mapping morphological and reproductive characteristics to the phylogenetic trees indicated that the ancestor of spionids might lack branchiae,broadcast spawn thick-envelop oocytes and ect-aquasperm,and produce planktotrophic larvae.
基金Supported by the Guangxi Science and Technology Base and Talent Special Project (No.AD23026114)。
文摘Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of burrowing clams within various substrates get less attention due to difficulty in carrying out physiological tests in buried conditions.Consequently,this study investigated the burrowing behavior,feeding physiology and energy budget of Paphia undulata,which is an important aquaculture bivalve species in south China.The clams were exposed to mud and sand substrates with variable physical properties in the laboratory,to determine the suitable substrate conditions for this species.The results showed that the percentage of burrowing clams,digging index,burrowing time,burrowing depth and scope for growth(SFG)were higher in mud substrates with≥40%water content.Likewise,burrowing percentage,digging index,and burrowing depths were higher in substrates with≤40%sand content.Moreover,the burrowing depth had significant effect on the feeding physiology and SFG of P.undulata as clams burrowed at 6.3±1.8 cm had higher clearance rates and SFG as compared to other buried depths.This study further revealed that low water content in the sediment inhibited physiological performances of P.undulata by impairing feeding or absorption,hence reducing the SFG.In conclusion,mud substrate with≥40%water content or with≤40%sand content is suitable for proper burrowing and growth of P.undulata.Our findings therefore provide fundamental knowledge that will be applicable in the improvement of bottom aquaculture and conservation of P.undulata.
基金supported by grants from National Natural Science Foundation of China (No.31860728 and 32172961)Special Fund for Ocean and Fisheries of Xiamen (No.21CZY018HJ01).
文摘Prostaglandin E2(PGE2)has been reported to be involved in reproduction as one of the most abundant and widely distributed prostaglandins in invertebrates.Regulating gonad development and gamete production in mollusks can greatly assist artificial breeding,which is believed to promote the commercial benefits of various mollusk species.In the present study,the contents of PGE2 in the gonads of abalone at different developmental stages(maturing stage,ripe stage,and spawning stage)and reproduction states(before and after spawning)were measured.A higher PGE2 level was found in the gonads of abalones at the ripe stage than other stages,and the highest PGE2 level was detected in the ovaries of female H.diversicolor in the UV-stimulated group.Then the effects of PGE2 injection on the spawning efficiency were explored,and the gamete emission rates of female and male abalone were significantly increased after PGE2 injection.Through qRT-PCR and in situ hybridization assay,higher expression levels and wide distribution of phospholipase A2(PLA2),cyclooxygenase 2(COX2),prostaglandin E synthases(PGES2),and prostaglandin E2 receptor 4(EP4)in the gonads of H.diversicolor were observed after spawning.It is speculated that PGE2 may promote the reproductive cycle in both male and female H.diversicolor,although the regulation mechanism of PGE2 in female and male abalone might be different.The results will be useful for the application of PGE2 in the abalone aquaculture practices to increase the reproduction efficiency in future.
基金This study was supported by grants from the National Natural Science Foundation of China(No.32273105)National Key R&D Program of China(2018YFD0901400),Key S&T Program of Fujian Province(No.2020NZ08003)+2 种基金Special Fund for Ocean and Fisheries of Xiamen(21CZY018HJ01)China Postdoctoral Science Foundation Grant[2019M650153,2021T140393]the Outstanding Postdoctoral Scholarship from the State Key Laboratory of Marine Environmental Science at Xiamen University.Thanks for the support from the Germplasm resources sharing platform of aquatic species in Fujian Province and XMU-MRB Abalone Research Center.
文摘The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus hannai,kept in various male and female groups,were significantly higher than those of sexually mature individuals,except when kept in mixed cultures of mature males and females.After mixed-culture,sexually mature males moved significantly further and for a longer duration than mature female abalones,and even more so than mature male abalones of any other group.Examination of the LC-MS metabolomics of mature males cultured with sexually mature females(AM)and those cultured with sexually immature females(JM)showed that cyclic adenosine monophosphate(cAMP)acted as a differential metabolic biomarker.After 24-h uninterrupted sampling,the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM.After further injection of 5-HT2 and 5-HT6 receptor antagonists,the concentrations of cAMP and PKA rose again,but the cumulative movement duration and distance of male abalones decreased significantly,showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways.The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females,providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.
