Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this rev...Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this review,we discuss the current studies about the effects of starvation on growth and development of fish larval stage. The goals of this review are to understand some adaptive mechanisms and ecological countermeasures of starved fish larvae and to provide the scientific guideline for exploring early life history processes,evaluating the nutrition condition and growth of larval fish,protecting fish resource and breeding fish larvae.展开更多
[Objective] The paper was to explore the species composition, number distribution and seasonal dynamics of fish eggs and larvae in Liaodong Bay in 2008. The protection and exploitation status of spawning ground in Lia...[Objective] The paper was to explore the species composition, number distribution and seasonal dynamics of fish eggs and larvae in Liaodong Bay in 2008. The protection and exploitation status of spawning ground in Liaodong Bay was analyzed, and the corresponding protection measures were put forward. [Methods] The species composition of fish eggs and larvae in spawning ground of Liaodong Bay was investigated by horizontal trawling associated with vertical trawling with zooplankton net in May, July, September and October in 2008. [Result] It was found that 7 724 eggs and 229 larvae of fishes belonging to 32 taxa were collected, in which 29 taxa were identified as species, belonging to 9 genera, 21 families and 28 orders, 2 taxa were identified to only family level, and one failed to be identified. The main spawning groups were Cynoglossus joyneri, Engraulis japonicus, Johnius belengerii, Larimichthys polyactis, Konosirus punctatus, Sardinella zunasi, and Scomberomorus niphonius, and the main spawning ground was found in northern waters and Changxing Island waters in Liaodao Bay. There was slightly less spawning species in 2008 compared with 1998, especially the number of fish eggs and larvae decreased greatly. [Conclusion] The effective measures for protection of spawning grounds in Liaodong Bay are suggested, including control of fishing intensity, development of artificial reefs, establishment of germplasm resources reserves, and standardization of compensation standards for marine ecological damage.展开更多
This study investigated abundance, species composition and spatial and temporal distributions of fish larvae and their relationship with some environmental variables in the Sukhothai floodplain in northern Thailand. F...This study investigated abundance, species composition and spatial and temporal distributions of fish larvae and their relationship with some environmental variables in the Sukhothai floodplain in northern Thailand. Fish larvae were collected from 33 sampling stations on 8 occasions between August 2010 and October 2013. The study collected and identified 149 296 individuals, representing 32 families and 165 taxa. The species composition of larval fish was dominated by the Cyprinidae(47.27%), Cobitidae(7.88%), Siluridae(6.67%), Bagridae(6.06%) and Mastacembelidae(3.33%) families. The mostabundant larval species were the Striped flying barb Esomus metallicus(16.90%), the Siamese mud carpHenicorhynchus siamensis(8.48%) and the Sumatran river sprat Clupeichthys goniognathus(8.31%). The greatest abundance and species diversity of larvae were found when the river flow runs onto the floodplain. PCA and nMDS analysis revealed that the samples plot is associated with temporal distribution among years. The discharge was a major factor determining fish larvae assemblage and environmental variables in the Sukhothai floodplain. Four fish larval species were positively correlated with the samples for 2013. The result of the CCA ordination plot showed that only the discharge variable was strongly correlated with fish larvae abundance, especially two cyprinid R asbora species.展开更多
A study on the assemblage composition and vertical distribution of larval fish was conducted in the southern area of the Moroccan Atlantic coast in Autumn 2011. A total of I 680 fish larvae taxa were identified from 2...A study on the assemblage composition and vertical distribution of larval fish was conducted in the southern area of the Moroccan Atlantic coast in Autumn 2011. A total of I 680 fish larvae taxa were identified from 21 families. The majority of the larvae were present in the upper layers. Clupeids were the most abundant larvae taxa followed by Myctophidae, Gadidae and Sparidae, hence the larval fish assemblages （LFA） were variable in different depth layers. Total fish larvae showed a preference for surface layers, and were mainly found above 75 m depth, with some exceptions. The maximum concentration of fish larvae was concentrated up to 25 m essentially above the thermocline, where chlorophyll a and mesozooplankton were abundant. Spatially, neritic families were located near the coast and at some offshore stations especially in the northern part, while oceanic families were more distributed towards offshore along the study area. Cluster analysis showed a segregation of two groups of larvae. However, a clear separation between neritic families and oceanic families was not found. Multivariate analysis highlighted the relationship between the distribution of larvae of different families and environmental parameters. Temperature and salinity seem to have been the factors that acted on associations offish larvae. Day/night vertical distributions suggest there was not a very significant vertical migration, probably due to adequate light levels for feeding.展开更多
Fish populations have declined in many estuarine and freshwater ecosystems in part due to the loss of habitat in recent decades.Reconstructing lost habitat for larvae fish is a potential method for recovering larvae f...Fish populations have declined in many estuarine and freshwater ecosystems in part due to the loss of habitat in recent decades.Reconstructing lost habitat for larvae fish is a potential method for recovering larvae fish populations.Three-dimensional artificial floating wetlands(AFWs)on which Phragmites australis was planted were experimentally deployed to recover the lost habitat in the Changjiang(Yangtze)River estuary from May to July 2018.The AFW area was characterized by slow velocity,high transparency,low dissolved oxygen,and relatively constant water temperature.The total individuals of larvae fish in the AFW area(12122 in total)was higher than that in the non-AFW area(1250 in total),and the densities of most larvae fish species were higher in the AFW habitat than in the non-AFW area.The distributions of larvae fish species were positively influenced by habitat type because they were strongly related to the negative part of the first axis of the redundancy analysis,and Cyprinus carpio and Cyprinus auratus were inclined to habitat in the slow velocity and high transparency AFW habitat area.These results indicate that larvae fish species are inclined to inhabit the AFW habitat.The use of three-dimensional P.australis AFWs would be a potential method for enhancing the habitat of larvae fish in the degraded habitats along the estuary.展开更多
Surveys were conducted in four seasons in the eastern Beibu Gulf from July 2006 to November 2007, to determine the ichthyoplankton composition, abundance, as well as environmental factors impacted on their spatiotempo...Surveys were conducted in four seasons in the eastern Beibu Gulf from July 2006 to November 2007, to determine the ichthyoplankton composition, abundance, as well as environmental factors impacted on their spatiotemporal distributions. The fish eggs and larvae were sorted from 303 zooplankton quantitative samples, in which at least 1 order, 60 families, 31 genera and 61 species of fish eggs and larvae were identified. The species number was highest in summer whereas lowest in winter. With the most abundant fish egg （the average density was 2.41 ind./m3）, spring was the main spawning season, while the greatest mean density of fish larva was 1.35 ind./m3 in summer. In the whole year around, fish eggs had the trends to aggregate in the nearshore of Guangxi coast, fish larvae were more abundant in the northern water. Relationships between fish eggs and larvae abundance and environmental factors were analyzed by using the Yield-Density model. The spatio- temporal distribution of ichthyoplankton in eastern Beibu Gulf was closely related to the Chl a concentration, and the optimal temperature, salinity and Chl a were 19.4-21.7℃, 31.8-33.1 and 1.5-4.8 mg/m3, respectively. Additionally, the distribution of fish larvae could be effected by ocean currents in summer and autumn.展开更多
Mesocosm hatcheries using semi-intensive culture methodologies are characterized by large tanks （40 m3） for fish larvae production at low densities （2-8 larvae/L）, with live prey production within the tank supplem...Mesocosm hatcheries using semi-intensive culture methodologies are characterized by large tanks （40 m3） for fish larvae production at low densities （2-8 larvae/L）, with live prey production within the tank supplemented by exogenous sources of feed. Due to the high biological quality of larvae produced and low level of technological input, these methodologies are regarded as an interesting option to meet the increasing fry demand from the aquaculture industry. This study aimed to describe the experience at Centro de Maricultura da Calheta, Madeira Island, Portugal, with the establishment of a mesocosm hatchery for the production of marine fish larvae. Production trials were initiated with gilthead seabream Sparus aurata. This larval species presented faster growth in total body length （TL） per day （TL = 3.7516e~ ~293day, R2 = 0.9404）, higher survival rate （SR = 31.9%） and comparable swimbladder inflation rates （SB = 90%） to those of larvae reared with intensive methodologies. High larval performance was obtained with two candidate species for aquaculture： the red porgy Pagruspagrus （TL = 3.212e~~39day, R2 = 0.995; SR = 15.3%; SB = 95.7%） and the white seabream Diplodus sargus （TL = 3.6355e~~413day, R2= 0.9824; SR = 25%; SB --- 100%）. Testing ofa 110 m3 mesocosm rearing tank with white seabream larvae revealed limitations associated to larger tanks namely, the amount and quality of live feed required daily. First trials with striped jack （Pseudocararoc dentex） larvae resulted in low larval survival （0.04%）, but the use of a white tank avoided culture management constraints related to positive phototropism. The present results suggest that a mesocosm using semi-intensive methodologies may contribute to species diversification and consequently, to the sustainable development of aquaculture.展开更多
In this study,we investigated the transcriptional spatio-temporal dynamics of the taste 1 receptor(T1R)gene family repertoire in seabream(Sparus aurata[sa]),during larval ontogeny and in adult tissues.In early larval ...In this study,we investigated the transcriptional spatio-temporal dynamics of the taste 1 receptor(T1R)gene family repertoire in seabream(Sparus aurata[sa]),during larval ontogeny and in adult tissues.In early larval development,sa T1R expression arises heterochronously,i.e.the extraoral taste-related perception in the gastrointestinal tract(GIT)anticipates first exogenous feeding(at 9 days post hatching[dph]),followed by the buccal/intraoral perception from 14 dph onwards,supporting the hypothesis that the early onset of the molecular machinery underlying sa T1R expression in the GIT is not induced by food but rather genetically hardwired.During adulthood,we characterized the expression patterns of sa T1R within specific tissues(n=4)distributed in oropharingeal,GIT and brain regions substantiating their functional versatility as chemosensory signaling players to a variety of biological functions beyond oral taste sensation.Further,we provided for the first time direct evidences in fish for m RNA coexpression of a subset of sa T1R genes(mostly sa T1R3,i.e.the common subunit of the heterodimeric T1R complexes for the detection of“sweet”and“umami”substances),with the selected gut peptides ghrelin(ghr),cholecystokinin(cck),hormone peptide yy(pyy)and proglucagon(pg).Each peptide defines the enteroendocrine cells(ECCs)identity,and establishes on morphological basis,a direct link for T1R chemosensing in the regulation of fish digestive processes.Finally,we analyzed the spatial gene expression patterns of 2 taste signaling components functionally homologous to the mammalian G(i)a subunit gustducin,namely sa G(i)a1 and sa G(i)a2,and demonstrated their co-localization with the sa T1R3in EECs,thus validating their direct involvement in taste-like transduction mechanisms of the fish GIT.In conclusion,data provide new insights in the evolutionary conservation of gut sensing in fish suggesting a conserved role for nutrient sensors modulating entero-endocrine secretion.展开更多
文摘Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this review,we discuss the current studies about the effects of starvation on growth and development of fish larval stage. The goals of this review are to understand some adaptive mechanisms and ecological countermeasures of starved fish larvae and to provide the scientific guideline for exploring early life history processes,evaluating the nutrition condition and growth of larval fish,protecting fish resource and breeding fish larvae.
基金Supported by Special Fund for Scientific Research(Marine)in the Public Interest(201405010)
文摘[Objective] The paper was to explore the species composition, number distribution and seasonal dynamics of fish eggs and larvae in Liaodong Bay in 2008. The protection and exploitation status of spawning ground in Liaodong Bay was analyzed, and the corresponding protection measures were put forward. [Methods] The species composition of fish eggs and larvae in spawning ground of Liaodong Bay was investigated by horizontal trawling associated with vertical trawling with zooplankton net in May, July, September and October in 2008. [Result] It was found that 7 724 eggs and 229 larvae of fishes belonging to 32 taxa were collected, in which 29 taxa were identified as species, belonging to 9 genera, 21 families and 28 orders, 2 taxa were identified to only family level, and one failed to be identified. The main spawning groups were Cynoglossus joyneri, Engraulis japonicus, Johnius belengerii, Larimichthys polyactis, Konosirus punctatus, Sardinella zunasi, and Scomberomorus niphonius, and the main spawning ground was found in northern waters and Changxing Island waters in Liaodao Bay. There was slightly less spawning species in 2008 compared with 1998, especially the number of fish eggs and larvae decreased greatly. [Conclusion] The effective measures for protection of spawning grounds in Liaodong Bay are suggested, including control of fishing intensity, development of artificial reefs, establishment of germplasm resources reserves, and standardization of compensation standards for marine ecological damage.
基金Supported by the Agricultural Research Development Agency(Public Organization)
文摘This study investigated abundance, species composition and spatial and temporal distributions of fish larvae and their relationship with some environmental variables in the Sukhothai floodplain in northern Thailand. Fish larvae were collected from 33 sampling stations on 8 occasions between August 2010 and October 2013. The study collected and identified 149 296 individuals, representing 32 families and 165 taxa. The species composition of larval fish was dominated by the Cyprinidae(47.27%), Cobitidae(7.88%), Siluridae(6.67%), Bagridae(6.06%) and Mastacembelidae(3.33%) families. The mostabundant larval species were the Striped flying barb Esomus metallicus(16.90%), the Siamese mud carpHenicorhynchus siamensis(8.48%) and the Sumatran river sprat Clupeichthys goniognathus(8.31%). The greatest abundance and species diversity of larvae were found when the river flow runs onto the floodplain. PCA and nMDS analysis revealed that the samples plot is associated with temporal distribution among years. The discharge was a major factor determining fish larvae assemblage and environmental variables in the Sukhothai floodplain. Four fish larval species were positively correlated with the samples for 2013. The result of the CCA ordination plot showed that only the discharge variable was strongly correlated with fish larvae abundance, especially two cyprinid R asbora species.
基金Supported by the Moroccan-Norwegian scientific team that participated in the survey on aboard the R/V Dr Fridtjof Nansen in the context of the regional project CCLME“Canary Current Large Marine Ecosystem”
文摘A study on the assemblage composition and vertical distribution of larval fish was conducted in the southern area of the Moroccan Atlantic coast in Autumn 2011. A total of I 680 fish larvae taxa were identified from 21 families. The majority of the larvae were present in the upper layers. Clupeids were the most abundant larvae taxa followed by Myctophidae, Gadidae and Sparidae, hence the larval fish assemblages （LFA） were variable in different depth layers. Total fish larvae showed a preference for surface layers, and were mainly found above 75 m depth, with some exceptions. The maximum concentration of fish larvae was concentrated up to 25 m essentially above the thermocline, where chlorophyll a and mesozooplankton were abundant. Spatially, neritic families were located near the coast and at some offshore stations especially in the northern part, while oceanic families were more distributed towards offshore along the study area. Cluster analysis showed a segregation of two groups of larvae. However, a clear separation between neritic families and oceanic families was not found. Multivariate analysis highlighted the relationship between the distribution of larvae of different families and environmental parameters. Temperature and salinity seem to have been the factors that acted on associations offish larvae. Day/night vertical distributions suggest there was not a very significant vertical migration, probably due to adequate light levels for feeding.
基金Supported by the National Key R&D Program of China(Nos.2019YFD0901202,2018YFD0900905)the China Postdoctoral Science Foundation(No.2018M632887)。
文摘Fish populations have declined in many estuarine and freshwater ecosystems in part due to the loss of habitat in recent decades.Reconstructing lost habitat for larvae fish is a potential method for recovering larvae fish populations.Three-dimensional artificial floating wetlands(AFWs)on which Phragmites australis was planted were experimentally deployed to recover the lost habitat in the Changjiang(Yangtze)River estuary from May to July 2018.The AFW area was characterized by slow velocity,high transparency,low dissolved oxygen,and relatively constant water temperature.The total individuals of larvae fish in the AFW area(12122 in total)was higher than that in the non-AFW area(1250 in total),and the densities of most larvae fish species were higher in the AFW habitat than in the non-AFW area.The distributions of larvae fish species were positively influenced by habitat type because they were strongly related to the negative part of the first axis of the redundancy analysis,and Cyprinus carpio and Cyprinus auratus were inclined to habitat in the slow velocity and high transparency AFW habitat area.These results indicate that larvae fish species are inclined to inhabit the AFW habitat.The use of three-dimensional P.australis AFWs would be a potential method for enhancing the habitat of larvae fish in the degraded habitats along the estuary.
基金The Chinese Offshore Investigation and Assessment under contract No. 908-01-ST09
文摘Surveys were conducted in four seasons in the eastern Beibu Gulf from July 2006 to November 2007, to determine the ichthyoplankton composition, abundance, as well as environmental factors impacted on their spatiotemporal distributions. The fish eggs and larvae were sorted from 303 zooplankton quantitative samples, in which at least 1 order, 60 families, 31 genera and 61 species of fish eggs and larvae were identified. The species number was highest in summer whereas lowest in winter. With the most abundant fish egg （the average density was 2.41 ind./m3）, spring was the main spawning season, while the greatest mean density of fish larva was 1.35 ind./m3 in summer. In the whole year around, fish eggs had the trends to aggregate in the nearshore of Guangxi coast, fish larvae were more abundant in the northern water. Relationships between fish eggs and larvae abundance and environmental factors were analyzed by using the Yield-Density model. The spatio- temporal distribution of ichthyoplankton in eastern Beibu Gulf was closely related to the Chl a concentration, and the optimal temperature, salinity and Chl a were 19.4-21.7℃, 31.8-33.1 and 1.5-4.8 mg/m3, respectively. Additionally, the distribution of fish larvae could be effected by ocean currents in summer and autumn.
文摘Mesocosm hatcheries using semi-intensive culture methodologies are characterized by large tanks （40 m3） for fish larvae production at low densities （2-8 larvae/L）, with live prey production within the tank supplemented by exogenous sources of feed. Due to the high biological quality of larvae produced and low level of technological input, these methodologies are regarded as an interesting option to meet the increasing fry demand from the aquaculture industry. This study aimed to describe the experience at Centro de Maricultura da Calheta, Madeira Island, Portugal, with the establishment of a mesocosm hatchery for the production of marine fish larvae. Production trials were initiated with gilthead seabream Sparus aurata. This larval species presented faster growth in total body length （TL） per day （TL = 3.7516e~ ~293day, R2 = 0.9404）, higher survival rate （SR = 31.9%） and comparable swimbladder inflation rates （SB = 90%） to those of larvae reared with intensive methodologies. High larval performance was obtained with two candidate species for aquaculture： the red porgy Pagruspagrus （TL = 3.212e~~39day, R2 = 0.995; SR = 15.3%; SB = 95.7%） and the white seabream Diplodus sargus （TL = 3.6355e~~413day, R2= 0.9824; SR = 25%; SB --- 100%）. Testing ofa 110 m3 mesocosm rearing tank with white seabream larvae revealed limitations associated to larger tanks namely, the amount and quality of live feed required daily. First trials with striped jack （Pseudocararoc dentex） larvae resulted in low larval survival （0.04%）, but the use of a white tank avoided culture management constraints related to positive phototropism. The present results suggest that a mesocosm using semi-intensive methodologies may contribute to species diversification and consequently, to the sustainable development of aquaculture.
基金covered by the National Research Agency(AEI,Spain)(grant number:PID2019-103969RB-C33)to Jos e M.Cerd a-Reverter。
文摘In this study,we investigated the transcriptional spatio-temporal dynamics of the taste 1 receptor(T1R)gene family repertoire in seabream(Sparus aurata[sa]),during larval ontogeny and in adult tissues.In early larval development,sa T1R expression arises heterochronously,i.e.the extraoral taste-related perception in the gastrointestinal tract(GIT)anticipates first exogenous feeding(at 9 days post hatching[dph]),followed by the buccal/intraoral perception from 14 dph onwards,supporting the hypothesis that the early onset of the molecular machinery underlying sa T1R expression in the GIT is not induced by food but rather genetically hardwired.During adulthood,we characterized the expression patterns of sa T1R within specific tissues(n=4)distributed in oropharingeal,GIT and brain regions substantiating their functional versatility as chemosensory signaling players to a variety of biological functions beyond oral taste sensation.Further,we provided for the first time direct evidences in fish for m RNA coexpression of a subset of sa T1R genes(mostly sa T1R3,i.e.the common subunit of the heterodimeric T1R complexes for the detection of“sweet”and“umami”substances),with the selected gut peptides ghrelin(ghr),cholecystokinin(cck),hormone peptide yy(pyy)and proglucagon(pg).Each peptide defines the enteroendocrine cells(ECCs)identity,and establishes on morphological basis,a direct link for T1R chemosensing in the regulation of fish digestive processes.Finally,we analyzed the spatial gene expression patterns of 2 taste signaling components functionally homologous to the mammalian G(i)a subunit gustducin,namely sa G(i)a1 and sa G(i)a2,and demonstrated their co-localization with the sa T1R3in EECs,thus validating their direct involvement in taste-like transduction mechanisms of the fish GIT.In conclusion,data provide new insights in the evolutionary conservation of gut sensing in fish suggesting a conserved role for nutrient sensors modulating entero-endocrine secretion.
