Pub Date : 2023-01-02DOI: 10.1080/17451000.2023.2194060
D.L. Grobler, J. Klein, J. Quattro, N. Bolaño-Martínez, R. Bennett, A. Bester-van der Merwe
ABSTRACT Due to continued overexploitation and anthropogenic change, hammerhead sharks (Carcharhiniformes: Sphyrnidae) have experienced drastic declines over most of their geographic range. Owing to the K-selected life histories of these sharks, their population resilience and persistence, remain severely strained, further compromising ecosystem stability. Moreover, some species are largely understudied e.g. the cryptic congener, the Carolina hammerhead shark (Sphyrna gilberti), whilst specific regions, such as the South-West Indian Ocean (SWIO), remain relatively devoid of data, risking the eventual extirpation of unique hammerhead shark lineages. The aim of the present study was to verify the phylogenetic placement of the cryptic S. gilberti within the family Sphyrnidae through the inclusion of underrepresented species sequences in order to provide a more comprehensive phylogenetic perspective for understanding historical drivers of Sphyrnidae biodiversity. The present study describes the first complete mitochondrial genome of the cryptic S. gilberti originating from the US Atlantic, as well as the mitogenomes of smooth hammerhead shark (Sphyrna zygaena) and scalloped hammerhead shark (Sphyrna lewini) samples originating from the data deficient South-West Indian Ocean (SWIO). Furthermore, we estimate the phylogenetic interrelationships of the Sphyrnidae family using mitochondrial protein-coding (PCG) and rRNA genes, reaffirming the placement of S. gilberti as a sister lineage to S. lewini. The resulting phylogenetic estimate is further used to evaluate the most likely age of the first occurrence of S. gilberti, corresponding to the Late Miocene to Early Pleiocene Epoch (3.8–10.8 million years ago). Comparative analysis of these Sphyrnids between ocean basins, as well as preliminary divergence estimates for S. lewini and S. gilberti has contributed towards resolving the global hammerhead phylogeny. This has provided unique insights into the evolution of the genus, thereby aiding future efforts directed towards effective conservation and management of hammerhead populations over a larger spatial scale.
{"title":"Phylogenetic placement and molecular dating of hammerhead sharks (Sphyrnidae) based on whole mitogenomes","authors":"D.L. Grobler, J. Klein, J. Quattro, N. Bolaño-Martínez, R. Bennett, A. Bester-van der Merwe","doi":"10.1080/17451000.2023.2194060","DOIUrl":"https://doi.org/10.1080/17451000.2023.2194060","url":null,"abstract":"ABSTRACT Due to continued overexploitation and anthropogenic change, hammerhead sharks (Carcharhiniformes: Sphyrnidae) have experienced drastic declines over most of their geographic range. Owing to the K-selected life histories of these sharks, their population resilience and persistence, remain severely strained, further compromising ecosystem stability. Moreover, some species are largely understudied e.g. the cryptic congener, the Carolina hammerhead shark (Sphyrna gilberti), whilst specific regions, such as the South-West Indian Ocean (SWIO), remain relatively devoid of data, risking the eventual extirpation of unique hammerhead shark lineages. The aim of the present study was to verify the phylogenetic placement of the cryptic S. gilberti within the family Sphyrnidae through the inclusion of underrepresented species sequences in order to provide a more comprehensive phylogenetic perspective for understanding historical drivers of Sphyrnidae biodiversity. The present study describes the first complete mitochondrial genome of the cryptic S. gilberti originating from the US Atlantic, as well as the mitogenomes of smooth hammerhead shark (Sphyrna zygaena) and scalloped hammerhead shark (Sphyrna lewini) samples originating from the data deficient South-West Indian Ocean (SWIO). Furthermore, we estimate the phylogenetic interrelationships of the Sphyrnidae family using mitochondrial protein-coding (PCG) and rRNA genes, reaffirming the placement of S. gilberti as a sister lineage to S. lewini. The resulting phylogenetic estimate is further used to evaluate the most likely age of the first occurrence of S. gilberti, corresponding to the Late Miocene to Early Pleiocene Epoch (3.8–10.8 million years ago). Comparative analysis of these Sphyrnids between ocean basins, as well as preliminary divergence estimates for S. lewini and S. gilberti has contributed towards resolving the global hammerhead phylogeny. This has provided unique insights into the evolution of the genus, thereby aiding future efforts directed towards effective conservation and management of hammerhead populations over a larger spatial scale.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"1 - 12"},"PeriodicalIF":1.1,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46819881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-26DOI: 10.1080/17451000.2023.2173782
R. A. Pescinelli, R. C. Costa
ABSTRACT Larval characteristics play an important role in life history, phylogenetic and systematic studies. The morphology of the first post-embryonic stages (zoeae I–III) of the snapping shrimp Alpheus petronioi were described in detail and illustrated based on laboratory-hatched larvae. The morphological characteristics of the species were compared with available descriptions of other Alpheus species with known first zoeal stages. We provided a combination of characteristics useful for the diagnosis of the early zoeal stages of A. petronioi. The species can be separated from the first zoeal stage of the other species of the genus using the following structures: basial endite of maxillule with 2 stout spines (both without rows of spinules), and 2 small plumose setae; endopod of maxillule with 1 terminal denticulate seta, 1 short terminal simple seta and 1 subterminal spine; basial endite of maxilla bilobed, with 4 and 5 simple setae on proximal and distal lobe, respectively and basis of second maxilliped with 5 (3 strong and 2 slender) simple setae arranged (2 + 2 + 1). This is the first study on the biology of A. petronioi after its description, adding new information on its life history.
{"title":"Filling gaps in the life history of the snapping shrimp Alpheus petronioi: morphology of the first post-embryonic stages reared in laboratory","authors":"R. A. Pescinelli, R. C. Costa","doi":"10.1080/17451000.2023.2173782","DOIUrl":"https://doi.org/10.1080/17451000.2023.2173782","url":null,"abstract":"ABSTRACT Larval characteristics play an important role in life history, phylogenetic and systematic studies. The morphology of the first post-embryonic stages (zoeae I–III) of the snapping shrimp Alpheus petronioi were described in detail and illustrated based on laboratory-hatched larvae. The morphological characteristics of the species were compared with available descriptions of other Alpheus species with known first zoeal stages. We provided a combination of characteristics useful for the diagnosis of the early zoeal stages of A. petronioi. The species can be separated from the first zoeal stage of the other species of the genus using the following structures: basial endite of maxillule with 2 stout spines (both without rows of spinules), and 2 small plumose setae; endopod of maxillule with 1 terminal denticulate seta, 1 short terminal simple seta and 1 subterminal spine; basial endite of maxilla bilobed, with 4 and 5 simple setae on proximal and distal lobe, respectively and basis of second maxilliped with 5 (3 strong and 2 slender) simple setae arranged (2 + 2 + 1). This is the first study on the biology of A. petronioi after its description, adding new information on its life history.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"589 - 598"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43341784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-26DOI: 10.1080/17451000.2023.2176882
J. Micael, A. Ramos-Esplá, Pedro Rodrigues, S. Gíslason
ABSTRACT Global shipping facilitates the introduction of fouling organisms to new geographic areas. The increase in maritime transport in recent decades has led to unprecedented development, where marine coastal waters have become one of the most invaded habitats around the globe. Among the most successful invaders are ascidians. Despite the geographic and oceanographic isolation of Iceland, it is far from being excluded as a recipient region. Ascidians have successfully been able to establish stable populations in Iceland that are slowly expanding around the SW region. Here we report the first record of Ascidiella scabra in Icelandic waters, and the spread of seven non-indigenous ascidians across the S-SW Icelandic harbours. We compare their relative abundances to our survey from 2018. The bulk of these ascidians is not only present in the temperate Atlantic Ocean, but also in the Northwest Pacific and temperate Australasia, revealing that global homogenization of the ascidiofauna is emerging in anthropized coastal areas. The rising of sea surface temperature, driven by climate change, is likely to continue to support the development of this scenario leading to biodiversity loss, which could endanger living resources with severe economic impacts.
{"title":"Recent spread of non-indigenous ascidians (Chordata: Tunicata) in Icelandic harbours","authors":"J. Micael, A. Ramos-Esplá, Pedro Rodrigues, S. Gíslason","doi":"10.1080/17451000.2023.2176882","DOIUrl":"https://doi.org/10.1080/17451000.2023.2176882","url":null,"abstract":"ABSTRACT Global shipping facilitates the introduction of fouling organisms to new geographic areas. The increase in maritime transport in recent decades has led to unprecedented development, where marine coastal waters have become one of the most invaded habitats around the globe. Among the most successful invaders are ascidians. Despite the geographic and oceanographic isolation of Iceland, it is far from being excluded as a recipient region. Ascidians have successfully been able to establish stable populations in Iceland that are slowly expanding around the SW region. Here we report the first record of Ascidiella scabra in Icelandic waters, and the spread of seven non-indigenous ascidians across the S-SW Icelandic harbours. We compare their relative abundances to our survey from 2018. The bulk of these ascidians is not only present in the temperate Atlantic Ocean, but also in the Northwest Pacific and temperate Australasia, revealing that global homogenization of the ascidiofauna is emerging in anthropized coastal areas. The rising of sea surface temperature, driven by climate change, is likely to continue to support the development of this scenario leading to biodiversity loss, which could endanger living resources with severe economic impacts.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"566 - 576"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43521525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT The false mussel Mytilopsis sallei (Récluz, 1849) invaded the Songkhla Lagoon System in southern Thailand more than two decades ago. The false mussel forms dense beds, creating three-dimensional habitat structures on soft substrata which harbour a myriad of organisms. We compare a community of benthic macroinvertebrates in a habitat modified by M. sallei with a community in an unmodified habitat. The study focused on a canal feeding into the southern end of the lagoon system and covered three seasons (north-east monsoon season, dry season and south-west monsoon season) in a 12-month period. A total of 26 taxa were present in the modified habitat and 22 in the unmodified habitat. In the modified habitat, abundances of other byssally attached bivalves, flatworms and some species of amphipods were more than an order of magnitude greater than abundances in the unmodified habitat. Differences in the community composition between habitats were observed but were dependent on sampling location and time. Although the modified habitat hosted greater numbers of species and individuals in most comparisons, the Shannon–Wiener index and Pielou's evenness index were lower for this habitat as it tended to be dominated by a few taxa. The results highlight the role of M. sallei as a habitat engineer that promotes species richness and abundance of some benthic macroinvertebrates. Nonetheless, temporal variation in environmental drivers, especially salinity, might also be important in determining biodiversity in the studied estuarine system.
{"title":"Bioengineering by the alien false mussel Mytilopsis sallei (Bivalvia: Dreissenidae) affects small-scale distribution pattern of benthic macroinvertebrates in an estuarine system","authors":"Lutfee Hayeewachi, Eknarin Rodcharoen, Kringpaka Wangkulangkul","doi":"10.1080/17451000.2023.2169465","DOIUrl":"https://doi.org/10.1080/17451000.2023.2169465","url":null,"abstract":"ABSTRACT The false mussel Mytilopsis sallei (Récluz, 1849) invaded the Songkhla Lagoon System in southern Thailand more than two decades ago. The false mussel forms dense beds, creating three-dimensional habitat structures on soft substrata which harbour a myriad of organisms. We compare a community of benthic macroinvertebrates in a habitat modified by M. sallei with a community in an unmodified habitat. The study focused on a canal feeding into the southern end of the lagoon system and covered three seasons (north-east monsoon season, dry season and south-west monsoon season) in a 12-month period. A total of 26 taxa were present in the modified habitat and 22 in the unmodified habitat. In the modified habitat, abundances of other byssally attached bivalves, flatworms and some species of amphipods were more than an order of magnitude greater than abundances in the unmodified habitat. Differences in the community composition between habitats were observed but were dependent on sampling location and time. Although the modified habitat hosted greater numbers of species and individuals in most comparisons, the Shannon–Wiener index and Pielou's evenness index were lower for this habitat as it tended to be dominated by a few taxa. The results highlight the role of M. sallei as a habitat engineer that promotes species richness and abundance of some benthic macroinvertebrates. Nonetheless, temporal variation in environmental drivers, especially salinity, might also be important in determining biodiversity in the studied estuarine system.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"577 - 588"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43543682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-26DOI: 10.1080/17451000.2023.2174263
Souvik Bag, Basanta Sarkar, M. Seal, A. Chatterjee, Ayan Mondal, S. Chatterjee
ABSTRACT The Sundarbans mangrove is a transitional zone between terrestrial land and sea, a unique location in our global geography. This study identifies the richness and population dynamics of bacterial populations along different seasons in the rooted and unrooted regions of soil sediments in Sundarbans, West Bengal. Throughout the year, bacterial populations were higher in the rooted sediment zone, than the unrooted area. The rooted zone contains more silt and clay but the unrooted zone harbours more silty, sandy soil. Salinity is lower in the unrooted zone. The heterotrophic bacterial populations were higher than other types of bacteria in both regions irrespective of seasonal variation. The results revealed that the most varied seasons were the monsoon season in the rooted and unrooted sediment region. The changes identified in this study were most likely due to variances in the microhabitat associated with mangrove root, physicochemical parameters and seasonal fluctuations.
{"title":"Diversity and seasonal prevalence of starch hydrolysing, phosphate solubilizing and nitrogen-fixing bacterial groups of rooted and un-rooted regions of tropical mangrove sediments of Sundarbans, West Bengal, India","authors":"Souvik Bag, Basanta Sarkar, M. Seal, A. Chatterjee, Ayan Mondal, S. Chatterjee","doi":"10.1080/17451000.2023.2174263","DOIUrl":"https://doi.org/10.1080/17451000.2023.2174263","url":null,"abstract":"ABSTRACT The Sundarbans mangrove is a transitional zone between terrestrial land and sea, a unique location in our global geography. This study identifies the richness and population dynamics of bacterial populations along different seasons in the rooted and unrooted regions of soil sediments in Sundarbans, West Bengal. Throughout the year, bacterial populations were higher in the rooted sediment zone, than the unrooted area. The rooted zone contains more silt and clay but the unrooted zone harbours more silty, sandy soil. Salinity is lower in the unrooted zone. The heterotrophic bacterial populations were higher than other types of bacteria in both regions irrespective of seasonal variation. The results revealed that the most varied seasons were the monsoon season in the rooted and unrooted sediment region. The changes identified in this study were most likely due to variances in the microhabitat associated with mangrove root, physicochemical parameters and seasonal fluctuations.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"531 - 543"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45902025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-26DOI: 10.1080/17451000.2023.2173783
Minghu Wang, Chih-Feng Chen, Frank Paolo Jay B. Albarico, Wen-Pei Tsai, Chiu-wen Chen, C. Dong
ABSTRACT Phthalate esters (PAEs) are emerging pollutants commonly found in plastic products. Thus, increasing plastic pollution in the marine environment amplify their entry and potential impacts on aquatic species. Likewise, pollutants may accumulate in top predators such as sharks and are highly consumed in many countries. Therefore, this study evaluated the concentrations of 10 PAEs plasticizers in commercially important Indian Ocean silky sharks Carcharhinus falciformis and their toxicity risks in children and adults. Results showed the concentrations of ΣPAEs in shark muscle ranging between 5,402–34,577 ng/g ww. PAEs in silky shark muscles appeared to be six times higher in locations near the coasts (islands) with higher anthropogenic impacts. Low molecular weight PAEs like DMP and DnBP dominated PAEs in shark muscle tissues. Moreover, the PAE levels in shark muscles did not significantly increase with length and weight, indicating their relative impacts in all shark sizes. For the estimate of the daily intakes (EDI), the DEHP was 32 μg/kg bw/day in preschool children and 23 μg/kg bw/day in adults (the DEHP Reference Dose (RfD) of 20 μg/kg bw/day). Toxicity risk assessment showed unacceptable levels indicating long-term dietary risks for consumers.
{"title":"Concentrations of phthalate esters on Indian Ocean silky sharks and their long-term dietary consumption risks","authors":"Minghu Wang, Chih-Feng Chen, Frank Paolo Jay B. Albarico, Wen-Pei Tsai, Chiu-wen Chen, C. Dong","doi":"10.1080/17451000.2023.2173783","DOIUrl":"https://doi.org/10.1080/17451000.2023.2173783","url":null,"abstract":"ABSTRACT Phthalate esters (PAEs) are emerging pollutants commonly found in plastic products. Thus, increasing plastic pollution in the marine environment amplify their entry and potential impacts on aquatic species. Likewise, pollutants may accumulate in top predators such as sharks and are highly consumed in many countries. Therefore, this study evaluated the concentrations of 10 PAEs plasticizers in commercially important Indian Ocean silky sharks Carcharhinus falciformis and their toxicity risks in children and adults. Results showed the concentrations of ΣPAEs in shark muscle ranging between 5,402–34,577 ng/g ww. PAEs in silky shark muscles appeared to be six times higher in locations near the coasts (islands) with higher anthropogenic impacts. Low molecular weight PAEs like DMP and DnBP dominated PAEs in shark muscle tissues. Moreover, the PAE levels in shark muscles did not significantly increase with length and weight, indicating their relative impacts in all shark sizes. For the estimate of the daily intakes (EDI), the DEHP was 32 μg/kg bw/day in preschool children and 23 μg/kg bw/day in adults (the DEHP Reference Dose (RfD) of 20 μg/kg bw/day). Toxicity risk assessment showed unacceptable levels indicating long-term dietary risks for consumers.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"599 - 610"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45971833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-26DOI: 10.1080/17451000.2023.2169463
L. Gao, Zhongjian Huang, Z. Zhong, Xiaomeng Shi, Xing Chang, Yuhong Sun, Nuoyan Zhang, Ning Zou, Shanying Tong
ABSTRACT Although numerous studies have examined the responses of coccolithophores to ocean acidification, less is known on the fate of those calcifying organisms when they sink to the ocean’s aphotic regions. In this study, the coccolithophore Emiliania huxleyi was first grown under a regular 12/12 light/dark cycle at 20°C, exposed to both high (1000 μatm) and ambient CO2 (410 μatm) levels. The cultures were then transferred to continuous darkness for 96 h at 20°C or 16°C. We found that elevated CO2 decreased the specific growth rate while increasing the cellular particulate organic carbon (POC) and nitrogen (PON) contents and the POC/PON ratio of E. huxleyi in the light/dark period. After 96 h of dark acclimation, the cell abundance decreased more obviously at 20°C than at 16°C but showed no significant difference between the two CO2 treatments. The decrease in volumetric POC concentration was most prominent in the high CO2/20°C treatment and least in the ambient CO2/16°C treatment. At 16°C, the PON concentration increased in the high CO2 cultures and exhibited no change in the ambient CO2 cultures. While at 20°C, the PON concentration decreased significantly both under high and ambient CO2 conditions. The final POC/PON ratio showed no significant differences among the different temperature and CO2 treatments. Overall, a higher percentage of POC relative to that of PON was lost in darkness with increasing CO2 concentration, with potential implications for the ocean’s nutrient cycle.
{"title":"Effects of elevated pCO2 on the response of coccolithophore Emiliania huxleyi to prolonged darkness","authors":"L. Gao, Zhongjian Huang, Z. Zhong, Xiaomeng Shi, Xing Chang, Yuhong Sun, Nuoyan Zhang, Ning Zou, Shanying Tong","doi":"10.1080/17451000.2023.2169463","DOIUrl":"https://doi.org/10.1080/17451000.2023.2169463","url":null,"abstract":"ABSTRACT Although numerous studies have examined the responses of coccolithophores to ocean acidification, less is known on the fate of those calcifying organisms when they sink to the ocean’s aphotic regions. In this study, the coccolithophore Emiliania huxleyi was first grown under a regular 12/12 light/dark cycle at 20°C, exposed to both high (1000 μatm) and ambient CO2 (410 μatm) levels. The cultures were then transferred to continuous darkness for 96 h at 20°C or 16°C. We found that elevated CO2 decreased the specific growth rate while increasing the cellular particulate organic carbon (POC) and nitrogen (PON) contents and the POC/PON ratio of E. huxleyi in the light/dark period. After 96 h of dark acclimation, the cell abundance decreased more obviously at 20°C than at 16°C but showed no significant difference between the two CO2 treatments. The decrease in volumetric POC concentration was most prominent in the high CO2/20°C treatment and least in the ambient CO2/16°C treatment. At 16°C, the PON concentration increased in the high CO2 cultures and exhibited no change in the ambient CO2 cultures. While at 20°C, the PON concentration decreased significantly both under high and ambient CO2 conditions. The final POC/PON ratio showed no significant differences among the different temperature and CO2 treatments. Overall, a higher percentage of POC relative to that of PON was lost in darkness with increasing CO2 concentration, with potential implications for the ocean’s nutrient cycle.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"509 - 519"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41488958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-26DOI: 10.1080/17451000.2023.2169464
Dining Nika Alina, Rita Rachmawati, N. Zamani, H. Madduppa
ABSTRACT Corals thrive in symbiotic relationships with a variety of microorganisms, including endosymbiont algae. The interaction between coral and microbial associations has been extensively researched since it is thought to play a function in coral health. Temperature and light are two abiotic elements that contribute to coral life. Corals in reef-flat environments frequently face variations in these two characteristics due to their proximity to shallow seas. This study aims to compare the microbial diversity and abundance associated with the coral Acropora pulchra on the reef flat under two conditions, namely corals that emerged to the surface at low tide (SF) and corals that submerged over time (SM) and to compare the microbial diversity of both with those found in its adjacent seawaters. Microbial analysis on 16S rRNA region V4 showed that the alpha diversity of coral microbial communities and seawaters was not significantly different. However, differences in abundance were noticed at the phylum and genus levels. With p-value < 0.05, PCoA analysis using the Bray–Curtis test showed that the coral microbial community was significantly different from the surrounding seawaters. This study indicates that under different conditions, corals of the same species can be dominated by different microbial groups. This study also confirms the uniqueness between coral microbes and their adjacent seawaters. The abundance of certain microbes is a host mechanism for survival.
{"title":"Exposure at low tide leads to a different microbial abundance of intertidal coral Acropora pulchra","authors":"Dining Nika Alina, Rita Rachmawati, N. Zamani, H. Madduppa","doi":"10.1080/17451000.2023.2169464","DOIUrl":"https://doi.org/10.1080/17451000.2023.2169464","url":null,"abstract":"ABSTRACT Corals thrive in symbiotic relationships with a variety of microorganisms, including endosymbiont algae. The interaction between coral and microbial associations has been extensively researched since it is thought to play a function in coral health. Temperature and light are two abiotic elements that contribute to coral life. Corals in reef-flat environments frequently face variations in these two characteristics due to their proximity to shallow seas. This study aims to compare the microbial diversity and abundance associated with the coral Acropora pulchra on the reef flat under two conditions, namely corals that emerged to the surface at low tide (SF) and corals that submerged over time (SM) and to compare the microbial diversity of both with those found in its adjacent seawaters. Microbial analysis on 16S rRNA region V4 showed that the alpha diversity of coral microbial communities and seawaters was not significantly different. However, differences in abundance were noticed at the phylum and genus levels. With p-value < 0.05, PCoA analysis using the Bray–Curtis test showed that the coral microbial community was significantly different from the surrounding seawaters. This study indicates that under different conditions, corals of the same species can be dominated by different microbial groups. This study also confirms the uniqueness between coral microbes and their adjacent seawaters. The abundance of certain microbes is a host mechanism for survival.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"520 - 530"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42146315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-26DOI: 10.1080/17451000.2022.2153869
K. S. Tkachenko, Vũ Việt Dũng, V. Ha
ABSTRACT A phase shift from a stony-coral community to an alternative state represented by octocorals and corallimorpharians was recorded on a coral reef at the Hon Noi Islands (offshore area of south-central Vietnam). For a seven-year period, average stony-coral cover decreased from 80% to 4.7%, diversity of reef-building corals decreased from 169 to 17 species, and in the shallow area of a reef (1–4 m depth), the cover of corallimorpharians (mainly Rhodactis indosinensis) and octocorals (mainly Clavularia sp.) increased to 62%. Mass scleractinian mortality could have resulted from an outbreak of crown-of-thorns starfish, Acanthaster sp., which developed in the surrounding area in the last decade. The only significant contributor to stony-coral recovery on the study reef to date was the blue coral, Heliopora coerulea. Given the serious coral decline on the upstream reefs as potential sources for coral recruitment and competitive advantages of corallimorpharians and octocorals over scleractinians, the prospects for rapid scleractinian recovery of the study site are poor.
在越南中南部的汉诺伊群岛(Hon Noi Islands)的一个珊瑚礁上，记录了从石珊瑚群落到以八珊瑚和珊瑚形动物为代表的另一种状态的相变。在7年的时间里，石珊瑚的平均覆盖率从80%下降到4.7%，造礁珊瑚的多样性从169种下降到17种，在一个珊瑚礁的浅水区(1 ~ 4 m深度)，珊瑚类(主要是Rhodactis indosinensis)和八栖珊瑚(主要是Clavularia sp.)的覆盖率增加到62%。大量的硬核海星死亡可能是由于过去十年在周围地区发展的棘冠海星的爆发造成的。迄今为止，研究珊瑚礁上唯一对石珊瑚恢复有重大贡献的是蓝珊瑚，Heliopora coerulea。鉴于上游珊瑚礁作为珊瑚补充的潜在来源的珊瑚数量严重下降，以及珊瑚形和八角珊瑚相对于硬珊瑚的竞争优势，研究地点的硬珊瑚目快速恢复的前景不佳。
{"title":"Phase shift from a stony-coral to a soft-coral community on a coral reef: a case study of an alternative state","authors":"K. S. Tkachenko, Vũ Việt Dũng, V. Ha","doi":"10.1080/17451000.2022.2153869","DOIUrl":"https://doi.org/10.1080/17451000.2022.2153869","url":null,"abstract":"ABSTRACT A phase shift from a stony-coral community to an alternative state represented by octocorals and corallimorpharians was recorded on a coral reef at the Hon Noi Islands (offshore area of south-central Vietnam). For a seven-year period, average stony-coral cover decreased from 80% to 4.7%, diversity of reef-building corals decreased from 169 to 17 species, and in the shallow area of a reef (1–4 m depth), the cover of corallimorpharians (mainly Rhodactis indosinensis) and octocorals (mainly Clavularia sp.) increased to 62%. Mass scleractinian mortality could have resulted from an outbreak of crown-of-thorns starfish, Acanthaster sp., which developed in the surrounding area in the last decade. The only significant contributor to stony-coral recovery on the study reef to date was the blue coral, Heliopora coerulea. Given the serious coral decline on the upstream reefs as potential sources for coral recruitment and competitive advantages of corallimorpharians and octocorals over scleractinians, the prospects for rapid scleractinian recovery of the study site are poor.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"544 - 554"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42516376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-26DOI: 10.1080/17451000.2023.2176883
Valeli J. Bugota, C. Rumisha
ABSTRACT The tropical sandfish Holothuria (Metriatyla) scabra Jaeger, 1833 has been severely depleted in the Western Indian Ocean because it is easy to catch and in high demand. In response, Mainland Tanzania closed the fishery; however, the fishery remains open in the semi-autonomous islands of Zanzibar. Yet, it is unknown whether the aforementioned contrasting management measures are consistent with the genetic stock structure of the fishery. Therefore, this study analysed partial sequences (706 base pairs) of the cytochrome oxidase subunit I gene (COI) from four sandfish populations from Tanzania to assess the extent of genetic diversity and population structure. The populations showed low haplotype (0.17–0.44) and nucleotide diversities (0.025–0.084%), as well as small mutation-scaled effective size (9 × 10−4−17 × 10−4) compared to other marine macroinvertebrates from Tanzania, suggesting that the fishery has not recovered despite the ban that was imposed 16 years ago. Furthermore, Analysis of Molecular Variance (AMOVA) revealed a low and non-significant genetic differentiation index (F ST = 0.0047, p > 0.05), indicating a lack of population structure. The lack of population structure was further supported by phylogenetic analysis, which grouped together all COI haplotypes of sandfishes from both Zanzibar and Mainland Tanzania. This suggests that populations in Mainland Tanzania and Zanzibar are genetically homogeneous and that Zanzibari fishers may be targeting the same stock that is protected in Mainland Tanzania. Therefore, the fishery should be managed as a single unit and management measures between Mainland Tanzania and Zanzibar should be harmonized.
{"title":"Low genetic diversity and lack of genetic structure among populations of the sandfish Holothuria (Metriatyla) scabra on the Tanzanian coast","authors":"Valeli J. Bugota, C. Rumisha","doi":"10.1080/17451000.2023.2176883","DOIUrl":"https://doi.org/10.1080/17451000.2023.2176883","url":null,"abstract":"ABSTRACT The tropical sandfish Holothuria (Metriatyla) scabra Jaeger, 1833 has been severely depleted in the Western Indian Ocean because it is easy to catch and in high demand. In response, Mainland Tanzania closed the fishery; however, the fishery remains open in the semi-autonomous islands of Zanzibar. Yet, it is unknown whether the aforementioned contrasting management measures are consistent with the genetic stock structure of the fishery. Therefore, this study analysed partial sequences (706 base pairs) of the cytochrome oxidase subunit I gene (COI) from four sandfish populations from Tanzania to assess the extent of genetic diversity and population structure. The populations showed low haplotype (0.17–0.44) and nucleotide diversities (0.025–0.084%), as well as small mutation-scaled effective size (9 × 10−4−17 × 10−4) compared to other marine macroinvertebrates from Tanzania, suggesting that the fishery has not recovered despite the ban that was imposed 16 years ago. Furthermore, Analysis of Molecular Variance (AMOVA) revealed a low and non-significant genetic differentiation index (F ST = 0.0047, p > 0.05), indicating a lack of population structure. The lack of population structure was further supported by phylogenetic analysis, which grouped together all COI haplotypes of sandfishes from both Zanzibar and Mainland Tanzania. This suggests that populations in Mainland Tanzania and Zanzibar are genetically homogeneous and that Zanzibari fishers may be targeting the same stock that is protected in Mainland Tanzania. Therefore, the fishery should be managed as a single unit and management measures between Mainland Tanzania and Zanzibar should be harmonized.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"18 1","pages":"611 - 619"},"PeriodicalIF":1.1,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48244243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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