Pub Date : 2023-05-28DOI: 10.1080/17451000.2023.2224027
Raibel Núñez-González, S. M. Pauls
ABSTRACT Echinometra lucunter is a common Caribbean sea urchin, which the abundance and distribution were evaluated along a rocky platform at Cepe beach, Venezuela. Two surveys were conducted along transects perpendicular and parallel to the coast, from the shore to the wave breaking zone (WB), using 1m2 quadrat method. In survey-1 the smaller sea urchins (<1.8 cm) occurred in the tide pool zone (TP) and medium and large dominated in the WB. The average density recorded in the WB and TP (140.2 and 272.7 ind/m2 respectively) are among the highest values reported in the Caribbean. The maximum density recorded was 562 ind/m2 in the TP and most of them were juveniles (<1.8 cm). In survey-2 sea urchins (³3.0 cm) density ranged from 1 to 156 ind/m2 and the overall average was 29.6 (± 32.4) ind/m2. The highest density occurred in the platform western sector (average 43.2 ±41.3 ind/m2). In the transects parallel to the coast the sea urchin's abundance gradually decreased from the WB (130 ±12 ind/m2) towards the coast (0.3 ±0.37 ind/m2). In conclusion, the E. lucunter densities recorded on the Cepe beach platform are the highest values reported in the Caribbean.
{"title":"Abundance and distribution of Echinometra lucunter (Echinodermata, Echinoidea) at a rocky platform on the central coast of Venezuela","authors":"Raibel Núñez-González, S. M. Pauls","doi":"10.1080/17451000.2023.2224027","DOIUrl":"https://doi.org/10.1080/17451000.2023.2224027","url":null,"abstract":"ABSTRACT Echinometra lucunter is a common Caribbean sea urchin, which the abundance and distribution were evaluated along a rocky platform at Cepe beach, Venezuela. Two surveys were conducted along transects perpendicular and parallel to the coast, from the shore to the wave breaking zone (WB), using 1m2 quadrat method. In survey-1 the smaller sea urchins (<1.8 cm) occurred in the tide pool zone (TP) and medium and large dominated in the WB. The average density recorded in the WB and TP (140.2 and 272.7 ind/m2 respectively) are among the highest values reported in the Caribbean. The maximum density recorded was 562 ind/m2 in the TP and most of them were juveniles (<1.8 cm). In survey-2 sea urchins (³3.0 cm) density ranged from 1 to 156 ind/m2 and the overall average was 29.6 (± 32.4) ind/m2. The highest density occurred in the platform western sector (average 43.2 ±41.3 ind/m2). In the transects parallel to the coast the sea urchin's abundance gradually decreased from the WB (130 ±12 ind/m2) towards the coast (0.3 ±0.37 ind/m2). In conclusion, the E. lucunter densities recorded on the Cepe beach platform are the highest values reported in the Caribbean.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"271 - 278"},"PeriodicalIF":1.1,"publicationDate":"2023-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41893764","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 : 2023-05-12DOI: 10.1080/17451000.2023.2203499
N. Başçınar, D. Misir, C. Altuntaş, Y. Genç, M. Dağtekin, M. Erbay, Gülsüm Balçık Mısır, Erdinç Aydın
ABSTRACT The sex ratio, length–weight relationship (LWR) and diets based on stomach contents of whiting (Merlangius merlangus) were investigated in the south-eastern Black Sea, Turkey. A total of 3507 females (7.5–24.0 cm), 1602 males (9.4–20.0 cm), and 78 unidentified sex (5.5–16.5 cm) whiting were caught during monthly sampling from February to December 2017. The sex ratio was dominated by females, and their ratio (♀:♂, 1:0.46) significantly deviated from 1:1. The LWR indicated a negative allometric growth for males, while females had a positive allometric growth pattern. The stomach content analysis based on the relative importance index (IRI%) indicated exclusively piscivorous diets dominant by Sprattus sprattus and Engraulis encrasicolus made up more than 91 IRI% of the total diets of M. merlangus. The modified Costello-Amundsen’s graphical analyses evinced the specialized feeding strategy of M. merlangus throughout this study. The contribution of these two preys to the diets of M. merlangus showed considerable seasonal variations that were totally dependent on their abundance. Sprattus sprattus contributed to more than 98% of the total diets during June, July and August, while in the following months, E. encrasicolus appeared to take its position. Based on fish size, a general trend of a rise in prey diversity was found with increasing fish size. Also, the contribution of S. sprattus tended to decrease with increasing predator size, which is replaced by a rise in E. encrasicolus contribution. Hence, larger M. merlangus predominantly fed on E. encrasicolus while smaller size predators preferred to feed on S. sprattus.
{"title":"Length–weight relationship and seasonal variations in diet composition of whiting (Merlangius merlangus) in the South-eastern Black Sea","authors":"N. Başçınar, D. Misir, C. Altuntaş, Y. Genç, M. Dağtekin, M. Erbay, Gülsüm Balçık Mısır, Erdinç Aydın","doi":"10.1080/17451000.2023.2203499","DOIUrl":"https://doi.org/10.1080/17451000.2023.2203499","url":null,"abstract":"ABSTRACT The sex ratio, length–weight relationship (LWR) and diets based on stomach contents of whiting (Merlangius merlangus) were investigated in the south-eastern Black Sea, Turkey. A total of 3507 females (7.5–24.0 cm), 1602 males (9.4–20.0 cm), and 78 unidentified sex (5.5–16.5 cm) whiting were caught during monthly sampling from February to December 2017. The sex ratio was dominated by females, and their ratio (♀:♂, 1:0.46) significantly deviated from 1:1. The LWR indicated a negative allometric growth for males, while females had a positive allometric growth pattern. The stomach content analysis based on the relative importance index (IRI%) indicated exclusively piscivorous diets dominant by Sprattus sprattus and Engraulis encrasicolus made up more than 91 IRI% of the total diets of M. merlangus. The modified Costello-Amundsen’s graphical analyses evinced the specialized feeding strategy of M. merlangus throughout this study. The contribution of these two preys to the diets of M. merlangus showed considerable seasonal variations that were totally dependent on their abundance. Sprattus sprattus contributed to more than 98% of the total diets during June, July and August, while in the following months, E. encrasicolus appeared to take its position. Based on fish size, a general trend of a rise in prey diversity was found with increasing fish size. Also, the contribution of S. sprattus tended to decrease with increasing predator size, which is replaced by a rise in E. encrasicolus contribution. Hence, larger M. merlangus predominantly fed on E. encrasicolus while smaller size predators preferred to feed on S. sprattus.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"305 - 316"},"PeriodicalIF":1.1,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46967672","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 : 2023-05-03DOI: 10.1080/17451000.2023.2203504
Hellen Ceriello, S. Stampar
ABSTRACT Behaviour research on Cnidaria, particularly Ceriantharia (Cnidaria, Anthozoa), is generally uncommon. Although ceriantharians or tube-dwelling anemones are known to build soft tubes, their tube-building behaviours remain unknown. In this study, we describe for the first time the tube-building behaviour of Ceriantheomorphe brasiliensis and detail its behaviour in natural habitat, including illustrations and videos of live specimens. Our results showed that C. brasiliensis can build more than one tube throughout its life, the tubes are usually ‘L-shaped’, longer than the polyp, and vertically oriented when built in deeper substrates, but horizontally oriented when built in shallower substrates. During tube construction, the polyp does not feed or use its tentacles to catch or select specific sediment particle sizes for tube construction. Given the vertical orientation of the tube, it is possible that the tube-building behaviour of C. brasiliensis differs from that of other species. Although this study only included a single specimen, the behaviours observed were constantly repeated by the animal in every test, from the first trial to the last, suggesting that they can occur on occasion. Furthermore, this research contains useful information that may guide future studies of tube-building behaviour in Ceriantharia which are, currently, non-existent.
{"title":"Ceriantheomorphe brasiliensis (Cnidaria; Ceriantharia): how does it behave?","authors":"Hellen Ceriello, S. Stampar","doi":"10.1080/17451000.2023.2203504","DOIUrl":"https://doi.org/10.1080/17451000.2023.2203504","url":null,"abstract":"ABSTRACT Behaviour research on Cnidaria, particularly Ceriantharia (Cnidaria, Anthozoa), is generally uncommon. Although ceriantharians or tube-dwelling anemones are known to build soft tubes, their tube-building behaviours remain unknown. In this study, we describe for the first time the tube-building behaviour of Ceriantheomorphe brasiliensis and detail its behaviour in natural habitat, including illustrations and videos of live specimens. Our results showed that C. brasiliensis can build more than one tube throughout its life, the tubes are usually ‘L-shaped’, longer than the polyp, and vertically oriented when built in deeper substrates, but horizontally oriented when built in shallower substrates. During tube construction, the polyp does not feed or use its tentacles to catch or select specific sediment particle sizes for tube construction. Given the vertical orientation of the tube, it is possible that the tube-building behaviour of C. brasiliensis differs from that of other species. Although this study only included a single specimen, the behaviours observed were constantly repeated by the animal in every test, from the first trial to the last, suggesting that they can occur on occasion. Furthermore, this research contains useful information that may guide future studies of tube-building behaviour in Ceriantharia which are, currently, non-existent.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"294 - 304"},"PeriodicalIF":1.1,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44586866","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 : 2023-05-01DOI: 10.1080/17451000.2023.2203503
Samia Ben Mohamed, M. Mejri, A. Chalh, Adel A. Basyouny Shahin, J. Quignard, M. Trabelsi, A. Ben Faleh
ABSTRACT This study aimed to assess the geographic variation in otoliths’ shape and size and the effect of potential fluctuating asymmetry (FA) in otolith size on the stock structure of Mullus barbatus collected from the Bizerte and Ghar El Melh lagoons located in northeastern Tunisia and to evaluate the relationship between the otolith mass asymmetry (OMA) and total length (TL). Analysis of the otolith shape showed a statistically significant intersexual shape difference, i.e. asymmetry, in the left and right and left-left and right-right otoliths between populations of the two lagoons. In addition, significant intersexual differences were detected in Lo, Wo, and Mo, as well as in FA, between the left and right otoliths among the two populations. Moreover, no statistically significant relationship (P > 0.05) was found between OMA and TL between and within the two populations. At the intrapopulation level, a significant intrasexual asymmetry was observed in the left and right, as well as on left-left and right-right sides, otoliths’ shape and size only within the Ghar El Melh lagoon. Discriminant function analysis of the otoliths’ contour shape confirmed the presence of two separate stocks representing the Bizerte and Ghar El Melh lagoons, which should be managed separately. This significant inter and intrapopulation asymmetry detected in otolith shape and size due to FA can be attributed to the instability of larval development caused either by environmental stress associated with variation in water temperature, salinity, feeding conditions and pollutants or due to poor living conditions of larvae resulting from unfavourable environments.
摘要本研究旨在评估突尼斯东北部比塞特和加尔梅尔泻湖采集的barbatus耳石形状和大小的地理差异，以及耳石大小的潜在波动不对称性(FA)对种群结构的影响，并评估耳石质量不对称性(OMA)与总长度(TL)之间的关系。耳石形状分析显示，两个泻湖种群的左右耳石、左右耳石和左右耳石存在统计学上显著的雌雄间性形状差异，即不对称。此外，在Lo, Wo和Mo以及FA中，两个人群的左耳石和右耳石之间存在显著的雌雄间性差异。此外，在两个人群之间和内部，OMA与TL之间没有统计学上的显著关系(P < 0.05)。在种群内水平上，仅在Ghar El Melh泻湖内，在左右、左右以及左右侧耳石的形状和大小上观察到明显的性内不对称。耳石轮廓形状的判别函数分析证实存在两个独立的群落，分别代表比塞特和加尔梅尔泻湖，应分别管理。由于FA导致的耳石形状和大小的显著种群间和种群内不对称性可归因于与水温、盐度、摄食条件和污染物变化相关的环境压力或不利环境导致的幼虫生存条件差造成的幼虫发育不稳定。
{"title":"Distinct inter and intrapopulation variation in the otolith shape and size of Mullus barbatus (Actinopterygii: Mullidae) from the Bizerte and Ghar El Melh lagoons in Tunisian waters","authors":"Samia Ben Mohamed, M. Mejri, A. Chalh, Adel A. Basyouny Shahin, J. Quignard, M. Trabelsi, A. Ben Faleh","doi":"10.1080/17451000.2023.2203503","DOIUrl":"https://doi.org/10.1080/17451000.2023.2203503","url":null,"abstract":"ABSTRACT This study aimed to assess the geographic variation in otoliths’ shape and size and the effect of potential fluctuating asymmetry (FA) in otolith size on the stock structure of Mullus barbatus collected from the Bizerte and Ghar El Melh lagoons located in northeastern Tunisia and to evaluate the relationship between the otolith mass asymmetry (OMA) and total length (TL). Analysis of the otolith shape showed a statistically significant intersexual shape difference, i.e. asymmetry, in the left and right and left-left and right-right otoliths between populations of the two lagoons. In addition, significant intersexual differences were detected in Lo, Wo, and Mo, as well as in FA, between the left and right otoliths among the two populations. Moreover, no statistically significant relationship (P > 0.05) was found between OMA and TL between and within the two populations. At the intrapopulation level, a significant intrasexual asymmetry was observed in the left and right, as well as on left-left and right-right sides, otoliths’ shape and size only within the Ghar El Melh lagoon. Discriminant function analysis of the otoliths’ contour shape confirmed the presence of two separate stocks representing the Bizerte and Ghar El Melh lagoons, which should be managed separately. This significant inter and intrapopulation asymmetry detected in otolith shape and size due to FA can be attributed to the instability of larval development caused either by environmental stress associated with variation in water temperature, salinity, feeding conditions and pollutants or due to poor living conditions of larvae resulting from unfavourable environments.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"234 - 248"},"PeriodicalIF":1.1,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44724733","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 : 2023-04-19DOI: 10.1080/17451000.2023.2193899
U. Motro, N. Simon‐Blecher, S. Frumin, Y. Achituv
ABSTRACT The toothed barnacle Chthamalus dentatus has a wide distribution in the intertidal zone along the coasts of Africa, ostensibly occurring from Madagascar and Mozambique in the West Indian Ocean to Senegal in the Eastern Atlantic Ocean. We studied the differences in the mitochondrial COI gene of 287 individuals from 15 different locations and found that this taxon, which morphologically is considered a single species, actually compromises three genetically distinct clades – the South African, the Namibian, and the Cameroonian. The genetic differences between these units are similar or larger than those found between different species of Chthamalus. We suggest that the nominal species C. dentatus is a cluster of three cryptic species. These cryptic species are separated by a series of upwelling systems that are likely to act as barriers to the distribution of propagules of C. dentatus. Based on molecular and morphological data, we indicate that C. dentatus is probably a close relative of the Caribbean and Central American species of Chthamalus.
{"title":"Brewed in the African pot: the phylogeography of the toothed barnacle Chthamalus dentatus (Chthamaloidea: Chthamalidae)","authors":"U. Motro, N. Simon‐Blecher, S. Frumin, Y. Achituv","doi":"10.1080/17451000.2023.2193899","DOIUrl":"https://doi.org/10.1080/17451000.2023.2193899","url":null,"abstract":"ABSTRACT The toothed barnacle Chthamalus dentatus has a wide distribution in the intertidal zone along the coasts of Africa, ostensibly occurring from Madagascar and Mozambique in the West Indian Ocean to Senegal in the Eastern Atlantic Ocean. We studied the differences in the mitochondrial COI gene of 287 individuals from 15 different locations and found that this taxon, which morphologically is considered a single species, actually compromises three genetically distinct clades – the South African, the Namibian, and the Cameroonian. The genetic differences between these units are similar or larger than those found between different species of Chthamalus. We suggest that the nominal species C. dentatus is a cluster of three cryptic species. These cryptic species are separated by a series of upwelling systems that are likely to act as barriers to the distribution of propagules of C. dentatus. Based on molecular and morphological data, we indicate that C. dentatus is probably a close relative of the Caribbean and Central American species of Chthamalus.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42370079","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 : 2023-03-16DOI: 10.1080/17451000.2023.2198240
Hannah Jacob, K. Springer, Laura Belter, A. Kunzmann
ABSTRACT Extreme seawater temperatures are linked to increasingly frequent cnidarian bleaching, a breakdown of the symbiosis between host and endosymbiotic dinoflagellates. This can be driven by several anthropogenic stressors, of which seawater warming is a major and frequent one. It remains unclear whether this is caused by intrinsic properties of the host or exclusively by the symbiont. This study investigates the response to elevated temperatures of dinoflagellate symbionts in and ex hospite, particularly to find out whether thermal tolerance differs between endosymbionts and free-living micro-algae. Maximum quantum yield of photosystem II (Fv/Fm ) and symbiont cell density were measured in seven different cnidarian species and five cultures of isolated endosymbionts subjected to temperatures of 26°C (control), 30°C and 34°C for 21 days. Isolated dinoflagellate cells showed a susceptibility to elevated temperatures of 30°C, evidenced by a decrease in photochemical efficiency and cell density of the cultures, as well as a progressive disintegration of cellular structures and loss of pigmentation of all but two cultures during the first week of exposure. Bleaching of coral holobionts at 30°C could be explained by reduced density of algae cells in host tissue. This effect was particularly evident in soft corals. Exposure to 34°C resulted in drastic bleaching of stony coral species, anemones and jellyfish, and even the death of soft corals. Data from this study show different responses to elevated thermal conditions across several species and different genera of symbionts and emphasize the important role of dinoflagellate symbionts in the holobiont response to elevated seawater temperatures.
{"title":"Symbiodiniaceae in and ex hospite have differential physiological responses under different heat stress scenarios","authors":"Hannah Jacob, K. Springer, Laura Belter, A. Kunzmann","doi":"10.1080/17451000.2023.2198240","DOIUrl":"https://doi.org/10.1080/17451000.2023.2198240","url":null,"abstract":"ABSTRACT Extreme seawater temperatures are linked to increasingly frequent cnidarian bleaching, a breakdown of the symbiosis between host and endosymbiotic dinoflagellates. This can be driven by several anthropogenic stressors, of which seawater warming is a major and frequent one. It remains unclear whether this is caused by intrinsic properties of the host or exclusively by the symbiont. This study investigates the response to elevated temperatures of dinoflagellate symbionts in and ex hospite, particularly to find out whether thermal tolerance differs between endosymbionts and free-living micro-algae. Maximum quantum yield of photosystem II (Fv/Fm ) and symbiont cell density were measured in seven different cnidarian species and five cultures of isolated endosymbionts subjected to temperatures of 26°C (control), 30°C and 34°C for 21 days. Isolated dinoflagellate cells showed a susceptibility to elevated temperatures of 30°C, evidenced by a decrease in photochemical efficiency and cell density of the cultures, as well as a progressive disintegration of cellular structures and loss of pigmentation of all but two cultures during the first week of exposure. Bleaching of coral holobionts at 30°C could be explained by reduced density of algae cells in host tissue. This effect was particularly evident in soft corals. Exposure to 34°C resulted in drastic bleaching of stony coral species, anemones and jellyfish, and even the death of soft corals. Data from this study show different responses to elevated thermal conditions across several species and different genera of symbionts and emphasize the important role of dinoflagellate symbionts in the holobiont response to elevated seawater temperatures.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"108 - 120"},"PeriodicalIF":1.1,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48317448","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 : 2023-03-16DOI: 10.1080/17451000.2023.2205148
M. Pinheiro, Fernanda V. B. Sousa, J. F. Perroca, Mauro M. T. Silva, Raimundo L. M. Souza, T. A. Mota, S. S. Rocha
ABSTRACT Monitoring focusing on target species is an important tool to better understand biodiversity. The density, size, extractive potential and population structure of Ucides cordatus reflects the conservation of the mangrove ecosystem. The Federal Brazilian Institution of Biodiversity Conservation (ICMBio) defined a protocol to standardize and estimate these parameters using an indirect method that does not depend on the capture of individuals of a species. In this protocol are used models to adjust diameter of crabs' gallery (DG) measures into largest carapace width (LC). Because this relationship (LC vs. DG) can differ according to geographic positions, the present study assessed it in three Brazilian mangrove areas (north, north-east, and south-east regions). Linear models of this relationship were compared between sexes, and also applied as a single model considering these Brazilian localities as a fixed factor and in three independent models for each locality separately. Equations did not differ significantly between sex and could be represented as one to each locality. However, a simpler linear model not including mangroves as fixed factors can be used to represent the entire latitudinal gradient, promoting a homogeneity of the estimation error, due to cover the entire body size (LC) variation of the Ucides cordatus crab. HIGHLIGHTS Body size and population structure of Ucides cordatus can be successfully estimated by measurements of the burrows, using an indirect method. Indirect method is advantageous in continuous monitoring, avoiding the higher impact promoted by capture in a specific mangrove area. Regional models can be more accurate, but a single and simpler model representing the entire latitudinal gradient can promote homogeneity of the estimation error and is more manageable.
{"title":"Advances in population monitoring of the mangrove ‘uçá’-crab (Ucides cordatus): reduction of body size variance for better evaluation of population structure and extractive potential","authors":"M. Pinheiro, Fernanda V. B. Sousa, J. F. Perroca, Mauro M. T. Silva, Raimundo L. M. Souza, T. A. Mota, S. S. Rocha","doi":"10.1080/17451000.2023.2205148","DOIUrl":"https://doi.org/10.1080/17451000.2023.2205148","url":null,"abstract":"ABSTRACT Monitoring focusing on target species is an important tool to better understand biodiversity. The density, size, extractive potential and population structure of Ucides cordatus reflects the conservation of the mangrove ecosystem. The Federal Brazilian Institution of Biodiversity Conservation (ICMBio) defined a protocol to standardize and estimate these parameters using an indirect method that does not depend on the capture of individuals of a species. In this protocol are used models to adjust diameter of crabs' gallery (DG) measures into largest carapace width (LC). Because this relationship (LC vs. DG) can differ according to geographic positions, the present study assessed it in three Brazilian mangrove areas (north, north-east, and south-east regions). Linear models of this relationship were compared between sexes, and also applied as a single model considering these Brazilian localities as a fixed factor and in three independent models for each locality separately. Equations did not differ significantly between sex and could be represented as one to each locality. However, a simpler linear model not including mangroves as fixed factors can be used to represent the entire latitudinal gradient, promoting a homogeneity of the estimation error, due to cover the entire body size (LC) variation of the Ucides cordatus crab. HIGHLIGHTS Body size and population structure of Ucides cordatus can be successfully estimated by measurements of the burrows, using an indirect method. Indirect method is advantageous in continuous monitoring, avoiding the higher impact promoted by capture in a specific mangrove area. Regional models can be more accurate, but a single and simpler model representing the entire latitudinal gradient can promote homogeneity of the estimation error and is more manageable.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"141 - 153"},"PeriodicalIF":1.1,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45089126","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 : 2023-03-16DOI: 10.1080/17451000.2023.2203502
T. Efimova, T. Churilova, E. Skorokhod, V. Buchelnikova, Anatoly S. Buchelnikov, N. Moiseeva, P. Salyuk, I. Stepochkin, Aleksandr Melnik
ABSTRACT Spectral bio-optical properties and phytoplankton photosynthetic parameters were measured in Black Sea coastal waters near Sevastopol in May–July 2020–2021. Chlorophyll a concentration (Chl-a) differed by more than one order of magnitude between stations (0.20–5.6 mg/m3) due to the effect of the Chyornaya river runoff. Light absorption coefficients by all optically active components as well as total non-water absorption coefficients co-varied with Chl-a, which reflected a link between trophic status and water optical properties. An increase in total non-water absorption resulted in a shift of the maximum of downwelling irradiance to the longer wavelength (from 511 nm to 567 nm). Phytoplankton photosynthetic parameters were depth-dependent variables due to phytoplankton acclimations to light intensity without dependence on water trophic status. Gross primary production was estimated by the full spectral approach. Primary production (1.3–31 mgC/m3/h) co-varied with Chl-a. Chlorophyll a specific photosynthesis rate (4.3–8.0 mgC/mgChl/h) varied by about twice at the sea surface but no dependence on Chl-a was revealed.
{"title":"Effect of water trophic status on bio-optical properties and productive characteristics of phytoplankton of the Black Sea coastal waters near Sevastopol","authors":"T. Efimova, T. Churilova, E. Skorokhod, V. Buchelnikova, Anatoly S. Buchelnikov, N. Moiseeva, P. Salyuk, I. Stepochkin, Aleksandr Melnik","doi":"10.1080/17451000.2023.2203502","DOIUrl":"https://doi.org/10.1080/17451000.2023.2203502","url":null,"abstract":"ABSTRACT Spectral bio-optical properties and phytoplankton photosynthetic parameters were measured in Black Sea coastal waters near Sevastopol in May–July 2020–2021. Chlorophyll a concentration (Chl-a) differed by more than one order of magnitude between stations (0.20–5.6 mg/m3) due to the effect of the Chyornaya river runoff. Light absorption coefficients by all optically active components as well as total non-water absorption coefficients co-varied with Chl-a, which reflected a link between trophic status and water optical properties. An increase in total non-water absorption resulted in a shift of the maximum of downwelling irradiance to the longer wavelength (from 511 nm to 567 nm). Phytoplankton photosynthetic parameters were depth-dependent variables due to phytoplankton acclimations to light intensity without dependence on water trophic status. Gross primary production was estimated by the full spectral approach. Primary production (1.3–31 mgC/m3/h) co-varied with Chl-a. Chlorophyll a specific photosynthesis rate (4.3–8.0 mgC/mgChl/h) varied by about twice at the sea surface but no dependence on Chl-a was revealed.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"81 - 93"},"PeriodicalIF":1.1,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42878440","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 : 2023-03-16DOI: 10.1080/17451000.2023.2214400
N. Fazelian, M. Yousefzadi, A. Movafeghi
ABSTRACT The growing application of nanotechnology has led to the release of nanoparticles in aquatic ecosystems. Thus, investigating the effect of nanoparticles on microalgae, as the primary producers of the food chain, is an important issue. The present study was conducted to examine the toxicity mechanisms of α- Fe2O3 nanoparticles (Fe2O3-NPs) dominated by oxidative stress in Nannochloropsis oculata. The accumulation of Fe2O3-NPs on the cell surface of N. oculata and in f2 medium was observed in SEM images and DLS analysis, respectively. EDX graph and TEM images also showed the presence of NPs in N. oculata. There was an increase of H2O2 and MDA content and growth inhibition was also elevated in N. oculata exposed to Fe2O3-NPs. Further, Fe2O3-NPs application caused a noticeable enhancement of non-enzymatic antioxidants (carotenoids, phenolic compounds and PUFAs) and APX activity, while the content of SFAs and MUFAs as well as the activity of CAT and PPO were reduced as a result of Fe2O3-NPs stress. Overall, the activation of defence mechanisms was not effective in N. oculata and treatment with concentrations of more than 50 mg l−1 Fe2O3-NPs could induce oxidative stress in this microalga.
{"title":"Toxicity of iron-based nanoparticles to Nannochloropsis oculata: effects of Fe2O3-NPs on oxidative stress and fatty acid composition","authors":"N. Fazelian, M. Yousefzadi, A. Movafeghi","doi":"10.1080/17451000.2023.2214400","DOIUrl":"https://doi.org/10.1080/17451000.2023.2214400","url":null,"abstract":"ABSTRACT The growing application of nanotechnology has led to the release of nanoparticles in aquatic ecosystems. Thus, investigating the effect of nanoparticles on microalgae, as the primary producers of the food chain, is an important issue. The present study was conducted to examine the toxicity mechanisms of α- Fe2O3 nanoparticles (Fe2O3-NPs) dominated by oxidative stress in Nannochloropsis oculata. The accumulation of Fe2O3-NPs on the cell surface of N. oculata and in f2 medium was observed in SEM images and DLS analysis, respectively. EDX graph and TEM images also showed the presence of NPs in N. oculata. There was an increase of H2O2 and MDA content and growth inhibition was also elevated in N. oculata exposed to Fe2O3-NPs. Further, Fe2O3-NPs application caused a noticeable enhancement of non-enzymatic antioxidants (carotenoids, phenolic compounds and PUFAs) and APX activity, while the content of SFAs and MUFAs as well as the activity of CAT and PPO were reduced as a result of Fe2O3-NPs stress. Overall, the activation of defence mechanisms was not effective in N. oculata and treatment with concentrations of more than 50 mg l−1 Fe2O3-NPs could induce oxidative stress in this microalga.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"207 - 217"},"PeriodicalIF":1.1,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47181620","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 : 2023-03-16DOI: 10.1080/17451000.2023.2198242
Christine C. Baran, R. Luciano, C. S. Segumalian, D. Valino, M. V. Baria‐Rodriguez
ABSTRACT Soft corals are zooxanthellate sessile animals supporting various organisms in coral reefs. However, their populations are threatened by the impacts of ocean warming. Under thermal stress conditions, soft corals may experience mild to severe bleaching which may lead to death. Understanding soft coral bleaching responses highlights the importance in predicting how populations and diversity may be affected by changing climate scenarios. In this study, we examined the bleaching responses of the three dominant soft coral genera (Lobophytum, n = 1318; Sarcophyton, n = 116; Sinularia, n = 639 colonies) in the Bolinao-Anda Reef Complex (BARC), Pangasinan, north-western Philippines during the 2020 thermal stress event in terms of genus and colony size susceptibility, and zooxanthellae density. Degree heating week (DHW) data from 1986–2020 were obtained using remotely sensed data to determine thermal anomalies in the study sites. The maximum DHW (6.3) in 2020 occurred between July–August while bleaching surveys were done during October of the same year. The percentage of bleached portions in each colony was used to determine bleaching category: no bleaching (0%), moderately bleached (1–50%) and heavily bleached (>50%). Quantification of bleaching prevalence and susceptibility of colony sizes were determined by colony count and mean diameter measurements taken from quadrat photographs in October 2020. Haphazard tissue collection (∼3 cm) in each colony of three soft coral genera per bleaching category was done to quantify zooxanthellae density. Results showed that Lobophytum colonies had the lowest bleaching prevalence (41%), followed by Sinularia (66%) and Sarcophyton (78%). All colony size classes of the three genera were susceptible to bleaching. However, smaller colonies of Lobophytum (<15 cm), Sarcophyton (<5 cm) and Sinularia (<5 cm) showed less susceptibility than large colonies. Zooxanthellae density was significantly reduced in moderately and heavily bleached colonies. The results of this study highlight that bleaching susceptibility is genus specific, with Sarcophyton and Sinularia being more susceptible to bleaching than Lobophytum. Smaller colonies seemed to be less susceptible to bleaching than large-sized soft corals suggesting a differential thermal stress response. Spatial variations in bleaching prevalence were also found among reef sites with varying environmental conditions and thermal stress histories. This work provided initial observations on how bleaching affects soft corals. Further studies on soft coral community recovery are recommended to fully understand how these organisms perform after thermal stress events.
{"title":"Genus and size-specific susceptibility of soft corals to 2020 bleaching event in the Philippines","authors":"Christine C. Baran, R. Luciano, C. S. Segumalian, D. Valino, M. V. Baria‐Rodriguez","doi":"10.1080/17451000.2023.2198242","DOIUrl":"https://doi.org/10.1080/17451000.2023.2198242","url":null,"abstract":"ABSTRACT Soft corals are zooxanthellate sessile animals supporting various organisms in coral reefs. However, their populations are threatened by the impacts of ocean warming. Under thermal stress conditions, soft corals may experience mild to severe bleaching which may lead to death. Understanding soft coral bleaching responses highlights the importance in predicting how populations and diversity may be affected by changing climate scenarios. In this study, we examined the bleaching responses of the three dominant soft coral genera (Lobophytum, n = 1318; Sarcophyton, n = 116; Sinularia, n = 639 colonies) in the Bolinao-Anda Reef Complex (BARC), Pangasinan, north-western Philippines during the 2020 thermal stress event in terms of genus and colony size susceptibility, and zooxanthellae density. Degree heating week (DHW) data from 1986–2020 were obtained using remotely sensed data to determine thermal anomalies in the study sites. The maximum DHW (6.3) in 2020 occurred between July–August while bleaching surveys were done during October of the same year. The percentage of bleached portions in each colony was used to determine bleaching category: no bleaching (0%), moderately bleached (1–50%) and heavily bleached (>50%). Quantification of bleaching prevalence and susceptibility of colony sizes were determined by colony count and mean diameter measurements taken from quadrat photographs in October 2020. Haphazard tissue collection (∼3 cm) in each colony of three soft coral genera per bleaching category was done to quantify zooxanthellae density. Results showed that Lobophytum colonies had the lowest bleaching prevalence (41%), followed by Sinularia (66%) and Sarcophyton (78%). All colony size classes of the three genera were susceptible to bleaching. However, smaller colonies of Lobophytum (<15 cm), Sarcophyton (<5 cm) and Sinularia (<5 cm) showed less susceptibility than large colonies. Zooxanthellae density was significantly reduced in moderately and heavily bleached colonies. The results of this study highlight that bleaching susceptibility is genus specific, with Sarcophyton and Sinularia being more susceptible to bleaching than Lobophytum. Smaller colonies seemed to be less susceptible to bleaching than large-sized soft corals suggesting a differential thermal stress response. Spatial variations in bleaching prevalence were also found among reef sites with varying environmental conditions and thermal stress histories. This work provided initial observations on how bleaching affects soft corals. Further studies on soft coral community recovery are recommended to fully understand how these organisms perform after thermal stress events.","PeriodicalId":18195,"journal":{"name":"Marine Biology Research","volume":"19 1","pages":"165 - 176"},"PeriodicalIF":1.1,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48812348","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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