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Ying Zhong Tang - One of the best experts on this subject based on the ideXlab platform.
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Contact micropredation may play a more important role than exotoxicity does in the lethal effects of Karlodinium australe blooms: Evidence from laboratory bioassays.
Harmful algae, 2020Co-Authors: Xiaoying Song, Lixia Shang, Chui Pin Leaw, Po Teen Lim, Ying Zhong TangAbstract:Abstract Multiple dinoflagellate species from the genus Karlodinium have been well known to form massive and toxic blooms that consequently cause fish kills in many coastal waters around the world. Karlodinium australe is a mixotrophic and potentially ichthyotoxic species associated with fish kills. Here, we investigated Phagotrophy of K. australe (isolate KaJb05) established from a bloom event in the West Johor Strait, Malaysia, using several prey species (phytoplankton, zooplankton, and larval fish). The results showed that K. australe ingested relatively small prey cells of co-occurring microalgae by direct engulfment, while it fed on larger prey cells of microalgae by tube feeding. The results of animal exposure bioassays using rotifer (Brachionus plicatilis), brine shrimp (Artemia salina), and larval fish (Oryzias melastigma) demonstrated that Phagotrophy (in terms of the trophic mode of the dinoflagellate), or micropredation (in terms of the mechanism of lethal effects on prey), played a more important role than the toxicity did in causing the lethal effects of K. australe on these aquatic animals under low cell densities of K. australe, while the mortalities of animals observed in the exposure to cell lysates of K. australe were solely caused by the toxicity. A comparison of the lethal effects between K. australe and K. veneficum revealed that the lethal effect of K. australe on rotifers was much stronger than that of K. veneficum at all cell densities applied in the experiments and the more "aggressive" micropredation of K. australe is suggested to explain the difference in lethal effect between K. austale and K. veneficum. Our results may explain why K. australe exhibited fish killings during moderate blooms at cell densities
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a strain of the toxic dinoflagellate karlodinium veneficum isolated from the east china sea is an omnivorous phagotroph
Harmful Algae, 2020Co-Authors: Huijiao Yang, Zhangxi Hu, Lixia Shang, Yunyan Deng, Ying Zhong TangAbstract:Abstract Karlodinium veneficum is a cosmopolitan, toxic, and harmful algal bloom-forming dinoflagellate, of which the mixotrophy has been suggested to be a key factor in the formation and maintaining of HABs and thus deserves more intensive explorations. Here, we report an investigation on the Phagotrophy of K. veneficum using a clonal culture isolated from the coastal water of East China Sea. We found K. veneficum is an omnivorous phagotroph feeding on both live and dead bodies/cells of a fish (Oryzias melastigma), brine shrimp (Artemia salina), rotifer (Brachionus plicatilis), co-cultivated microalgae Akashiwo sanguinea, Margalefidinium polykrikoides, Alexandrium leei, Rhodomonas salina, Isochrysis galbana, and its own species. Karlodinium veneficum extracted the cell contents of all species provided through either a peduncle (i.e. myzocytosis) or by engulfing the whole cell of small preys (i.e. Phagotrophy sensu stricto). Karlodinium veneficum preferred to ingest non-motile or newly dead preys, no matter whether they were fish, zooplankton, or phytoplankton. Importantly, K. veneficum exhibited micropredation on animals with sizes much larger than itself (fish, rotifer, and brine shrimp), especially when they were injured or newly dead. The LysoSensor- and LysoTracker-stained lysosomes or/and phagolysosomes of K. veneficum increased when preys were added. Cannibalism in K. veneficum, i.e. a cell feeds on other unhealthy or dead cells of the same species, was observed as the first time in the study, which can help the growth and elongated maintaining of the population under nutrient deficiency (i.e. the culture maintained viable in culture plates without nutrient supplement up to a year). The growth rate of K. veneficum exhibited significant positive correlation with ingestion rate, which differed among prey species, and the highest growth rate was observed when feeding on R. salina. The ingest ability of K. veneficum was triggered by nutrient deficiency. In conclusion, the omnivorous mixotrophy is proposed to be a key autecological mechanism for K. veneficum to widen its ecological niche and succeed in forming a cosmopolitan distribution and frequent blooms.
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a strain of the toxic dinoflagellate karlodinium veneficum isolated from the east china sea is an omnivorous phagotroph
Harmful Algae, 2020Co-Authors: Huijiao Yang, Zhangxi Hu, Lixia Shang, Yunyan Deng, Ying Zhong TangAbstract:Abstract Karlodinium veneficum is a cosmopolitan, toxic, and harmful algal bloom-forming dinoflagellate, of which the mixotrophy has been suggested to be a key factor in the formation and maintaining of HABs and thus deserves more intensive explorations. Here, we report an investigation on the Phagotrophy of K. veneficum using a clonal culture isolated from the coastal water of East China Sea. We found K. veneficum is an omnivorous phagotroph feeding on both live and dead bodies/cells of a fish (Oryzias melastigma), brine shrimp (Artemia salina), rotifer (Brachionus plicatilis), co-cultivated microalgae Akashiwo sanguinea, Margalefidinium polykrikoides, Alexandrium leei, Rhodomonas salina, Isochrysis galbana, and its own species. Karlodinium veneficum extracted the cell contents of all species provided through either a peduncle (i.e. myzocytosis) or by engulfing the whole cell of small preys (i.e. Phagotrophy sensu stricto). Karlodinium veneficum preferred to ingest non-motile or newly dead preys, no matter whether they were fish, zooplankton, or phytoplankton. Importantly, K. veneficum exhibited micropredation on animals with sizes much larger than itself (fish, rotifer, and brine shrimp), especially when they were injured or newly dead. The LysoSensor- and LysoTracker-stained lysosomes or/and phagolysosomes of K. veneficum increased when preys were added. Cannibalism in K. veneficum, i.e. a cell feeds on other unhealthy or dead cells of the same species, was observed as the first time in the study, which can help the growth and elongated maintaining of the population under nutrient deficiency (i.e. the culture maintained viable in culture plates without nutrient supplement up to a year). The growth rate of K. veneficum exhibited significant positive correlation with ingestion rate, which differed among prey species, and the highest growth rate was observed when feeding on R. salina. The ingest ability of K. veneficum was triggered by nutrient deficiency. In conclusion, the omnivorous mixotrophy is proposed to be a key autecological mechanism for K. veneficum to widen its ecological niche and succeed in forming a cosmopolitan distribution and frequent blooms.
Edna Granéli - One of the best experts on this subject based on the ideXlab platform.
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the ecophysiology and bloom dynamics of prymnesium spp
Harmful Algae, 2012Co-Authors: Edna Granéli, Bente Edvardsen, Daniel L Roelke, Johannes A HagstromAbstract:Abstract Members of Prymnesium belong to the division Haptophyta, class Prymnesiophyceae, order Prymnesiales and family Prymnesiaceae. As most haptophytes, members of the genus Prymnesium are unicellular and planktonic. The most known of these species is the ichthyotoxic P. parvum, which may form nearly monospecific dense blooms in coastal and inland waters. This species possesses extraordinary plasticity concerning life survival strategies, and is specifically addressed in this review. Toxins produced by P. parvum have hemolytic properties, that not only kill fish but also co-existing plankton. These substances are allelopathic (when other algae are killed) and grazer deterrent (when grazers are killed). Allelopathy enables P. parvum to utilize inorganic nutrients present in the surrounding water without competition from other algal species; and by eliminating its grazers P. parvum reduces cell losses. The paralized microalgae and/or zooplankton, are therefter ingested by the P. parvum cells, a process called Phagotrophy. P. parvum is also able of osmotrophy, i.e. utilization of dissolved organic matter. In this review, the cellular characteristics, life cycles, bloom formation, and factors affecting toxicity, allelopathy, Phagotrophy, and osmotrophy of P. parvum are discussed.
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contribution of Phagotrophy versus autotrophy to prymnesium parvum growth under nitrogen and phosphorus sufficiency and deficiency
Harmful Algae, 2010Co-Authors: Wanderson Fernandes De Carvalho, Edna GranéliAbstract:Laboratory experiments were conducted to test the effects of nitrogen (N) and phosphorus (P) sufficiency and deficiency on mixotrophy in Prymnesium parvum (Haptophyta). P. parvum was grown with and without algal prey (Rhodomonas salina) and observed for 120 h. Detection and enumeration of cells containing food vacuoles with prey (i.e. Phagotrophy) was based on flow cytometric detection of fluorescence of an acidotropic probe. Overall, the presence of R. salina increased Phagotrophy in P. parvum suggesting that, at least in this strain of P. parvum, the presence of suitable prey can stimulate phagotrophic behavior in P. parvum. Feeding frequency (the percentage of P. parvum cells containing food vacuoles in a given time) was significantly higher under N and P deficiency than in the nutrient-sufficient treatments. A nutrient budget constructed from the data indicated that ingestion of organic matter (OM) supplied with 78 ± 7% of the N (3.9 ± 0.3 μM) incorporated by P. parvum in the N-deficient treatment, and 45 ± 9% of the P (0.3 ± 0 μM) acquired in the P-deficient cultures. Even under nutrient sufficiency, ingestion of OM was estimated to have supplied 43 ± 16% of the N and 48 ± 16% of the P incorporated into P. parvum cells. Phagotrophy was observed even in the NP-sufficient cultures (non-axenic mixed and monocultures), although P. parvum cells did not lose their photosynthetic capability, suggesting that Phagotrophy is probably a permanent nutritional adaptation to this species. The ingestion of organic nutrients played an important role in P. parvum growth, being a reliable source of nutrition for P. parvum inorganic nutrient limitation, and could explain its capabilities to form persistent blooms.
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dinophysis norvegica dinophyceae more a predator than a producer
Harmful Algae, 2008Co-Authors: Wanderson Fernandes De Carvalho, Susanna Minnhagen, Edna GranéliAbstract:Several studies have proved that some Dinophysis species are capable of ingesting particulate organic matter besides of being photosynthetic, a form of nutrition termed mixotrophy. Phagotrophy may be an important aspect of the life history of the genus Dinophysis and the key to understand its ecology. We used modern techniques coupling flow cytometry and acidotropic probes to detect and score food vacuolated Dinophysis norvegica cells in natural samples. In addition, feeding experiments were conduced under controlled conditions to observe if D. norvegica would grow feeding on the cryptophyte Teleaulax amphioxeia. The results of the field observations showed a frequency of Phagotrophy between 25 and 71% in a natural D. norvegica population from the Baltic Sea, which is higher than previous reports (1–20%). Although molecular methods have proved that the kleptoplastids of the D. norvegica from the Baltic Sea are from T. amphioxeia, the laboratory experiments showed that the presence of T. amphioxeia in the cultures did not enhance the survival rate of D. norvegica neither in phototrophic nor in heterotrophic conditions. We suggest that the D. norvegica Kleptoplats are obtained through a heterotrophic or mixotrophic protist, which have been feeding on cryptophytes, as it has recently been shown for Dinophysis acuminata. Our main conclusion is that D. norvegica, and probably all other species from the genus Dinophysis, is mainly phagotrophic and feeds on a larger prey than T. amphioxeia. Autotrophy through kleptoplastidy would be a secondary feature used as a complementary or short-term survival strategy.
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Acidotropic probes and flow cytometry: a powerful combination for detecting Phagotrophy in mixotrophic and heterotrophic protists
Aquatic Microbial Ecology, 2006Co-Authors: Wanderson Fernandes De Carvalho, Edna GranéliAbstract:Acidotropic probes and flow cytometry: a powerful combination for detecting Phagotrophy in mixotrophic and heterotrophic protists
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Effects of nutrient limitation on food uptake in the toxic haptophyte Prymnesium parvum.
Aquatic Microbial Ecology, 2003Co-Authors: Alf Skovgaard, Per Juel Hansen, Catherine Legrand, Edna GranéliAbstract:The haptophyte Prymnesium parvum Carter is toxic and frequently responsible for harmful algal blooms in coastal waters. It is a mixotrophic species having the capability to feed on various planktonic microorganisms. It is frequently suggested that mixotrophic algae may obtain inorganic nutrients through Phagotrophy and that nutrient depletion should then lead to increased food uptake. To study this, we investigated the feeding activity of P. parvum in semi-continuous, nutrient-limited cultures, using the cryptophyte Rhodomonas baltica as prey. P. parvum showed to be an active predator under all conditions investigated. After 2 h of incubation with prey, 40% of P. parvum cells were either feeding or contained recently formed food vacuoles. However, under the conditions used, no difference in feeding activity was found between treatments. On the contrary, the feeding activity was similar in P. parvum cultures that had been grown under N-limiting, P-limiting, N- and P-limiting, as well as under nutrient-replete conditions. It cannot be excluded that P. parvum under limiting nutrient conditions may acquire nutrients to be used in photosynthetic growth through Phagotrophy. It is evident, however, that the species also feeds when inorganic nutrients are present in concentrations sufficient to support maximum phototrophic growth.
Lixia Shang - One of the best experts on this subject based on the ideXlab platform.
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Contact micropredation may play a more important role than exotoxicity does in the lethal effects of Karlodinium australe blooms: Evidence from laboratory bioassays.
Harmful algae, 2020Co-Authors: Xiaoying Song, Lixia Shang, Chui Pin Leaw, Po Teen Lim, Ying Zhong TangAbstract:Abstract Multiple dinoflagellate species from the genus Karlodinium have been well known to form massive and toxic blooms that consequently cause fish kills in many coastal waters around the world. Karlodinium australe is a mixotrophic and potentially ichthyotoxic species associated with fish kills. Here, we investigated Phagotrophy of K. australe (isolate KaJb05) established from a bloom event in the West Johor Strait, Malaysia, using several prey species (phytoplankton, zooplankton, and larval fish). The results showed that K. australe ingested relatively small prey cells of co-occurring microalgae by direct engulfment, while it fed on larger prey cells of microalgae by tube feeding. The results of animal exposure bioassays using rotifer (Brachionus plicatilis), brine shrimp (Artemia salina), and larval fish (Oryzias melastigma) demonstrated that Phagotrophy (in terms of the trophic mode of the dinoflagellate), or micropredation (in terms of the mechanism of lethal effects on prey), played a more important role than the toxicity did in causing the lethal effects of K. australe on these aquatic animals under low cell densities of K. australe, while the mortalities of animals observed in the exposure to cell lysates of K. australe were solely caused by the toxicity. A comparison of the lethal effects between K. australe and K. veneficum revealed that the lethal effect of K. australe on rotifers was much stronger than that of K. veneficum at all cell densities applied in the experiments and the more "aggressive" micropredation of K. australe is suggested to explain the difference in lethal effect between K. austale and K. veneficum. Our results may explain why K. australe exhibited fish killings during moderate blooms at cell densities
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a strain of the toxic dinoflagellate karlodinium veneficum isolated from the east china sea is an omnivorous phagotroph
Harmful Algae, 2020Co-Authors: Huijiao Yang, Zhangxi Hu, Lixia Shang, Yunyan Deng, Ying Zhong TangAbstract:Abstract Karlodinium veneficum is a cosmopolitan, toxic, and harmful algal bloom-forming dinoflagellate, of which the mixotrophy has been suggested to be a key factor in the formation and maintaining of HABs and thus deserves more intensive explorations. Here, we report an investigation on the Phagotrophy of K. veneficum using a clonal culture isolated from the coastal water of East China Sea. We found K. veneficum is an omnivorous phagotroph feeding on both live and dead bodies/cells of a fish (Oryzias melastigma), brine shrimp (Artemia salina), rotifer (Brachionus plicatilis), co-cultivated microalgae Akashiwo sanguinea, Margalefidinium polykrikoides, Alexandrium leei, Rhodomonas salina, Isochrysis galbana, and its own species. Karlodinium veneficum extracted the cell contents of all species provided through either a peduncle (i.e. myzocytosis) or by engulfing the whole cell of small preys (i.e. Phagotrophy sensu stricto). Karlodinium veneficum preferred to ingest non-motile or newly dead preys, no matter whether they were fish, zooplankton, or phytoplankton. Importantly, K. veneficum exhibited micropredation on animals with sizes much larger than itself (fish, rotifer, and brine shrimp), especially when they were injured or newly dead. The LysoSensor- and LysoTracker-stained lysosomes or/and phagolysosomes of K. veneficum increased when preys were added. Cannibalism in K. veneficum, i.e. a cell feeds on other unhealthy or dead cells of the same species, was observed as the first time in the study, which can help the growth and elongated maintaining of the population under nutrient deficiency (i.e. the culture maintained viable in culture plates without nutrient supplement up to a year). The growth rate of K. veneficum exhibited significant positive correlation with ingestion rate, which differed among prey species, and the highest growth rate was observed when feeding on R. salina. The ingest ability of K. veneficum was triggered by nutrient deficiency. In conclusion, the omnivorous mixotrophy is proposed to be a key autecological mechanism for K. veneficum to widen its ecological niche and succeed in forming a cosmopolitan distribution and frequent blooms.
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a strain of the toxic dinoflagellate karlodinium veneficum isolated from the east china sea is an omnivorous phagotroph
Harmful Algae, 2020Co-Authors: Huijiao Yang, Zhangxi Hu, Lixia Shang, Yunyan Deng, Ying Zhong TangAbstract:Abstract Karlodinium veneficum is a cosmopolitan, toxic, and harmful algal bloom-forming dinoflagellate, of which the mixotrophy has been suggested to be a key factor in the formation and maintaining of HABs and thus deserves more intensive explorations. Here, we report an investigation on the Phagotrophy of K. veneficum using a clonal culture isolated from the coastal water of East China Sea. We found K. veneficum is an omnivorous phagotroph feeding on both live and dead bodies/cells of a fish (Oryzias melastigma), brine shrimp (Artemia salina), rotifer (Brachionus plicatilis), co-cultivated microalgae Akashiwo sanguinea, Margalefidinium polykrikoides, Alexandrium leei, Rhodomonas salina, Isochrysis galbana, and its own species. Karlodinium veneficum extracted the cell contents of all species provided through either a peduncle (i.e. myzocytosis) or by engulfing the whole cell of small preys (i.e. Phagotrophy sensu stricto). Karlodinium veneficum preferred to ingest non-motile or newly dead preys, no matter whether they were fish, zooplankton, or phytoplankton. Importantly, K. veneficum exhibited micropredation on animals with sizes much larger than itself (fish, rotifer, and brine shrimp), especially when they were injured or newly dead. The LysoSensor- and LysoTracker-stained lysosomes or/and phagolysosomes of K. veneficum increased when preys were added. Cannibalism in K. veneficum, i.e. a cell feeds on other unhealthy or dead cells of the same species, was observed as the first time in the study, which can help the growth and elongated maintaining of the population under nutrient deficiency (i.e. the culture maintained viable in culture plates without nutrient supplement up to a year). The growth rate of K. veneficum exhibited significant positive correlation with ingestion rate, which differed among prey species, and the highest growth rate was observed when feeding on R. salina. The ingest ability of K. veneficum was triggered by nutrient deficiency. In conclusion, the omnivorous mixotrophy is proposed to be a key autecological mechanism for K. veneficum to widen its ecological niche and succeed in forming a cosmopolitan distribution and frequent blooms.
Huijiao Yang - One of the best experts on this subject based on the ideXlab platform.
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a strain of the toxic dinoflagellate karlodinium veneficum isolated from the east china sea is an omnivorous phagotroph
Harmful Algae, 2020Co-Authors: Huijiao Yang, Zhangxi Hu, Lixia Shang, Yunyan Deng, Ying Zhong TangAbstract:Abstract Karlodinium veneficum is a cosmopolitan, toxic, and harmful algal bloom-forming dinoflagellate, of which the mixotrophy has been suggested to be a key factor in the formation and maintaining of HABs and thus deserves more intensive explorations. Here, we report an investigation on the Phagotrophy of K. veneficum using a clonal culture isolated from the coastal water of East China Sea. We found K. veneficum is an omnivorous phagotroph feeding on both live and dead bodies/cells of a fish (Oryzias melastigma), brine shrimp (Artemia salina), rotifer (Brachionus plicatilis), co-cultivated microalgae Akashiwo sanguinea, Margalefidinium polykrikoides, Alexandrium leei, Rhodomonas salina, Isochrysis galbana, and its own species. Karlodinium veneficum extracted the cell contents of all species provided through either a peduncle (i.e. myzocytosis) or by engulfing the whole cell of small preys (i.e. Phagotrophy sensu stricto). Karlodinium veneficum preferred to ingest non-motile or newly dead preys, no matter whether they were fish, zooplankton, or phytoplankton. Importantly, K. veneficum exhibited micropredation on animals with sizes much larger than itself (fish, rotifer, and brine shrimp), especially when they were injured or newly dead. The LysoSensor- and LysoTracker-stained lysosomes or/and phagolysosomes of K. veneficum increased when preys were added. Cannibalism in K. veneficum, i.e. a cell feeds on other unhealthy or dead cells of the same species, was observed as the first time in the study, which can help the growth and elongated maintaining of the population under nutrient deficiency (i.e. the culture maintained viable in culture plates without nutrient supplement up to a year). The growth rate of K. veneficum exhibited significant positive correlation with ingestion rate, which differed among prey species, and the highest growth rate was observed when feeding on R. salina. The ingest ability of K. veneficum was triggered by nutrient deficiency. In conclusion, the omnivorous mixotrophy is proposed to be a key autecological mechanism for K. veneficum to widen its ecological niche and succeed in forming a cosmopolitan distribution and frequent blooms.
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a strain of the toxic dinoflagellate karlodinium veneficum isolated from the east china sea is an omnivorous phagotroph
Harmful Algae, 2020Co-Authors: Huijiao Yang, Zhangxi Hu, Lixia Shang, Yunyan Deng, Ying Zhong TangAbstract:Abstract Karlodinium veneficum is a cosmopolitan, toxic, and harmful algal bloom-forming dinoflagellate, of which the mixotrophy has been suggested to be a key factor in the formation and maintaining of HABs and thus deserves more intensive explorations. Here, we report an investigation on the Phagotrophy of K. veneficum using a clonal culture isolated from the coastal water of East China Sea. We found K. veneficum is an omnivorous phagotroph feeding on both live and dead bodies/cells of a fish (Oryzias melastigma), brine shrimp (Artemia salina), rotifer (Brachionus plicatilis), co-cultivated microalgae Akashiwo sanguinea, Margalefidinium polykrikoides, Alexandrium leei, Rhodomonas salina, Isochrysis galbana, and its own species. Karlodinium veneficum extracted the cell contents of all species provided through either a peduncle (i.e. myzocytosis) or by engulfing the whole cell of small preys (i.e. Phagotrophy sensu stricto). Karlodinium veneficum preferred to ingest non-motile or newly dead preys, no matter whether they were fish, zooplankton, or phytoplankton. Importantly, K. veneficum exhibited micropredation on animals with sizes much larger than itself (fish, rotifer, and brine shrimp), especially when they were injured or newly dead. The LysoSensor- and LysoTracker-stained lysosomes or/and phagolysosomes of K. veneficum increased when preys were added. Cannibalism in K. veneficum, i.e. a cell feeds on other unhealthy or dead cells of the same species, was observed as the first time in the study, which can help the growth and elongated maintaining of the population under nutrient deficiency (i.e. the culture maintained viable in culture plates without nutrient supplement up to a year). The growth rate of K. veneficum exhibited significant positive correlation with ingestion rate, which differed among prey species, and the highest growth rate was observed when feeding on R. salina. The ingest ability of K. veneficum was triggered by nutrient deficiency. In conclusion, the omnivorous mixotrophy is proposed to be a key autecological mechanism for K. veneficum to widen its ecological niche and succeed in forming a cosmopolitan distribution and frequent blooms.
Richard E Triemer - One of the best experts on this subject based on the ideXlab platform.
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PHYLOGENETIC RELATIONSHIPS OF SELECTED EUGLENOID GENERA BASED ON MORPHOLOGICAL AND MOLECULAR DATA
Journal of Phycology, 1997Co-Authors: Ann E. Montegut-felkner, Richard E TriemerAbstract:The small subunit rRNA (SSU rRNA) coding regions sequenced from the euglenoids Petalomonas cantuscygni, Peranema trichophorum, and Khawkinea quartana were used to assess the phylogenetic relationships of these genera within the Euglenozoa. Phylogenies derived from distance, parsimony, and maximum likelihood methods infer that the euglenoids and kinetoplastids form sister clades within a monophyletic assemblage. Distances representative of closely related lineages separate the genera within the Kinetoplastida, whereas larger distance values separate genera within the euglenoid assemblage. The results of the morphological and molecular studies suggest that Phagotrophy arose early in the euglenozoan lineage with the subsequent acquisition of phototrophy, osmotrophy, and parasitism. Phagotrophic euglenoids with a pellicle composed of longitudinal strips appear to have diverged prior to genera with helically arranged strips. This study suggests that the hypothetical ancestor to the Euglenozoa was a phagotroph with two flagella, both containing paraxonemal rods. Furthermore, its basal bodies contained proximal cartwheels, were connected by a prominent fiber, and were anchored with three asymmetrically arranged flagellar roots.
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PHYLOGENETIC RELATIONSHIPS OF SELECTED EUGLENOID GENERA BASED ON MORPHOLOGICAL AND MOLECULAR DATA
Journal of Phycology, 1997Co-Authors: Ann E. Montegut-felkner, Richard E TriemerAbstract:The small subunit rRNA (SSU rRNA) coding regions sequenced from the euglenoids Petalomonas cantuscygni, Peranema trichophorum, and Khawkinea quartana were used to assess the phylogenetic relationships of these genera within the Euglenozoa. Phylogenies derived from distance, parsimony, and maximum likelihood methods infer that the euglenoids and kinetoplastids form sister clades within a monophyletic assemblage. Distances representative of closely related lineages separate the genera within the Kinetoplastida, whereas larger distance values separate genera within the euglenoid assemblage. The results of the morphological and molecular studies suggest that Phagotrophy arose early in the euglenozoan lineage with the subsequent acquisition of phototrophy, osmotrophy, and parasitism. Phagotrophic euglenoids with a pellicle composed of longitudinal strips appear to have diverged prior to genera with helically arranged strips. This study suggests that the hypothetical ancestor to the Euglenozoa was a phagotroph with two flagella, both containing paraxonemal rods. Furthermore, its basal bodies contained proximal cartwheels, were connected by a prominent fiber, and were anchored with three asymmetrically arranged flagellar roots.