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HABs taxon detailsAzadinium dexteroporum Percopo & Zingone, 2013
839790 (urn:lsid:marinespecies.org:taxname:839790)
accepted
Species
marine
Percopo, I.; Siano, R.; Rossi, R.; Soprano, V.; Sarno, D.; Zingone, A. (2013). A new potentially toxic Azadinium species (Dinophyceae) from the Mediterranean Sea, A. dexteroporum sp. nov. <em>Journal of Phycology.</em> 49: 950-966., available online at https://doi.org/10.1111/jpy.12104 [details] Available for editors
Harmful effect Produces small amounts of azaspiracids (Gulf of Naples), toxins implicated in shellfish poisonings in humans
Harmful effect Produces small amounts of azaspiracids (Gulf of Naples), toxins implicated in shellfish poisonings in humans [details] Identification The main morphological features that allow the discrimination of A. dexteroporum from the other congeneric species are the...
Identification The main morphological features that allow the discrimination of A. dexteroporum from the other congeneric species are the marked asymmetry of the Po plate and the position of the ventral pore (vp) at its right posterior end, in touch with 1′ and 4′ plates. The position of the vp in A. dexteroporum is opposite to that observed in A. poporum, where it is located at the posterior left end of the Po plate, touching plate 1′ and 2′, but in that case the Po plate is more symmetrical. In the type species A. spinosum and in A. obesum and A. polongum the vp is located on the mid left margin of 1′ plate (Tillmann et al. 2009, 2011, 2012b). Therefore, A. dexteroporum is so far the only species, among those originally described as Azadinium, having the vp onthe right side of the theca. Indeed, in A. caudatum var. caudatum, recently transferred from the genus Amphidoma to Azadinium, the vp is placed along the right margin of the 1′ plate, while in A. caudatum var. margalefii, it is in a subapical position, in a notch of the right margin of the Po plate, in contact with the 4′ plate. The two varieties also differ in the shape of the antapical spine. Despite these differences, the small genetic distance and the presence of a morphotype with intermediate morphology of the antapical spine prevented to assign the latter taxa the rank of distinct species (Nézan et al. 2012). The variability of the vp position shown in A. caudatum casts some doubts on the use of this character in species delimitation. In the case of A. dexteroporum, however, no variation was observed for the vp position within the strain examined or in the single specimen from natural material. Differently from the other described species, A. dexteroporum showed the second intercalary plate concave and collapsed in respect with the other plates. This peculiar feature, initially attributed to a SEM preparation artifact, was evident in all specimens where the plate was observable, and in two different SEM preparations, one obtained few days from the isolation date and the other more than 1 year later. A concave 2a plate may also be present in specimens from Argentinian waters classified as A. cf. spinosum, which were responsible for two intense blooms in 1990 and 1991 (Akselman and Negri 2012). Those specimens differ from A. dexteroporum for slightly larger dimensions and larger 1a and 3a plates. Unfortunately the most peculiar and clarifying character, i.e., the position of the ventral pore, was not resolved in those specimens. Several other morphological features distinguish A. dexteroporum from the other species of the genus. Both Azadinium poporum and Azadinium obesum lack the antapical spine, and the former has several pyrenoids while the latter does not have a pyrenoid, as compared to the single pyrenoid of A. dexteroporum. Like A. spinosum and A. polongum, A. dexteroporum has a small antapical spine, but it is less slender than A. spinosum and has smaller 1a and 3a plates, as well as a narrower 1′ plate than those two species. Finally, A. dexteroporum is almost three times smaller than the two varieties of A. caudatum which, in addition, have a conspicuous antapical horn rather than a small spine. Yet in LM it could be difficult to discriminate A. dexteroporum from other small Azadinium, and even from other tiny peridinioids. Azadinium dexteroporum is the smallest species of the genus but its size range overlaps with almost all other Azadinium species, while the presence and the position of the spine and the number of pyrenoids are not always resolved in LM. Besides, the number of pyrenoids cannot be considered a good taxonomic character for dinoflagellate identification, as it may vary over the life cycle and even over the diel cycle (Nagh [details]
Guiry, M.D. & Guiry, G.M. (2024). AlgaeBase. World-wide electronic publication, National University of Ireland, Galway (taxonomic information republished from AlgaeBase with permission of M.D. Guiry). Azadinium dexteroporum Percopo & Zingone, 2013. Accessed through: Lundholm, N.; Churro, C.; Escalera, L.; Fraga, S.; Hoppenrath, M.; Iwataki, M.; Larsen, J.; Mertens, K.; Moestrup, Ø.; Murray, S.; Tillmann, U.; Zingone, A. (Eds) (2009 onwards) IOC-UNESCO Taxonomic Reference List of Harmful Micro Algae at: https://www.marinespecies.org/hab/aphia.php?p=taxdetails&id=839790 on 2024-04-19
Lundholm, N.; Churro, C.; Escalera, L.; Fraga, S.; Hoppenrath, M.; Iwataki, M.; Larsen, J.; Mertens, K.; Moestrup, Ø.; Murray, S.; Tillmann, U.; Zingone, A. (Eds) (2009 onwards). IOC-UNESCO Taxonomic Reference List of Harmful Micro Algae. Azadinium dexteroporum Percopo & Zingone, 2013. Accessed at: https://www.marinespecies.org/hab/aphia.php?p=taxdetails&id=839790 on 2024-04-19
Date action by
original description
Percopo, I.; Siano, R.; Rossi, R.; Soprano, V.; Sarno, D.; Zingone, A. (2013). A new potentially toxic Azadinium species (Dinophyceae) from the Mediterranean Sea, A. dexteroporum sp. nov. <em>Journal of Phycology.</em> 49: 950-966., available online at https://doi.org/10.1111/jpy.12104 [details] Available for editors
basis of record Guiry, M.D. & Guiry, G.M. (2023). AlgaeBase. <em>World-wide electronic publication, National University of Ireland, Galway.</em> searched on YYYY-MM-DD., available online at http://www.algaebase.org [details]  Present Inaccurate Introduced: alien Containing type locality
From regional or thematic species database
Description Photosynthetic thecate dinoflagellate. Ellipsoidal cells, 7.0–10.0 μm long and 5.0–8.0 μm wide. One lobed chloroplast extending into both epi- and hyposome, with one pyrenoid visible in the episome. Nucleus spherical, placed in the posterior part of the cell. Thecal tabulation: Po, cp, X, 4′, 3a, 6″, 6C, 5?S, 6‴ and 2″″. Episome with a conspicuous apical pore complex. Hyposome asymmetric, smaller than the episome and bearing a small antapical spine on its right side, on the 2″″ plate. Cingulum excavated and wide about one quarter of the cell length. Po asymmetrical, its right end extending posteriorly in the epitheca between plates 1′ and 4′. Ventral pore located at the posterior right end of the Po plate, surrounded by 1′ and 4′ plates. 1″ plate in contact with the 1a intercalary plate. Plate 2a four-sided and concave. Postcingular plates quadrangular, with 1‴ and 6‴ smaller than the others. [details]Harmful effect Produces small amounts of azaspiracids (Gulf of Naples), toxins implicated in shellfish poisonings in humans [details] Identification The main morphological features that allow the discrimination of A. dexteroporum from the other congeneric species are the marked asymmetry of the Po plate and the position of the ventral pore (vp) at its right posterior end, in touch with 1′ and 4′ plates. The position of the vp in A. dexteroporum is opposite to that observed in A. poporum, where it is located at the posterior left end of the Po plate, touching plate 1′ and 2′, but in that case the Po plate is more symmetrical. In the type species A. spinosum and in A. obesum and A. polongum the vp is located on the mid left margin of 1′ plate (Tillmann et al. 2009, 2011, 2012b). Therefore, A. dexteroporum is so far the only species, among those originally described as Azadinium, having the vp onthe right side of the theca. Indeed, in A. caudatum var. caudatum, recently transferred from the genus Amphidoma to Azadinium, the vp is placed along the right margin of the 1′ plate, while in A. caudatum var. margalefii, it is in a subapical position, in a notch of the right margin of the Po plate, in contact with the 4′ plate. The two varieties also differ in the shape of the antapical spine. Despite these differences, the small genetic distance and the presence of a morphotype with intermediate morphology of the antapical spine prevented to assign the latter taxa the rank of distinct species (Nézan et al. 2012). The variability of the vp position shown in A. caudatum casts some doubts on the use of this character in species delimitation. In the case of A. dexteroporum, however, no variation was observed for the vp position within the strain examined or in the single specimen from natural material. Differently from the other described species, A. dexteroporum showed the second intercalary plate concave and collapsed in respect with the other plates. This peculiar feature, initially attributed to a SEM preparation artifact, was evident in all specimens where the plate was observable, and in two different SEM preparations, one obtained few days from the isolation date and the other more than 1 year later. A concave 2a plate may also be present in specimens from Argentinian waters classified as A. cf. spinosum, which were responsible for two intense blooms in 1990 and 1991 (Akselman and Negri 2012). Those specimens differ from A. dexteroporum for slightly larger dimensions and larger 1a and 3a plates. Unfortunately the most peculiar and clarifying character, i.e., the position of the ventral pore, was not resolved in those specimens. Several other morphological features distinguish A. dexteroporum from the other species of the genus. Both Azadinium poporum and Azadinium obesum lack the antapical spine, and the former has several pyrenoids while the latter does not have a pyrenoid, as compared to the single pyrenoid of A. dexteroporum. Like A. spinosum and A. polongum, A. dexteroporum has a small antapical spine, but it is less slender than A. spinosum and has smaller 1a and 3a plates, as well as a narrower 1′ plate than those two species. Finally, A. dexteroporum is almost three times smaller than the two varieties of A. caudatum which, in addition, have a conspicuous antapical horn rather than a small spine. Yet in LM it could be difficult to discriminate A. dexteroporum from other small Azadinium, and even from other tiny peridinioids. Azadinium dexteroporum is the smallest species of the genus but its size range overlaps with almost all other Azadinium species, while the presence and the position of the spine and the number of pyrenoids are not always resolved in LM. Besides, the number of pyrenoids cannot be considered a good taxonomic character for dinoflagellate identification, as it may vary over the life cycle and even over the diel cycle (Nagh [details] |
