Amphidomataceae (Dinophyceae) in the western Greenland area, including description of Azadinium perforatum sp. nov.

Abstract

Azaspiracids (AZA) are lipophilic marine biotoxins associated with shellfish poisoning which are produced by some species of Amphidomataceae. Diversity and global biogeography of this family are still poorly known. In summer 2017 plankton samples were collected from the central Labrador Sea and western Greenland coast from 64°N (Gothaab Fjord) to 75°N for the presence of Amphidomataceae and AZA. In the central Labrador Sea, light microscopy revealed small Azadinium-like cells (9200 cells l −1 ). Clonal strains established from plankton samples and scanning electron microscopy of fixed plankton samples revealed at least eight species of Amphidomataceae: Azadinium obesum, Az. trinitatum, Az. dexteroporum, Az. spinosum, Az. polongum, Amphidoma languida, Azadinium spec., and a new species described here as Azadinium perforatum sp. nov. The new species differed from other Azadinium species by the presence of thecal pores on the pore plate. All samples, including cultured strains, filtered seawater samples, and solid phase adsorption toxin tracking (SPATT) samplers deployed during the expedition in a continuous water-sampling system (FerryBox), were negative for AZA. DNA samples and PCR assays were positive for Amphidomataceae from most stations, whereas species-specific assays for three toxigenic species were rarely positive (two stations for Az. poporum, one station for Am. languida). The results highlight the presence of Amphidomataceae in the area but the lack of toxins and low abundance of toxigenic species currently indicate a low risk of toxic Amphidomataceae blooms in Arctic coastal waters.

Morphological and molecular characterization of multiple new Azadinium strains revealed a high diversity of non‐toxigenic species of Amphidomataceae (Dinophyceae) including two new Azadinium species in Irish waters, North East Atlantic

“…dexteroporum strain from the Mediterranean had a quadra 2a, but in a strain from the Labrador Sea both quadra and penta 2a were documented (Tillmann et al . 2020).…”

“…PCR were conducted in a Nexus Gradient Mastercycler (Eppendorf) with conditions described in Tillmann et al . (2020). The PCR amplicons were checked on a 1% agarose gel (in TE buffer, 70 mV, 30 min) to verify the expected length.…”

“…2020), and most have been described in the last decade alone (Tillmann et al . 2009, 2010, 2011, 2012b, 2014a, 2020; Luo et al . 2013, 2017; Percopo et al .…”

Distribution and abundance of azaspiracid-producing dinophyte species and their toxins in North Atlantic and North Sea waters in summer 2018

“…languida also produces AZA [13,19]. However, the currently known diversity of Amphidomataceae is much larger with 23 species in the family described to date, and most of those species were assigned as non-toxigenic based on cultured strains [20][21][22]. One main reason for the late discovery of these tiny unicellular organisms (most are~10-15 μm in cell length) is their inconspicuousness, which challenges their detection and morphological description using traditional light microscopy.…”

“…languida), and Smith et al [33] designed a SYBR Green assay targeting the DNA of all amphidomatacean species. These qPCR assays have been used to detect Amphidomataceae in field samples, for example on research surveys along the Danish coastline [34], the Norwegian coast [35], the Irish coastline [32], the Argentine shelf [36] and in western Greenland [22], or are in use for the regular monitoring of Az. spinosum and Az.…”