Pseudo-nitzschia delicatissima (Cleve) Heiden
Pseudo-nitzschia delicatissima is a domoic-acid-producing, pennate diatom (Smith et al. 1991).
Lectin-binding probes were not able to distinguish between New Zealand-derived cultures of P. delicatissima and P. pseudodelicatissima (Rhodes 1998a). Whole cell fluorescent LSU targeted probes have been developed for identifying P. delicatissima cultures from the west coast of the United States (Miller & Scholin 1996). These probes were used to develop whole cell and sandwich hybridization methods for detection of P. delicatissima in natural samples at near real time (Scholin et al. 1997, Miller & Scholin 1998). A suite of probes based on clone libraries has been developed in the Gulf of Naples to identify P. delicatissima.
Non-toxic isolates from western Scottish waters achieved a greater cell density under a 9 hour light:15 hour dark photoperiod than under an 18 hour light:6 hour dark photoperiod (Fehling et al. 2005). A Tasmanian isolate of P. delicatissima had a maximum specific growth rate of 1.47 ± 0.01 and a maximum pH for growth of 9.3 in the laboratory (100 micromolar photons m-2 s-1 and 15 deg C; Lundholm et al. 2004).
The size of cells within a laboratory strain decreases over time. The average cell volume of a Tasmanian isolate was 128 ± 13 cubic microns (Lundholm et al. 2004).
Pseudo-nitzschia delicatissima is found in tropical and temperate coastal waters. It is abundant on the west coast of the United States in the spring and summer (Fryxell et al. 1997). In the Skagerrak, P. delicatissima is primarily a winter-spring species (Hasle et al. 1996). It has been reported in the Bay of Fundy, Canada (Kaczmarska et al. 2005). From Hasle 2002:Atlantic: north of Svalbard, ca 80°N (Quillfeldt von, 1996) to State of Rio Janeiro, Brazil, ca 32°S ( Villac and Tenenbaum, 2001), including Kings Bay, Svalbard ( Hasle and Heimdal, 1998), east and west of Svalbard and the Barents Sea ( Quillfeldt von, 1996), Norwegian coastal waters ( Hasle and Hasle), Danish ( Skov et al., 1999), Scottish ( Gallacher et al., 2001) and Irish ( Cusack et al., 2000) coastal waters, Skagerrak ( Hasle et al., 1996), Galician waters, northwest Spain ( Fraga et al., 1998), Portuguese waters ( Moita and Vilarinho, 1999), Gulf of Naples ( Sarno and Dahlman, 2000. D. Sarno and J. Dahlman , Production of domoic acid in another species of Pseudo-nitzschia: P. multistriata in the Gulf of Naples (Mediterranean Sea). Harmful Algae News 21 (2000), p. 5.Sarno and Dahlman, 2000), off northwest Africa ( Hasle, 1965), Atlantic Moroccan waters ( Akallal et al., 2000); Resolute Bay and west coast of Greenland ( Quillfeldt von, 1996), Nuuk, Greenland, ( Skov et al., 1999), Gulf of St. Lawrence, Canada ( Bérard-Therriault et al., 1999), Georges Bank and outer continental shelf of New Jersey (Hargraves, personal communication), Gulf Stream ( Kaczmarska et al., 1986), Gulf of Mexico ( Parsons et al., 1999). Pacific: Monterey Bay, CA, ca 37°N (Villac et al., 1993) to Chilean waters, 42°07′S ( Rivera, 1985), including Tasmanian and New South Wales, Australia waters ( Lapworth et al., 2001) and Bay of Plenty, New Zealand ( Rhodes et al., 1998).
Nitrate and Nitrite concentrations play an important role in the abundance of Pseudo-nitzschia delicatissima in the Bay of Fundy, Canada (Kaczmarska et al. 2007). P. delicatissima abundance is positively correlated with nitrates in the Bay of Fundy, Canada (Kaczmarska et al. 2007).
Pseudo-nitzschia delicatissima can reproduce asexually through cell division and sexually to restore cell size (Amato et al. 2005). Sexual reproduction can occur when the cell is 80-19 microns long.