Harmful algal bloom of the dinoflagellate Blixaea quinquecornis (Abé) Gottschling in bays of North-Central Peru

Harmful algal blooms of the thecate dinoflagellate, Blixaea quinquecornis, generally distributed in tropical, marine, and estuarine areas, are reported in Peru. The identification of this species was done using light, scanning electron microscopy (SEM), and differential interference contrast (DIC) microscopy. This species was found in Miraflores, Paracas and Sechura Bays in 2015 and 2016. The maximum density of B. quinquecornis observed in Miraflores bay was 3.2 x 105 cells L-1 in summer of 2016. In Paracas Bay, the maximum cell counts were 2.11 x 105 and 4.11 x 104 cells L-1 in the summer and autumn of 2016, respectively. Low cell densities (160 cells L-1) were observed in Sechura Bay. In Miraflores and Paracas Bays, B. quinquecornis was found coincidentally with blooms with the athecate dinoflagellate Akashiwo sanguinea. The physicochemical variables associated with blooms of B. quinquecornis in Miraflores and Paracas Bays were surface sea temperature ranging from 19.9 to 26.6° C, salinities from 34.7 to 35.3, pH from 7.32 to 8.21, and dissolved oxygen from 2.46 to 7.44 mL L-1.