First record of Ceratium Schrank, 1973 (Dinophyceae: Ceratiaceae) in freshwater ecosystems in the semiarid region of Brazil

Abstract

This paper reports the first record of the genus Ceratium Schrank, 1973 in six freshwater ecosystems in the semiarid region of Brazil. From 2006 to 2010, 1176 samples were collected from 98 different sites using conical-cylindrical plankton nets with a 25 μm mesh size. Twenty individuals from each sample were measured for the obtainment of the morphological measurements. A 25% NaClO solution was used for the clarification of the cells and visualization of the plates. The appearance of this genus in such ecosystems is likely related to climatic and hydrological changes in the region.

First record of expansive Ceratium Schrank, 1793 species (Dinophyceae) in Southern Brazil, with notes on their dispersive patterns in Brazilian environments

“…Ceratium furcoides is the main recorded species, always accompanied by illustrations that allow corroborating the identification (Santos-Wisniewski et al 2007;Matsumura-Tundisi et al 2010;Oliveira et al 2011). Conversely, C. hirundinella has few unconfirmed records.…”

“…We believe that this taxon also corresponds to C. furcoides, considering the conical shape of apical horn from depicted specimen (Oliveira et al 2011, Figure 2D) and the hipothecal variability of Ceratium spp.…”

“…Ferrareze and Nogueira (2006), in an ecological survey, registered C. hirundinella, but no illustrations were added and the study area is located near to that where C. furcoides cells have been found. Oliveira et al (2011) (Figures 23, 24) and 20 µm (Figures 15-22, 25). …”

“…Finally, C. furcoides and Ceratium cf. hirundinella were detected by Oliveira et al (2011) For scanning electron microscopy (SEM), subsamples were washed with distilled water, air-dried on stubs and covered with gold by Balser Sputtering/SDC 300 equipment. These samples were observed on Jeol JSM 6360LV electronic microscope (Centro de Microscopia Eletrônica, Universidade Federal do Paraná), at 15 kV and 8 mm work distance.…”

First record of a bloom of the invasive species Ceratium furcoides (Levander) Langhans 1925 in Rio Grande do Sul state, Brazil

“…In the rivers semiarid region of Brazil the occurrences of C. furcoides and also of C. hirundinella were described by Oliveira et al (2011). C. furcoides e C. hirundinella are ecologically and morphologically similar (Gil et al, 2012) differing only in the number of apical plates (Santos-Wisniewski et al, 2007).…”