A Seasonal Study Reveals the Occurrence of Exotic Rotifers, the River Antigua, Veracruz, Close to the Gulf of Mexico

Abstract

Abstracts Zooplankton studies in Mexican rivers are few despite the fact that Mexico has >200 rivers. We present data on the seasonal diversity of rotifers during 2013–2014 from the river La Antigua, near Veracruz. We collected samples from 15 stations along a horizontal gradient of ~5 km, from the upper reaches to about 2 km from the sea. The physico‐chemical variables analysed were temperature, pH, dissolved oxygen, conductivity, nitrates, phosphates, Secchi depth and salinity. From each site, 80 L of water was filtered with a 50‐μm plankton net. Rotifers were identified and quantified using a Sedgewick Rafter cell. The river is shallow (maximum depth 2.5 m during the rainy season). Our observations indicated that the phytoplankton community was dominated by diatoms; the chlorophyll a concentrations ranged from 0.55 to 26.1 μg L−1 over the study period. We found >125 rotifer species belonging to 21 families, mostly from the Lecanidae, Brachionidae, Notommatidae and Lepadellidae. The density of rotifers was low, <40 ind. L−1, but species diversity (Shannon–Wiener) ranged, except for a onetime minimum of 0.25, from 2.0 to 4.0 for most part of the year. We also encountered Notholca cf. liepetterseni, an endemic species to Europe and Lecane yatseni, endemic to Asia. Other new records included Lecane rhytida and Ptygura melicerta. The importance of long‐term studies in rivers is emphasized. Copyright © 2017 John Wiley & Sons, Ltd.

Temperature-dependent demographic differences in sessile rotifers of the genus Limnias (Rotifera: Gnesiotrocha)

“…Although common and abundant, they are rarely reported in rotifer field studies. Edmondson (1940) Nandini et al, 2017). The application of molecular tools for systematics of sessile rotifers, including Limnias, has been gaining momentum (Kordbacheh et al, 2018).…”

Planktonic indicators of water quality: A case study in the Amacuzac River Basin (State of Morelos, Mexico)

“…In the river Amacuzac, on the other hand, we observed only 60 species and a diversity ranging from around 0.5 to 2.5. The most dominant families of rotifers in riverine systems are Lecanidae and Brachionidae (Ferrari, Farabegoli, & Mazzoni, ; Nandini et al, ). In this study too, of a total of 65 rotifer species, we found nine brachionids and 21 lecanids.…”

“…Site 1 in the river had the highest species diversity. Riverine plankton richness has been reported to be quite high although the density may be very low, probably due to the constant flow that brings new taxa with it (Gaytán‐Herrera et al, ; Nandini et al, ). The species richness and diversity of phytoplankton and rotifers in this river is, however, lower than that in the River La Antigua, perhaps due to the water quality or lower availability of algae as reflected in the Chlorophyll‐ a levels.…”

“…Site 1 in the river had the highest species diversity. Riverine plankton richness has been reported to be quite high although the density may be very low, probably due to the constant flow that brings new taxa with it (Gaytán-Herrera et al, 2017;Nandini et al, 2017).…”

“…During the same period, very few individuals of cladocerans and copepods were found in the river. Some exotic and invasive species of zooplankton such as the Asiatic copepod, Mesocyclops pehpeiensis , Notholca lieppeterseni , first reported from Norway, and the Chinese endemic rotifer Lecane yatseni have also been found in rivers (Nandini et al, ; Sarma, Jiménez‐Contreras, Fernández, Nandini, & García‐García, ). Among phytoplankton, the dominant groups in rivers are diatoms, chlorophytes, and cyanobacteria (Gaytán‐Herrera, Cuna‐Pérez, & Ramírez‐García, ).…”