Notholca

Notholca is a genus of planktonic rotifers belonging to the family Brachionidae. These microscopic animals are commonly found in both freshwater and brackish water environments, including lakes, ponds, and estuaries. They are characterized by a lorica, a rigid or semi-rigid shell-like structure that encloses most of their body. The shape and ornamentation of the lorica are important features used in species identification within the genus.

Notholca rotifers are primarily filter feeders, utilizing their ciliated corona (a crown-like structure with cilia) to generate water currents that draw suspended particles, such as bacteria, algae, and detritus, towards their mouth. They play a significant role in aquatic food webs, serving as a food source for larger zooplankton and small fish.

The taxonomy of Notholca has been subject to revisions and debate, with various species and subspecies recognized based on morphological characteristics. Different species can exhibit varying tolerances to environmental factors such as salinity, temperature, and pH, leading to their distribution in specific aquatic habitats. Certain Notholca species are considered indicators of water quality, as their presence or abundance can reflect the trophic state and pollution levels of an aquatic ecosystem. Further research, including molecular studies, continues to refine our understanding of the evolutionary relationships and species boundaries within the Notholca genus.