Ключевые слова: antennae, aquatic invertebrate, aquatic organism, biological specimen, biology class, brood chamber, circulatory system, cladocera, classroom slide, compound eye, compound lens, compound microscope, crustacean, curved spine, daphnia, digestive tract, ecological study, ecological system, embryo cell, environmental indicator, exoskeleton layer, fine bristles, fresh water, heart organ, internal organs, internal structure, lab study, micro crustacean, microscope image, nauplius eye, organism view, outer shell, pond life, reproductive organ, research sample, science education, shell structure, stained preparation, stained slide, stained tissue, swimming antennae, thoracic legs, translucent body, transparent body, water analysis, water flea, water quality, zooplankton,