Ceriodaphnia has six pairs of lobed legs which bear numerous hairs. Their head is bent
downwards and is set from the body by a cervical sinus. The head also has two large secondary
antennas that are positioned laterally near the posterior margin. (Pennak, 1989) The
Ceriodaphnia's mouth is located near the junction of the head and body. The Ceriodaphnia's body
is covered by a carapace which allows protrusion of only the head and abdomen. One of the
Ceriodaphnia's most noticeable features is its large compound eye.
Reproduction: The Ceriodaphnia reproduces parthenogenetically, which means the Ceriodaphnia
can reproduce without fertilization of the egg. The egg undergoes a single maturation division in
the ovary and a number are released at a time by the oviducts. (Pennak, 1989) Usually 10-20 eggs
Ecological Niche: Ceriodaphnia are very diverse as they can live in either oxygen rich or oxygen
poor environments due to their ability to synthesize hemoglobin. Ceriodaphnia live in all regions
of lakes and ponds whether it is on the surface or near the bottom soil. Ceriodaphnia serves as the
main food source for the Hydra in an ecosystem.
Notes of Interest: Ceriodaphnia feed on green algae. They also have thoracic appendages that are
modified phyllopodia that has bristles for food collecting and respiratory functions. (Prescott,