Daphnia Research Paper

Common name of animal Daphnia

Phylogeny (classification and Scientific name)

Kingdom Animalia

Phylum Arthropoda

Class Crustacea

Order Cladocera

Family Daphniidae

Genus Daphnia species Daphnia magna

Why is this organism a member of this phylum?

Daphnia are a member of Arthropoda because daphnia have an exoskeleton made of chitin and proteins and a segmented body, which are defining characteristics of arthropods.

1. What type of symmetry bilateral symmetry 2. How many germ layers three

3. Type of body cavity hemocoel

4. Type of segmentation and number and name of segments

The segments of a daphnia are difficult to distinguish compared to other arthropods. “The head is usually covered by a head shield

The daphnia, similarly to most simple invertebrates does not have red blood cells or lungs. Hemoglobin is responsible for carrying oxygen and nutrients to the blood for daphnia. Hemoglobin production increases under stressful situations for daphnia, allowing survival in low oxygen environments. Daphnia have an open circulatory system, similarly to most other arthropods. Hemolymph is pumped through the hemocoel, a body cavity during circulation. Since the daphnia has no major veins or arteries, the blood pressure is high and the hemolymph being pumped is directly distributed throughout the body.

7. Describe the digestive and excretory systems In order to bring food up the digestive tract, the daphnia beat the legs at a constant rate through the carapace, or hard upper shell. Food bolus forms when the food particles get trapped. After the food particles travel down the digestive tract, the waste gets released through the anus, which is “located on the ventral surface of the terminal appendage. The first and second pairs of legs are used in the organisms' filter feeding, ensuring that particles too large to handle are kept out while the other sets of legs create the stream of water rushing into the organism,” (Daphnia).

8. Describe the type of nervous