Mussel Shrimp: Ostracoda

Physical characteristics: This ostracod measures 0.12 inches (3 millimeters) in length. It has a beaklike projection on the front of the smooth, round, clear carapace. The black eyes are visible through the carapace. The carapace has large notches through which the antennae stick out. The appendages at the tip of the abdomen are very large and visible between the folded halves of the carapace.

Geographic range: They are found along the Pacific coast of central Japan.

Habitat: This species is very common in shallow waters with sandy bottoms.

Diet: In captivity they will attack worms, scavenge dead fish, or eat fish food.

Behavior and reproduction: Vargula hilgendorfii remain buried just under the surface of the sand during the day. At night they use their At night Vargula hilgendorfii use their antennae to move across the bottom or swim over the bottom. (Illustration by Patricia Ferrer. Reproduced by permission.) antennae to move across the bottom or swim over the bottom. When threatened they will use the large appendages on the tip of the abdomen to push themselves into the sand. They also use these structures to lift themselves quickly up from the sand and into the water.

Males hold females for about 30 to 60 minutes before mating actually begins. Males transfer a packet of sperm to the female's reproductive organs. Females brood their eggs under the carapace. The larvae molt five times before reaching adulthood. Young larvae are capable of crawling, digging, and swimming.

Vargula hilgendorfii and people: They are eaten by some fish that are caught and used as food for people.

Conservation status: This species is not considered threatened or endangered by the World Conservation Union (IUCN). ∎