Maritrema

Maritrema is a genus of trematodes (flukes) belonging to the family Microphallidae. These parasitic worms are primarily known for their complex life cycles involving multiple hosts, often including marine invertebrates, crustaceans, and birds.

Maritrema species typically infect birds as their definitive hosts, residing in the intestines and reproductive tracts. The life cycle begins when eggs are shed in the feces of infected birds. These eggs are then ingested by the first intermediate host, usually a marine snail. Within the snail, the parasite undergoes asexual reproduction, producing cercariae.

The cercariae are released from the snail and actively seek out a second intermediate host, commonly a crustacean such as a shrimp or amphipod. The cercariae penetrate the crustacean and encyst as metacercariae within its tissues.

The life cycle is completed when a bird consumes an infected crustacean. The metacercariae excyst in the bird's digestive system and mature into adult worms, initiating the cycle anew.

Different Maritrema species exhibit variations in their host specificity and geographical distribution. They are commonly found in coastal environments worldwide. Studies on Maritrema have contributed to our understanding of parasite ecology, host-parasite interactions, and the evolution of complex life cycles. The effects of Maritrema infections on their hosts can vary, ranging from mild to severe depending on the species and the intensity of infection. In birds, heavy infections may cause intestinal inflammation and reduced reproductive success.