Abstract
The present study described a new species of the genus Echinocephalus that was isolated from the intestine of the common carp Cyprinus carpio inhabiting Burullus Lake, Kafr el-Sheikh Governorate, Egypt. Thirty-two out of 70 examined specimens (45.71 %) were found to be naturally infected. The adult male worms were elongated and measured 0.79-0.85 mm (0.81 +/- 0.02) in length and 0.21-0.32 mm (0.28 +/- 0.002) in width, while females reached 0.89-0.98 mm (0.9 +/- 0.02) long and 0.25-0.38 mm (0.28 +/- 0.002) wide. The reported species are investigated microscopically, genetically, and compared with previous related ones. The present study recorded this new nematode parasite as Echinocephalus carpiae with accession no. KC493258, inhabiting new host and locality records in Egypt. It is especially characterized by short body length, cephalic bulb with few (six to eight) multiple rows of spines, clear annulated cuticle, and new genetic sequences, which identify the paraphyly of Gnathostomatinae.