Morphological and molecular evidence for the recognition of Allocreadium bursensis n. sp. (Trematoda: Allocreadiidae) from Angora loach Oxynoemacheilus angorae from Turkey.

Abstract

This is the first study reporting parasites from the freshwater cyprinid Oxynoemacheilus angorae (Steindachner 1897) caught in Nilüfer Stream, Bursa, in the Northwest Anatolian Region of Turkey. Allocreadium bursensis n. sp. was described from the intesine of O.angorae based on morphological and genetic characteristics. Allocreadium bursensis n. sp. was differentiated from other Allocreadium spp. in having a combination of external (ventral and oral suckers ratio; body length and width and its ratio to forebody) and internal (cirrus pouch position; uterus extension in hindbody; egg size; disposition of anterior border of vitellarium; esophagus length) features. Phylogenetic hypotheses based on maximum parsimony, maximum likelihood, Bayesian inferrence, and neighbor joining analyses of sequence data strongly supported the hypothesis that A. bursensis is nested within the clade of Allocreadium species hosted by cypriniform fish, and it is more closely related to the Far Eastern species A. pseudoisoporum (Primorsky region, Russia) than to the African A. apokryfi. According to genetic p-distances, the taxonomic status of trematodes collected in Turkey was established as independent relative to nine of the valid Allocreadium spp.: 1.8-5.8% in 28S gene and 18.8-22.6% in cox1 gene. The present study increases the number of Allocreadium species and their definitive hosts recorded in Turkey and raises the number of Palearctic representatives of Allocreadium spp. to 26.