Deretrema philippinensis n. sp. (Digenea: Zoogonidae) from Anomalops katoptron (Beryciformes: Anomalopidae) from the Philippines

Abstract

Deretrema philippinensis n. sp. is proposed for zoogonid Digenea found in pairs in the gallbladder of 10 of 12 flashlight fish (Anomalops katoptron Bleeker) from the Philippines. Deretrema philippinensis is characterized by intestinal caeca extending posterior to the testes to the posterior one-fourth of body length; comparatively large oral and ventral suckers; ratio of oral sucker: ventral sucker, 1:1.18–1.36; ventral sucker equatorial; comparatively small testes situated at level of ventral sucker and extensive uterine coils in the preacetabular region. These features are used to separate D. philippinensis from the 17 described species currently assigned to Deretrema. The importance of some of the morphological features previously used in the separation of Deretrema spp. is briefly discussed.