Morphological and molecular analyses of Bipteria lusitanica n. sp. in wild white seabream, Diplodus sargus (Linnaeus, 1758) in Portugal.

Abstract

The present study records the presence of Bipteria lusitanica n. sp. in wild white seabream, Diplodus sargus (Linnaeus, 1758) off the Portuguese coast. Myxosporean parasites were found in the interstitial tissue of kidney and free in urinary bladder of D. sargus with a 33.3% of prevalence of infection. Myxospores were triangular or inversely pyramidal in shape and anteriorly wider in frontal view, measuring 11.2 ± 1.0μm in length, 12.6 ± 0.9μm in width, and 11.6 ± 0.4 μm in thickness. The sinuous sutural line was parallel to the axis that connects the center of the two polar capsules. Spore valves were smooth without ridges. Wing-like appendages extended from the posterior part of each valve in sutural view, measuring 3.9 ± 1.1μm in length. Spherical polar capsules measured 4.4 ± 0.2μm in diameter and the polar filaments were helical arranged in 5-6 turns. Molecular data showed that this parasite clusters within species of the Sinuolineidae Shulman, 1959 family, and they all infect the urinary bladder. Using molecular and morphological characterization, we were able to identify this parasite as a novel species of the genus Bipteria Kovaleva, Zubtchenko, and Krasin, 1983.