Parasitological and Histopathological Observations of Huffmanela Species Infesting Spot-Tail Shark Carcharhinus sorrah from Water of Arabian Gulf; Saudi Arabia

Fifteen (10%) of Spot-Tail Shark; Carcharhinus sorrah ; out of one hundred and fifty samples that were caught from the water of the Arabian Gulf and examined during the period of May till November 2018. They showed unusual black irregular discolouration in the form of linear tracks together with fine, tiny black spots on the skin. The Parasitological examination showed bipolar eggs somewhat resemble those of the nematode genus Huffmanela (Nematode, Trichosomoididae). The parasitological examination revealed the presence of dark-shelled trichinelloid embryonated eggs dispersed at some stage in the skin and muscular tissue. The eggs were 110 to 140 (130 ± 2.4) ×55 to 65(59±2.8) µm in size, with large polar plugs 11.2-11.8(11.5±0.15) ×6.5-7.1(6.7±0.13) µm length by width. The species of trichosomoidid nematode, Huffmanela sp. was recorded from C. sorrah . Brief egg morphology was reported and compared with most related previously described species. The histopathological examination of the infected shark fish revealed that the epidermal layer showed clear, dark brown eggs of Huffmanela in between the placoid scales and most prominent in the epidermal layers. Huffmanela eggs showed morphological differences from the previously identified ones, so they could be considered a new species in a new geographical location and in a newly infected shark fish host.