Morphological and molecular characterization of Cucullanus hainanensis sp. nov. (Ascaridida: Cucullanidae) from Muraenichthys gymnopterus (Bleeker) (Anguilliformes: Ophichthidae) in the South China Sea

Abstract

Cucullanus hainanensis sp. nov., collected from Muraenichthys gymnopterus (Bleeker) (Anguilliformes: Ophichthidae) in the South China Sea, was described using both light and scanning electron microscopy. The new species can be readily distinguished from its congeners by the large pseudobuccal capsule, the position of excretory pore and deirids, the length of spicules (0.64-0.76 mm, 5.84-6.67% of body length) and gubernaculum (0.21-0.24 mm), the number and arrangement of caudal papillae and the particular morphology of cloacal region in male. The new species was also characterized using molecular methods by sequencing and analysing the small subunit (18S) and the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA). In addition, Cucullanus muraenesocis (Yin et Zhang, 1983) was regarded a homonym of C. muraenesocis Yamaguti, 1961, and a new name, Cucullanus wangi nom. nov. was given to it.

Cucullanus carettae Baylis, 1923, in a loggerhead sea turtle (Caretta caretta) from the Adriatic sea: first detection and molecular characterization

“…Phylogenetic distances support the assumption that our samples belong to a species not yet molecularly characterized, thus not present in GenBank. The results from the present study confirm the cox1 region to be a suitable and useful genetic marker for distinguishing and identifying Cucullanus species (Xu et al 2014;Li et al 2016;Pereira and Luque 2017). As no sequences of C. carettae were present in the database, we provided the first molecular characterization of the species, which could be of help in the correct identification of the specimens, whenever morphological identification cannot be obtained.…”

Three new species of Cucullanus (Nematoda: Cucullanidae) from marine fishes off New Caledonia, with a key to species of Cucullanus from Anguilliformes

“…egyptae Abdel-Ghaffar, Bashtar, Abdel-Gaber, Morsy, Mehlhorn, Al Quraishy & Mohammed, 2014 [ species inquirenda ; 31] from Anguilla anguilla (Linnaeus) in Egypt [ 1 ]; C . hainanensis Xu, Zhang & Li, 2014 from Muraenichthys gymnopterus (Bleeker) in the South China Sea [ 41 ]; C . hians (Dujardin, 1845) [syn.…”

“…wangi Xu, Zhang & Li, 2014 (syn. Indocucullanus muraenesocis Yin & Zhang, 1983) from Muraenesox cinereus off China [ 41 , 48 ].…”

“…Nevertheless, some papers published during last two decades (e.g. [ 15 , 17 , 22 – 24 , 27 , 30 , 32 – 34 , 41 , 42 , 44 ]) have shown the importance of the use of SEM for the taxonomy of these nematodes, because some features are difficult to observe or are not visible at all under the LM.…”