Morphological, ultrastructural, and phylogenetic analysis of Ascaridia columbae infecting domestic pigeons (Columba livia domestica).

Ascaridia species are the most common nematodes infecting pigeons. The current study investigated specific identity of nematode parasites collected from domestic pigeons (Columba livia domestica) in Al-Qassim Region, Saudi Arabia. Out of 354 pigeons, 13.3 % were infected with nematode parasites. The morphological structure and genetic relationship of nematode worms were studied using conventional methods (Light and scanning electron microscopes) coupled with the newly introduced molecular method. Microscopical and ultrastructure observations showed that the present nematode worms belong to the genus Ascaridia and have all the characteristic features of Ascaridia columbae. Moreover, Random Amplifier morphometric (RAPD) PCR analysis revealed that the present A. columbae had a close identity of up to 98.3 % to Ascaridia columbae JX624729 for Cox-1 gene regions, and up to 98.3 % to Ascaridia nymphii LC057210, and Ascaridia galli EF180058 for ITS1-5.8s- ITS2 rDNA gene regions. Phylogenetic analysis supported the placement of this Ascaridia species within Ascaridiidae family with close relationships to other nematode species obtained from GenBank. Finally, our study recommends using molecular analysis in helminths identification as the main methodology for correct identification especially in closely related species.

New record of Tylodelphys metacercariae (Diplostomidae) from Perccottus glenii (Odontobutidae) and their phylogenetic assessment.

Metacercariae of Tylodelphys sp. were found in the abdominal cavity of the Chinese sleeper (Perccottus glenii) collected in Liaoning Province and Inner Mongolia Autonomous Region of China. The sequences of the mitochondrial cox1 gene and ribosomal ITS1-5.8S rDNA-ITS2 region were obtained and used for molecular identification and phylogenetic assessment of this parasite species. Results of phylogenetic analyses based on ITS and cox1 markers showed that the metacercariae of Tylodelphys sp. ex P. glenii from China were conspecific with specimens of Tylodelphys sp. collected by Sokolov et al. (2013) from the same fish-host species captured earlier in West Siberia, Russia. The examined Tylodelphys sp. ex. P. glenii is the only member of the genus whose metacercariae parasitise the abdominal cavity of fish in northern Eurasia. Tylodelphys sp. ex P. glenii clustered with T. darbyi, T. immer, T. podicipina, and Tylodelphys sp. of Soldánová et al., 2017 based on mitochondrial DNA markers, and with T. darbyi, T. immer, T. kuerepus, and T. schreuringi using nuclear DNA markers.

Studies on Woloszynskioid Dinoflagellates X: Ultrastructure, Phylogeny and Colour Variation in Tovellia rubescens n. sp. (Dinophyceae).

The external morphology and internal cell fine structure of a new species of Tovelliaceae, Tovellia rubescens n. sp., is described. Phylogenetic analyses based on partial LSU rDNA sequences place the new species in a clade containing Tovellia species that accumulate red pigments and identify T. aveirensis as its closest known relative. Cells of T. rubescens n. sp. were mostly round and had the cingulum located near the middle, with its ends displaced about one cingular width. Small numbers of distinctly flat cells appeared in culture batches; their significance could not be determined. Cells of the new species in culture batches progressively changed from a yellowish-green, mainly due to chloroplast colour, to a reddish-brown colour that appeared associated with lipid bodies. The switch to a reddish colour happened earlier in batches grown in medium lacking sources of N or P. Pigment analyses by HPLC-MS/MS revealed the presence of astaxanthin and astaxanthin-related metabolites in the new species, but also in T. aveirensis, in which a reddish colour was never observed. The chloroplast arrangement of T. rubescens n. sp. resembled that of T. aveirensis, with lobes radiating from a central pyrenoid complex. The flagellar apparatus and pusular system fell within the general features described from other Tovelliaceae. A row of microtubules interpretable as a microtubular strand of the peduncle was present. Spiny resting cysts with red contents and an ITS sequence identical to that of cultured material of the new species were found in the original locality.

MORPHOLOGY AND MOLECULAR PHYLOGENY OF AUREOPHYCUS ALEUTICUS GEN. ET SP. NOV. (LAMINARIALES, PHAEOPHYCEAE) FROM THE ALEUTIAN ISLANDS(1).

A previously unknown species of kelp was collected on Kagamil Island, Aleutian Islands. The species can be easily distinguished from any known laminarialean alga: the erect sporophytic thallus is composed of a thin lanceolate blade attaining ∼2 m in height and ∼0.50 m in width, without midrib, and the edge of the blade at the transition zone is thickened to form a V-shape; the stipe is solid and flattened, slightly translucent, attaining ∼1 m in length; the holdfast is semidiscoidal and up to 0.15 m in diameter. Anatomically, the blade has the typical trumpet-shaped hyphae characteristic of the Chordaceae and derived foliose laminarialean species (i.e., Alariaceae/Laminariaceae/Lessoniaceae). No hair pits or mucilaginous structures were observed on the blade or stipe. No fertile sporophytes were collected, but abundant juvenile sporophytes were observed in the field. In the molecular phylogenetic analyses using chloroplast rbcL gene, nuclear ITS1-5.8S-ITS2 rDNA, and mitochondria nad6 DNA sequences, the new species (Aureophycus aleuticus gen. et sp. nov.) showed a closer relationship with Alariaceae of conventional taxonomy, or the "Group 1" clade of Lane et al. (2006) including Alaria and related taxa than with other groups, although the species was not clearly included in the group. Aureophycus may be a key species in elucidating the evolution of the Alariaceae within the Laminariales. Because of the lack of information on reproductive organs and insufficient resolution of the molecular analyses, we refrain from assigning the new species to a family, but we place the new species in a new genus in the Laminariales.