ABSTRACT
The acanthocephalan Moniliformis saudi Amin, Heckmann, Mohammed, Evans, 2016 was originally described from the desert hedgehog, Paraechinus aethiopicus (Ehrenberg) in central Saudi Arabia. The distribution of P. aethiopicus extends to North Africa and west to Mauritania. Moniliformis saudi was recently found in the Algerian hedgehog Atelerix algirus (Lereboullet) in Malta. The distribution of A. algirus is restricted to the North African and east Iberian Mediterranean coast and associated islands. Both host species cohabit and share the same feeding grounds in northern Algeria where common infections appear to take place. The morphology of specimens from both acanthocephalan populations was similar, with minor variations mostly related to the relatively larger Maltese specimens especially the trunk and the male reproductive system. Taxonomic features like the cone-shaped anterior trunk, size and formula of proboscis and hooks, the receptacle, size and shape of eggs, anatomy of the apical proboscis sensory pores, and the stellate body wall giant nuclei were, however, practically identical. SEM and microscope images of specimens of the Maltese population emphasize their qualitative characteristics such as the degree of the extreme spiral muscle development and the development of the posterior nucleated pouches of the proboscis receptacle. Proboscis hooks of specimens from both the Maltese and the Saudi populations had similarly high levels (percent weights) of calcium, moderate levels of phosphorus, and minimal levels of sulfur, magnesium and sodium marking the diagnostic value of the Energy Dispersive x-ray analysis in species recognition. Newly generated partial sequences of the 18S ribosomal RNA and cytochrome C oxidase subunit 1 (Cox1) of the mitochondrial gene were generated from M. saudi from Malta. Moniliformis saudi from Malta, when compared with other available sequences of the same species isolates available in the GenBank database, formed a strongly supported clade with other congeners. The comparison of the molecular profiles of specimens from populations in Malta, Spain, and Saudi Arabia shows no or low genetic variation between them. Ultimately, we provide a morphological and molecular description of a new population of M. saudi from a new host species in a new geographical location, vastly exceeding the originally described ones from Saudi Arabia. A Cox 1 haplotype network inferred with 10 sequences revealed the presence of eight haplotypes, one of which was shared between the populations of Malta and Spain of M. saudi.
Subject(s)
Acanthocephala , Moniliformis , Animals , Male , Acanthocephala/genetics , Hedgehogs , Malta , Saudi Arabia , Species SpecificityABSTRACT
PURPOSE: Immature Southwellina hispida (Van Cleave, 1925) Witenberg, 1932 from the body cavity of the paratenic host Gillichthys mirabilis Cooper (Gobiidae) in California are described. METHODS: New Scanning Electron images and features of micropores, hook and spine Gallium cut sections and chemistry using Energy Dispersive X-ray analysis (EDXA), and molecular profile are provided for the first time. The 18S rDNA and mt Cox1 sequences were performed for molecular and phylogenetic study. RESULTS: Our specimens were somewhat comparable to those reported from other paratenic hosts in Asia, Europe, and North and South America but varied in relative sizes of trunk and other structures, proboscis formula, and distribution of trunk spines. About 60 publications were reviewed of which one third included line drawings used for comparative morphometrics. In our specimens, the trunk measured 2.72-3.10 mm long by 0.92-1.07 mm wide and the proboscis 700-800 × 270-312 µm had 20-21 rows of 14-15 hooks each measuring 47-55 long by 12-15 µm wide at base anteriorly, 47-48 × 20-23 µm at middle bulge, and 43-50 × 13-20 µm basally. These measurements, among others were compared with measurements of juveniles from 13 other collections world-wide and intraspecific variability was noted especially in the shape of hook roots that were occasionally misinterpreted. EDXA showed hooks with high levels of Sulfur especially at the tip and edge of all hooks and low levels of Calcium and Phosphorus. Anterior spines had higher levels of Sodium but Gallium cut spine sections had higher levels of Calcium at middle and of Sulfur at base of spines. Micropores were variably distributed on the body wall and extended to the cortical layer of spines. Gene sequences of the 18S and the mitochondrial cytochrome c oxidase subunit 1 (cox 1) region were amplified for specimens of S. hispida. Molecular phylogenetic analysis inference from 18S rDNA and mt Cox1 gene sequences show a close relationship with previously reported myxozoan sequences available on GenBank database. Phylogenetic analysis positioned our S. hispida in a well-supported clade including other members of Polymorphidae. CONCLUSION: The present study combined morphological, morphometric and molecular data to identify S. hispida.
