Systematic Parasitology最新文献

Two new species of Scyphophyllidium Woodland, 1927 are described from the Hooktooth shark, Chaenogaleus macrostoma (Bleeker), from the Persian Gulf, Iran. Scyphophyllidium hormuziense n. sp. is assigned to morphological category 2 of its genus because it possesses bothridial marginal loculi and an apical sucker on each flat bothridium, and lacks bothridial facial loculi. Within category 2, it is distinguished from its congeners, except for S. janineae (Ruhnke, Healy and Shapero, 2006), by possessing, rather than lacking, a prominent cephalic peduncle. It differs from S. janineae in the distribution of the vitelline follicles. Scyphophyllidium iraniense n. sp. is assigned to morphological category 5 because its bothridia are essentially flat and lack proximal apertures, marginal loculi, facial loci and semi-circular muscle bands, and bears weakly serrate gladiate spinitriches on its distal bothridial surfaces. Within its morphological category, the presence of a long cephalic peduncle distinguishes S. iraniense n. sp. from its congeners lacking this structure or possessing a short cephalic peduncle. It further differs from S. arnoldi (Ruhnke and Thompson, 2006) and S. typicum (Subhapradha, 1955) in total length, from S. paulum (Linton, 1897) in lacking a conspicuous band of muscles along the locular periphery of the bothridia, and from S. kirstenae (Ruhnke, Healy and Shapero, 2006) in the distribution of the vitelline follicles. This study brings the number of the valid Scyphophyllidium species of the Persian Gulf to five.

Two new dactylogyrid species were found infecting the gill filaments of two freshwater fishes collected in the Amazon River basin around Madre de Dios, Peru, namely, Demidospermus wilveri n. sp. from Loricaria sp. (Siluriformes: Loricariidae), and Notozothecium agusti n. sp. from Brycon amazonicus (Spix & Agassiz) (Characiformes: Bryconidae). Demidospermus wilveri n. sp. is characterized by having the following combination of characteristics: (1) a male copulatory organ (MCO) with 1½ rings and a spoon-shaped distal end, (2) an accessory piece with expanded distal end, (3) dorsal and ventral bars with broadly V-shaped and expanded ends, and (4) hooks similar in size. Notozothecium agusti n. sp. differs from its ten congeners by the following combination of characteristics: (1) a coiled MCO with 1½ rings and a sinuous accessory piece with kidney-shaped distal end, (2) an rod-shaped and straight dorsal bar, (3) and anchors with robust superficial roots. Demidospermus wilveri n. sp. represents the thirty-second species in the genus, the eighth from Peru and the fifth parasitising a loricariid catfish from the Peruvian Amazon. Notozothecium agusti n. sp. is the second species of the genus described in Peru and the first species infecting a bryconid host.

Bunocotylid trematodes represent a group of 149 species with a rather complex taxonomic history. The current concept of the subfamily only includes three genera, Bunocotyle, Saturnius, and Robinia. Specimens of a bunocotylid were collected from the silver mullet, M. curema, from a coastal lagoon of Yucatán and identified as belonging to Saturnius. Further detailed morphological study revealed they corresponded to S. maurepasi, a species previously reported from the stripped mullet, Mugil cephalus in Mississippi, USA. Specimens were sequenced for the LSU of nuclear ribosomal RNA gene (28S) to test their phylogenetic position. We discovered that they do not belong in Saturnius since they nest as an independent lineage which is the sister taxa of a clade formed by Robinia, and Saturnius + Bunocotyle; additionally, the new genus exhibits high genetic divergence (10-12%) with respect to species allocated in the other bunocotylid genera. The species S. maurepasi was then transferred to the new genus as Parasaturnius maurepasi n. gen., n. comb. that was created to accommodate it, and was redescribed based on newly sampled specimens.

Examining the intestinal cestode fauna of the shark species Carcharhinus dussumieri (Müller and Henle), C. sorrah (Müller and Henle), C. leucas (Müller and Henle), and Rhizoprionodon acutus (Rüppell) from the Persian Gulf and C. macloti (Müller and Henle) from the Gulf of Oman resulted in the description of three new species of the tetraphyllidean genus Anthobothrium van Beneden, 1850, along with the establishment of new host and locality records. Anthobothrium afsanae sp. nov. and A. barsami sp. nov. were found in C. dussumieri and C. sorrah. Carcharhinus macloti was the additional host of A. barsami and new host record for A. parimae Sadeghi Kamachali and Haseli, 2022, for which a new locality record was established in the Gulf of Oman. Carcharhinus leucas is the type host of A. elenae sp. nov. and a new host record for A. lesteri Williams, Burt and Caira, 2004. A new locality record for A. lesteri is the Persian Gulf, which is far away from the type locality, Australia. Rhizoprionodon acutus is new host record for A. samae Sadeghi Kamachali and Haseli, 2022 and A. shayani Sadeghi Kamachali and Haseli, 2022. With 14 valid species of Anthobothrium and given the relatively uniform morphology of members of this genus, a key to the species of Anthobothrium is presented. The biogeographical distribution and host specificity are also discussed for the species of Anthobothrium.

In the present study, we describe Oxysomatium brevispiculum n. sp. (Ascaridida: Cosmocercidae) parasitizing Amphisbaena alba Linnaeus (Squamata: Amphisbaenidae) in the municipality of Uberlândia, Cerrado Biome, Minas Gerais, Brazil. Oxysomatium brevispiculum n. sp. differs from its congeners by having shorter spicules and by the number and arrangement of caudal papillae. The males of the new species have a precloacal unpaired papilla and can be easily distinguished from O. caucasicum in which this morphological trait is absent. Oxysomatium brevispiculum n. sp. differs from the other three species of the genus by the number and arrangement of caudal papillae, with 13 pairs + 1 unpaired precloacal papilla, arrangement 8+1:2:3, while O. brevicaudatum has 14-16 pairs +1 unpaired papilla, and 7-9+1:1:6 arrangement, O. petrolinensis has 16 pairs +1 unpaired papilla, and 8+1:1:7 arrangement, and O. dollfusi with 15-16 pairs +1 unpaired papilla, and 8-9+1:1:6 arrangement. Oxysomatium brevispiculum n. sp. is the fifth species of this genus, the second species in a Neotropical host, and the first species of this genus described in amphisbaenid hosts. In addition, the present study provides an identification key for the species of this genus.

We describe a new kudoid species, Kudoa tanakai n. sp., in the scalpel sawfish, Prionurus scalprum (Actinopterygii: Acanthuriformes: Acanthuridae), from the natural water around western Japan. The plasmodia were filamentous, localized in pseudocysts in the myofibers of the trunk muscles. The occurrence of plasmodia in the trunk muscle showed no site preference. Its myxospores were spheroid, measuring 6.6-7.6 (7.0) µm by 5.8-6.9 (6.3) µm in apical view (width) and 5.7-6.6 (6.2) in length (n = 30), with four shell valves and a corresponding number of spheroid polar capsules. Shell valves lacked apical protrusions, but scanning electron microscopy revealed that one of the four shell valves had two semi-lunar flaps at its apical terminus. Nucleotide sequencing of the small and large subunit ribosomal RNA genes of the present isolate showed phylogenetic affinities to kudoid species characterized by spheroid myxospores, such as K. musculoliquefaciens, K. hemiscylli, and K. carcharhini, but was molecularly and morphometrically distinct from these and other kudoid species. For direct comparison, Kudoa hemiscylli was collected from the Pacific spadenose shark, Scoliodon macrorhynchos (Elasmobranchii: Carcharhiniformes: Carcharhinidae), in the South China Sea off Guangdong Province, China, and the myxospore surface of the species was observed using scanning electron microscopy. Our study describes the new host and distribution record of this kudoid species originally described from a variety of elasmobranchs in the Australian Coral Sea.

Trematodes of the genus Mesocoelium Odhner, 1910 (Digenea: Plagiorchioidea: Mesocoeliidae) are globally distributed and parasitize amphibians, reptiles, or occasionally fishes. This genus is one of the most confusing taxa in trematodes because of its poor morphological features. In this study, we examined species of Mesocoelium collected from Japanese amphibians and found that they can be morphologically assigned to two species of Mesocoelium. Mesocoelium brevicaecum Ochi in Goto and Ozaki, 1929 parasitizes various both urodelan and anuran amphibians and occurred widely in Japan, while M. japonicum Goto and Ozaki, 1930 parasitizes a few hynobiid species in a limited part of Japan. We proposed ceca length as a valid key characteristic for species identification in this genus. M. elongatum Goto and Ozaki, 1929, M. lanceatum Goto and Ozaki, 1929, M. minutum Park, 1939, M. ovatum Goto and Ozaki, 1930, and M. pearsei Goto and Ozaki, 1930 are junior synonyms of M. brevicaecum, while M. japonicum can be distinguishable from them by morphologically and molecularly. Our molecular study supported the validity of both species and showed intraspecific divergence associated with geographic distance. Molecular identification suggests that the land snail Euhadra quaesita can serve as the first intermediate host for M. japonicum in Japan. This study also indicates the extremely low specificity of this genus for vertebrate hosts. Finally, we conclude that at least three species of Mesocoelium (M. brevicaecum, M. japonicum, and Mesocoelium sp. 1) are distributed in Japan. Further studies in other regions are undoubtedly required for a better understanding of the taxonomy and ecology of the genus Mesocoelium.

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.

West Indian manatees (Trichechus manatus) harbor a variety of endoparasites, including the nasal trematode Pulmonicola cochleotrema, which infects the respiratory tract, especially the nasal passages. Previous studies have described and identified this digenean using morphological data only. This study presents the first molecular identification of P. cochleotrema in West Indian manatees from Puerto Rico and Florida. Samples of the trematode were collected from seven manatees found stranded dead at both locations. The small subunit ribosomal DNA (18S rDNA) was amplified from each sample using universal primers for different regions of the gene, resulting in a consensus sequence of 1871 base pairs. The phylogenetic reconstruction was carried out using DNA sequences of other species of digenean parasites from other hosts, including a trematode of the same taxonomic family from another sirenian species. Specimens collected from both locations show the same molecular identity using SSU rDNA sequence data. The identity of P. cochleotrema was confirmed using the Basic Local Alignment Search Tool from the National Center for Biotechnology Information database, yielding a high similarity of 98.8 % with Opisthotrema dujonis and 98.2 % with Lankatrema mannarense located in the same clade in our analysis. The latter two digeneans belong to the Opisthotrematidae as does P. cochleotrema and previous studies reported them infecting the Eustachian tubes, esophagus, and digestive tract in dugongs (Dugong dugon). These findings evidence that the nasal trematode of manatees in Florida and Puerto Rico and the dugong, all inhabiting and feeding in marine environments, will have a marine mollusk as an intermediate host, probably a gastropod. The question remains, which species of nasal trematode are harbored by lotic-dwelling manatees in other parts of their distribution like South America.

Members of the genus Microphallus Ward, 1901, are endoparasites mainly of birds and mammals distributed worldwide. Unencysted metacercariae of Microphallus sp., were collected from the mesoglea of ctenophores of the genus Pleurobrachia Fleming; adult digeneans were recovered from the intestines of Eudocimus albus Linnaeus (Threskiornithidae) and Buteogallus urubitinga Gmelin (Accipitridae), in four locations from southeastern Mexico. Adult specimens were identified as M. basodactylophallus (Bridgman, 1969) based on the following features: body pyriform entirely covered by minute spines, prepharynx short, oesophagus very long, caeca short and widely divergent, testes slightly symmetrical and excretory vesicle short and V-shaped. Sequences from D1–D3 domain of the large subunit of ribosomal DNA (LSU) were generated, aligned, and compared with those of congeneric species available in GenBank. Phylogenetic analyses indicated that the metacercariae and adults formed a clade together with an isolate identified as M. basodactylophallus from Florida, USA (GenBank: AY220628). The intraspecific genetic divergence among isolates was low ranged from 0.0% to 0.6%, allowing the link between the two stages of the life cycle. We observed phenotypic plasticity in the morphological traits of M. basodactylophallus adults in definitive hosts (mammals and birds) throughout the distribution, which ranged from the USA to southeastern Mexico. Finally, the unencysted metacercariae identified as M. basodactylophallus represent the first report of a microphallid in ctenophores.