Histopathological Lesions Caused by a Digenean Trematode in a Pest Apple Snail, , in Its Native Geographic Distribution Area.

is one of the most dangerous invasive species. Morphological and molecular analyses have revealed that a digenean species belonging to the family Echinostomatidae parasitizes this snail at two sites in Buenos Aires Province, Argentina, South America. Molecular results confirmed that the species belongs to a genus closely related to .

The elucidation of the life cycle of Szidat, 1954 (Digenea: Haploporidae) using molecular techniques.

In South America, the knowledge of trematode diversity parasitizing freshwater fishes is still scarce, as less than 5% of the freshwater fish fauna has been examined for parasites. A similar situation applies to studies on digenean life cycles, which have become increasingly rare. Among the digenean families parasitizing freshwater fishes in the region, Haploporidae is considered the richest in species diversity.

Host-parasite relationship Octopus tehuelchus - Aggregata valdessensis in Patagonian coast, southwestern Atlantic Ocean.

Histopathology associated with the apicomplexan Aggregata valdessensis in the wild population of Octopus tehuelchus was studied. Moreover, to analyze the impact of the prevalence and infection intensity on the dorsal mantle length, sex, maturity stages, condition index and total hemocyte counts on wild O. tehuelchus, Generalized Linear Models (GLMs) were applied.

New perspectives on morphological and genetic variability of [Linstow, 1892] parasitizing southern elephant seals from the Antarctic Peninsula.

Previous descriptions of (Linstow, 1892) show that specimens vary greatly in the proportions of different body structures, measurements of females and males, number of rows of hooks, and egg measurements, among other features. We redescribe this species from specimens found in southern elephant seal faeces from King George Island. We also provide a molecular characterization, in addition to 5.

Parasitological survey of coastal birds from the Magellanic coast, Southwestern Atlantic Ocean.

Ecto and endoparasites of four species of coastal birds, Haematopus ater, Larus dominicanus, Leucophaeus scoresbii (Charadriiformes), and Lophonetta specularioides (Anseriformes), are reported from Puerto Deseado on the Patagonian coast, Argentina. Only H. ater was infested with lice (Phthiraptera), belonging to 2 species (Ischnocera, Amblycera).

Comparative genomics for Agmasoma sp. (Microsporidia) parasitising invasive Carcinus aestuarii and Carcinus maenas in Argentina.

Carcinus spp. are global aquatic invaders and carriers of several parasites, including a taxonomically unrecognised microsporidian recently observed from Argentina. We provide genome drafts for two parasite isolates, one from Carcinus maenas and one from Carcinus aestuarii, and use multi-gene phylogenetics and genome comparison methods to outline their similarities.

n. sp. (Digenea: Notocotylidae) parasitizing the South American Black Oystercatcher and their atypical life cycle from the Patagonian coast.

By way of morphological and molecular analysis we describe a new species of notocotylid, n. sp., parasitizing from Argentina and we contribute to elucidate its life cycle.

A phylogenetically unresolved apicomplexan (APXSc) causing swirl lesions in the Tehuelche scallop, , from the Southwest Atlantic coast.

The study reports a previously unknown apicomplexan (APXSc) parasite infecting wild scallops (d'Orbigny, 1842) from two separate areas (La Tapera and Punta Conos) of the San José gulf, in Patagonia Argentina. Histology, transmission electron microscope, molecular analyses and hybridization were performed to describe the morphology of APXSc, and confirm its phylogenetic status. The prevalence of APXSc infection was 24% and 72% in scallops from La Tapera and Punta Conos, respectively.

A new species of Auriculostoma (Digenea: Allocreadiidae) in South America: life cycle and phylogenetic relationships.

Auriculostoma is a genus of digenean (Trematoda) whose adults are parasites of Neotropical freshwater fishes. We describe Auriculostoma ocloya n. sp.

Pathological conditions of the sentinel bivalve, the little mussel Brachidontes rodriguezii, from contaminated intertidal sites in the Southwestern Atlantic coast.

A survey of pathological conditions affecting the natural beds of the dominant bivalve species of the intertidal rocky coasts of the Southern Atlantic Ocean, was performed. Samples of the little mussel (n = 992), Brachidontes rodriguezii, which is considered a sentinel species, were collected from seven sites that present different anthropogenic activity (low anthropogenic activity, harbor, and sewage waste) along the Argentinean coast, and processed by standard histological techniques. Our results showed for the first time in a B.

Symbionts of invasive and native crabs, in Argentina: The most recently invaded area on the Southwestern Atlantic coastline.

Biological invasions have the capacity to introduce non-native parasites. This study aimed to determine whether the invasive green crab population, Carcinus spp., on the Southwestern Atlantic coast of Argentina harbours any symbionts, and whether these may spillover or spillback between native crabs, Cyrtograpsus altimanus and C.

Gulls as carriers of antimicrobial resistance genes in different biogeographical areas of South America.

The aim of this communication was to establish if Enterobacterales associated with gulls in Argentina harbored antimicrobial resistance (AMR) genes. We analyzed cloacal swabs in two contrasting areas: Ensenada, Buenos Aires province (26 Larus dominicanus and 22 Chroicocephalus maculipennis) and Puerto Madryn, Chubut province (20 L. dominicanus).

Cryptic speciation of the zoogonid digenean Diphterostomum flavum n. sp. demonstrated by morphological and molecular data.

Diphterostomum brusinae (Zoogonidae) is a digenean species that has been recorded worldwide parasitizing marine fishes. Several species have been synonymized with D. brusinae because they lack conspicuous morphological differences.

Diseases and parasites of wild and cultivated mussels along the Patagonian coast of Argentina, southwest Atlantic Ocean.

A histological survey of the commercially edible mussels Mytilus platensis and M. chilensis from wild and cultivated populations along the coast of Patagonia, Argentina (42°00' to 54°47'S), was carried out to determine their health status. Diagnostic results included 3 types of inflammatory responses (infiltrative, nodular, and encapsulation), disseminated neoplasia disease, 2 abnormal reproductive conditions (gonadal atresia and intersex), prokaryotic inclusions, protozoans, and metazoans.

A single clonal lineage of transmissible cancer identified in two marine mussel species in South America and Europe.

Transmissible cancers, in which cancer cells themselves act as an infectious agent, have been identified in Tasmanian devils, dogs, and four bivalves. We investigated a disseminated neoplasia affecting geographically distant populations of two species of mussels ( in South America and in Europe). Sequencing alleles from four loci (two nuclear and two mitochondrial) provided evidence of transmissible cancer in both species.

Histopathological study of Corydoras micracanthus (Siluriformes: Callichthyidae) parasitized by the nematode Procamallanus (Spirocamallanus) pintoi (Camallanidae) from Lesser River, northwestern Argentina, South America.

The nematode parasites can cause mechanical injuries such as irritation or atrophy of tissue and occlusions of the digestive tract, blood vessels or other ducts in their hosts. Some species belonging to the family Camallanidae have been the focus of histopathological studies because they lacerate the host´s intestinal wall with their buccal capsule. In this study, we describe the histopathological effects produced by Procamallanus (Spirocamallanus) pintoi in the small fish Corydoras micracanthus from Lesser River, in the northwest of Argentina, South America.

Notocotylus primulus n. sp. (Trematoda: Notocotylidae) from the crested duck Lophonetta specularioides (Aves, Anatidae) from Patagonian coast, southwestern Atlantic Ocean.

Species in the genus Notocotylus (Trematoda, Notocotylidae) are cosmopolitan parasites of mainly aquatic birds and, to a lesser extent, mammals. In this paper we describe Notocotylus primulus n. sp.

Morphology and molecular systematic of marine gregarines (Apicomplexa) from Southwestern Atlantic spionid polychaetes.

Gregarines are a common group of parasites that infect the intestines of marine invertebrates, and particularly polychaetes. Here, we describe for the first time four gregarine species that inhabit the intestines of three spionid species: Dipolydora cf. flava, Spio quadrisetosa and Boccardia proboscidea from the Patagonian coast, Argentina, using light and scanning electron microscopy and molecular phylogenetic analyses of small subunit (SSU) rDNA sequences.

Atypical lesions and infection sites of larval trematodes in marine gastropods from Argentina.

This study documents the lesions caused by 9 digenean larvae parasitizing 6 marine gastropod species from Patagonia, Argentina. Most digeneans produce a lesion where the parthenitae replace the gonadal tissues and also occupy part of the digestive gland. Three atypical lesions and tropism were observed in (1) Trophon geversianus (Muricidae) infected by Renicolidae gen.

Parasites in two coexisting bivalves of the Patagonia coast, southwestern Atlantic Ocean: The Puelche oyster (Ostrea puelchana) and false oyster (Pododesmus rudis).

The purpose of this study was to compare the parasites of two coexisting bivalves, the edible Puelche oyster (Ostrea puelchana) and the false oyster (Pododesmus rudis) that lives attached to O. puelchana shells, and to investigate their host specificity. Samples from wild populations, 465 O.

Life Cycle of the Parasite Profilicollis chasmagnathi (Acanthocephala) On the Patagonian Coast of Argentina Based On Morphological and Molecular Data.

This study verifies the identity of adult specimens of the parasite Profilicollis chasmagnathi (Acanthocephala, Polymorphidae) recovered from kelp gulls Larus dominicanus (Aves, Laridae), and cystacanths found in crabs Cyrtograpsus altimanus (Crustacea, Decapoda) from the southwestern Atlantic coast. The life cycle of this parasite is elucidated in the intertidal zone of Patagonia, Argentina, based on morphological and molecular data. Preferences by size and sex of the intermediate host and seasonal variation of this parasite are provided, contributing to the knowledge of this host-parasite association.

Survey of trematodes in intertidal snails from Patagonia, Argentina: new larval forms and diversity assessment.

Larval trematodes are the main parasites of snails, and they play a crucial role because they usually castrate their snail hosts and can thus alter their population and community dynamics. This study involved a survey of seven gastropod species (Crepipatella dilatata, Fissurella radiosa, Nacella magellanica, Pareuthria fuscata, Siphonaria lessonii, S. lateralis and Trophon geversianus) parasitized by 12 trematode species (one hemiurid, one gymnophallid, two lepocreadiids, two microphallids, one notocotylid, two renicolids, one philophtalmid, one schistosomatid and one zoogonid) from southern Patagonia (47°S, 65°W), Argentina.

A new species of Procyrnea (Nematoda: Habronematidae) parasitic in Rhea pennata (Aves: Rheidae) from Patagonia, Argentina, with a key to species of the genus.

Procyrnea choique n. sp. is described from the lesser rhea, Rhea pennata d´Orbigny (Aves: Rheidae), from the Protected Natural Area Península Valdés, Chubut province, Argentina.