Abstract 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). A total of 19 helminth species were found parasitizing the coastal birds studied: 4 cestodes (1 Tetrabothriidae, 3 Cyclophyllidea); 11 trematodes (2 Gymnophallidae, 3 Microphallidae, 2 Notocotylidae, 1 Philophthalmidae, 2 Renicolidae, 1 Schistosomatidae); 3 nematodes (1 Anisakidae, 2 Acuariidae); and 1 acanthocephalan (Polymorphidae). Although some isolated records have been previously reported for these birds, the present work provides a parasitofauna study for H. ater, L. scoresbii, and L. specularioides for the first time. Endoparasites reflected the feeding habits of the birds; the parasite assemblage of L. dominicanus was the richest, indicating their wide prey spectrum and the diversity of the habitats frequented. A great species richness of trematodes, whose life cycles are partially known, suggests that L. specularioides feeds upon crustaceans and small bivalves. The blackish oystercatcher H. ater preys upon the limpet Nacella magellanica which hosts two larval trematodes corresponding to the adults found parasitizing it.

Abstract Auriculostoma is a genus of digenean (Trematoda) whose adults are parasites of Neotropical freshwater fishes. We describe Auriculostoma ocloya n. sp. using morphological and molecular tools, and we elucidated its life cycle, the first known of a species of this genus. The first intermediate host is the bivalve Pisidium ocloya, the second intermediate host is the amphipod Hyalella sp., and the definite hosts are siluriform fishes. The adult presents a single pair of muscular lobes on either side of the oral sucker with a broad base, stretching from ventrolateral to dorsolateral side, a structure also present in the rest of species of the genus. Nevertheless, the new species differs from all congeners by the combination of several traits, and mainly because on the dorsal side “free” ends of the lobes are absent because they are fused. This is the first study to provide sequence data on larval and adult stages of a species of Auriculostoma. Our phylogenetic analysis demonstrated its basal position among species of the genus. Therefore, integrative morphological, molecular, and life cycle data on other South American species of the genus, would contribute to reveal more patterns in the allocreadiid systematics.

Abstract 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). In Ensenada, bla CTX-M and mcr-1 genes, were isolated from both gull species, whereas in the Puerto Madryn, only bla CTX-M gene was found. We report for the first time C. maculipennis as carrier of AMR. The finding of AMR in wildlife constitutes a useful tool in evaluating the anthropogenic impact on environmental health.

A total of 175 specimens of mussels, Mytilus chilensis (Mytilidae), and 56 specimens of clams, Gari solida (Psammobiidae), were collected in natural beds and culture sites of southern Chile. Juvenile mussel specimens (3 cm of maximum length) were free of parasites and diseases, whilst the commercial sized populations was parasitized by intracellular inclusions of bacteria-like organisms in the digestive gland epithelium and in the gills, by ciliates in the gills, turbellarians similar to Paravortex (Rhabocoela) in the intestine lumen and copepods attached to the gills. In addition, the disseminated neoplasia disease was also present although in low prevalences. In the clam, G. solida, prokariotic inclusions were found in the digestive gland epithelium and bacteria-like organisms in the gills, often encapsulated by haemocytes; oocysts containing up to 8 sporozoites similar to Nematopsis (Apicomplexa) in the connective tissue, causing haemocytic infiltration when the intensity of infection was high; ciliates belonging to two different species (one of them similar to Trichodina) inhabiting the gills; and a turbellarian similar to Paravortex in the lumen of digestive system without apparent host reaction. The populations of the bivalve species here studied were devoid of serious pathogens.

Un total de 175 choritos, Mytilus chilensis (Mytilidae), y 56 almejas, Gari solida (Psammobiidae), fueron recolectados en bancos naturales y sitios de cultivo en el sur de Chile. Los choritos de hasta 3 cm de longitud máxima estaban libres de parásitos y enfermedades, mientras que los especímenes de tamaño comercial estaban parasitados por inclusiones intracelulares de organismos similares a bacterias en los epitelios de la glándula digestiva y de la branquia; ciliados en las branquias; turbelarios similares a Paravortex (Rhabocoela) en el lumen del intestino y copépodos anclados en las branquias. Además, la enfermedad neoplasia diseminada estuvo presente, aunque en bajas prevalencias. En G. solida, se encontraron organismos procariotas en el epitelio de la glándula digestiva y organismos similares a bacterias en la branquia, frecuentemente encapsulados por hemocitos; ooquistes conteniendo hasta 8 esporozoítos similares a Nematopsis (Apicomplexa) se hallaron en el tejido conectivo, causando infiltración hemocítica cuando la intensidad de infección fue alta; ciliados pertenecientes a dos especies diferentes (una de ellas similar a Trichodina) habitando las branquias y un turbelario similar a Paravortex en el lumen del sistema digestivo, sin causar reacción aparente en el hospedador. Las poblaciones de bivalvos estudiadas estaban libres de patógenos severos.

We report the finding of Tetrameres spirospiculum Pinto & Vicente, 1995 from Theristicus melanopis melanopis (Threskiornithidae) from Patagonia, Argentina. These constitute new host and locality records. We propose the assignation of this species to the subgenus T. (Gynaecophila) Gubanov, 1950, based on the presence of labia and the absence of cuticular flanges at the anterior end. Some new morphological data are provided, such as the arrangement of cuticular spines and the presence of a pair of somatic papillae at beginning of posterior third of body length. T. (G.) spirospiculum may probably be regarded as specific to birds of the genus Theristicus.