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. Charadriiformes, Charadriiformes , (Charadriiformes) Anseriformes, Anseriformes (Anseriformes) coast Argentina H Phthiraptera, Phthiraptera (Phthiraptera) Ischnocera, Ischnocera (Ischnocera Amblycera. Amblycera . Amblycera) studied ( Tetrabothriidae Cyclophyllidea Cyclophyllidea) Gymnophallidae Microphallidae Notocotylidae Philophthalmidae Renicolidae Schistosomatidae Schistosomatidae) Anisakidae Acuariidae Acuariidae) Polymorphidae. Polymorphidae (Polymorphidae) L time richest frequented known bivalves it (Charadriiformes (Anseriformes (Phthiraptera (Polymorphidae

Abstract Through evolutionary time, seal lice have developed morphological, behavioral, and ecological adaptations to cope with the amphibious lifestyle of their hosts in a co-evolutionary process. Consequently, the dynamics of lice populations are determined by seals behavior. We aim to study the effects of host sex, age class, year, and sampling location, on the prevalence and mean abundance of Antarctophthirus carlinii, on Weddell seals (WS) Leptonychotes wedelli. The study was conducted at two sites in the Antarctic Peninsula, namely, Marambio/Seymour Island (MI) and the Danco Coast (DC). We collected lice from 71 WS: 33 from MI, during the reproductive season, and 38 from DC, during the molting season, between 2014 and 2017. According to our analyses, host age class and sex were the variables that affected prevalence levels of lice on WS. Whereas, age class, year, site, and sex affected lice mean abundance. Juveniles presented higher prevalence and mean abundance than adults, possibly acting as reservoirs for lice as they move through different colonies until they reach reproductive age. Concurrently, seals during molting season were more infested. Unlike nursing, during the molting season seals spend much time ashore forming mixed groups that favor both egg development and lice transmission.

We present a new record of sperm whale with notes on diet, age determination and a review of strandings along the continental Argentine coast. A complete necropsy was made in the field, and morphometric data were taken. The specimen stranded was a mature male of 64+ years old. This is the oldest specimen determined for a sperm whale in the Southwest Atlantic coast. In the stomach contents a total of 302 cephalopod lower beaks were recovered. Cestodes were present in the blubber but parasites were not found in stomach and intestine contents.

Presentamos un nuevo registro de un cachalote, con notas sobre la dieta, la determinación de edad y la presencia de parásitos, junto con una revisión de los varamientos a lo largo de toda la costa continental argentina. El animal varado fue un macho maduro de 64+ años. Este es el individuo más longevo registrado para esta especie en el Atlántico Sudoccidental. En el contenido estomacal se colectaron 302 picos inferiores de cefalópodos. Los únicos parásitos presentes fueron cestodes en la capa de grasa; no se encotraron helmintos gastrointestinales.