Julia I. Diaz

FURTHER STUDY OF CONTRACAECUM PELAGICUM (NEMATODA: ANISAKIDAE) IN SPHENISCUS MAGELLANICUS (AVES: SPHENISCIDAE) FROM ARGENTINEAN COASTS

The anisakid species Contracaecum pelagicum Johnston and Mawson, 1942, is reported for first time at 2 different sites on the Argentine coast (Península Valdés, 42°04′S, 63°38′W and Mar del Plata, 38°05′S, 57°38′W), parasitizing the Magellanic penguin, Spheniscus magellanicus Foster. Morphometric analysis and further studies of adult specimens of C. pelagicum were done using light and scanning electron microscopy. The presence of bifurcated interlabia differentiates the present species from most others in the genus, except (1) from Contracaecum travassosi, which possesses higher interlabia and longer spicules, and a blunt, more constrained tail; (2) from Contracaecum rudolphii, which has longer spicules, blunter spicule tips, postparacloacal papillae with oblique disposition, and a blunter constrained tail; (3) from Contracaecum eudyptulae, which has a blunter tail and longer spicules; and (4) from Contracaecum variegatum, which possesses smaller-diameter, hooklike extensions on auricle lips, and a less robust interlabium with a more marked furrow. In this paper we present the first detailed description of C. pelagicum adults from S. magellanicus. Morphometric data between adult specimens of C. pelagicum from S. magellanicus and those from the black-browed albatross, Diomedea melanophris Temminck, from Argentinean coasts were compared. In addition, fourth-stage larvae that parasitized both hosts were assigned to a nondeterminated Contracaecum species. Ecological parameters for adults and larvae nematodes were calculated.

Helminths of the Magellanic penguin, Spheniscus magellanicus (Sphenisciformes), during the breeding season in Patagonian coast, Chubut, Argentina.

Abstract Twenty-seven Magellanic penguins, Spheniscus magellanicus (Sphenisciformes), were collected from September 1996 to November 2000 from Península Valdés (42°04′–42°53′S; 63°38′–64°30′W), on the Patagonian coast, Argentina and the gastrointestinal tract was examined for helminths. All birds were parasitized by at least 1 of the 5 following parasite species: Tetrabothrius lutzi (Cestoda); Cardiocephaloides physalis (Lutz, 1926) (Digenea), Contracaecum pelagicum (Johnston and Mawson, 1942), Cosmocephalus obvelatus (Creplin, 1825) (Nematoda), and Corynosoma sp. (Acanthocephala). The total mean intensity was 686. The helminth community composition of S. magellanicus is reported for first time in Argentina increasing the host range of many of the species registered.

Pollution and physiological variability in gentoo penguins at two rookeries with different levels of human visitation.

Abstract Human activity and specifically tourism has been increasing in Antarctica over the last few years. Few studies have examined the indirect effects of human visits on Antarctic penguin rookeries. This work aims to study the differences between a highly visited (Hannah Point) and a rarely visited (Devils Point, Byers Peninsula) gentoo penguin rookery on Livingston Island. Our results suggest that potential indirect effects of human impact are observed in gentoo penguins at Hannah Point, a colony heavily visited by tourists. Penguins at Hannah Point showed a higher presence of heavy metals such as Pb and Ni and a higher number of erythrocytic nuclear abnormalities than penguins at Devils Point. Immunological parameters showed different results depending on whether we consider the cellular response - the number of lymphocytes being higher in penguins from Hannah Point - or the humoral response - the level of immunoglobulins being higher in penguins from Devils Point. Measurements of corticosterone levels in feathers and heterophil/lymphocyte (H/L) ratio in blood showed lower levels in the heavily visited rookery than in the rarely visited rookery. Finally, we did not detect Campylobacter jejuni, a bacteria potentially transmitted by humans in either of the populations and we did not find any difference in the prevalence of Campylobacter lari between the populations.

Seabird ticks (Ixodes uriae) distribution along the Antarctic Peninsula

The distribution of the tick Ixodes uriae is studied in the South Shetlands and different locations along the Antarctic Peninsula. Ticks were found beneath stones close to penguin rookeries of chinstrap, gentoo and adelie penguin, although no individuals were found parasitized. Our results showed that ticks are not distributed evenly along the Antarctic Peninsula being more common and abundant in the northern part with relative abundances of ticks ranging from 1 to 57 individuals per stone and from 2 to 26% of the stone inspected. Ticks are probably absent in the south.

Development from Metacercaria to Adult of a New Species of Maritrema (Digenea: Microphallidae) Parasitic in the Kelp Gull, Larus dominicanus, from the Patagonian Coast, Argentina

Abstract Maritrema madrynensis n. sp. is described from the Patagonian coast, Argentina, based on naturally obtained adults from the kelp gull Larus dominicanus and cultured metacercariae from the crab Cyrtograpsus altimanus. The new species fits into the “eroliae complex” and can be distinguished from other related species mainly in shape, size, and distribution of the spines on the cirrus and vitellarium in a complete ring in all specimens. Based on morphological and morphometric features of the naturally and experimentally obtained specimens and the trophic relationship between invertebrate and vertebrate hosts, we suggest that the crab C. altimanus acts as a second intermediate host of M. madrynensis n. sp. This is the first report of a Maritrema species in Patagonia and the southernmost record for the genus.

A New Anisakid Species Parasitizing the Imperial Cormorant Phalacrocorax atriceps From the North Patagonian Coast, Argentina

The anisakid species Contracaecum chubutensis n. sp. was found parasitizing the imperial cormorant Phalacrocorax atriceps at 2 different localities, Bahía Bustamante (45°11′S, 66°30′W) and Puerto Madryn (42°47′S, 65°02′W) on the Patagonian coast. Morphometrical analysis and further studies of adult specimens of C. chubutensis n. sp. and fourth-stage larvae of Contracaecum sp. were done using light and scanning electron microscopy. The possession and disposition of 7 pairs of tail papillae differentiate this new species from C. osculatum, C. radiatum, C. plagiaticium, and C. mirounga. Double-sized spicules separate it from C. variegatum and C. pelagicum. Moreover, the paracloacal papillae disposition and tail shape differentiate this new species from C. travassosi. The presence of bifurcated interlabia separate it from C. ogmorhini and C. margolisi. Three well-marked lip notches, a sharp tail shape, and the of the transversal paracloacal papillae disposition distinguishes C. chubutensis n. sp. from C. magnipapillatum and C. septentrionale. The species here described can be differentiated from C. caballeroi by its bifurcated interlabia, longer spicules, and for possessing more precloacal papillae pairs. It can be separated from C. rudolphii by a thinner interlabia at the base, deeper lip notches, a sharper tail, the disposition of transversal paracloacal papillae, and greater distance between both papillae of the first subventral distal papillae pair. In addition, fourth-stage larvae recovered from the same host and localities were identified and described as Contracaecum sp. Prevalence of adult parasites was 66.7 %, mean intensity was 4.0, and mean abundance was 7.1.

Leucocyte Levels in Some Antarctic and Non-Antarctic Penguins

Summary. We studied leucocyte levels in several Antarctic and non-Antarctic penguins. A total of 107 blood samples of chinstrap Pygoscelis antarctica, gentoo P. papua and Adélie P. adeliae penguins at Isla 25 de Mayo/King George Island (South Shetland Islands, Antarctica) and Magellanic penguins Spheniscus magellanicus at Península Valdés (Chubut, Argentina), were collected and analysed during the 2009–2010 breeding season. We observed that chinstrap and Adélie penguins had lower total leucocyte counts than Magellanic and gentoo penguins. We provide some potential explanations for species differences in leucocyte levels.

First Record of the Acuarioid Nematode Paracuaria adunca from South America, with New Morphological Details and Discussion of Cordons

Abstract The acuarioid nematode Paracuaria adunca (Creplin, 1846) was found in 7 of 13 (54%) Larus dominicanus (Aves: Laridae) examined from several locations along the Argentine coast. It was only present in specimens from Patagonia; the intensity of infection ranged from 1 to 14 (mean = 5.4). This is the first record of P. adunca from South America and as a parasite of L. dominicanus. Using both light and scanning electron microscopy (SEM), the complexity of the left spicule and the number and arrangement of male caudal papillae were observed. Although P. adunca is parasitic in several unrelated bird families and has a wide geographical distribution, the dimensions of our specimens fully agree with previous reports. The genus Paracuaria was characterized by the presence of rudimentary cordons; thus, it was considered the most primitive acuarioid. The cordons appear as finger-like structures within shallow grooves held tightly against the surface and extend posteriorly from the ends of the mouth and for this reason cannot be easily seen under SEM.

Himasthla escamosa n. sp. (Digenea: Echinostomatidae) from the kelp gull, Larus dominicanus (Charadriiformes: Laridae), on the Patagonian coast, Argentina.

In this article, we describe a new species of Himasthla Dietz, 1909 (Digenea: Echinostomatidae) from Larus dominicanus Lichtenstein (Aves: Laridae) in northern Patagonia, Argentina. We also describe the hosts, localities, and key diagnostic features and the measurements of the so far 25 described species. Of these species, Himasthla militaris, H. leptosoma, H. elongata, H. secunda, H. megacotyla, H. multilecithosa, H. piscicola, H. compacta, H. schachtachtinskoi, H. littorinae, H. continua, H. avosettae, and H. interrupta are similar to H. escamosa n. sp. in having 29 head collar spines. Himasthla leptosoma, H. piscicola, H. multilecithosa, H. interrupta, H. continua, and H. militaris can be differentiated from the new species mainly by the extension of the vitellaria. Himasthla avosettae, H. megacotyla, H. elongata, H. compacta, and H. littorinae have a different size or arrangement (or both) of head collar spines compared with H. escamosa. Himasthla secunda can be distinguished from H. escamosa n. sp. in having a larger body, testes, and ovary and a different position of the ovary. The comparison with H. schachtachtinskoi could not be done because the bibliography was not available. This is the first record of the genus in Argentina and from L. dominicanus.

Redescription of Ingliseria cirrohamata (Linstow, 1888) (Nematoda: Acuariidae), Including New Hosts and Geographical Records

Abstract Inglisera cirrohamata (Linstow, 1888) (Nematoda: Acuariidae) is redescribed based on specimens collected from the type host, Phalacrocorax verrucosus (Aves: Phalacrocoracidae), and the type locality, Kerguelen Island, in the southern Indian Ocean. Three new hosts and 2 new localities were recorded, i.e., Phalacrocorax [atriceps] albiventer and P. brasilianus from Puerto Madryn, Argentina and P. magellanicus from Puerto Williams, Chile. The structure of the cephalic ornamentations was observed and fully described. The presence of 6 pairs of postcloacal papillae is confirmed, a description of the tip of left spicule is given, and the presence of post-deirids is reported for the first time. This constitutes the first record of this nematode in South America and provides the first study of the genus by scanning electron microscopy.