Morphotypes of Varroa destructor collected in Apis mellifera colonies from different geographic locations of Argentina.

Parasites display considerable phenotypic plasticity in life-history traits such as, body size. Varroa destructor is an ectoparasitic mite of the western honey bee Apis mellifera. Several studies have reported that in V. destructor, there is a wide phenotypic plasticity within a population of mites. However, it is unknown if there are morphologic variations in V. destructor populations affecting different A. mellifera populations. A morphometric study of V. destructor populations was conducted to provide information concerned to the relationships among parasite populations found in different geographic locations from A. mellifera colonies of Argentina. The hypothesis tested was different morphotypes of V. destructor populations parasitizing different A. mellifera populations from Argentina exist. A discriminant analysis employing eight morphologic variables revealed that it is possible to differentiate morphotypes of mites in Argentina. However, the level of discrimination detected among mites population varied according to the grouping of mite's population. Possible causes explaining the morphometric variability in the V. destructor populations were discussed.

First detection of Varroa destructor resistance to coumaphos in Argentina.

In Argentina, studies on Varroa destructor resistance to coumaphos are still unknown. At present, high infestation levels of V. destructor are being detected in colonies of Apis mellifera after treatment with this acaricide. The aim of the present study was to determine the LC50 of coumaphos in V. destructor from four apiaries with high mite density after treatment with coumaphos. The LC50's were 112, 319, 127 and 133 microg/Petri dish for mites from the four apiaries. Significant LC50 differences were detected between resistant and susceptible mites. LC50 increased 197-559-fold when compared to the corresponding baseline, suggesting the development of resistance. These results are the first report of resistance to coumaphos in V. destructor in Argentina.

A new species of Cardicola Short, 1953 (Digenea: Sanguinicolidae) parasitizing the Brazilian flathead, Percophis brasiliensis Quoy et Gaimard 1824, from the coasts of Mar del Plata, Argentina.

Cardicola ambrosioi n. sp. (Digenea: Sanguinicolidae) is found in the blood vessels of liver and gills of the Brazilian flathead, Percophis brasiliensis Quoy and Gaimard, 1824 (Pisces: Percophidae), from Mar del Plata, Argentina. Among the 13 known species within Cardicola Short, 1953, the new species closely resembles Cardicola coridodacis Manter, 1954, from which it is distinguished by having a relatively shorter oesophagus, the vitellaria extending anteriorly to the nerve commissure, rather than to the end of anterior caeca, the female pore located closer to male pore, the latter situated medially instead of laterally and by possessing a larger Mehlis gland and a smaller seminal vesicle.

A new species of Dichelyne (Nematoda: Cucullanidae) parasitizing Pogonias cromis (Pisces: Sciaenidae) from Mar Chiquita coastal lagoon, Argentina.

A new nematode species Dichelyne (Cucullanellus) mariajuliae n. sp., is described based on specimens collected from the black drum, Pogonias cromis (Linnaeus, 1766), from Mar Chiquita coastal lagoon, Buenos Aires Province, Argentina (37 degrees 32'S, 57 degrees 19'W) (prevalence 75%, mean intensity 3.75). Among Dichelyne (Cucullanellus), the new species is unique in having the papillae 2 situated at the level of ventral sucker in males and bearing subcuticular ornamentation in the female tail.

A new species of Dichelyne (Nematoda: Cucullanidae) parasitizing Acanthistius brasilianus (Pisces: Serranidae) from Argentinean waters.

During a parasitological examination of 45 specimens of Acanthisthius brasilianus (Valenciennes, 1828) Jordan et Eigenmann, 1890, from waters off Mar del Plata, Argentina (38 degrees 08'S, 57 degrees 32'W), several specimens of cucullanid nematodes were collected from the intestines. A new species, Dichelyne (Cucullanellus) szidati n. sp., is described (prevalence 42.2%, mean intensity 2.7). The new species differs from its congeners inhabiting the southwestern Atlantic by the distribution pattern of caudal papillae, particularly the ninth pair, length of the body and spicules, and the position of the intestinal cecum (ventral), the excretory pore (posterior to esophagus), and the deirids (at the level of esophageal posterior end).

Cucullanus bonaerensis n. sp. (Nematoda: Cucullanidae) parasitizing Urophycis brasiliensis (Pisces: Phycidae) from Argentinean waters.

A total of 8 specimens of Urophycis brasiliensis (Kaup, 1858) from waters off Mar del Plata, Argentina (38 degrees 08'S, 57 degrees 32'W), were examined for parasitic nematodes. A new nematode species, Cucullanus bonaerensis n. sp., is described (prevalence 50%, mean intensity 15.5). The new species differs from its congeners in the distribution pattern of caudal papillae (particularly fourth pair) and phasmids, length of the body and spicules, and by the position of the excretory pore (in the posterior third of esophagus). Species of Cucullanus, reported previously as C. heterochrous Rudolphi, 1812, and Cucullanus sp. from U. brasiliensis from Puerto Quequén, Argentina (38 degrees 37'S, 58 degrees 53'W), are considered as members of the new species.

Argentinochondria patagonensis n. gen., n. sp. (Copepoda: Chondracanthidae) parasitic on Genypterus brasiliensis (Pisces: Ophidiidae) from Patagonia, Argentina.

Argentinochondria patagonensis n. gen., n. sp. (Copepoda: Chondracanthidae) is described from adult specimens recovered from the smooth kingklip Genypterus brasiliensis Reagan, 1903, from San Jorge Gulf, Patagonia, Argentina. The new genus is placed in the Chondracanthinae. Females of the new genus differ from other members of this subfamily in having 2 pairs of modified legs, a bulbose head, a long neck region, and a trunk devoid of processes. Males have usual chondracanthid form, oral appendages as in female, except a longer paragnath, fewer teeth on maxilla, and 2 pairs of reduced legs.

Paleoparasitological analysis of rodent coprolites in holocenic samples from Patagonia, Argentina.

The aim of the present study was to examine the parasite fauna present in rodent coprolites collected from Cerro Casa de Piedra (CCP7), located in Perito Moreno National Park (P.N.PM., 47 degrees 57'S and 72 degrees 05'W), Santa Cruz Province, Argentina. Eight coprolites obtained from the layer XIII of CCP7, with an antiquity considered as 7,920 +/- 130 yr B.P, were examined for parasites. Each coprolite was whole processed, rehydrated, homogenized, spontaneously sedimented, and examined using light microscopy. Eggs of parasites were measured and photographed. All the samples were parasitized by nematodes, with 267 eggs of Trichuris sp., 24 eggs of an aspidoderid, and 3 capillariid eggs. The rodent host was tentatively identified as a species of Ctenomys, the hypogeic rodents endemic to South America. The finding of Paraspidodera in Patagonian samples represents new evidence that strengthens the co-phylogenies between nematodes of this genus and Ctenomys and reinforces the value of parasites as tags in paleoparasitology.

Capillaria spp. eggs in Patagonian archaeological sites: statistical analysis of morphometric data.

Discriminant analysis was used to identify eggs of Capillaria spp. at specific level found in organic remains from an archaeological site in Patagonia, Argentina, dated of 6,540 +/- 110 years before present. In order to distinguish eggshell morphology 149 eggs were measured and grouped into four arbitrary subsets. The analysis used on egg width and length discriminated them into different morphotypes (Wilks' lambda = 0.381, p < 0.05). The correlation analysis suggests that width was the most important variable to discriminate among the Capillaria spp. egg morphotypes (Pearson coefficient = 0.950, p < 0.05). The study of eggshell patterns, the relative frequency in the sample, and the morphometric data allowed us to correlate the four morphotypes with Capillaria species.

Terranova galeocerdonis (Thwaite, 1927) (Nematoda: Anisakidae) from Carcharias taurus (Chondrichthyes: Odontaspididae) off Argentina, with comments on some related species.

The purpose of this study was to study and redescribe Terranova galeocerdonis (Thwaite, 1927) from Carcharias taurus off Argentina. Its fourth larval stage was described, measured and illustrated for the first time. The host and geographical range of this species is extended into the southwestern Atlantic Ocean. When the present material was compared with T. rochalimai (Pereira, 1935) and T. ginglymostomae Olsen, 1952, it was considered that both morphological and morphometrical differences between the three species did not justify differentiation at the specific level. As a result, T. rochalimai and T. ginglymostomae are considered to be junior synonyms of T. galeocerdonis.

Corynosoma australe Johnston, 1937 and C. cetaceum Johnston & Best, 1942 (Acanthocephala: Polymorphidae) from marine mammals and fishes in Argentinian waters: allozyme markers and taxonomic status.

Genetic and morphological studies were carried out on acanthocephalans belonging to Corynosoma Lühe, 1904 and referable to the species C. cetaceum Johnston & Best, 1942 and C. australe Johnston, 1937, which were recovered from both definitive and intermediate hosts in Argentinian waters. The aims were to estimate the level of genetic differentiation between the two taxa at any stage of their life-cycle, to provide genetic (allozyme) markers for their recognition and to analyse the systematic status of both taxa. Acanthocephalans were collected from the stomach and intestine of Arctocephalus australis (Zimmerman), the intestine of Mirounga leonina (Linnaeus) and the stomach of Pontoporia blainvillei Gervais & D'Orbigny (definitive hosts) in Argentinian waters. Alternative alleles at all the 13 enzymatic loci studied were observed for C. australe and C. cetaceum. The specimens from the stomach of both P. blainvillei and A. australis were identified, on the basis of the great number of diagnostic loci found, as C. cetaceum; those from intestine of both A. australis and M. leonina as C. australe. A high level of genetic differentiation (D(Nei)=infinity: I(Nei)=0.00) between the two taxa was found, suggesting a generic distinction between the two species. Cystacanths of the two species from the body-cavity of the fish Cynoscion guatucupa (Cuvier) collected from the same geographical area were identified genetically. Morphological patterns, such as the number of hooks and hook rows on the proboscis, the distribution of somatic and genital armature, and other morphometric and meristic differences, in addition to ecological data, enabled the identification of these two species at cystacanth, juvenile and adult stages. However, a number of morphological and morphometric features of the Argentinian material were different to those of C. australe and C. cetaceum described from other regions of the world.

Capillaria spp. eggs in Patagonian archaeological sites: statistical analysis of morphometric data

Discriminant analysis was used to identify eggs of Capillaria spp. at specific level found in organic remains from an archaeological site in Patagonia, Argentina, dated of 6,540 ± 110 years before present. In order to distinguish eggshell morphology 149 eggs were measured and grouped into four arbitrary subsets. The analysis used on egg width and length discriminated them into different morphotypes (Wilks' lambda = 0.381, p < 0.05). The correlation analysis suggests that width was the most important variable to discriminate among the Capillaria spp. egg morphotypes (Pearson coefficient = 0.950, p < 0.05). The study of eggshell patterns, the relative frequency in the sample, and the morphometric data allowed us to correlate the four morphotypes with Capillaria species.