Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Marcelo E. Oliva is active.

Publication


Featured researches published by Marcelo E. Oliva.


Fisheries Research | 2002

Metazoan parasites of the Chilean hake Merluccius gayi gayi as a tool for stock discrimination

Marcelo E. Oliva; Isabel Ballón

Abstract The value of metazoan parasites of the hake Merluccius gayi as biological tags for stock identification is assessed. Seven hundred and eighty-two hake ( Merluccius gayi gayi ), obtained from the four most important landing ports in central and southern Chile (Coquimbo, San Antonio, Talcahuano and Puerto Montt) as well as previously published data on 140 Peruvian hake ( Merluccius gayi peruanus ) from Callao, Peru are analyzed. Thirty species of metazoan parasites (22 in Chilean hake, 17 in Peruvian) were obtained. A canonical discriminant function using the most prevalent parasites suggests that the Chilean hake subspecies includes two stocks: a southern stock, associated with the fishing port of Puerto Montt, and a central stock, associated with the fishing ports of Talcahuano, San Antonio and Coquimbo. Identification of stocks is based on significant differences in the mean intensity of adult Clestobothrium crassiceps and larval Hepatoxylon trichiuri (Eucestoda), the monogenean Anthocotyle merlucci and the copepod Neobrachiella insidiosa f . pacifica .


Journal of Shellfish Research | 2007

SUITABILITY OF THREE STAINS TO MARK SHELLS OF CONCHOLEPAS CONCHOLEPAS (GASTROPODA) AND MESODESMA DONACIUM (BIVALVIA)

José M. Riascos; Nury Guzman; Jürgen Laudien; Olaf Heilmayer; Marcelo E. Oliva

Abstract Different stains are used to internally mark calcified structures of mollusc shells in growth experiments. Because of interspecific variations in marking success, an assessment of suitability for each species is necessary. The potential of calcein, alizarin red, and strontium chloride hexahydrate (strontium chloride) was investigated for the Chilean abalone Concholepas concholepasr and the surf clam Mesodesma donacium, two molluscs of commercial importance in Chile. Wild specimens from Northern Chile were marked using different concentrations and immersion periods of the three stains. Animals were reared for 20 days to allow growth, mortality, body condition index (BCI), and growth rate was measured to assess the effects of the treatments. To detect marks, individuals were culled and shell sections analyzed using scanning electron microscopy for strontium chloride and fluorescence microscopy for calcein and alizarin red, respectively. Strontium chloride produced narrow bright bands only at concentrations of 2,880 mg·l−1 and 24 h exposure. Calcein markings produced fluorescent bands detectable in all treatments (50 and 100 mg·l−1, 3 and 6 h) whereas alizarin red only yielded irregular bands with 50–100 mg·l−1 and 6 h exposure. Our results show that growth rates of C. concholepas are significantly affected by the stains factor: Strontium chloride showed the lowest growth rates whereas that of alizarin red and calcein was similar to the control group. High concentrations of strontium chloride negatively affected (P < 0.05) the body condition of the gastropod. Although no statistical differences were found, BCI of M. donacium followed the same trend as observed for C. concholepas. In conclusion, calcein was the best growth marker for both species because it produced bright, long-lasting bands even at low concentrations and immersion times without detectable lethal or sublethal effects.


Memorias Do Instituto Oswaldo Cruz | 1996

Parasites of the flatfish Paralichthys adspersus (Steindachner, 1867) (Pleuronectiformes) from northern Chile

Marcelo E. Oliva; Raúl E Castro; Rodrigo Burgos

Three species of protistan and 22 species of metazoan parasites were obtained from a sample of 179 flatfish, (Paralichthys adspersus) taken-off Antofagasta, northern Chile. Prevalence of infection of seven parasites (Protista: 1, Copepoda: 2, Digenea: 1, Acantocephala: 1, Nematoda: 2) was significantly and positively correlated with host size. Hosts sex do not seem to affect prevalence of infection, except for Nybelinia surmenicola, Capillaria sp. and Anisakis sp. (prevalence of infection significantly greater in males than females) and Philometra sp. (prevalence higher in females). Mean abundance is correlated with size in nine species (Protista: 1, Copepoda: 2, Digenea: 3, Acantocephala: 1, Nematoda: 2). Hosts sex do not affect mean abundance, except for Cainocreadium sp. and Philometra sp.(mean abundance higher in females) and Nybelinia surmenicola, Capillaria sp. and Anisakis sp. (mean abundance higher in males).


Parasitology | 2006

Similarity and structure of the ectoparasite communities of rockfish species from the southern Chilean coast in a temporal scale

M. T. González; Marcelo E. Oliva

The understanding of the patterns and processes underlying the structure of parasite communities has progressed significantly in the last years; however, much of the evidence available to date on parasite community comes from unconfirmed studies. In this study the ectoparasite communities of 2 related rockfishes, Sebastes capensis and Helicolenus lengerichi, from the southern Chilean coast (ca. 40 degrees S) were examined to determine whether their specific compositions are similar, structured in non-random ways, and repeatable among years. From 2001 to 2004, 189 specimens of S. capensis and 101 of H. lengerichi were examined, 10 and 9 parasite species were recorded in S. capensis and H. lengerichi, respectively. Component ectoparasite communities of these hosts were taxonomically similar (60%), but the abundances and prevalences of their parasites differed significantly among years and between hosts. The most prevalent species were Lepeophtheirus chilensis, and Microcotyle sp. for S. capensis, and Microcotyle sp., Juanetia continentalis, and Interniloculus chilensis for H. lengerichi. Infracommunities of S. capensis showed higher species richness and parasite numbers than those of H. lengerichi. The similarity among infracommunities (measured as parasite abundance) varied significantly among years both within and between hosts. Despite this, temporal nestedness patterns were observed in infracommunities of these hosts, suggesting that their ectoparasite communities are structured and might be predictable in time, at least in the southern Chilean coast where they share the same habitat.


Journal of Parasitology | 2004

METAZOAN PARASITE FAUNA AS A BIOLOGICAL TAG FOR THE HABITAT OF THE FLOUNDER HIPPOGLOSSINA MACROPS FROM NORTHERN CHILE, IN A DEPTH GRADIENT

Marcelo E. Oliva; Ma. Teresa Gonzalez; Enzo H. Acuña

Quantitative changes in the parasite communities of the flounder Hippoglossina macrops (Steindachner) were studied along a depth gradient. Samples were obtained from the waters off Coquimbo, Chile (29°18′S to 30°50′S), at depths ranging from 160 to 342 m. Samples were assigned to 3 depths, i.e., shallow water (less than 200 m), midwater (from 200 to 300 m), and deep water (more than 300 m). Twelve parasite species were recorded: Neoheterobothrium chilensis and Entobdella hippoglossi (Monogenea); Holobomolochus chilensis and Protochondria longicauda (Copepoda); Gliptonobdella sp. (Hirudinea); Nybelinia surmenicola, Scolex pleuronectis, and Neobothriocephalus adspinosus (Cestoda); Floridosentis sp. and Corynosoma australe (Acanthocephala); Anisakidae (Nematoda); and an unidentified hemiurid (Digenea). Univariate analyses showed that C. australe has its highest prevalence and mean intensity of infection in hosts from shallow waters. Floridosentis sp. showed significant differences along the depth gradient, with higher mean intensity and prevalence of infection in fish from midwater. Among the ectoparasites, only N. chilensis exhibited differences in mean intensity with depth, where intensity of infection increased with depth of host habitat. A canonical multivariate analysis demonstrated that parasite burdens can be a good predictor of the environment (shallow, mid-, or deep water) occupied by the flounders.


Memorias Do Instituto Oswaldo Cruz | 1990

The metazoan parasites of Stellifer minor (Tschudi, 1844): an ecological approach

Marcelo E. Oliva; José L. Luque; José Iannacone

A quantitative and qualitative analysis of the parasite fauna of the sciaenid Stellifer minor (Tschudi) from Chorrillos, Perú, was made. Some characteristics of the infectious processes, in terms of intensity and prevalence of infection, as a function of host sex and size, are given. Moreover, comments on the characteristics of the parasite fauna, related with host role in the marine food webs are included. The parasite fauna of Stellifer minor taken off Chorrillos, Perú, include the monogeneans Pedocotyle annakohni, Pedocotyle bravoi, Rhamnocercus sp. and Cynoscionicola sp., the digenean Helicometra fasciata, the adult acantocephalan Rhadinorhynchus sp. and the larval Corynosoma sp., the nematode Procamallanus sp., the copepods Caligus quadratus, Clavellotis dilatata and Bomolochus peruensis and one unidentified isopod of the family Cymothoidae. A distinctive characteristic of the parasite fauna (Metazoa) of S. minor is the almost absence of larval forms.


Memorias Do Instituto Oswaldo Cruz | 2001

Metazoan parasite fauna of the bigeye flounder, Hippoglossina macrops, from Northern Chile. Influence of host age and sex

M. Teresa González; Enzo Acuña; Marcelo E. Oliva

The metazoan parasite fauna of Hippoglossina macrops (n = 123) from northern Chile (30 degrees S) is quantitatively described for the first time, and the role of host age and sex was evaluated. Twelve parasite species were recovered, including 5 ectoparasites (2 Monogenea, 2 Copepoda and 1 Piscicolidae) and 7 endoparasites (1 Digenea, 3 Cestoda, 2 Acanthocephala, and 1 Nematoda). The copepod Holobomolochus chilensis, the monogenean Neoheterobothrium sp., the adult acanthocephalan Floridosentis sp. and the hirudinean, Gliptonobdella sp. are new geographical and host records. The most prevalent ectoparasitic species were the monogenean, Neoheterobothrium sp. and the copepod, H. chilensis. Among endoparasites, the acanthocephalans Floridosentis sp. and Corynosoma australe were most prevalent and abundant. Prevalence and mean intensity of infection for most parasitic species were not affected by host sex, however the prevalence of Floridosentis sp. was significantly greater in males. Intensity of infection was positively correlated with host age for Neoheterobothrium sp., and negatively correlated for Floridosentis sp. and H. chilensis. The helminth species richness of the host H. macrops was lower compared to related flatfishes from the Northern Hemisphere. The relationship of the helminth fauna of H. macrops, its feeding habits and ecological habitats are discussed.


Parasitology Research | 2010

Molecular and experimental evidence refuse the life cycle of Proctoeces lintoni (Fellodistomidae) in Chile

Marcelo E. Oliva; Isabel M. Valdivia; Leyla Cárdenas; Mario George-Nascimento; Karen González; Ricardo E. Guiñez; Diego Cuello

The mussel Perumitylus purpuratus has been described as the first intermediate host for the digenea Proctoeces lintoni (Fellodistomidae) in the Chilean coast. The study of more than 3000 specimens of P. purpuratus, taken off northern Chile revealed the absence of sporocysts. Experimental infection of mussels with eggs obtained from the known host for P. lintoni was unsuccessful. We analyze the V4 region of the SSU rRNA of living sporocysts and cercariae obtained from P. purpuratus from central Chile in order to confirm the proposed life cycle for this digenea. Our results demonstrated that sporocysts and cercariae obtained from P. purpuratus do not belong to P. lintoni but to an undescribed digenea from the Chilean coast.


Journal of Parasitology | 2000

PROGENESIS IN PROCTOECES LINTONI (FELLODISTOMIDAE), A PARASITE OF FISSURELLA CRASSA (ARCHAEOGASTROPODA) IN A LATITUDINAL GRADIENT IN THE PACIFIC COAST OF SOUTH AMERICA

Marcelo E. Oliva; Laura G. Huaquin

The fellodistomid Proctoeces lintoni is a common parasite of the gonads of key-hole limpets Fissurella spp. (Archaeogastropoda). It has also been found in the mantle of Octopus vulgaris and as an intestinal parasite of haemulid and gobiesocid fishes. Fissurella crassa, a host for progenetic P. lintoni, can be found from Huarmey, Perú (10°S) to Chiloé, Chile (42°S). Proctoeces lintoni has been found parasitizing fishes and molluscs from Callao, Perú (12°S) to Valdivia, Chile (39°S). Progenesis is thought to be a latitude-dependent phenomenon, and high progenesis is expected at higher latitude. In the present article, the association between latitude and progenesis was examined over a latitudinal gradient of about 3,000 km. Data suggest that progenesis of P. lintoni infecting F. crassa was not associated with latitude. Low levels of progenesis found in the Peruvian population could be a consequence of parasite-induced mortality rather than of low latitude, as would be predicted by the latitude dependence hypothesis.


Journal of Helminthology | 2007

Local variability in metazoan parasites of the pelagic fish species, Engraulis ringens: implications for fish stock assessment using parasites as biological tags.

Rosa A. Chávez; Isabel M. Valdivia; Marcelo E. Oliva

Parasites have been used successfully as biological tags in population studies, mainly in marine fishes, but also in marine mammals, crustaceans and molluscs. Almost all published information dealing with parasites as biological tags evaluates differences between localities. However, local variability in the component community has not been assessed. In this work, we examined whether local variation of the metazoan parasite fauna of Engraulis ringens, extracted from five independent samples from two nearby localities in northern Chile, can be a factor causing bias in stock identification. Our results show that local variability, as estimated by a single sample, may suffice to represent component community variability with no need for replicated data.

Collaboration


Dive into the Marcelo E. Oliva's collaboration.

Top Co-Authors

Avatar

Jürgen Laudien

Alfred Wegener Institute for Polar and Marine Research

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Olaf Heilmayer

Alfred Wegener Institute for Polar and Marine Research

View shared research outputs
Top Co-Authors

Avatar

Wolf Arntz

Alfred Wegener Institute for Polar and Marine Research

View shared research outputs
Top Co-Authors

Avatar

José L. Luque

Universidade Federal Rural do Rio de Janeiro

View shared research outputs
Top Co-Authors

Avatar

Aldo S. Pacheco

University of Antofagasta

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Rosa A. Chávez

University of Antofagasta

View shared research outputs
Top Co-Authors

Avatar

Manuel Rojo

University of Antofagasta

View shared research outputs
Top Co-Authors

Avatar

Martin Thiel

Catholic University of the North

View shared research outputs
Researchain Logo
Decentralizing Knowledge