0000000000116774
AUTHOR
J. A. Raga
showing 34 related works from this author
Endoparasites of the blue whiting, Micromesistius poutassou from north-west Spain.
2005
AbstractThe communities of metazoan endoparasites of blue whiting, Micromesistius poutassou, in waters of north-west Spain were analysed and a geographical comparison made with other localities. Four hundred blue whiting collected in July 1999 and September 2000 were examined for parasites, excluding the head and gills. Six species were found: Anisakis simplex s.l. (L3), A. physeteris (L3), Hysterothylacium aduncum (L2 and L3), Stephanostomum lophii (metacercaria), S. pristis (adult), and Prosorhynchus crucibulum (metacercaria). The latter is a new host record, and A. physeteris is reported for the first time in blue whiting from the north-east Atlantic. Host gender was not a significant pr…
Host specificity ofOschmarinella rochebruniandBrachycladium atlanticum(Digenea: Brachycladiidae) in five cetacean species from western Mediterranean …
2010
AbstractWe investigated patterns of specificity of liver flukes (fam. Brachycladiidae) in a community of cetaceans from the western Mediterranean. The liver and pancreas of 103 striped dolphins,Stenella coeruleoalba, 18 Risso's dolphins,Grampus griseus, 14 bottlenose dolphins,Tursiops truncatus, 8 common dolphins,Delphinus delphis, and 5 long-finned pilot whales,Globicephala melas, were analysed for brachycladiid species. Two species were found:Oschmarinella rochebruniin striped dolphins (prevalence (P): 61.2%; mean intensity (MI) (95% CI): 34.2 (25.7–45.6)), andBrachycladium atlanticumin striped dolphins (P: 39.8%; MI: 7.1 (4.8–13.1)) and a single individual of common dolphin (P: 12.5%; in…
Cephalopod prey of two Ziphius cavirostris (Cetacea) stranded on the western Mediterranean coast
2000
The stomach contents of two Cuvier's beaked whales (Ziphius cavirostris), male and female, stranded on the western Mediterranean coast were analysed. Food consisted exclusively of hard cephalopod remains. The character of this teuthophagous diet agrees with the offshore and deep diving behaviour of Z. cavirostris.
Parasites as fish population tags and pseudoreplication problems: the case of striped red mullet Mullus surmuletus in the Spanish Mediterranean
2007
AbstractStudies of parasites as fish population tags often apply a single round of sampling to identify potential stocks or predict harvest localities. However, the lack of replication generates pseudoreplication, implicitly assuming that infection levels are more similar between samples from the same locality than between samples from different localities. We evaluated this assumption in the case of the striped red mullet Mullus surmuletus in three localities of the Spanish Mediterranean separated by c. 300 km. Samples of 25 fish of similar size were collected in each locality in the summer and autumn of two consecutive years. Prevalence and abundance of three long-lived parasite taxa diff…
Intestinal helminth fauna of the South American sea lion Otaria flavescens and fur seal Arctocephalus australis from northern Patagonia, Argentina
2012
AbstractWe report on the intestinal helminth fauna of 56 South American sea lions, Otaria flavescens, and 5 South American fur seals, Arctocephalus australis, from northern Patagonia, Argentina. A total of 97,325 helminth specimens were collected from sea lions. Gravid individuals were represented by 6 species of parasites: 1 digenean (Ascocotyle (Ascocotyle) patagoniensis), 1 cestode (Diphyllobothrium spp.), 3 nematodes (Uncinaria hamiltoni, Contracaecum ogmorhini s.s., Pseudoterranova cattani) and 1 acanthocephalan (Corynosoma australe). In addition, third-stage larvae of 2 nematodes (Contracaecum sp. and Anisakis sp. type I) and 3 juvenile acanthocephalans (Andracantha sp., Profilicollis…
Presence of genital spines in a male Corynosoma cetaceum Johnston and Best, 1942 (Acanthocephala).
2002
We collected 83 females and 80 males of Corynosoma cetaceum from 2 common dolphins, Delphinus delphis, collected in northern Patagonia (Argentina). Worms were most similar to specimens collected in other South American localities. However, 1 male had 2 spines adjacent to the genital pore and isolated from the rest of body spines. This finding confirms the recent reassignment of C. cetaceum to Corynosoma. Absence of genital spines is suggested to be avoided as the sole criterion to exclude specimens from Corynosoma or Andracantha.
Cardicola aurata sp. n. (Digenea: Sanguinicolidae) from Mediterranean Sparus aurata L. (Teleostei: Sparidae) and its unexpected phylogenetic relation…
2008
A new sanguinicolid trematode, Cardicola aurata sp. n., is described from gilthead seabream Sparus aurata L., from off the Spanish Mediterranean coast. The morphology of C. aurata sp. n. generally agrees with the diagnosis of the genus, however, in contrast to all other reported Cardicola spp. the male pore is located sub-medially at the posterior end of the body instead of sinistrally before the posterior end of the body. Based on a comparison of the morphology as well as partial 28S and ITS2 rDNA sequence data from the present species with that from closely related species, it was decided to emend the diagnosis of Cardicola rather than create a new genus, as the aberrant position of the m…
Molecular and Morphological Differentiation of Two Similar Species of Accacoeliidae (Digenea):Accacladocoelium macrocotyleandA. nigroflavumfrom Sunfi…
2014
In a study of 106 sunfish, Mola mola (L.), from Mediterranean waters, 2,731 worms, belonging to 2 congeneric species of accacoeliids, Accacladocoelium macrocotyle (Diesing, 1858) Robinson, 1934 and Accacladocoelium nigroflavum (Rudolphi, 1819) Robinson, 1934 , were collected from the digestive system. It is often difficult to differentiate between these 2 species as they are sympatric and very similar; in fact, according to previous descriptions, the extent of the vitellarium is the only interspecific difference, described as extending posteriorly to the ovary in A. macrocotyle and as anterior to the anterior testis in A. nigroflavum. However, this diagnostic trait is not always valid; more…
Changes in epizoic crustacean infestations during cetacean die-offs: the mass mortality of Mediterranean striped dolphins Stenella coeruleoalba revis…
2006
In the summer and autumn of 1990, a cetacean morbillivirus caused a massive epizootic mortality of striped dolphins Stenella coeruleoalba in the western Mediterranean. Previous circum- stantial evidence suggested that the disease could also have increased host susceptibility to infesta- tions with epizoic crustaceans. In this study we provide strong evidence supporting this hypothesis. We examined striped dolphins stranded along the Mediterranean central coast of Spain from 1981 to 2004 (n = 136), and recorded data on prevalence, intensity of infestation, size and reproductive status of 2 sessile crustacean species specific to cetaceans, the phoront cirriped Xenobalanus globicipitis and the…
Host–parasite relationship of Ceratomyxa puntazzi n. sp. (Myxozoa: Myxosporea) and sharpsnout seabream Diplodus puntazzo (Walbaum, 1792) from the Med…
2011
Sparidae are economically important fishes to both, fisheries and aquaculture in the Mediterranean. Species diversification is an important strategy for the development of Mediterranean aquaculture. One of the species recently introduced is the sharpsnout seabream Diplodus puntazzo (Walbaum, 1792). During a parasitological study of fish from the Gulf of Valencia and the Mar Menor (Spain), myxozoan spores belonging to the genus Ceratomyxa were found in the gall bladder of D. puntazzo. A morphological description of the spores, which includes histology and transmission electron microscopy (TEM) as well as molecular (SSU ribosomal DNA) data resulted in the erection of a new species, Ceratomyxa…
Discrimination of fish populations using parasites: Random Forests on a ‘predictable’ host-parasite system
2010
SUMMARYWe address the effect of spatial scale and temporal variation on model generality when forming predictive models for fish assignment using a new data mining approach, Random Forests (RF), to variable biological markers (parasite community data). Models were implemented for a fish host-parasite system sampled along the Mediterranean and Atlantic coasts of Spain and were validated using independent datasets. We considered 2 basic classification problems in evaluating the importance of variations in parasite infracommunities for assignment of individual fish to their populations of origin: multiclass (2–5 population models, using 2 seasonal replicates from each of the populations) and 2…
Contribution to the taxonomy of the family Campulidae Odhner, 1926 (Digenea) by means of a morphometric multivariate analysis
1996
Digeneans of the family Campulidae occur exclusively in marine mammals, particularly in cetaceans. Their taxonomy is confused, being based on adult morphology only. We used a multivariate discriminant analysis of morphometric data to provide new evidence on the taxonomy of the Campulidae. Measurements of 217 specimens from 21 species of all seven genera of the family were taken. The percentage of specimens correctly assigned into their own species was 96.3%. The first three discriminant functions accounted for most of the variation between the species, which were grouped together in suprageneric groups along the first and the second function. The ordination pattern observed conforms partly …
Uncinaria hamiltoni (Nematoda: Ancylostomatidae) in South American Sea Lions, Otaria flavescens, From Northern Patagonia, Argentina
2004
Thirty-one South American sea lion pups (Otaria flavescens) found dead in Punta León, Argentina, during the summer of 2002, were examined for hookworms (Uncinaria hamiltoni). Parasite parameters were analyzed in 2 locations of the rookery, i.e., a traditional, well-structured breeding area and an expanding area with juveniles and a lax social structure. Prevalence of hookworms was 50% in both localities, and no difference was observed in prevalence between pup sexes (P > 0.05). Hookworms were concentrated in the small intestine. Transmammary transmission is assumed because only adult hookworms were found in the pups. The mean intensity of hookworms per pup was 135; the mean intensity in fem…
Follow-up trends of parasite community alteration in a marine fish after the Prestige oil-spill: shifting baselines?
2008
This study evaluates the follow-up trends in the composition and structure of the parasite communities in the marine sparid Boops boops after the Prestige oil-spill. A total of 400 fish comprising 11 seasonal samples was analyzed from three impacted localities on the Atlantic coast of Spain. A large number of parasite species was recovered only after the spill thus suggesting a substantial alteration of the marine food webs. Post-spill communities exhibited higher richness and abundance due to the significant changes in the abundance of the common species, the latter indicating accelerated parasite transmission rates. Multivariate analyses at two nested scales detected a directional trend i…
Molecular phylogeny of the families Campulidae and Nasitrematidae (Trematoda) based on mtDNA sequence comparison.
1998
Abstract Historically, the systematic arrangement of the genera within the family Campulidae, and its relationship with its allied family Nasitrematidae have been rather confused, particularly because only adult morphology has been available to classical taxonomic analysis. In this paper we provide a partial phylogeny of the genera of these families based on mtDNA from five campulid species: Campula oblonga, Zalophotrema atlanticum, Hadwenius tursionis, Oschmarinella rochebruni and ; and one nasitrematid, Nasitremaglobicephalae . Fasciola hepatica and Dicrocoelium dendriticum were used as outgroups. Maximum parsimony and neighbour-joining methods were applied. Both methods produced similar …
Assessing host-parasite specificity through coprological analysis: a case study with species of Corynosoma (Acanthocephala: Polymorphidae) from marin…
2011
In this paper we report an investigation of the utility of coprological analysis as an alternative technique to study parasite specificity whenever host sampling is problematic; acanthocephalans from marine mammals were used as a model. A total of 252 scats from the South American sea lion, Otaria flavescens, and rectal faeces from 43 franciscanas, Pontoporia blainvillei, from Buenos Aires Province, were examined for acanthocephalans. Specimens of two species, i.e. Corynosoma australe and C. cetaceum, were collected from both host species. In sea lions, 78 out of 145 (37.9%) females of C. australe were gravid and the sex ratio was strongly female-biased. However, none of the 168 females of …
Aporocotyle mariachristinae n. sp., and A. ymakara VillalbaFernández, 1986 (Digenea: Aporocotylidae) of the pink cusk-eel, Genypterus blacodes (Ophid…
2012
Aporocotyle mariachristinae n. sp. and A. ymakara Villalba & Fernández, 1986 were collected from the bulbus arteriosus and ventral aorta of pink cusk-eels, Genypterus blacodes (Forster, 1801) from Patagonia, Argentina. A. mariachristinae n. sp. can be distinguished from all the species of Aporocotyle by the asymmetrical extension of posterior caeca (right posterior caecum longer, terminating at the area between mid-level of ovary and posterior body end; left posterior caecum shorter, terminating at the area between mid-level of cirrus sac and posterior to reproductive organs), the distribution of spines along the ventro-lateral body margins and the number of testes. The new species clearly …
Ontogenetic Habitat Selection by Hadwenius pontoporiae (Digenea: Campulidae) in the Intestine of Franciscanas (Cetacea)
1997
The linear habitat selection of 4 sequential maturity stages (1, 2, 3, and 4) of the trematode Hadwenius pontoporiae in the intestines of 26 South American dolphins Pontoporia blanvillei was investigated. The franciscana is a suitable host for H. pontoporiae because all 26 hosts were infected, the infrapopulations being composed mostly of gravid (stage 4) worms. Most trematodes were found in the first third of the intestine. The niches of the maturity stages decreased from stage 1 to 4. Gravid worms favored the most anterior part of the duodenum, whereas stages 1, 2, and 3 occurred more posteriorly in every host. The distributions of the maturity stages showed a narrow site fidelity and wer…
Corynosoma cetaceumin the Stomach of Franciscanas,Pontoporia blainvillei(Cetacea): an Exceptional Case of Habitat Selection by an Acanthocephalan
2001
Adult acanthocephalans are typically found in the intestine of vertebrates, where they can readily absorb nutrients. However, Corynosoma cetaceum has been frequently reported in the stomach of cetaceans from the Southern Hemisphere. The ecological significance of this habitat was investigated by examining data on number, sex ratio, maturity status, biomass, and fecundity of C. cetaceum in different parts of the digestive tract of 44 franciscanas Pontoporia blainvillei. Individual C. cetaceum occurred in the pyloric stomach (PS) and, to lesser degrees, in the duodenal ampulla (DA) and the main stomach (MS). Females outnumbered males in all chambers, although the sex ratio was closer to 1:1 i…
Living in a harsh habitat: epidemiology of the whale louse, Syncyamus aequus (Cyamidae), infecting striped dolphins in the Western Mediterranean
2017
Whale lice (Cyamidae) are ectoparasitic amphipods exclusive to cetaceans. Data on their epidemiology usually come from species infecting baleen whales, which are large, slow-moving hosts. In this study, we provide data on infection parameters, population structure and microhabitat selection in a whale louse exclusive to delphinids, Syncyamus aequus, with the aim of comparing them with those from cyamid species from large whales. A total of 176 striped dolphins Stenella coeruleoalba stranded along the Mediterranean coast of Spain during 1980–2016 were examined. The prevalence of S. aequus was 27.3% (95% CI: 20.9–34.3), and populations were sparse, with a mean number of whale lice per infecte…
Biometric variability of Hadwenius tursionis (Marchi, 1873) (Digenea, Campulidae) from the intestine of the bottlenose dolphin Tursiops truncatus (Mo…
1995
The species discrimination in the family Campulidae is largely based on morphometric characters (absolute measurements and ratios). To assess the variability of this characters we have studied the campulid species Hadwenius tursionis from four Mediterranean bottlenose dolphins Tursiops truncatus from the Western Mediterranean. In H. tursionis most absolute measurements differed significantly across the infrapopulations, showing high coefficients of variation. Only egg dimensions appeared to be fairly conservative. Body ratios were less variable than absolute measurements, but growth patterns did vary significantly between the infrapopulations studied. None of the ratios previously used in r…
Gastrointestinal Helminths of Loggerhead Turtles (Caretta caretta) from the Western Mediterranean: Constraints on Community Structure
1998
Richness and composition of gastrointestinal helminth communities of 54 loggerhead turtles, Caretta caretta, from the western Mediterranean were interpreted from patterns of helminth exchange at 2 host taxonomic scales: exchange between marine turtles and other marine hosts and exchange within turtles. We predicted exchange of the former to be unimportant ecologically and evolutionarily because of the host phylogenetic distance. The absence of records of successful exchange at this host taxonomic scale confirmed that host physiological barriers seem to prevent contemporary parasite transfer between marine turtles and other sympatric hosts. Marine turtles also seem to exhibit an evolutionary…
Morphological and molecular redescription of the myxozoanUnicapsula pflugfelderiSchubert, Sprague & Reinboth 1975 from two teleost hosts in the M…
2009
Elongate plasmodia with myxosporean spores belonging to the genus Unicapsula, Davis, 1924 were found in the skeletal muscle of the striped seabream, Lithognathus mormyrus (L.), a candidate for the mediterranean aquaculture. The only species of Unicapsula described from the Mediterranean is Unicapsula pflugfelderi Schubert et al. 1975, which occurs in the picarel, Spicara smaris (L.). For morphological and molecular comparison of U. pflugfelderi from S. smaris with Unicapsula sp. from L. mormyrus measurements of plasmodia and spores, ultrastructural details and 18S and 28S rDNA sequences were analysed. Whereas plasmodia were 2-3 times larger in S. smaris than in L. mormyrus (length 2.47-0.81…
Girdles as the main infection site for Paradeontacylix kampachi (Sanguinicolidae) in the greater amberjack Seriola dumerili.
2003
In this study, we provide new information about the habitats selected by the blood fluke Paradeontacylix kampachi in the greater amberjack Seriola dumerili based on an exhaustive anatomical examination. From May to October 1998, 21 fish of the 0+ age class were collected from tanks of the Spanish Institute of Oceanography in Puerto de Mazarrón, Spain, for parasitological analysis. Individuals of P. kampachi were found in 17 of the 21 fish analysed (mean intensity +/- SD: 13.6 +/- 16.6; median: 6). Worms occurred in the girdles, cephalic kidney, sinus venosus, kidney and branchial arteries. A Friedman test with a post-hoc contrast revealed a significantly higher number of worms in the girdle…
Two decades of monitoring in marine debris ingestion in loggerhead sea turtle, Caretta caretta, from the western Mediterranean
2018
Abstract Anthropogenic marine debris is one of the major worldwide threats to marine ecosystems. The EU Marine Strategy Framework Directive (MSFD) has established a protocol for data collection on marine debris from the gut contents of the loggerhead sea turtle (Caretta caretta), and for determining assessment values of plastics for Good Environmental Status (GES). GES values are calculated as percent turtles having more than average plastic weight per turtle. In the present study, we quantify marine debris ingestion in 155 loggerhead sea turtles collected in the period 1995–2016 in waters of western Mediterranean (North-east Spain). The study aims (1) to update and standardize debris inges…
Epizootic of dolphin morbillivirus on the Catalonian Mediterranean coast in 2007
2011
BETWEEN 1990 and 1992, thousands of striped dolphins (Stenella coeruleoalba) stranded along the Mediterranean coast due to a newly described virus, the dolphin morbillivirus (DMV) (Domingo and others 1990, 1992). DMV is one of the several morbilliviruses that have killed marine mammals worldwide since 1987 (Di Guardo and others 2005). A new DMV epizootic has been recently confirmed from the Mediterranean Spanish and French coasts during 2007 to 2008 (Fernández and others 2008, Raga and others 2008, Keck and others 2010). This short communication describes the pathological findings associated with DMV infection and secondary infections, observed during this epizootic on the Mediterranean coa…
Morphological and molecular characterization of tetraphyllidean merocercoids (Platyhelminthes: Cestoda) of striped dolphins (Stenella coeruleoalba) f…
2005
Two types of tetraphyllidean merocercoids, Phyllobothrium delphini and Monorygma grimaldii, are well known from most cetaceans world-wide. The role of cetaceans in the life-cycle of these merocercoids is unclear because their specific identity is as yet unknown. The problem is compounded by poor descriptions of both merocercoids. We used light and scanning electron microscopy, and histological techniques to provide a thorough description of merocercoids collected from 11 striped dolphins, Stenella coeruleoalba, from the Spanish Mediterranean. We also described, for the first time, specimens of P. delphini with immature proglottides. Our merocercoids were morphologically similar to those des…
Distribution of Pholeter gastrophilus (Digenea) within the stomach of four odontocete species: the role of the diet and digestive physiology of hosts
2005
We compared the distribution of the digenean Pholeter gastrophilus in the stomach of 27 harbour porpoises, Phocoena phocoena, 27 striped dolphins, Stenella coeruleoalba, 18 bottlenose dolphins, Tursiops truncatus, and 100 long-finned pilot whales, Globicephala melas. The stomach of these species is composed of 4 chambers of different size, structure and function. In all species, P. gastrophilus was largely restricted to the glandular region of the stomach, but the parasite tended to favour the fundic chamber in bottlenose dolphins and harbour porpoises, the pyloric chamber in pilot whales, and none in striped dolphins. However, predictability at infrapopulation level was generally low, sugg…
Parasite infracommunities as predictors of harvest location of bogue (Boops boops L.): a pilot study using statistical classifiers
2005
The accuracy of classifying bogue (Boops boops) according to the fishery from which it was harvested was evaluated by applying several statistical classification techniques to fish parasite abundances. Bogue captured in 2001 in two fisheries off the Atlantic coast of Spain were compared with one off the Spanish Mediterranean coast. One hundred bogue were classified to each harvest location (fishery) using different numbers of parasite species chosen as predictors by a best subset method. Two parametric methods of classification (linear and quadratic discriminant analysis) were compared with two non-parametric approaches (k-nearest neighbour classification and feed-forward neural network) an…
Halfway up the trophic chain: development of parasite communities in the sparid fish Boops boops
2007
SUMMARYWe examined the patterns of composition and structure of parasite communities in the Mediterranean sparid fish Boops boops along a gradient of fish sizes, using a large sample from a single population. We tested the hypothesis that species forming the core of the bogue parasite fauna (i.e. species which have a wide geographical range and are responsible for recognizable community structure) appear early in the fish ontogeny. The sequential community development observed supported the prediction that core species appear in the fish population earlier than rare and stochastic species. There was also a strong correlation between the order of ‘arrival’ of the species and their overall pr…
POPULATION STRUCTURE OF ANISAKIS SIMPLEX (NEMATODA) IN HARBOR PORPOISES PHOCOENA PHOCOENA OFF DENMARK
2004
The population structure and habitat selection of Anisakis simplex in 35 harbor porpoises off Denmark are described. The nematodes were collected from the stomach and duodenal ampulla and were categorized as third-stage larvae, fourth-stage larvae, subadults, and adults. The porpoises harbored 8,043 specimens of A. simplex. The proportion of adults and subadults increased with infrapopulation size. The number of development stages across infrapopulations covaried significantly (Kendall's test of concordance). Concordance was higher in hosts with the highest intensities than in those with low and medium intensities. All stages occurred mainly in the forestomach, but this trend was stronger f…
Seroprevalence of Toxoplasma gondii antibodies in wild dolphins from the Spanish Mediterranean coast.
2004
Although Toxoplasma gondii infection has been found occasionally in cetaceans, little is known of the prevalence of antibodies to T. gondii in wild dolphins. Antibodies to T. gondii were determined in serum samples from 58 dolphins stranded in the Spanish Mediterranean coast. Modified agglutination test was used to determine T. gondii antibodies, and a titer of 1:25 was considered indicative of T. gondii infection. Antibodies to T. gondii were found in 4 of 36 striped dolphins (Stenella coeruleoalba), in 2 of 4 common dolphins (Delphinus delphis), in 4 of 7 bottlenose dolphins (Tursiops truncatus), and in 1 harbour porpoise (Phocoena phocoena). Antibodies were not found in 9 Risso's dolphin…
Epibiont communities of loggerhead marine turtles (Caretta caretta) in the western Mediterranean: influence of geographic and ecological factors
2014
This study reports for the first time on the whole epibiont fauna of loggerhead marine turtles,Caretta caretta, in the western Mediterranean, analysing the factors that account for the predictability and composition of the assemblage. A total of 104 loggerhead turtles stranded along the coasts of eastern Spain during 1995–2006 were surveyed for epibionts. A total of 39 epibiont taxa were identified, three of them being new records for loggerhead turtles:Bittiumsp.,Idotea metallicaandJassasp. The assemblage was composed of a group of 27 facultative taxa that use turtles as any inanimate buoyant substrate, and 12 taxa that have developed more specific associations to marine turtles, including…
The origin of Lecithodesmus (Digenea: Campulidae) based on ND3 gene comparison
2000
Species of Lecithodesmus (Campulidae) occur almost exclusively in baleen whales throughout a wide geographical distribution. Other campulids occur only in odontocetes and, secondarily, in pinnipeds and the sea otter. Therefore, the ancestor of Lecithodesmus might have either cospeciated with mysticetes during the early divergence of mysticete and odontocete cetaceans or originated later via host switching. We evaluate both possibilities based on a phylogenetic analysis. The ND3 mitochondrial gene sequence of a species of Lecithodesmus was included in a previous partial molecular phylogeny of the Campulidae. Fasciola hepatica and Dicrocoelium dendriticum were used as outgroups. Maximum parsi…