Molecules and morphology reveal cryptic variation among digeneans infecting sympatric mullets in the Mediterranean.
SUMMARYWe applied a combined molecular and morphological approach to resolve the taxonomic status of Saccocoelium spp. parasitizing sympatric mullets (Mugilidae) in the Mediterranean. Eight morphotypes of Saccocoelium were distinguished by means of multivariate statistical analyses: 2 of Saccocoelium obesum ex Liza spp.; 4 of S. tensum ex Liza spp.; and 2 (S. cephali and Saccocoelium sp.) ex Mugil cephalus. Sequences of the 28S and ITS2 rRNA gene regions were obtained for a total of 21 isolates of these morphotypes. Combining sequence data analysis with a detailed morphological and multivariate morphometric study of the specimens allowed the demonstration of cryptic diversity thus rejecting…
Parasite communities in two sparid fishes from the western Mediterranean: a comparative analysis based on samples from three localities off the Algerian coast
Summary We provide the first known comparative assessment of metazoan parasite communities in two taxonomically and ecologically related sparids, Boops boops and Spicara maena, that are common in the coastal infralittoral habitats in the Mediterranean. Using abundant data for infracommunities in three localities off the Algerian coasts of the Mediterranean, we tested the general prediction that the phylogenetic proximity of the two hosts, their overlapping geographical distribution and habitat occupation, as well as the similar feeding habits and diet would contribute to a homogenization of their parasite community composition and structure. The regional fauna of parasites of B. boops and S…
Development and habitat selection of a new sanguinicolid parasite of cultured greater amberjack, Seriola dumerili, in the Mediterranean
Abstract This study presents a description of the developmental stages of a new sanguinicolid disease agent (Paradeontacylix ibericus) of cultured Seriola dumerili (greater amberjack) in the Mediterranean, and investigates parasite habitat selection in the definitive host and the development of sanguinicolidosis in experimental, inshore cultures of S. dumerili . Two experimental surveys were carried out using fish captured as wild 0+ juveniles in the aquaculture facilities at Puerto de Mazarron (Spain). Encysted, early post-cercarial stages (schistosomula) were detected in histological sections of the pelvic and thoracic muscles of fish and four subsequent stages of parasite development wer…
Seasonal population dynamics of Zeuxapta seriolae (Monogenea: Heteraxinidae) parasitising Seriola dumerili (Carangidae) in the Western Mediterranean.
We examined the seasonal and yearly population dynamics of the monogenean pathogen Zeuxapta seriolae on juvenile fish from wild populations of Seriola dumerili. The study is based on bimonthly monitoring between April, 2005 and April, 2007 off Majorca, and newly obtained monogenean population data for juvenile fish from three additional localities in the Western Mediterranean (off Alicante, Corsica and Sardinia). We documented the highest intensities and abundances of Z. seriolae, with mean abundance values similar to or higher than those reported in the single case of wild fish mortalities reported to date. There was a recurrent pattern of seasonal change in infection with Z. seriolae in t…
Random forests, a novel approach for discrimination of fish populations using parasites as biological tags.
Due to the complexity of host-parasite relationships, discrimination between fish populations using parasites as biological tags is difficult. This study introduces, to our knowledge for the first time, random forests (RF) as a new modelling technique in the application of parasite community data as biological markers for population assignment of fish. This novel approach is applied to a dataset with a complex structure comprising 763 parasite infracommunities in population samples of Atlantic cod, Gadus morhua, from the spawning/feeding areas in five regions in the North East Atlantic (Baltic, Celtic, Irish and North seas and Icelandic waters). The learning behaviour of RF is evaluated in …
Mining parasite data using genetic programming.
Genetic programming is a technique that can be used to tackle the hugely demanding data-processing problems encountered in the natural sciences. Application of genetic programming to a problem using parasites as biological tags demonstrates its potential for developing explanatory models using data that are both complex and noisy.
Molecular and morphological evidence for three species of Diplostomum (Digenea: Diplostomidae), parasites of fishes and fish-eating birds in Spain
Background Recent molecular studies have revealed high species diversity of Diplostomum in central and northern Europe. However, our knowledge of the distribution of Diplostomum spp. in the southern distributional range in Europe of the snail intermediate hosts (Lymnaea stagnalis and Radix spp.) is rather limited. This study aims to fill this gap in our knowledge using molecular and morphological evidence. Methods Nineteen fish species and six fish-eating bird species were sampled opportunistically in three regions (Catalonia, Extremadura and Aragon) in Spain. All isolates of Diplostomum spp. were characterised morphologically and molecularly. Partial sequences of the barcode region of the …
Abundance–variance and abundance–occupancy relationships in a marine host–parasite system: The importance of taxonomy and ecology of transmission
Abundance-occupancy and abundance-variance relationships are two of the most general macroecological patterns capturing essential fundamentals of the structuring of species distributions and are widely documented for free-living animal and plant species populations at different spatial scales. However, empirical data for parasites have been gathered using appropriate sampling designs only recently. We performed analyses across species of the variation in infection parameters and patterns of aggregation of the most widespread parasites in the marine sparid fish Boops boops across seven localities of two marine biogeographical regions, the North East Atlantic and the Mediterranean. We used a …
Composition and structure of the parasite faunas of cod, Gadus morhua L. (Teleostei: Gadidae), in the North East Atlantic.
Abstract Background Although numerous studies on parasites of the Atlantic cod, Gadus morhua L. have been conducted in the North Atlantic, comparative analyses on local cod parasite faunas are virtually lacking. The present study is based on examination of large samples of cod from six geographical areas of the North East Atlantic which yielded abundant baseline data on parasite distribution and abundance. Materials and Methods A total of 826 fish was sampled in the Baltic, Celtic, Irish and North seas, Icelandic waters and Trondheimsfjord (Norway) in 2002 (spring and autumn) and 2003 (spring). The gills and internal organs (oesophagus, stomach, intestine, pyloric caeca, liver, heart, splee…
Discrimination of fish populations using parasites: Random Forests on a ‘predictable’ host-parasite system
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…
Drivers of parasite community structure in fishes of the continental shelf of the Western Mediterranean: the importance of host phylogeny and autecological traits
15 pages, 5 figures, 6 tables, supplementary data https://doi.org/10.1016/j.ijpara.2019.04.004
Molecular and morphological identification of larval opecoelids (Digenea: Opecoelidae) parasitising prosobranch snails in a Western Mediterranean lagoon.
In a study of the digeneans parasitising molluscs in the Els Alfacs lagoon (Ebro Delta, Western Mediterranean) we found heavy infections with sporocysts emitting two types of cotylocercous cercariae in the prosobranch trochid gastropod Gibbula adansonii and with metacercariae in the prosobranch nassariid gastropod Cyclope neritea. A comparative analysis using ITS ribosomal DNA sequences from these larval stages and published sequences of 17 larval and adult opecoelid stages allowed us to elucidate the life-cycle of Macvicaria obovata and to confirm the identification of Cainocreadium labracis based on cercarial morphology. We provide molecular evidence for the identification and the first d…
Follow-up trends of parasite community alteration in a marine fish after the Prestige oil-spill: shifting baselines?
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…
Robinia aurata n. g., n. sp. (Digenea: Hemiuridae) from the mugilid Liza aurata with a molecular confirmation of its position within the Hemiuroidea.
Robinia aurata n. g., n. sp. is described from Liza aurata (Mugilidae), the golden grey mullet, from the Ebro Delta, Spanish Mediterranean. The new genus differs from all other hemiurid genera in the combined possession of muscular flanges and a vestigial ecsoma. Within the Bunocotylinae, which currently accommodates 2 genera, Bunocotyle and Saturnius, the new genus exhibits a unique combination of blind caeca, Juel's organ, post-ovarian bulk of the uterus in the hind-body, and tegumental papillae surrounding the oral and ventral sucker apertures. Furthermore, Robinia n. g. differs from both Bunocotyle and Saturnius in the nature of the muscular extensions around the oral sucker, with the s…
Parasite communities in Boops boops (L.) (Sparidae) after the Prestige oil-spill: Detectable alterations
Environmental pollution affects parasite populations and communities, both directly and through effects on intermediate and final hosts. In this work, we present a comparative study on the structure and composition of metazoan parasite communities in the bogue, Boops boops, from two localities (Galician coast, Spain) affected by the Prestige oil-spill (POS). We focus on the distribution of both individual parasite species and larger functional groupings by using both univariate and multivariate analyses. Our results indicate directional trends in community composition that might be related to the Prestige oil-spill disturbance of the natural coastal communities off Galicia. Endoparasite com…
Mediterranean Diplodus annularis (Teleostei: Sparidae) and its brain parasite: Unforeseen outcome
Patterns of parasite load and aggregation of the bird trematode Cardiocephaloides longicollis in its main intermediate host in the Mediterranean, the annular sea bream, Diplodus annularis, were studied in a large sample collected off Valencia (Spain) and are discussed within the context of the parasite induced host mortality hypothesis. The metacercariae were located within large composite cysts of host origin in the ventricles of the optic lobes of the cerebrum. A weak immunological response was detected in older fish, which was significantly associated with the total parasite load. Although the mean abundance of C. longicollis showed a tendency to increase with host size, the infection le…
Not everything is everywhere: the distance decay of similarity in a marine host-parasite system
Aim We test the similarity–distance decay hypothesis on a marine host–parasite system, inferring the relationships from abundance data gathered at the lowest scale of parasite community organization (i.e. that of the individual host). Location Twenty-two seasonal samples of the bogue Boops boops (Teleostei: Sparidae) were collected at seven localities along a coastal positional gradient from the northern North-East Atlantic to the northern Mediterranean coast of Spain. Methods We used our own, taxonomically consistent, data on parasite communities. The variations in parasite composition and structure with geographical and regional distance were examined at two spatial scales, namely loca…
Morphological and molecular characterization of tetraphyllidean merocercoids (Platyhelminthes: Cestoda) of striped dolphins (Stenella coeruleoalba) from the Western Mediterranean.
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…
Parasite communities in the red mullet, Mullus barbatus L., respond to small-scale variation in the levels of polychlorinated biphenyls in the Western Mediterranean
We examined parasite populations and communities in the Mediterranean sentinel fish species, Mullus barbatus, sampled at a small-scale PCB gradient at the shelf sediments off Catalonian coasts of the Western Mediterranean. A recurrent feature at both the population and community level was the differentiation of the samples along the increasing PCB levels simultaneously registered in the sediments. Both directly transmitted ectoparasites and endoparasites with complex life-cycles transmitted via food chains exhibited a decrease in abundance with the increase in PCB levels. Parasite numerical responses translated into significant differences in infracommunity structure with decreasing predict…
Halfway up the trophic chain: development of parasite communities in the sparid fish Boops boops
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…
A new cystidicolid nematode from Mullus surmuletus (Perciformes: Mullidae) from the western Mediterranean.
Ascarophis valentina n. sp. is described from Mullus surmuletus off the Valencian coast of Spain on the basis of both light and scanning electron microscopy. It can be distinguished from the other members of the genus by the length of the left (long) spicule of the males and by egg morphology. An updated grouping of the species of Ascarophis considered valid is provided with respect to these characters. The new species resembles Ascarophis capelanus, belonging to the group of species possessing eggs with a single polar knob with filaments, but is distinguished by the size of the body, the length of the esophagus (especially in relation to body length), the position of the vulva, and the siz…
Interrelationships of the Haploporinae (Digenea: Haploporidae): A molecular test of the taxonomic framework based on morphology
The taxonomic framework of the Haploporidae is evaluated and the relationships within the Haploporinae are assessed for the first time at the generic level using molecular data. Partial 28S and complete ITS2 rDNA sequences from representatives of six of the nine recognised genera within the Haploporinae were analysed together with published sequences representing members of two haploporid subfamilies and of the closely related family Atractotrematidae. Molecular analyses revealed: (i) a close relationship between the Atractotrematidae and the Haploporidae; (ii) strong support for the monophyly of the Haploporinae, Dicrogaster and Saccocoelium, and the position of Ragaia within the Haplopori…
Three species of Magnibursatus Naidenova, 1969 (Digenea: Derogenidae) from Atlantic and Black Sea marine teleosts
Three species of Magnibursatus Naidenova, 1969 are described from marine teleosts: M. skrjabini (Vlasenko, 1931), the type species of the genus, from the gobiid Zosterisessor ophiocephalus on the Bulgarian Black Sea coast; M. bartolii sp. n. from the sparid Boops boops off the Atlantic coast of Spain; and M. minutus sp. n. from the gobiid Neogobius eurycephalus on the Bulgarian Black Sea coast. M. bartolii differs from all other Magnibursatus species in its larger sinus-sac (length >250 µm, width >150 µm) and the more posterior location of testes. This species is also unusual in that it occurs in the branchial chamber and on the gills of its host. M. minutus is distinguished by the distinct…
Fauna Europaea: Helminths (Animal Parasitic)
The Laotian Rock Rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 was originally discovered in Lao People's Democratic Republic in 2005. This species has been recognized as the sole surviving member of the otherwise extinct rodent family Diatomyidae. Laonastes aenigmamus was initially reported only in limestone forests of Khammouane Province, Central Lao. A second population was recently discovered in Phong Nha Ke Bang National Park (PNKB NP), Quang Binh Province, Central Vietnam in 2011. The confirmed distribution range of L. aenigmamus in Vietnam is very small, approximately 150 km , covering low karst mountains in five communes of Minh Hoa District, Quang Binh Provi…