The Systematics of the Trematoda.

The platyhelminth class Trematoda comprises two subclasses with largely disparate species diversity, with the small Aspidogastrea with c.80 species and the speciose Digenea with c.18,000 species, which has attracted much effort towards our understanding of evolutionary relationships among suprageneric taxa. This chapter focuses on insights into the classification of the Digenea, that have become apparent from our advanced understanding of both morphological and molecular data. The field of molecular systematics of the Digenea has experienced significant advances over the past 15 years. Phylogenetic analyses of sequence data predominantly from the 18S and 28S rRNA genes have incorporated a considerable diversity of taxa, thus increasing the accuracy of phylogenetic inferences at higher taxonomic levels. As a result, the status of long-standing supraspecific taxa has been revised, new higher-level taxa have been defined, and inferences made in association with morphological and life-cycle evidence. A substantial effort has been made towards a classification reflecting a natural system of the Digenea by considering morphological evidence in conjunction with phylogenies inferred from molecular data; this has resulted in considerable congruence. However, limited taxon sampling in the phylogeny of the Digenea still remains relevant, especially in relation to some higher-level taxa, and an outline of these omissions is presented. A framework that has led to robust estimates of phylogeny is outlined, and the application of advanced morphological and molecular approaches in digenean taxonomy and systematics is illustrated using the most comprehensively studied digenean superfamilies.

Parasite communities in a marine fish indicate ecological recovery from the impacts of the Prestige oil-spill 12-13 years after the disaster.

The Prestige oil-spill (2002) is one of the major marine accidents resulting in contamination of virtually all types of marine habitat along c.900 km of coastline in the North-East Atlantic. Environmental pollution affects parasite populations and communities, both directly and through effects on intermediate and definitive hosts. However, the effects of oil-spills on shelf benthic communities are poorly known. This study addressed the hypothesis of recovery of parasite communities in a marine sparid teleost, the bogue Boops boops (L.) (Teleostei: Sparidae), as indicators of environmental pollution and its effects on benthic/pelagic invertebrate communities in an impacted area off the Galician coast, Spain, 12-13 years after the Prestige oil-spill. Novel data for the metazoan parasite communities collected during 2014-2015 were analysed in association with two unique datasets, one comprising baseline data collected in 2001, one year before the Prestige oil-spill, and one comprising data collected 3-4 years post-spill (2005-2006). Using the taxonomically consistent data on parasites in a series of fish seasonal samples, we found significant differences between the two seasonal post-spill datasets taken at a 9-year time interval (3-4 years and 12-13 years post-spill) in most community metrics and infection parameters of the common species. This was in sharp contrast with the few differences between the long-term post-spill dataset of 2014-2015 and the pre-spill dataset of 2001. Multivariate community similarity analyses confirmed that these differences reflected in the substantial differentiation of parasite community composition and structure of the post-spill communities and the significant homogenisation of communities sampled 12-13 years post-spill and baseline communities. Overall, the novel analyses demonstrated a long-term directional trend in parasite community succession towards ecological recovery irrespective of the natural seasonal variability. These findings suggest longer-term oil-spill impacts on shelf benthic/pelagic invertebrate communities lasting over 10 years.

Bacterial diversity in six species of fresh edible seaweeds submitted to high pressure processing and long-term refrigerated storage.

Seaweeds are highly perishable foods due to their richness in nutrients. High pressure processing (HPP) has been applied for extending the shelf life of fresh seaweeds but there is no information on the effect of HPP on the bacterial diversity of seaweeds. The culturable bacteria of six species of fresh edible seaweeds (green seaweeds Codium fragile and Ulva lactuca, brown seaweeds Himanthalia elongata, Laminaria ochroleuca and Undaria pinnatifida, and red seaweed Chondrus crispus) were investigated and compared to those of HPP-treated (400 and 600 MPa for 5 min) seaweeds, at the start and end of their refrigerated storage period. A total of 523 and 506 bacterial isolates were respectively retrieved from untreated and HPP-treated seaweeds. Isolates from untreated seaweeds belonged to 18 orders, 35 families, 71 genera and 135 species whereas isolates from HPP-treated seaweeds belonged to 13 orders, 23 families, 43 genera and 103 species. HPP treatment significantly reduced the number of isolates belonging to 6 families and greatly increased the number of Bacillaceae isolates. At the end of storage, decreases in bacterial diversity at the genus and species level were observed for untreated as well as for HPP-treated seaweeds.

Using Boops boops (osteichthyes) to assess microplastic ingestion in the Mediterranean Sea.

This study assesses microplastic ingestion in Boops boops at different geographical areas in the Mediterranean Sea. A total of 884 fish were caught at 20 coastal sites in Spain, France, Italy and Greece and analyzed using a common methodological protocol. Microplastics were found in 46.8% of the sampled fish, with an average number of items per individual of 1.17 ± 0.07. Filaments were the predominant shape type, while polyethylene and polypropylene were indicated by FTIR as the most common polymer types of ingested microplastics. The frequency of occurrence, as well as the abundance and proportion of types (size, shape, color and polymer) of ingested microplastics, varied among geographical areas. The spatial heterogeneity of the abundance of ingested microplastics was mainly related to the degree of coastal anthropogenic pressure at the sampling sites. Our findings further support the suitability of B. boops as bioindicator of microplastic pollution in the Mediterranean Sea.

First steps to restructuring the problematic genus Lasiotocus Looss, 1907 (Digenea: Monorchiidae) with the proposal of four new genera.

Lasiotocus Looss, 1907 is the largest genus within the Monorchiidae Odhner, 1911, with 52 species currently considered valid. Species belonging to this genus exhibit wide morphological variation and it is likely that many of them belong in other genera; however, testing the validity of the group has been hampered by a lack of molecular sequence data, especially for the type-species. Here, we report the first DNA sequences for Lasiotocus mulli (Stossich, 1883) Odhner, 1911, the type-species of the genus, and only the sixth Lasiotocus species to be sequenced. Sequences were generated for three ribosomal DNA markers, the ITS2, 18S and 28S regions, and for one mitochondrial DNA marker, the cox1 region. Phylogenetic analyses show that the six sequenced species form four clearly distinct clades, each of which we argue require separate genera. On the basis of these relationships and review of the morphology of all species in the genus, we propose a system of six genera. Four genera, Lasiotocus, the resurrected concept of Ancylocoelium Nicoll, 1912, Infundiburictus n. gen., and Sinistroporomonorchis n. gen., represent the four molecular clades. Two genera, Paralasiotocus n. gen. and Alloinfundiburictus n. gen., are proposed on the basis of morphology only. Ancylocoelium is resurrected for Ancylocoelium typicum Nicoll, 1912, Infundiburictus is erected for Lasiotocus arrhichostoma Searle, Cutmore & Cribb, 2014, Sinistroporomonorchis is erected for Lasiotocus glebulentus Overstreet, 1971and Lasiotocus lizae Liu, 2002, Paralasiotocus is erected for Lasiotocus okinawaensis Machida, 2011, and Alloinfundiburictus is erected for Lasiotocus cacuminatus Nicoll, 1915. Of the 52 species presently recognised in Lasiotocus, 43 are distributed among these genera; nine are considered species inquirendae or are transferred to other genera. We think it likely that more genera will be required for the species reviewed here but more sequence data are essential to further refine the classification.

Considerations on the taxonomy and morphology of Microcotyle spp.: redescription of M. erythrini van Beneden & Hesse, 1863 (sensu stricto) (Monogenea: Microcotylidae) and the description of a new species from Dentex dentex (L.) (Teleostei: Sparidae).

BACKGROUND: Microcotyle erythrini van Beneden & Hesse, 1863 (Platyhelminthes: Monogenea) and other closely related species of the genus are often considered as cryptic. Records in hosts other than the type-host with no species confirmation by molecular analyses have contributed to this situation. METHODS: Gill parasites of five sparid fishes, Boops boops (L.), Pagellus erythrinus (L.), P. acarne (Risso), Dentex dentex (L.) and Pagrus pagrus (L.), from the Western Mediterranean off Spain were collected. Specimens of Microcotyle spp. were characterised both molecularly and morphologically. Partial fragments (domains D1-D3) of the 28S rRNA gene and the cytochrome c oxidase subunit 1 (cox1) gene were amplified and used for molecular identification and phylogenetic reconstruction. Principal components analysis was used to look for patterns of morphological separation. RESULTS: Molecular analyses confirmed the identity of three species: M. erythrini ex P. erythrinus and Pa. pagrus; M. isyebi Bouguerche, Gey, Justine & Tazerouti, 2019 ex B. boops; and a species new to science described herein, M. whittingtoni n. sp. ex D. dentex. The specific morphological traits and confirmed hosts (P. erythrinus and Pa. pagrus) are delimited here in order to avoid misidentifications of M. erythrini (sensu stricto). Microcotyle erythrini (s.s.) is mostly differentiated by the shape of its haptor, which is also longer than in the other congeners. New morphological and molecular data are provided for M. isyebi from the Spanish Mediterranean enlarging the data on its geographical range. Microcotyle whittingtoni n. sp. is described from D. dentex and distinguished from the remaining currently recognised species of the genus by the number and robustness of the clamps. CONCLUSIONS: New diagnostic morphological traits useful to differentiate Microcotyle spp. are suggested: (i) haptor dimensions including lobes; (ii) the thickness of the clamps; (iii) the size and shape of spines of the genital atrium; (iv) the extension of the posterior extremities of vitelline fields; and (v) the shape of egg filaments. The use of new morphological approaches may allow considering these species of Microcotyle as being pseudocryptic. The use of representative undamaged specimens that have been genetically confirmed as conspecific is considered crucial to avoid abnormally wide morphological ranges that prevent species differentiation.

The Systematics of the Trematoda.

The platyhelminth class Trematoda comprises two subclasses with largely disparate species diversity, the small Aspidogastrea with c.80 species and the speciose Digenea with c.18,000 species, which has attracted much effort towards our understanding of evolutionary relationships among suprageneric taxa. This chapter focuses on insights into the classification of the Digenea that have become apparent from our advanced understanding of both morphological and molecular data. The field of molecular systematics of the Digenea has experienced significant advances over the past 15 years. Phylogenetic analyses of sequence data predominantly from the 18S and 28S rRNA genes have incorporated a considerable diversity of taxa thus increasing the accuracy of phylogenetic inferences at higher taxonomic levels. As a result, the status of long-standing supraspecific taxa has been revised, new higher-level taxa have been defined, and inferences made in association with morphological and life-cycle evidence. A substantial effort has been made towards a classification reflecting the natural system of the Digenea by considering morphological evidence in conjunction with phylogenies inferred from molecular data; this has resulted in considerable congruence. However, limited taxon sampling in the phylogeny of the Digenea still remains relevant especially in relation to some higher-level taxa, and an outline of these omissions is presented. A framework that has led to robust estimates of phylogeny is outlined, and the application of advanced morphological and molecular approaches in digenean taxonomy and systematics is illustrated using the most comprehensively studied digenean superfamilies.

Drivers of parasite community structure in fishes of the continental shelf of the Western Mediterranean: the importance of host phylogeny and autecological traits.

We explored the relationships between features of host species and their environment, and the diversity, composition and structure of parasite faunas and communities using a large taxonomically consistent dataset of host-parasite associations and host-prey associations, and original environmental and host trait data (diet, trophic level, population density and habitat depth vagility) for the most abundant demersal fish species off the Catalonian coast of the Western Mediterranean. Altogether 98 species/taxa belonging to seven major parasite groups were recovered in 683 fish belonging to 10 species from seven families and four orders. Our analyses revealed that (i) the parasite fauna of the region is rich and dominated by digeneans; (ii) the host parasite faunas and communities exhibited wide variations in richness, abundance and similarity due to a strong phylogenetic component; (iii) the levels of host sharing were low and involved host generalists and larval parasites; (iv) the multivariate similarity pattern of prey samples showed significant associations with hosts and host trophic guilds; (v) prey compositional similarity was not associated with the similarity of trophically transmitted parasite assemblages; and (vi) phylogeny and fish autecological traits were the best predictors of parasite community metrics in the host-parasite system studied.

Medium-term dynamics of element concentrations in a sparid fish and its isopod parasite after the Prestige oil-spill: Shifting baselines?

Historically, the European Atlantic is probably the most important oil-spill hotspot worldwide. One of the most recent accidents occurred in 2002 when the oil-tanker Prestige sank over the Galician Bank causing two major oil-spills followed by several small leaks until March 2003. This resulted in contamination of virtually all types of marine habitat. Considering that parasites have proved to be good effect and accumulation bioindicators, the present study addresses the medium-term changes in trace element content after the Prestige oil-spill in a model host-parasite system, the bogue, Boops boops (Sparidae) and the isopod Ceratothoa oestroides. To our knowledge, this study is the first to address trace element concentrations in natural fish and parasite populations associated with the effects of an oil-spill. We observed that both test organisms examined, the host and the parasite, indicate a detectable change in the relative composition of trace element concentrations before and after the Prestige oil-spill. Multivariate analyses also indicated a differential response of the different tissues to the temporal sampling sequence. However, analyses of both host and parasite tissues supported the pattern of a gradual temporal transition to a state of relative trace element content distinctly departing from the pre-spill situation. Moreover, the parasite-host element accumulation ratios better depicted this temporal pattern. Additionally, changes in V concentrations in fish liver tissues and Ni concentrations in the parasite tissues suggest that this host-parasite system may be a useful tool to assess these two element contaminations linked to heavy fuel oil-spill.

Determining suitable fish to monitor plastic ingestion trends in the Mediterranean Sea.

The presence of marine litter is a complex, yet persistent, threat to the health and biodiversity of the marine environment, and plastic is the most abundant, and ubiquitous type of marine litter. To monitor the level of plastic waste in an area, and the prospect of it entering the food chain, bioindicator species are used extensively throughout Northern European Seas, however due to their distribution ranges many are not applicable to the Mediterranean Sea. Guidance published for the Marine Strategy Framework Directive suggests that the contents of fish stomachs may be analyzed to determine trends of marine plastic ingestion. In order to equate transnational trends in marine plastic ingestion, the use of standardized fish species that widely occur throughout the basin is favoured, however for the Mediterranean Sea, specific species are not listed. Here we propose a methodology to assess how effective Mediterranean fish species, that are known to have ingested marine plastic, are as bioindicators. A new Bioindicator Index (BI) was established by incorporating several parameters considered important for bioindicators. These parameters included species distribution throughout the Mediterranean basin, several life history traits, the commercial value of each species, and the occurrence of marine litter in their gut contents. By collecting existing data for Mediterranean fish, ranked scores were assigned to each trait and an average value (BI value) was calculated for each species. Based on their habitat preferences, Engraulis encrasicolus (pelagic), Boops boops (benthopelagic), three species of Myctophidae (Hygophum benoiti, Myctophum punctatum and Electrona risso) (mesopelagic), Mullus barbatus barbartus (demersal) and Chelidonichthys lucerna (benthic), were identified as currently, the most suitable fish for monitoring the ingestion of marine plastics throughout the Mediterranean basin. The use of standardized indicator species will ensure coherence in the reporting of marine litter ingestion trends throughout the Mediterranean Sea.

Species of Lepidapedon Stafford, 1904 (Digenea: Lepidapedidae) from deep-sea fishes in the Western Mediterranean: molecular and morphological evidence.

The species diversity of Lepidapedon Stafford, 1904 (Lepidapediae) in the Western Mediterranean was assessed based on samples from five deep-sea gadiform fishes collected between the Balearic Islands and the Catalonian coast of Spain: Lepidion lepidion (Risso) and Mora moro (Risso) (both Moridae); Coelorinchus mediterraneus Iwamoto & Ungaro and Trachyrincus scabrus (Rafinesque) (both Macrouridae); and Phycis blennoides (Brünnich) (Phycidae). Integration of morphological and molecular evidence (28S rRNA gene and the mitochondrial nad1 gene) revealed that the deep-sea fishes in the Western Mediterranean share two species of Lepidapedon. Lepidapedon desclersae Bray & Gibson, 1995 was recovered in all five fish species of three families [Moridae (L. lepidion and M. moro); Macrouridae (C. mediterraneus and T. scabrus); and Phycidae (P. blennoides)] and L. guevarai Lopez-Roman & Maillard, 1973 was recovered in three fish species of three families [Phycidae (P. blennoides); Macrouridae (T. scabrus); and Moridae (L. lepidion)]. Therefore, both species are considered to be euryxenic but restricted to gadiforms. The voucher material for the two species from different fish hosts is described in detail and the host-related variability based on the morphometric data is assessed.

Parasite communities of the white seabream Diplodus sargus sargus in the marine protected area of Medes Islands, north-west Mediterranean Sea.

Marine protected areas are considered a useful tool to preserve and recover the biodiversity of ecosystems. It is suggested that fisheries not only affect populations of target and bycatch species but also their parasite communities. Parasites can indicate fishery effects on host species and also on the whole local community, but the effects of fisheries and protection measures on parasite communities are relatively unknown. This study analyses parasite communities of the white seabream Diplodus sargus sargus in order to assess potential effects exerted by protection measures within and by fisheries outside a reserve in the western Mediterranean Sea. This small scale analysis offered the opportunity to study different degrees of fishery effects on parasite infracommunities, without considering climatic effects as an additional factor. Parasite infracommunities of fishes from the no-take zone (NTZ) differed in their composition and structure compared with areas completely or partially open to fisheries. The detected spatial differences in the infracommunities derived from generalist parasites and varied slightly between transmission strategies. Monoxenous parasites were richer and more diverse in both fished areas, but more abundant in the no-take, whereas richness and abundance of heteroxenous parasites were higher for the NTZ. In addition to host body size as one factor explaining these spatial variations, differences within parasite infracommunities between the areas may also be linked to increased host densities and habitat quality since the implementation of the NTZ and its protection measures.

The microbiota of eight species of dehydrated edible seaweeds from North West Spain.

The microbiota of eight species (Chondrus crispus, Himanthalia elongata, Laminaria ochroleuca, Palmaria palmata, Porphyra umbilicalis, Saccharina latissima, Ulva lactuca and Undaria pinnatifida) of edible seaweeds collected in North West Spain, marketed as dehydrated product, was quantitatively determined on nine solid media. Representative colonies were selected from solid culture media. The isolated microorganisms were identified by means of morphological characteristics, 16S rDNA sequencing and biochemical tests. U. pinnatifida was the seaweed species showing the most abundant microbial population, with counts on Marine agar up to 7.7 log cfu/g in individual samples and 5.0 log cfu/g as the mean value, and counts of coliforms up to 4.6 log cfu/g in individual samples and 2.4 log cfu/g as the mean value. The 225 identified bacterial isolates belonged to 11 families, 27 genera and 56 species. Bacillaceae was the family accounting for the highest number of isolates (111) followed by Enterobacteriaceae (60), Bacillales Family XII Incertae Sedis (20), Planococcaceae (11), Moraxellaceae (7), Paenibacillaceae (5) and Pseudomonadaceae (5). Bacterial species showing the highest occurrence in dehydrated seaweeds were Bacillus megaterium, B. licheniformis, Pantoea sp. and termoresistant Pantoea sp. Four of the Bacillus species isolated from dehydrated seaweeds (B. cereus, B. licheniformis, B. pumilus and B. subtilis) are among those containing strains considered to be foodborne pathogens and nine of the isolated non-Bacillales bacterial species have been reported to contain human opportunistic pathogenic strains.

New molecular and morphological data for opecoelid digeneans in two Mediterranean sparid fishes with descriptions of Macvicaria gibsoni n. sp. and M. crassigula (Linton, 1910) (sensu stricto).

Molecular and morphological data were gathered for specimens of species of Macvicaria Gibson & Bray, 1982 and Pseudopycnadena Saad-Fares & Maillard, 1986 (Digenea: Opecoelidae) collected from two sparid fishes, Diplodus vulgaris (Geoffroy Saint-Hilaire) and Sparus aurata L., off the Algerian coast of the Western Mediterranean. Phylogenetic analyses based on ITS1-5.8S-ITS2 and partial 28S rDNA sequences provided evidence for the distinct species status of eight Mediterranean species of Macvicaria. Novel molecular data are provided for four species, M. gibsoni n. sp. and M. crassigula (Linton, 1910) (sensu stricto) based on specimens from D. vulgaris, and M. mormyri (Stossich, 1885) and M. maamouriae Antar, Georgieva, Gargouri & Kostadinova, 2015 based on specimens from S. aurata; descriptions of the molecular voucher material of the former three species are provided. Two species were delineated within the "crassigula" species complex of Macvicaria, M. gibsoni n. sp. and M. crassigula (s. str.), the distinctive differentiating features being the distribution of the dorsal vitelline fields in the forebody, confluent in M. gibsoni n. sp. and non-confluent in M. crassigula (s. str.), and the molecular data for both markers. Sequences associated with morphological description are also provided for the type-species of Pseudopycnadena, P. fischthali Saad-Fares & Maillard, 1986, based on material from D. vulgaris.

A new species of Tinrovia Mamaev, 1987 (Monogenea: Microcotylidae) from the deep-sea fish Notacanthus bonaparte Risso (Notacanthiformes: Notacanthidae) in the Western Mediterranean and the North East Atlantic.

A new microcotylid, Tinrovia mamaevi n. sp. (Monogenea: Polyopisthocotylea), is described from the gills of Notacanthus bonaparte Risso (Notacanthiformes: Notacanthidae), sampled in the Western Mediterranean and North East Atlantic. This species is allocated to the subfamily Syncoelicotylinae Mamaev & Zubchenko, 1978 due to the possession of a symmetrical haptor with two separate frills. The clamps in T. mamaevi n. sp. are of the "microcotylid" type, arranged in two distinct lateral haptoral frills; the genital atrium and the copulatory organ are armed and the vaginal pore is unarmed. The new species differs from the type- and only species of the genus, T. papiliocauda Mamaev, 1987, in having a shorter and narrower haptor with a smaller number of clamps. Clamps are also smaller in the new species, testes are more numerous, the genital atrium is smaller, divided into two lateral lobes (instead of five) with a smaller number of spines and the eggs have a short and a long filament (instead of two short filaments). The host species and locality of T. mamaevi n. sp. also differ as T. papiliocauda which was recorded in Notacanthus sexspinis Richardson from the South Pacific.

Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses, exposure, and controversy.

Benzoic acid is an aromatic carboxylic acid naturally present in plant and animal tissues, which can also be produced by microorganisms. Benzoic acid and a wide range of derivatives and related benzenic compounds, such as salts, alkyl esters, parabens, benzyl alcohol, benzaldehyde, and benzoyl peroxide, are commonly used as antibacterial and antifungal preservatives and as flavoring agents in food, cosmetic, hygiene, and pharmaceutical products. As a result of their widespread occurrence, production, and uses, these compounds are largely distributed in the environment and found in water, soil, and air. Consequently, human exposure to them can be high, common, and lengthy. This review is mainly focused on the presence and use of benzoic acid in foods but it also covers the occurrence, uses, human exposure, metabolism, toxicology, analytical methods for detection, and legal limits for benzoic acid and its derivatives. Their controversial effects and potential public health concerns are discussed.

An optimised multi-host trematode life cycle: fishery discards enhance trophic parasite transmission to scavenging birds.

Overlapping distributions of hosts and parasites are critical for successful completion of multi-host parasite life cycles and even small environmental changes can impact on the parasite's presence in a host or habitat. The generalist Cardiocephaloides longicollis was used as a model for multi-host trematode life cycles in marine habitats. This parasite was studied to quantify parasite dispersion and transmission dynamics, effects of biological changes and anthropogenic impacts on life cycle completion. We compiled the largest host dataset to date, by analysing 3351 molluscs (24 species), 2108 fish (25 species) and 154 birds (17 species) and analysed the resultant data based on a number of statistical models. We uncovered extremely low host specificity at the second intermediate host level and a preference of the free-swimming larvae for predominantly demersal but also benthic fish. The accumulation of encysted larvae in the brain with increasing fish size demonstrates that parasite numbers level off in fish larger than 140mm, consistent with parasite-induced mortality at these levels. The highest infection rates were detected in host species and sizes representing the largest fraction of Mediterranean fishery discards (up to 67% of the total catch), which are frequently consumed by seabirds. Significantly higher parasite densities were found in areas with extensive fishing activity than in those with medium and low activity, and in fish from shallow lagoons than in fish from other coastal areas. For the first time, C. longicollis was also detected in farmed fish in netpens. Fishing generally drives declines in parasite abundance, however, our study suggests an enhanced transmission of generalist parasites such as C. longicollis, an effect that is further amplified by the parasite's efficient host-finding mechanisms and its alteration of fish host behaviour by larvae encysted in the brain. The anthropogenic impact on the distribution of trophically-transmitted, highly prevalent parasites likely results in a strong effect on food web structure, thus making C. longicollis an ideal bioindicator to compare food webs in natural communities versus those impacted by fisheries and aquaculture.

The Mediterranean: high discovery rates for a well-studied trematode fauna.

Our knowledge of trematode diversity in Mediterranean Sea fishes is based on many contributions since the early 1800s (e.g. by Rudolphi, Stossich, Looss, Bartoli, Bray and Gibson). We have updated data from the Natural History Museum Host-Parasite Database and listed 302 digenean trematode species allocated to 146 genera in 29 families from 192 fish species (27% of the known fish-fauna) belonging to 76 families. The most diverse (with 31-41 species) digenean families (Opecoelidae Ozaki, 1925, Didymozoidae Monticelli, 1888 and Hemiuridae Looss, 1899) represent more than a third of the total richness (36% of species) and have been most frequently recorded (43% of the records). The overall mean number of species per host is close to recent global estimates for digenean richness in teleosts (1.57 vs 2.04, respectively), indicating a high diversity in the Mediterranean. The most diverse host families are also the best studied. However, three speciose host families (Rajidae de Blainville, Gobiidae Cuvier and Myctophidae Gill) appear under-studied and no digenean reports exist for 94 of 169 fish families present in the Mediterranean. Thus, although Mediterranean fishes appear well studied, further efforts are needed. Nevertheless, the descriptions of a large number of new taxa since 2000 indicate that focused efforts have resulted in a high discovery rate (2.4 species per year). Many of these new (often cryptic) taxa are the result of combined morphological and molecular methods, which promise more reliable estimates of digenean diversity in this region. We provide host-parasite lists for 192 species of fish in the Mediterranean comprising 890 host-parasite associations.

Proteolysis and Flavor Characteristics of Serrano Ham Processed under Different Ripening Temperature Conditions.

UNLABELLED: Physicochemical, proteolysis and sensory characteristics of Serrano hams processed under low, medium and high ripening temperature conditions (RTC), with respective average temperatures of 9.3, 14.3, and 19.1 °C, were determined throughout a 15-mo period. In addition, quantitative relationships among variables were calculated. Medium and high RTC hams showed lower moisture contents and lower levels of low- and high-ionic-strength soluble proteins than low RTC hams. At 15 mo, aldolase was the most abundant low-ionic-strength soluble protein and actin the most abundant high-ionic-strength soluble protein in all hams while creatine kinase was no longer detected and H-meromyosin was detected only in low and medium RTC hams. Levels of all the molecular-weight peptide fractions increased during ripening, with higher factors of increase for the fractions of lower molecular weight. Total free amino acids were at significantly higher concentrations in medium and high RTC hams than in low RTC hams from month 7 onwards. The correlations of flavor preference and flavor intensity with ripening time, thermal integral, total free amino acids and most individual free amino acids were highly significant, while raw-meat taste was negatively correlated with all those variables. From month 5 to month 9 of ripening, development of a high quality flavor evolved more rapidly in medium RTC hams, flavor intensity increased at a faster rate in high RTC hams and raw-meat taste declined more rapidly in medium and high RTC hams. Medium and high RTC may be applied to accelerate the ripening process of Serrano ham without impairing flavor preference. PRACTICAL APPLICATION: Medium and high ripening temperature conditions (RTC) may be applied to Serrano ham in order to enhance the phenomena associated with ripening, without loss of product quality. Moisture loss, degradation of proteins and formation of free amino acids were accelerated in medium and high RTC hams. From month 5 to month 9 of ripening, development of a high quality flavor evolved more rapidly in medium RTC hams, flavor intensity increased at a faster rate in high RTC hams, and raw-meat taste declined more rapidly in medium and high RTC hams.

Morphological and molecular characterisation of Ditrachybothridium macrocephalum Rees, 1959 (Cestoda: Diphyllidea) from Galeus melastomus Rafinesque in the Western Mediterranean.

New morphological, molecular and ecological data for Ditrachybothridium macrocephalum Rees, 1959 (Cestoda: Diphyllidea) are presented and discussed based on specimens recovered from the blackmouth catshark Galeus melastomus Rafinesque (Scyliorhinidae) in the Western Mediterranean. A redescription of the plerocercus of this parasite is provided and new data on immature and mature worms including the first description of the eggs are reported, based on light and scanning electron microscopy observations. Analysis of 28S rDNA (domains D1-D3) sequences from plerocerci, immature and adult specimens revealed that they are conspecific with specimens from the North East Atlantic. Although previous authors considered that museum specimens identified as D. macrocephalum may represent more than one species, examination of type- and voucher material revealed no relevant morphological differences between museum specimens and the present material. Information on infection levels of D. macrocephalum is provided from a large number of host specimens (n = 170). This species was more abundant in juvenile than in adult hosts and on the middle slope than on the upper slope; this may be related to ontogenetic and bathymetric diet shifts of G. melastomus.