Anisakis pegreffii Larvae in Sea Eels (Astroconger myriaster) from the South Sea,Republic of Korea

Anisakis simplex sensu stricto (s.s.), Anisakis pegreffii, Anisakis berlandi (=A. simplex sp. C), and Anisakis typica are the 4 major species of Anisakis type I larvae. In the Republic of Korea (Korea), A. pegreffii, A. berlandi, and A. typica larvae in fish hosts has seldom been documented. In this study, molecular analysis was performed on Anisakis larvae from the sea eels (Astroconger myriaster), the major source of human anisakiasis in Korea, collected from Tongyeong City, a southern coastal area of Korea. All 20 sea eels examined were infected with Anisakis type I larvae (160 larvae; 8 per fish). Their species were analyzed using PCR-RFLP patterns and nucleotide sequences of internal transcribed spacers (ITS1, 5.8 subunit gene, and ITS2) and mitochondrial cytochrome c oxidase 2 (cox2). Most (86.8%; 112/129) of the Anisakis type I larvae were A. pegreffii, and 7.8% (10/129) were A. typica. The remaining 5.4% (7/129) was not identified. Thus, A. pegreffii is the major species of anisakid larvae in sea eels of the southern coast of Korea.     

A new species of Anisakis Dujardin, 1845 (Nematoda, Anisakidae) from beaked whales (Ziphiidae): allozyme and morphological evidence

Larvae and adults of Anisakis, recovered from the beaked whales Mesoplodon layardii and Ziphius cavirostris from the Mediterranean Sea and South African waters, were analysed morphologically and by molecular markers (allozymes). A new Anisakis species was identified, showing fixed allele differences at a number of loci from the other Anisakis spp. tested (A. simplex complex, A. physeteris). The lack of hybrid or recombinant genotypes in mixed infections with A. pegreffii, A. simplex C and A. physeteris, as well as the high values of genetic distance (average D_Nei = 1.65 from the members of the A. simplex complex, and D_Nei = 3.09 from A. physeteris) showed that the new species is reproductively isolated. This new Anisakis species is morphologically different from the other Anisakis retained by Davey (1971) as either good species or species inquirendae. The name Anisakis ziphidarum n. sp. is proposed for the new species.     

Molecular identification and infection levels of Anisakis species (Nematoda: Anisakidae) in the red scorpionfish Scorpaena scrofa (Scorpaenidae) from the Aegean Sea

The red scorpionfish Scorpaena scrofa (Scorpaenidae) is a high commercial value marine fish species along the Mediterranean coasts. Anisakiasis is a fish–borne parasitic zoonoses caused by Anisakis larvae in consumers. To date, there are only a few epidemiological studies on the presence and molecular identification of Anisakis larvae infecting S. scrofa. A total of 272 S. scrofa captured from the Gulf of Izmir in the Turkish Aegean coasts (FAO 37.3.1) were examined for Anisakis larvae between March 2019 and March 2020. The prevalence, mean intensity and mean abundance of Anisakis larvae were 9.6% (95% CI 6.5–13.7%), 2.8 (95% CI 1.88–5.19), and 0.27 (95% CI 0.15–0.56), respectively. All Anisakis larvae were collected from the viscera and body cavity of S. scrofa. Anisakis pegreffii, A. typica, and A. ziphidarum were genetically identified by RFLP analysis of the ITS region. These species were also confirmed by cox2 sequence analysis. A weak positive and statistically significant correlation between the total length (ρS 0.204; p = 0.001) and total weight (ρS 0.200; p = 0.001) of S. scrofa and the number of Anisakis larvae was observed. This survey presents the first molecular detection of A. typica and A. ziphidarum in S. scrofa. Thus, this fish species is a new host for A. typica and A. ziphidarum. This is also the first report of the presence of A. ziphidarum in the Aegean Sea.     

Morphological differences between larvae and in vitro-cultured adults of Anisakis simplex (sensu stricto) and Anisakis pegreffii (Nematoda: Anisakidae)

Proper identification of Anisakis species infecting host fishes is very important to both human health and fish disease diagnosis. The foremost problem in the identification of Anisakis larvae in fishes is that L3 larvae cannot be easily differentiated morphologically, especially between A. simplex (sensu stricto) (s.s.) (Rudolphi, 1809) and A. pegreffii Campana-Rouget et Biocca, 1955. Instead, molecular means such as allozyme, mitochondrial DNA (mtDNA) cox2 region and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses had been successfully used. In this study, morphological differences of L3 larvae collected from fishes and in vitro-cultured L4 larvae and adult A. simplex (s.s.) and A. pegreffii were evaluated. Anisakis larvae were collected from 7 different host fishes within Japan. Undamaged A. simplex (s.s.) and A. pegreffii collected from Oncorhynchus keta (Walbaum) and Scomber japonicus Houttuyn, respectively, were used for in vitro-culture in order to obtain L4 and adult stages. Species identification was confirmed by PCR-RFLP analysis of the ITS region (ITS1-5.8S-ITS2) of ribosomal DNA and by mtDNA cox2 gene sequencing. Results revealed that L3, L4 and adult stages of A. simplex (s.s.) and A. pegreffii are morphologically distinguishable based on ventriculus length, wherein the former has longer ventriculus (0.90–1.50 mm) than the latter (0.50–0.78 mm). For oesophagus/ventriculus ratio, these two species are distinguishable only during L4 and adult stages. Also, adult male A. simplex (s.s.) and A. pegreffii were found to be distinguishable by differences in the distribution pattern of the caudal papillae, particularly the 3rd pair of distal papillae.     

<Emphasis Type="Italic">Anisakis nascettii</Emphasis> n. sp. (Nematoda: Anisakidae) from beaked whales of the southern hemisphere: morphological description,genetic relationships between congeners and ecological data

A new anisakid nematode, Anisakis nascettii n. sp., is described from beaked whales Mesoplodon spp. off the coast of New Zealand and South Africa. Morphological and molecular (allozymes and mtDNA cox2 sequence) data were used for diagnostic and identification purposes. Among the 19 allozymes studied, 10 were found to be unique and characteristic for A. nascettii n. sp. Analysis of allozymes demonstrated reproductive isolation from A. ziphidarum Paggi, Nascetti, Webb, Mattiucci, Cianchi & Bullini, 1998 and mtDNA cox2 sequences depict this Anisakis species as a distinct and unique entity. Key morphological diagnostic traits for A. nascettii with respect to the genetically closely related species A. ziphidarum include: spicule length, the spicule/body length ratio, the arrangement of the caudal papillae and the shape of the plectanes of the adult males. Genetic data confirmed that Anisakis sp. A of Pontes et al. (2005), which was partly described by Iglesias et al. (2008), and Anisakis sp. of Valentini et al. (2006) are conspecific with A. nascettii. Both molecular and morphological data indicate that the new species belongs to the ‘ziphidarum-group’; however, it is genetically very distinct from A. ziphidarum (D _Nei  = 0.69, K2P = 0.09), as well as from all of the previously genetically characterised Anisakis spp. All tree topologies inferred by different methods (MP, NJ and Bayesian) support the finding that A. nascettii n. sp. and A. ziphidarum are sister-species. It is also confirmed that A. nascettii n. sp. is, at the adult stage, a parasite of beaked whales of the genus Mesoplodon, whereas, as a larva, it has been identified from the squid Moroteuthis ingens Smith. Furthermore, Mesoplodon bowdoini Andrews represents a new host record for A. ziphidarum. The parallelism between the clade formed by these two anisakine taxa, i.e. A. ziphidarum and A. nascettii, and that formed by their definitive hosts further supports the hypothesis of host–parasite co-evolutionary relationships, as previously suggested for Anisakis spp. and their cetacean hosts.     

Occurrence and Molecular Identification of Anisakis Dujardin, 1845 from Marine Fish in Southern Makassar Strait,Indonesia

Anisakis spp. (Nematoda: Anisakidae) parasitize a wide range of marine animals, mammals serving as the definitive host and different fish species as intermediate or paratenic hosts. In this study, 18 fish species were investigated for Anisakis infection. Katsuwonus pelamis, Euthynnus affinis, Caranx sp., and Auxis thazard were infected with high prevalence of Anisakis type I, while Cephalopholis cyanostigma and Rastrelliger kanagurta revealed low prevalence. The mean intensity of Anisakis larvae in K. pelamis and A. thazard was 49.7 and 5.6, respectively. A total of 73 Anisakis type I larvae collected from K. pelamis and A. thazard were all identified as Anisakis typica by PCR-RFLP analysis. Five specimens of Anisakis from K. pelamis and 15 specimens from A. thazard were sequenced using ITS1-5.8S-ITS2 region and 6 specimens from A. thazard and 4 specimens from K. pelamis were sequenced in mtDNA cox2 region. Alignments of the samples in the ITS region showed 2 patterns of nucleotides. The first pattern (genotype) of Anisakis from A. thazard had 100% similarity with adult A. typica from dolphins from USA, whereas the second genotype from A. thazard and K. pelamis had 4 base pairs different in ITS1 region with adult A. typica from USA. In the mtDNA cox2 regions, Anisakis type I specimens from A. thazard and K. pelamis showed similarity range from 94% to 99% with A. typica {"type":"entrez-nucleotide","attrs":{"text":"AB517571","term_id":"283379497","term_text":"AB517571"}}AB517571/{"type":"entrez-nucleotide","attrs":{"text":"DQ116427","term_id":"74229655","term_text":"DQ116427"}}DQ116427. The difference of 4 bp nucleotides in ITS1 regions and divergence into 2 subgroups in mtDNA cox2 indicating the existence of A. typica sibling species in the Makassar Strait.     

Molecular characterization of larval anisakid nematodes from marine fishes off the Moroccan and Mauritanian coasts

A total of 242 larval forms of Anisakis collected from marine fishes at different sites off the Moroccan and Mauritanian coasts, recognised as belonging to Type I and Type II larvae, were identified by PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphisms) of the ITS (Internal Transcribed Spacers) region (ITS-1, 5.8 subunit rRNA gene and ITS-2), using a previously established molecular key. The Type I larvae were found with a frequency of 98.34% and were identified as belonging to the following species: A. simplex s.str., A. pegreffii, A. simplex s.str/A. pegreffii heterozygote genotypes, A. typica, A. ziphidarum and Anisakis sp. A. The Type II larvae were found to belong to A. physeteris, with the frequency of 1.65%. The results reported in the present study provide further epizootiological and biological data on the Anisakis spp. in marine fishes off the Moroccan and Mauritanian coasts, improving the picture of the occurrence of these species in the central Atlantic coasts.     

Anisakis spp. in fishery products from Japanese waters: Updated insights on host prevalence and human infection risk factors

The nematodes of the genus Anisakis are among the most relevant parasitic hazards in fishery products since they are responsible for human infection and allergy cases. In a food safety and epidemiological perspective, several marine hosts from different locations around Japan were examined to characterize the parasitism of Anisakis larvae. Chum salmon (Oncorhynchus keta) and Alaska pollock (Gadus chalcogrammus) showed the highest overall prevalence (100%), followed by blue mackerel (Scomber australasicus) (97.5%), Pacific cod (Gadus macrocephalus) (80%), chub mackerel (Scomber japonicus) (60.1%), Japanese flying squid (Todarodes pacificus) (17%) and Japanese pilchard (Sardinops sagax melanostictus) (2%). In Pacific krill (Euphausia pacifica), apart from one Hysterothylacium aduncum larva, no Anisakis specimens were detected. Anisakis simplex sensu stricto was molecularly identified (PCR-RFLP) for the first time in Japanese flying squid and Japanese pilchard distributed in the Northwestern Pacific ocean. That was the most frequent parasitic species detected followed by A. pegreffii, mostly in the western areas of Japan, hybrid genotypes between the two sibling species as well as A. typica and A. berlandi. Surprisingly, A. simplex s.s. was the most abundant species in one batch of chub mackerel from the East China Sea and A. pegreffii was the main species found in one batch from the Pacific coast of Aomori, which seems to indicate that the ranges of these two sibling species might be more variable than previously thought.     

Anisakis spp. in toothed and baleen whales from Japanese waters with notes on their potential role as biological tags

In this study, Anisakis nematodes isolated from toothed and baleen whales from localities around Japan were molecularly (PCR-RFLP) identified. In Wakayama, common bottlenose dolphins (Tursiops truncatus) were infected with A. simplex sensu stricto (s.s.), A. typica and A. pegreffii, while A. typica was the only species found in pantropical spotted dolphin (Stenella attenuata) and striped dolphin (S. coeruleoalba). Offshore common minke whales (Balaenoptera acutorostrata) and sei whales (B. borealis) were almost exclusively infected with A. simplex s.s.. However, in common minke whales from two Hokkaido localities, mature worms mostly consisted of A. simplex s.s. in some individuals and of A. pegreffii in others, but immature worms were mainly A. simplex s.s.. Gross and histopathological examination on gastric mucosa attached by anisakids resulted in mild and superficial reactions by the two baleen whale species in contrast to severe inflammatory reaction associated with ulcer formations by common bottlenose dolphin. Host specificity and adaptability of Anisakis spp. in these baleen and toothed whales were discussed from the points of view of adult worm size, worm population and pathological reactions by hosts. Interestingly, most of the common minke whales predominantly harboring mature A. pegreffii adults belonged to the Yellow Sea – East China Sea stock (J stock), which migrates through the Sea of Japan, whereas most of those mainly parasitized by mature A. simplex s.s. adults were from the Okhotsk Sea – West Pacific stock (O stock), mostly inhabiting the Pacific side, suggesting that these sibling species may have utility as biological tags to differentiate whale stocks. These results represent the first definitive host records for A. pegreffi in the Northwestern Pacific Ocean.     

GEOLOGICALLY DATED SEA BARRIERS CALIBRATE A PROTEIN CLOCK FOR AEGEAN WATER FROGS

Reliable estimates of phylogenetic relationships and divergence times are a crucial requirement for many evolutionary studies, but are usually difficult because fossils are scarce and their interpretation is often uncertain. Frogs are fresh water animals that generally are unable to cross salt water barriers (their skin is readily permeable to both salt and water). The geologically determined ages of salt water barriers that isolate related frog populations thus provide an independent measure of the minimum date of genetic divergence between pairs of such populations. For the genetically well-studied western Palearctic water frogs (Rana esculenta group), the Aegean region provides an ideal area for determining the relationship between genetic divergence and time of spatial isolation, using a nested set of geologically determined isolation times (12,000 yr, 200,000 yr, 1.8 Myr, 2–3 Myr, and 5.2 Myr). Using 31 electrophoretic loci for 33 pairs of neighboring frog populations, a linear relationship between geologically determined isolation time and Hillis' modified Nei genetic distance was found: D^*_Nei = (0.04 ± 0.01) + (0.10 ± 0.01) isolation time [Myr] corresponding to an average divergence rate (“molecular clock” pace) of 0.10 D^*_Nei/Myr (0.10 D_Nei/Myr). This rate is in the range of previous estimates reported for protein electrophoretic data; the value is conservative because relatively few of the loci used are “fast evolvers” (13%; sAAT, ALB, EST-5, MPI). Removing these fast evolvers from the analysis results in 0.08 D^*_Nei/Myr (0.08 D_Nei/Myr). The confidence limits for estimation of the divergence time given the genetic distance are large, but unusually narrow for this kind of study; they permit us to estimate divergence times during the Pliocene and Miocene. Few previous studies, including sequence analyses, have provided reasonable estimates of divergence time for the Pliocene. A test using the outgroup taxa Rana perezi and Rana saharica (also isolated for 5.2 Myr by the Strait of Gibraltar) fits the calibration well: observed genetic Nei distance D^*_Nei = 0.55, expected D^*_Nei = 0.56. The calculated divergence times, based on this absolute molecular clock, suggest a series of speciation events after the Messinian (5.2 Myr), possibly triggered by the rapid ecological changes accompanying the desiccation and refilling of the Mediterranean Basin.     

Anisakis simplex and Anisakis physeteris: physicochemical properties of larval and adult hemoglobins

To resolve the taxonomic relationship between two types of parasitic nematode larvae (Type I and II) and two species of parasitic nematode adults (Anisakis simplex and A. physeteris) of the aquatic ascarid genus Anisakis, collected in Japanese coastal water, a comparison was made of their hemoglobins' physicochemical properties. The larval hemoglobins were more similar to each other in electrophoretic pattern than to either adult, indeed there were few similarities whatsoever in these patterns of larval and adult hemoglobins. However, isoelectric points were 6.2 for the Type I larva and for A. simplex and 5.4 for the Type II larva and for A. physeteris. All samples showed identical patterns in spectrophotometric scanning. The circular dichroic spectra of the samples were also virtually identical, although slight differences were noted in the oxygenated hemoglobins; the Type II larva and A. physeteris exhibited a small positive peak at 575 nm but the Type I larva and A. simplex exhibited a much smaller peak (negative position). The sedimentation coefficients of the samples possessed essentially identical values (11.2–12.4). The molecular weights of the samples were estimated, roughly, to be in the range 33 to 43 × 10⁴ by thin-layer chromatography on Sephadex G-200. The evidence suggests that a relationship may exist between the Type I larva and A. simplex, and between the Type II larva and A. physeteris.     

Effects of temperature on eggs and larvae of Anisakis simplex sensu stricto and Anisakis pegreffii (Nematoda: Anisakidae) and its possible role on their geographic distributions

Effects of temperature on development of eggs, recently hatched larvae and L3 larvae of the marine parasitic nematodes Anisakis simplex sensu stricto (s.s.) and A. pegreffii were examined in vitro. The eggs of A. simplex s.s. hatched at 3–25 °C and those of A. pegreffii hatched at 3–27 °C. Days before hatching varied between 2 days at 25 °C and 35–36 days at 3 °C in A. simplex s.s. and between 2 and 3 days at 27 °C and 65 days at 3 °C in A. pegreffii. Hatching rates of A. simplex s.s. were maintained high at temperatures between 3 and 25 °C but decreased to 0% at 27 °C. In contrast, those of A. pegreffii were lowest particularly at 3 °C, but also at 27 °C. The mean 50% survivals of hatched larvae ranged from 5.3 days at 25 °C to 82.3 days at 9 °C in A. simplex s.s., while in A. pegreffii it ranged from 1.2 days at 27 °C to 77.2 days at 9 °C. L3 larvae of A. pegreffii exhibited higher survival rates and activity than those of A. simplex s.s., particularly at 20 and 25 °C. These results suggest that the early stages of A. simplex s.s. are more adapted to lower temperatures whereas those of A. pegreffii are more tolerant to warm environments, which may correspond to their distribution patterns in Japan and Europe.     

Molecular Analysis of Anisakis Type I Larvae in Marine Fish from Three Different Sea Areas in Korea

Anisakiasis, a human infection of Anisakis L3 larvae, is one of the common foodborne parasitic diseases in Korea. Studies on the identification of anisakid larvae have been performed in the country, but most of them have been focused on morphological identification of the larvae. In this study, we analyzed the molecular characteristics of 174 Anisakis type I larvae collected from 10 species of fish caught in 3 different sea areas in Korea. PCR-RFLP and sequence analyses of rDNA ITS and mtDNA cox1 revealed that the larvae showed interesting distribution patterns depending on fish species and geographical locations. Anisakis pegreffii was predominant in fish from the Yellow Sea and the South Sea. Meanwhile, both A. pegreffii and A. simplex sensu stricto (A. simplex s.str.) larvae were identified in fish from the East Sea, depending on fish species infected. These results suggested that A. pegreffii was primarily distributed in a diverse species of fish in 3 sea areas around Korea, but A. simplex s.str. was dominantly identified in Oncorhynchus spp. in the East Sea.     

First record of the Brassy Chub Kyphosus vaigiensis (Quoy & Gaimard, 1825) in the Eastern Mediterranean (Osteichthyes: Perciformes: Kyphosidae)

The Brassy Chub, Kyphosus vaigiensis, first recorded in the Mediterranean in 1998, is reported herein from the coast of Israel. The identity of the specimen was confirmed by morphological and molecular analysis. This is the first record of K. vaigiensis from the Eastern Mediterranean. The possible origins of the Israeli record is discussed.     

Redescription of Bradya typica Boeck, 1873 (Copepoda: Harpacticoida: Ectinosomatidae) with the first description of the male

Bradya typica Boeck, 1873 is described from samples collected in the course of a colonisation experiment in Kongsfjorden, Spitsbergen (2003–2005). The male of B. typica, the type-species of the genus is described for the first time. B. typica can be distinguished from its congeners by its caudal rami (1.4 times longer than wide) and by its P5 (exopod longer than wide, inner terminal seta of exopod longest, inner seta of baseoendopod longer than outer one and surface seta rigid and curved). Variability within the species is rather small as only the length of some setae is slightly different. B. cladiofera Lang, 1965, B. congenera Sars, 1920, B. minutiseta Soyer, 1973 and B. pugiochaeta Arlt, 1983 are closely related to B. typica. Some details of the morphology, such as the body ornamentation and the longer hair-like pinnules on the spines of the swimming legs, are very difficult to observe even with maximum magnification. With certainty, B. typica is distributed near the Norwegian coast (Oslo Fjord to Trondheim Fjord), the Swedish coast (Skagerak to Öresund), around Spitsbergen and around the polar islands north of Grinnelland (Canadian Arctic Archipelago near Baffin Bay). Records of B. typica from the Kara Sea (near Novaya Zemlya), near Franz Joseph Land, Iceland, Greenland, the British Isles and from deep waters of the North Sea have to be confirmed.     

<Emphasis Type="Italic">Corynosoma australe</Emphasis> Johnston, 1937 and <Emphasis Type="Italic">C. cetaceum</Emphasis> Johnston &; Best, 1942 (Acanthocephala: Polymorphidae) from marine mammals and fishes in Argentinian waters: allozyme markers and taxonomic status

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

Phylogeny, evolution and biogeography of the Quadrifoliovariinae Yamaguti, 1965 (Digenea: Lecithasteridae)

The Quadrifoliovariinae is revised and three new species of Quadrifoliovarium Yamaguit, 1965 from acanthurid fishes of the genus Naso from waters of the Indo-Pacific are described: Q, maceria n. sp. from N.␣tonganus, N. annulatus, N. fageni and N. brevirostris; Q. simplex n. sp. from N. tonganus and N.␣annulatus; and Q. quattuordecim n. sp. from N. tonganus. Amendments are made to the characterisation of the Quadrifoliovariinae, Quadrifoliovarium, Bilacinia Manter, 1969 and Unilacinia Manter, 1969 in light of observations on type and new material. A molecular phylogeny based on ITS2 and 28S regions of the ribosomal DNA is proposed. The phylogeny suggests that U. asymmetrica is the most basal taxon and Q.␣simplex n. sp. and Q. quattuordecim n. sp. the most derived. Evolution of morphological traits within the Quadrifoliovariinae are discussed in light of the molecular phylogeny. Molecular sequences of the ITS2 rDNA were identical between specimens of Q. pritchardae collected off Exmouth (Indian Ocean), Heron Island and Lizard Island (Western Pacific) and Moorea (far Eastern Indo-Pacific), indicating a broad Indo-Pacific distribution. All members of the subfamily are recorded only from the acanthurid genus Naso, with the exception of B. lobatum (Yamaguti, 1970), which has been recorded from a pomacanthid. The restricted host range of the group is discussed in the light of the phylogeny of the host genus Naso.     

Morphometric variations among larval Anisakis simplex (Nematoda: Ascaridoidea) from fishes of the North Atlantic and their use as biological indicators of host stocks

Synopsis Analysis of variance on mean dimensions of samples of larval Anisakis simplex from Atlantic salmon (Salmo salar) and Atlantic herring (Clupea harengus harengus) indicated that highly significant morphometric differences existed. Subsequent analyses were simplified by using only the total body length of the larvae which was easily measured. Also the multiple range tests indicated that length showed the highest degree of heterogeneity. No difference (P > 0.2) was detected in the lengths of larvae from male and female salmon and most analyses suggested there was no change in length of the larvae with an increase in age of the host. There was, however, significant heterogeneity in the length of larvae in salmon which had spent more than one winter at sea and this heterogeneity was related in some way to the geographic localities in which the samples were taken. Possible reasons for these differences and the use of morphometric variants of Anisakis as a biological indicator are discussed.     

Consequences of Mediterranean warming events in seagrass (Posidonia oceanica) flowering records

Posidonia oceanica, a seagrass endemic to the Mediterranean forms extended and extremely persistent meadows. It is a clonal plant with an apparently irregular pattern of flowering events. An extensive bibliographic review allowed the reconstruction of past flowering events of this species around the Mediterranean, with a high degree of confidence for the last 30 years. The data series on annual flowering prevalence (FP, flowering records per total records) and flowering intensity (FI, fraction of flowering shoots) produced have been compared with four series on Sea Surface annual Temperature maxima (SST_max) obtained for the NW Mediterranean (averaged from the local data series of l'Estartit and Villefranche: 1957–2005) and for the Eastern, Western basin and the whole Mediterranean sea (extracted from NCEP Reynolds interpolated SST maps: 1982–2005). Significant warming trends are detected in the Mediterranean SST_max series, at a rate of (mean+SE) 0.04±0.01°C yr⁻¹ (R²=0.24, P<0.01, N=24 years), in the Eastern basin series (0.06±0.01°C yr⁻¹, R²=0.43, P<0.001, N=24 years) and in the long SST_max series of the NW Mediterranean (0.02±0.01 C yr⁻¹, R²=0.12, P<0.02, N=49 years). The magnitudes of the SST_max anomalies around the absolute warming trend do not increase with time in any SST_max series. Peaks of FP and FI in the Mediterranean seem to occur each 9–11 years, and coincide with peaks of annual SST_max. Annual FP and FI increase with the residuals of annual SST_max warming trend in all Mediterranean basins (FP_MED: R²=0.27, P<0.01, N=23; FP_NW: R²=0.34, P<0.01, N=31; FP_E: R²=0.20; P<0.10, N=23). An outstanding event of P. oceanica flowering across the Mediterranean has been registered in Autumn 2003; 1 month after the highest annual SST_max recorded in the series. The hypothesis of flowering induction by thermal stress as the possible cause of this relationship is discussed, as well as the potential use of P. oceanica flowering record as early indicator of biological change induced by global sea warming in Mediterranean marine ecosystems.     

In vitro and in vivo activity of three sesquiterpenes against L(3) larvae of Anisakis type I

In order to investigate the possible use of terpenic derivatives to treat anisakiasis caused by L₃ larvae of Anisakis, we studied the in vitro and in vivo larvicidal activity of three sesquiterpenes (nerolidol, farnesol and elemol). In vitro experiments included the histological study of larval damage and in vivo studies the measurement of myeloperoxidase activity in rat gastrointestinal tract after administration of the sesquiterpenes. In the in vitro assays, the most active compound against the L₃ larvae was nerolidol, followed by farnesol; both caused the death of all nematodes, which showed cuticle changes and intestinal wall rupture. In the in vivo assays, only 20% of infected rats treated with nerolidol or farnesol showed gastric wall lesions in comparison to 86.6% of control animals. According to these results, nerolidol and farnesol are good candidates for further research as biocidal agents against L₃ larvae of Anisakis type I.