Digeneans of fishes from the Adriatic Sea with a description of Lecithaster atherinae n. sp. from Atherina (Hepsetia) boyeri

A collection of whole mount preparations of digeneans was studied. The parasites were collected from several species of fishes caught in a fishing area of the South Adriatic Sea. A host-parasite list is given. Twenty species of fish were analysed and twenty-seven species of digeneans were found, twenty of which had previously been described in the same host, and six of which were observed in new hosts and/or localities. One digenean, hitherto undescribed, is illustrated in this paper and described as Lecithaster atherinae n.sp. The new species can be distinguished from L. bombayensis by the testes not being lobed; from L. extralobus by having four rather than five ovarian lobes; from L. indicus and L. maeoticus by the ovarian lobes not being finger-like; from L. leiostomi by having definitely smaller eggs.     

Age and Growth of Atherina Atherina boyeri (Atherinidae) from Southwestern Crimea (Black Sea)

Journal of Ichthyology - The size and age structure and growth of Atherina boyeri from southwestern Crimea were studied. The ratio of males and females was 1.00 : 1.38, the proportion of males...     

Phylogenetic relationships of Atherina hepsetus and Atherina boyeri (Pisces: Atherinidae) populations from Greece, based on mtDNA sequences

The genetic divergence and the phylogenetic relationships of six Atherina boyeri (freshwater and marine origin) and five Atherina hepsetus populations from Greece were investigated using partial sequence analysis of 12s rRNA, 16s rRNA and control region mtDNA segments. Three different well divergent groups were revealed; the first one includes A. boyeri populations living in the sea, the second includes A. boyeri populations living in the lakes and lagoons whereas the third one includes all A. hepsetus populations. Fifty-seven different haplotypes were detected among the populations studied. In all three mtDNA segments examined, sequence analysis revealed the existence of fixed haplotypic differences discriminating A. boyeri populations inhabiting the lagoon and the lakes from both the coastal A. boyeri and the A. hepsetus populations. The genetic divergence values estimated between coastal (marine) A. boyeri populations and those living in the lagoon and the lakes are of the same order of magnitude as those observed among coastal A. boyeri and A. hepsetus populations. The results obtained by different phylogenetic methods were identical. The deep sequence divergence with the fixed different haplotypes observed suggests the occurrence of a cryptic or sibling species within A. boyeri complex.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 151–161.     

Enzymatic survey of four populations of Atherina boyeri based on electrophoresis and the occurrence of a microsporidiosis

Biochemical genetics of a Atherinid species, Atherina boyeri were undertaken to determine variability. Among the 17 loci studied, 7 were polymorphic, of which three were retained for a more detailed comparison of populations inhabiting the French Mediterranean coastal lagoons. A microsporidiosis is present in these fishes and is limited to certain lagoons. Comparison of allelic frequencies at the polymorphic loci between fish populations of infected and healthy lagoons yielded no significant differences. Several hypotheses are discussed and attempt to agree parasite distribution with genetical results.     

The biology of Boyer's sand smelt, Atherina boyeri Risso in the Bardawil Lagoon on the Mediterranean coast of Sinai

The present study describes some aspects of the life history of Boyer's sand smelt Atherina boyeri in the hypersaline Bardawil Lagoon on the Mediterranean coast of the Sinai peninsula, Egypt. Monthly samples were collected with a small-mesh experimental beach-seine during the years 1973–1974. Age determinations were based on otoliths readings and length frequency distributions which indicate that the Bardawil Lagoon population consists mostly of 0-age group. The largest recorded fish was 63 mm in standard length (S.L.). Length-weight relationship has been calculated as: W = 13.7 × 10⁻⁶× L ^2.93 where W = weight (g) and L =S.L. (mm). Atherina boyeri mature at the length of 34 mm. Spawning takes place from March to September. The average number of eggs in the ovary of a ripe female at the beginning of the spawning season was found to be 522. Females of all sizes were more numerous than males. In immature fish, less than 34 mm long, females constituted 53% of the population. In larger fish the number of females was higher; in fish over 34 mm long females constituted 64% and in fish over 51 mm—96%. Atherina boyeri in the Bardawil Lagoon feeds on both zoobenthos and zooplankton, mainly amphipods and copepods. Polychaetes, mysidaceans, insects and fish were also represented. Atherina boyeri is the host of endoparasitic Trematoda, Acanthocephala and Nematoda. The examined fish were found to have metacercaria in their mesenteries and liver.     

Age,growth and reproduction of the sand smelt Atherina boyeri Risso, 1810 in Mellah Lagoon (Eastern Algeria)

This aim of this paper was the study of the reproductive biology and growth of the sand smelt, Atherina boyeri, in Mellah Lagoon (Algeria). These data are important for the sustainable exploitation of the stocks of this species. Examined was a total of 1402 Atherina boyeri specimens captured monthly from March 2010 to March 2011, in a population with a 3‐year life cycle. Length–weight relationship was estimated as W = 0.0047 L^3.077 (r² = 0.935) for males and W = 0.0047 L^3.176 (r² = 0.935) for females. Using scales, the von Bertalanffy growth function fitted to back‐calculated size‐at‐age data was Lt = 9.49 [1 ? e^{?0.316 (t + 0.928)}] for males, and Lt = 11.67 [1 ? e^{?0.179 (t + 1.514)}] for females; using otoliths this was Lt = 9.68 [1 ? e^{?0.3 (t + 1.02)}] for males, and Lt = 11.93 [1 ? e^{?0.171 (t + 1.55)}] for females. The growth performance index (Φ) indicated that males (Φ_scales = 3.34, Φ_otoliths = 3.33) grew at the same rate as females (Φ_scales = 3.19, Φ_otoliths = 3.24), with a sex ratio of 1 : 1.6 in favor of females. The reproductive season extended from February to June. Individual length at first sexual maturity was 4.20 cm for 1‐year‐old males and 4.35 cm for 1‐year‐old females.     

A catalogue of the nominal species of the monogenean family Dactylogyridae Bychowsky, 1933 (excluding Dactylogyrus Diesing, 1850)

A list of the nominal species of the Dactylogyridae Bychowsky, 1933 (with the exception of Dactylogyrus Diesing, 1850) is presented. It consists of almost 100 specific names in 10 genera, with their hosts (to the generic level) and geographical region. A reference list to the authorities for the taxa is included.     

Phenotypic and genetic diversity of coexisting Listonella anguillarum, Vibrio harveyi and Vibrio chagassi recovered from skin haemorrhages of diseased sand smelt, Atherina boyeri, in the Gulf of Trieste (NE Adriatic Sea)

Aims: This study identified and characterized coexisting Vibrios associated with haemorrhagic skin lesion bearing sand smelt fishes (Atherina boyeri) in north‐eastern Adriatic Sea. Methods and Results: Bacteria were isolated from external skin lesions of four samples, and representative morphotypes grown on thiosulfate–citrate–bile salt–sucrose agar were isolated. In total 25 isolates, presumptively assigned to Vibrio genus, were biochemically characterized and were grouped in 10 phenotypic profiles. Phenotypes were heterogeneously distributed among the diseased sand smelt analysed; only one phenotype was recovered from all the samples. Sequencing of 16S rRNA was performed to identify representatives of all phenotypes. Phylogenetic analysis using the neighbour‐joining method revealed six isolates clustered within the Vibrio harveyi group, three clustered with known Vibrio chagasii strains and three clustered with Listonella anguillarum. Conclusions: Vibrios with a broad phenotypic variability were found in the external lesions of diseased A. boyeri. In total three species of Vibrio were identified: V. harveyi showed the wider phenotypical and ribotypical heterogeneity while L. anguillarum shared similar biochemical characteristics with typical strains. Significance and Impact of the study: Previously unreported coexistence of potential pathogenic species colonizing diseased A. boyeri has ecological as well as epidemiological significance.     

Phyllobothrium squali Yamaguti, 1952 (Tetraphyllidea,Phyllobothriidae): redescription and first record in the Black Sea

Phyllobothrium squali Yamaguti, 1952 is redescribed and illustrated on the basis of the holotype from Squalus acanthias from Japanese waters and specimens from the same host off the Bulgarian Black Sea coast (new geographical record). The species is characterised by: a scolex diameter of 2.9-4.3 mm, a glandular apical organ, foliose bothridia with folded and posteriorly bifid margins, accessory suckers of 286-367 micro m in diameter, 222-373 testes per proglottis, an oval cirrus-sac with a length of 354-655 micro m, the vagina opening anteriorly to the cirrus-sac, and the terminal part of vagina with a circular musculature. Specimens from Etmopterus spinax off Naples, Mediterranean Sea, recorded by Euzet (1959) as Crossobothrium squali, are redescribed and their identification not confirmed. P. squali is recognised as a specific parasite of S. acanthias; it is presently known only from Japanese waters, the Black Sea and the Irish Sea. Changes to the generic diagnosis of Phyllobothrium, as given by Ruhnke (1996a), are proposed in order to include the characters of P. squali.     

The description of Gyrodactylus mulli sp. n. (Monogenea: Gyrodactylidae) from the Black Sea blunt-snouted mullet Mullus barbatus ponticus

A new species Gyrodactylus mulli sp. n. is described from the thorax fins of blunt-snouted mullet Mullus barbatus ponticus by the collections of B. E. Bychowsky made in 1947 near Karadag on the Black Sea. Gyrodactylus mulli sp. n. differs from G. alviga Dmitrieva et Gerasev, 2000 (described from blunt-snouted mullet too) in having another morphotype of the marginal hooks. The new species differs from G. proterorhini Ergens, 1967, which has the identical type of the marginal hooks, in having longer membrane of the ventral connective bar, longer point of the anchors, shorter marginal hooks, and lesser size of the cirrus.     

A multivariate morphometric investigation of Atherina boyeri Risso, 1810 and A. presbyter Cuvier, 1829 (Teleostei: Atherinidae): morphometric evidence in support of the two species

Two recently developed morphometric methodologies, multiple group principal components analysis (MGPCA) and the box truss method of body form transformation are used to re-address whether Atherina boyeri Risso, 1810 and A. presbyter Cuvier, 1829 are morphometrically distinct. The results revealed that morphometric differences are present between A. boyeri and A. presbyter , consistent with expectations of the existence of two species.
Females of the two species were clearly discriminated into two separate groups because the within-group covariances of several characters within populations of each species were different between species i.e., the covariances were heteroscedastic. The occurrence of heteroscedasticity within the data, although statistically invalidating the results of canonical variates anslysis, indicated there to be a large amount of morphological variation between females of the two species. Males were differentiated as a result of differences in body 'shape', particularly the relationship between head 'shape' and body 'shape'.
Several probable reasons are given for the failure of a previous study to differentiate the two species. The data rejects the synonymy of the two species in support of the continued use of the taxa A. boyeri Risso, 1810 and A. presbyter Cuvier, 1829.     

Atherina punctata and Atherina lagunae (Pisces,Atherinidae), new species in the Mediterranean Sea. 1. Biometric investigations of three Atherinid species

Discriminative canonical analysis of 87 biometric parameters in the marine and lagoon atherinids of 'Atherina boyeri' complex from the Mediterranean Sea helps defining three distinct atherinid groups: marine punctuated, marine unpunctuated and lagoon atherinids. Each atherinid group constitutes a clearly independent original entity. Besides, each one is a more or less heterogeneous group with geographical disparities, characterising specimen collected from France and Tunisia. Concordance of biometric, biochemical and genetic results as well help define two new species of atherinids: Atherina punctata = punctuated marine atherinids, and Atherina lagunae = atherinids living in lagoon environments.     

An electrophoretic investigation of populations of Atherina boyeri Risso, 1810 and A. presbyter Cuvier, 1829 (Teleostei: Atherinidae): genetic evidence in support of the two species

The data obtained using electrophoresis strongly support the specific status of Atherina boyeri Risso, 1810 and A. presbyfer Cuvier, 1829, and thuscontradict the recently proposedsynonymyof the two species. Four populations of A. boyeri and six populations of A. presbyter were assayed for 11 enzymes and general protein using muscle and liver extracts. Eight of the 11 enzymes were shown to be polymorphic at the 95% level. Sixteen loci, encoding 40 putative alleles were consistently resolved in all 10 populations.
The two species were fixed for different alleles at the EST-3 locus. At the G3PDH locus. with the exception of two heterozygotes, all individuals of each species were also homozygous for different alleles. At the PGM locus the common allele was unique to each species.
The mean Nei's genetic distance ( ), over all loci, calculated between populations of A. boyeri (= 0.10 ± 0.06); between populations of A. presbyter ( = 0.02 0.02) and between populations of A. boyeri and A. presbyter ( = 0.42 0.09) indicated the separateness of the two species.
UPGMA cluster analysis based on genetic distances produced a dendrogram whose principal dichotomy resulted in the formation of two clusters. The ordination of populations in the UPGMA cluster analysis strongly reflected the geographic distribution of populations in both species.     

Age and growth of the sand smelt, Atherina boyeri (Risso 1810), in the Mar Menor coastal lagoon (SE Iberian Peninsula)

The age and growth of sand smelt, Atherina boyeri (Risso 1810), in the Mar Menor (SE Iberian Peninsula) were studied in samples taken from catches of local fishermen obtained between November 1997 and September 1998. The maximum lengths were 94 mm (FL, fork length) in females and 87 mm (FL) in males. Age determination based on scale readings and validated by length frequency analysis shows that the population has a 3‐year life cycle. Females were significantly longer than males in each of the age classes. Both sexes of the sand smelt grow allometrically (b = 3.113 males; b = 3.043 females) and attain approximately 56.2% of their maximum fork length in their immature first year, after which the annual growth rate drops quickly. The highest growth rate was observed from winter to spring (G_L = 16.01 males 1+; G_L = 11.25 males 2+; G_L = 17.18 females 1+; G_L = 9.62 females 2+). The condition cycles were similar for both sexes, with a minimum in June–July and two maximums in April and November.     

Host-parasite relationships: occurrence and effect of the parasitic isopod Mothocya epimerica on sand smelt Atherina boyeri in the Mesolongi and Etolikon Lagoons (W. Greece)

The parasite-host relationship between Mothocya epimerica, Costa 1851 (Isopoda: Flabellifera: Cymothoidae) and sand smelt Atherina boyeri (Osteichthyes: Atherinidae) fish populations were studied in the Mesolongi and Etolikon Lagoons (W. Greece). Prevalence varied during the year from 12.5% in November to 52.5% in September; overall mean prevalence was 41.9%. Parasite size increased with host size. Infections did not have a significant effect on the host's body condition, such as length-weight relationship, gonadosomatic index, hepatosomatic index and relative condition factor. Histological damage to the host was observed on the gills (especially in the second and third and arches upon which the female parasite rests her abdomen). The physiological cost resulting from this infection seems to be little and probably does not constitute a serious threat for individual host survival.     

Reproduction of Mothocya epimerica (Crustacea: Isopoda: Cymothoidae), parasitic on the sand smelt Atherina boyeri (Osteichthyes: Atherinidae) in Greek lagoons

The reproduction and growth pattern of Mothocya epimerica (Crustacea: Isopoda: Cymothoidae), a protandrous hermaphroditic gill parasite of Atherina boyeri (Osteichthyes: Atherinidae), were investigated in the Mesolongi and Etolikon lagoons. The parasite shows an extensive reproductive period. Gravid females were found between April and November, and juveniles between May and December. M. epimerica grew allometrically (slopes of the total weight-total length regressions were >3). Females were significantly heavier than males. The relationship between number of eggs or mancas larvae (F) and total length (TL) was investigated in gravid female parasites in which the marsupium was still closed; the relationship was clearly curvilinear: F = 0.128TL3.18. The number of eggs or mancas larvae held in the marsupia of females increased proportionally with female length, varying from 39 in an isopod of 6.3 mm length to 158 in one of 8.5 mm length. The average number of eggs or mancas larvae was 76.70 +/- 27.8.     

A review of the genus Eodiaptomus Kiefer, 1932, with the description of E. sanuamuangae n.sp. from Thailand, and a redescription of E. lumholtzi (Sars, 1889) from Australia (Copepoda, Calanoida)

The genus Eodiaptomus Kiefer contains six species, five of which are distributed in Asia, and one in Australia and New Guinea. A seventh species, E. sanuamuangae n.sp., is now added from Thailand. It has hitherto been misidentified as E. sinensis (Burckhardt), but can be recognized by various morphologic criteria. In the female, both spines on either wing of the fifth pediger are laterally placed. The third endopodite-segment of P2–P4 has seven, instead of six, setae. The sensory seta on the basis of P5 is extraordinarily long. On the male right antennule, the spine on segment 8 is much reduced, whereas that on segment 15 is relatively strong; the spinous process on the antepenultimate segment is slender, straight, with a hooked tip and as long as the next segment. Morphologically and geographically, E. sanuamuangae n.sp. links the Asian to the Australian forms. The Australian E. lumholtzi (Sars) is redescribed. A detailed morphological comparison is made of all Eodiaptomus spp. Their taxonomic characters, interspecies relationship, and biogeography are discussed.