Traditional and geometric morphometrics detect morphological variation of lower pharyngeal jaw inCoris julis(Teleostei, Labridae)

In the present study, variation in the morphology of the lower pharyngeal element between two Sicilian populations of the rainbow wrasse Coris julis has been explored by the means of traditional morphometrics for size and geometric morphometrics for shape. Despite close geographical distance and probable high genetic flow between the populations, statistically significant differences have been found both for size and shape. In fact, one population shows a larger lower pharyngeal element that has a larger central tooth. Compared to the other population, this population also has medially enlarged lower pharyngeal jaws with a more pronounced convexity of the medial-posterior margin. The results are discussed in the light of a possible more pronounced durophagy of this population

Genomic properties of chromosomal bands are linked to evolutionary rearrangements and new centromere formation in primates

Chromosomal rearrangements in humans are largely related to pathological conditions, and phenotypic effects are also linked to alterations in the expression profile following nuclear relocation of genes between functionally different compartments, generally occupying the periphery or the inner part of the cell nuclei. On the other hand, during evolution chromosomal rearrangements may occur apparently without damaging phenotypic effects, and are visible in currently phylogenetically-related species. To increase our insight into chromosomal reorganisation in the cell nucleus, we analysed eighteen chromosomal regions endowed with different genomic properties in cell lines derived from eight primate species covering the entire evolutionary tree. We show that homologous loci, in spite of their evolutionary relocation along the chromosomes, generally remain localised to the same functional compartment of the cell nuclei. We conclude that evolutionarily succesfull chromosomal rearrangements are those that leave the nuclear position of the regions involved unchanged. On the contrary, in pathological situations, the effect typically observed is on gene structure alteration or gene nuclear reposition. Moreover, our data indicate that new centromere formation could potentially occur everywhere in the chromosomes, but only those emerging in very GC-poor/gene-poor regions, generally located in the nuclear periphery, have a high probability of being retained through evolution. This suggests that, in the cell nucleus of related species, evolutionary chromosomal reshufflings or new centromere formation does not alter the functionality of the regions involved or the interactions between different loci, thus preserving the expression pattern of orthologous genes

A multivariate morphometric investigation to delineate stock structure of gangetic whiting, Sillaginopsis panijus (Teleostei: Sillaginidae)

This study was conducted to delineate the stock structure of Sillaginopsis paniijus based on morphometric characters of the species. A total of 194 specimens were collected from the Meghna, Tentulia and Baleswar rivers located in the southern coastal zone of Bangladesh. Data were subjected to univariate ANOVA, multivariate ANOVA, discriminate function analysis (DFA), and principal component analysis. Mean variations of ten morphometric characters; HD, HBD, LBD, PsOL, ED, SnL, SPrDL, HAF, LSDB and LPB showed significant differences (p < 0.05) among 27 morphometric traits that were selected for the study. In DFA, the overall assignments of individuals into their correctly classified original groups were 71.1 and 70.6 % for male and female, respectively. A scatter plot of the first two discriminant functions was used to visually depict the discrimination among the populations. The results showed different stocks of S. panijus in the rivers of Baleswar, Tentulia and Meghna in southwest coast of Bangladesh

Atlantic-Mediterranean and within-Mediterranean molecular variation in Coris julis (L. 1758) (Teleostei, Labridae)

Sequence variation in the mitochondrial control region was studied in the Mediterranean rainbow wrasse (Coris julis), a species with pronounced pelagic larval phase inhabiting the Mediterranean Sea and the adjacent coastal eastern Atlantic Ocean. A total of 309 specimens from 19 sampling sites were analysed with the aim of elucidating patterns of molecular variation between the Atlantic and the Mediterranean as well as within the Mediterranean Sea. Phylogeographic analyses revealed a pronounced structuring into a Mediterranean and an Atlantic group. Samples from a site at the Moroccan Mediterranean coast in the Alboran Sea showed intermediate frequencies of “Mediterranean” and “Atlantic” haplotypes. We recognised a departure from molecular neutrality and a star-like genealogy for samples from the Mediterranean Sea, which we propose to have happened due to a recent demographic expansion. The results are discussed in the light of previous studies on molecular variation in fish species between the Atlantic and the Mediterranean and within the Mediterranean

Les macroinvertébrés benthiques de la rivière Simeto (Sicile) et de quelques-uns de ses affluents

Les résultats d'une étude du peuplement des macroinvertébrés benthiques dans le réseau hydrographique de la rivière Simeto sont exposés. La recherche a été menée sur 8 stations du cours principal et sur une station de chacun des affluents : T. Saracena, T. Cutò, R. Troina, R. Salso. Les échantillonnages ont été effectués mensuellement d'octobre 1988 à novembre 1989. L'analyse a mis en évidence la présence d'une richesse faunistique considérable (267 taxa) représentée surtout par les Hydracariens, Ephéméroptères, Odonates, Plécoptères, Coléoptères, Trichoptères et Diptères. Cette richesse est maximale dans la partie haute du bassin, tandis que dans la partie inférieure le nombre de taxons de chaque groupe diminue considérablement. Cet appauvrissement est attribué aux impacts directs ou indirects des différentes activités humaines

Comparative pattern of genetic structure in two Mediterranean killifishes Aphanius fasciatus and Aphanius iberus inferred from both mitochondrial and nuclear data

Received 20 March 2014, Accepted 8 March 2015© 2015 The Fisheries Society of the British Isles. In this study, genetic variation was assessed in Aphanius fasciatus and Aphanius iberus characterized by similar ecological traits but with very different distribution ranges in the Mediterranean area. Five populations of A. iberus and five of A. fasciatus were analysed using five polymorphic microsatellite loci and partial mitochondrial control region (D-loop) sequences. Congruent results were found with both nuclear and mitochondrial molecular markers. The results showed that similar levels of genetic divergence, based on mitochondrial control region sequences, are present among populations of A. iberus and among populations of A. fasciatus despite the very different geographic distance existing among the examined populations of the two species (low geographic distance in A. iberus and high in A. fasciatus). A possible explanation could be that the populations of A. iberus were isolated for a longer time than the populations of A. fasciatus supporting the hypothesis that the split in the lineage leading to A. iberus is older than the split in the lineage leading to A. fasciatus. The possibility that the wide circum-Mediterranean distribution of A. fasciatus ensures the high connectivity of its populations, preventing, in some cases, local differentiation, however, cannot be ruled out.This work was supported by a SYNTHESYS grant and an Ambassadorial Scholarship of the Rotary Foundation for A.M.P. research activities in the laboratory of Rafael Zardoya at the National Museum of Natural Science of Madrid.Peer Reviewe

Morphology of scale lepidonts in the genusAphanius(Teleostei, Cyprinodontidae) using SEM

The microstructure of the anterior region of the scales in several species of the genus Aphanius was studied by SEM with the aim of determining whether scale morphology could be used to discriminate between the species of this genus. The characters examined concern the morphology of lepidonts, or “scale‐teeth”, their distribution and mode of implantation on the circuli. These characters were also subjected to UPGMA cluster analysis. Results from phenetic analysis of scale‐teeth characters agree overall with those of previously published morphological and biogeographical studies and in part with molecular analysis of the phylogenetic relationships between species of Aphanius. An affinity between A. danfordii and A. mento (found previously in studies based on osteological observations) was seen. The separation of A. apodus from the other species of the fasciatus group, which had also been noticed from molecular observations, was also observed, as well as the affinity of A. ginaonis with the group of A. dispar+A. sirhani. This study demonstrates that scale morphology can provide useful information on the relationships among species of the genus Aphanius encouraging the use of scale characters, combined with other traits, in phylogenetic analyses