European checkerspots (Melitaeini: Lepidoptera,Nymphalidae) are not aposematic – the point of view of great tits (Parus major)

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ONTOGENETIC NICHE SHIFT IN THE BRACHIOPOD TEREBRATALIA TRANSVERSA: RELATIONSHIP BETWEEN THE LOSS OF ROTATION ABILITY AND ALLOMETRIC GROWTH

Abstract: Many articulated brachiopods experience marked life habit variations during ontogeny because they experience their fluid environment at successively higher Reynolds numbers, and they can change the configuration of their inhalant and exhalant flows as body size increases. We show that the extant brachiopod Terebratalia transversa undergoes a substantial ontogenetic change in reorientation governed by rotation around the pedicle. T. transversa′s reorientation angle (maximum ability to rotate on the pedicle) decreases during ontogeny, from 180 degrees in juveniles to 10–20 degrees in individuals exceeding 5 mm, to complete cessation of rotation in individuals larger than 10 mm. Rotation ability is substantially reduced after T. transversa achieves the adult lophophore configuration and preferred orientation with respect to ambient water currents at a length of 2.5–5 mm. We hypothesize that the rotation angle of T. transversa is determined mainly by the position of ventral and dorsal points of attachment of dorsal pedicle muscles relative to the pedicle. T. transversa shows a close correlation between the ontogenetic change in reorientation angle and ontogeny of morphological traits that are related to points of attachment of dorsal pedicle muscles, although other morphological features can also limit rotation in the adult stage. The major morphological change in cardinalia shape and the observed reduction of rotation affect individuals 2.5–10 mm in length. The position of ventral insertions of dorsal pedicle muscles remains constant, but contraction of dorsal pedicle muscles is functionally handicapped because dorsal insertions shift away from the valve midline, rise above the dorsal valve floor, and become limited by a wide cardinal process early in ontogeny (<5 mm). The rate of increase of cardinal process width and of distance between dorsal pedicle muscle scars substantially decreases in the subadult stage (5–10 mm), and most of the cardinalia shell traits grow nearly isometrically in the adult stage (>10 mm). T. transversa attains smaller shell length in crevices than on exposed substrates. The proportion of small‐sized individuals and population density is lower on exposed substrates than in crevices, indicating higher juvenile mortality on substrates prone to grazing and physical disturbance. The loss of reorientation ability can be a consequence of morphological changes that strengthen substrate attachment and maximize protection against biotic or physical disturbance (1) by minimizing torques around the pedicle axis and/or (2) by shifting energy investments into attachment strength at the expense of the cost involved in reorientation.     

Phylogenetic relationships of silver crucian carp Carassius auratus gibelio, C. auratus cuvieri, crucian carp C. carassius, and common carp Cyprinus carpio as inferred from mitochondrial DNA variation

PCR-RFLP analysis of the ND3/ND4L/ND4 and 12S/16S rRNA regions and nucleotide sequence variation of the cytochrome b gene were used to study the mtDNA divergence in species of the family Cyprinidae, to examine the phylogenetic relationships of the species, and to identify their taxonomic status. The results indicated that an ancestral form diverged into silver crucian carp and crucian carp after its separation from the common carp lineage. The divergence of continental Carassius auratus gibelio and Japanese C. auratus cuvieri occurred more recently. Two well distinguishable mtDNA phylogroups, suggesting divergent evolution, were observed in continental C. auratus gibelio populations. The divergence was possibly related to the formation of two silver crucian carp groups with different types of reproduction, triploid gynogenetic and diploid gonochoric. At the same time, the results supported the high probability of current genetic exchange between the forms. In view of these findings and high morphological similarity of the two forms, they were not considered to be separate species.     

Diversity and ecology of algae from the Nahal Qishon river,northern Israel

In 59 samples of periphyton and phytoplankton collected in 2002 - 2003 from the Nahal Qishon (Qishon River), northern Israel, we found 178 species from seven divisions of algae and cyanoprocaryotes. Diatoms, clorophytes, and cyanoprocaryotes prevail. Nitzschia and Navicula (Bacillariophyta) are the most abundant. Most of the species are cosmopolitan or widespread, except Lagynion janei (Chrysophyta), which is endemic for the Mediterranean Realm. About 17% of species (26) are new for Israel and five of them represent the first recorded genera: Crinalium endophyticum Crow, Actinocyclus normanii (Gregory) Hustedt, Rhizoclonium hieroglyphicum (Agardh) Kütz (Chlorophyta), Lagynion janei Bourelly, and Stylococcus aureus Chodat. Most of them come from a rare riverine assemblage with red alga Audouinella pygmea, as well as from the estuarine assemblage. Alkaliphiles predominate among the indicators of acidity, with few acidophiles confined to the communities under the impact of industrial wastes. Among the indicators of salinity, most numerous are the oligohalobien-indifferents and species adapted to a moderate salinity level. The relative species richness of ecological groups and the indices of saprobity are correlated with changes in conductivity, pH, and N-nitrate concentration. Indicators of organic pollution fall in the range of betameso- to alfamesosaprobic self-purification grades. Our studies show ecological significance of the Nahal Qishon as a model for a strongly disturbed aquatic ecosystem in the coastal zone of eastern Mediterranean.     

Changes in fatty acids contents and growth characteristics in transformed oilseed rape (Brassica napus)

Spring oilseed rapeBrassica napus L. ssp.oleifera cv. HM-81 was transformed with T_L-DNA of the Ri plasmid of the agropine strainAgrobacterium rhizogenes 15834. Selfed progenies (R₂ and R₃ generations) were studied for changes in values of growth characteristics and fatty acids contents. Transformants are ‘homozygous’ for T_L-DNA. Both generations of transformants differed significantly from the nontransformed control plants in reduced length, lower number of pods per plant, lower total mass of seeds and the higher number of branches. The contents of palmitic, linoleic and linolenic acids were significantly higher in transformants when compared with the control. On the contrary, the contents of both stearic and oleic acids were in most of transformants significantly lower. Only traces of erucic acid (less than 0.05 % ) were found, both in transformed and nontransformed plants.     

Concentrations and ecological risks of metals in surface sediments of some coastal creeks in the Niger Delta,Nigeria

The concentrations of nine metals were measured by atomic absorption spectrophotometry in surface sediments of three coastal creeks, namely, the Ifie, Egbokodo and Ubeji creeks, in the Niger Delta of Nigeria, from August 2012 to January 2013. The aim of the study was to provide information on the spatial and seasonal distribution patterns, degree of contamination, and ecological risks of metals in these sediments. The mean concentrations of the nine metals in these creek sediments ranged from 0.30 to 3.20?mg kg^?1 Cd; 10.7 to 24.7?mg kg^?1 Pb, 125 to 466?mg kg^?1 Cr; 3.1.10 to 14.9?mg kg^?1 Cu; 4.7 to 14.3?mg kg^?1 Co; 61.1 to 115?mg kg^?1 Ni; 106 to 183?mg kg^?1 Mn; 52.0 to 170?mg kg^?1 Zn and 5 469 to 20 639?mg kg^?1 Fe. In general, the metal concentrations were higher in the dry season than the wet season, except for Cr. The concentrations of Cd, Cr, Ni and Zn were above their regulatory control limits in sediment as specified by the Nigerian Regulatory Authority and Cd was identified as the main ecological risk factor. The enrichment factors for the studied metals followed the order: Cd > Cr > Ni > Zn > Pb > Co > Mn > Cu. The average multiple pollution index values indicated that these sediments were severely polluted with significant inputs from Cd, Ni and Cr.     

Collation of data on the ploidy levels and mitochondrial DNA phylogenetic lineages in the silver crucian carp Carassius auratus gibelio from Far Eastern and Central Asian populations

The distribution of the diploid and triploid forms and the correspondence between ploidy and mitochondrial DNA (mtDNA) phylogenetic lineages of the silver crucian carp have been studied in Far Eastern water bodies and the Syr Darya River. Both diploid and triploid forms have been found in large river systems (the Amur, Suifun, Tumangan, and Syr Darya river basins). Only the diploid form has been detected in lakes of Bol'shoi Pelis Island (Peter the Great Bay of the Sea of Japan), Sakhalin Island, and the Kamchatka River basin (the Kamchatka Peninsula). It has been confirmed that there are two mtDNA phylogroups in the silver crucian carp in the area studied. Both mtDNA phylogenetic lineages are present in the Suifun and Tumangan river basins. Only one mtDNA phylogroup (characteristic of the gynogenetic form) has been detected in two samples from the Amur River and in the Syr Darya population. The other mtDNA phylogroup is predominant in insular populations and in Kamchatka. The gynogenetic form carries only mtDNA phylogroup I, whereas both phylogroups have been found in diploid bisexual fish. The existence of only two mtDNA phylogroups substantially differing from each other indicates that the gynogenetic form has emerged from the diploid form only once and evolved independently for a long time after that. The absence of haplotypes transitional between the two mtDNA phylogroups suggests that the secondary contact between the gynogenetic and bisexual forms in continental populations occurred within recent historical time. The obtained data confirm that genetic (though asymmetric) exchange between the two forms is possible, which explains the high morphological and, probably, genetic similarity between them.