NICHE PARTITIONING AND THE COEXISTENCE OF TWO CRYPTIC DICTYOTA (DICTYOTALES,PHAEOPHYCEAE) SPECIES FROM THE CANARY ISLANDS1

Coexistence in a homogeneous environment requires species to specialize in distinct niches. Sympatry of cryptic species is of special interest to both ecologists and evolutionary biologists because the mechanisms that facilitate their persistent coexistence are obscure. In this study, we report on two sympatric Dictyota species, D. dichotoma (Huds.) J. V. Lamour. and the newly described species D. cymatophila sp. nov., from the Canary Islands. Gene sequence data (rbcL, psbA, nad1, cox1, cox3, and LSU rDNA) demonstrate that D. dichotoma and D. cymatophila do not represent sister species. Rather, D. cymatophila and D. dichotoma have converged on a nearly identical morphology, only to be distinguished with detailed morphometric observations. Both species co‐occur in eulittoral pools and the shallow subtidal in Tenerife. Even though D. cymatophila was more dominant in wave‐exposed places and D. dichotoma in less exposed areas, the spatial distribution of both species overlapped in intermediate habitats. The species display radically different phenologies. D. dichotoma reached its highest density in winter and early spring and disappeared nearly completely in autumn, while D. cymatophila dominated the study site from July until November. The timing of gamete release also differs between both species, D. dichotoma releasing gametes twice every lunar cycle, while the release of gametes in D. cymatophila occurred roughly every other day.     

Occurrence and chemical diversity of the genus Bryoria in the Sučí Potok Valley, Veporské Vrchy Mountains (Central Slovakia)

Four species of the genus, Bryoria were found in the Sučí Potok Valley: B. capilaris (Ach.) Brodo & D. Hawksw., B. fuscescens (Gyeln.) Brodo & D. Hawksw., B. implexa (Hoffm.) Brodo & D. Hawksw., B. nadvornikiana (Gyeln.) Brodo & D. Hawksw. The most common species in the valley was B. implexa. Four chemotypes of this lichen were recognized.     

TOXICITY OF SUBTROPICAL MARINE ALGAE USING FISH MORTALITY AND RED BLOOD CELL HEMOLYSIS FOR BIOASSAYS1

Two bioassays (fish mortality and fish erythrocyte hemolysis) were used to survey for the presence of toxic principles in aqueous extracts of 19 species of marine macro-algae found in south Florida coastal waters. Extracts from six species (Chlorophyta—Anadyomene stellata (Wulfen) C. Ag., Caulerpa prolifera (Forsskål) Lamour., Penicillus capitatus Lamarck: Rhodophyta—Centroceras clavulatum (C. Ag.) Montague, Laurencia papillosa (Forsskål) Grev., L. poitel (Lamour.) Howe) showed lethal toxicity to the spotfin mojarra, Euconistomus argenteus Baird & Girard. Extracts from three species (Chlorophyta—A. stellata: Phaeophyta—Dictyota dichotoma (Hudson) Lamour.: Rhodophyta—Wrangelia penicillata C. Ag.) lysed erythrocytes of sea bream, Archosargus rhomboidalis (L.).     

FATTY ACIDS,AMINO ACIDS,MINERAL CONTENTS,AND PROXIMATE COMPOSITION OF SOME BROWN SEAWEEDS1

This study was conducted to create a nutritional database on brown seaweeds and to popularize their consumption and utilization in Iran. The fatty acid contents, amino acids profiles, and certain mineral elements composition of some brown seaweeds, Padina pavonica (L.) Thivy, Dictyota dichotoma (Huds.) J. V. Lamour., and Colpomenia sinuosa (Mert. ex Roth) Derbés et Solier were determined. Total lipid content ranged from 1.46 ± 0.38 to 2.94 ± 0.94 g · 100 g^?1dry weight (dwt), and the most abundant fatty acids were C16:0, C18:1, C20:4 ω6, and C20:5 ω3. The unsaturated fatty acids predominated in all species and had balanced sources of ω3 and ω6 acids. Highest total polyunsaturated fatty acid (PUFA) levels occurred in C. sinuosa. The protein content of D. dichotoma was 17.73 ± 0.29 g · 100 g^?1dwt, significantly higher than the other seaweeds examined. Among amino acids essential to human nutrition, methionine (Met; in D. dichotoma and P. pavonica) and lysine (Lys; in C. sinuosa) were present in high concentrations. The crude fiber content varied by 9.5 ± 11.6 g · 100 g^?1dwt in all species. Chemical analysis indicated that ash content was between 27.02 ± 0.6 and 39.28 ± 0.7 g · 100 g^?1dwt, and that these seaweeds contained higher amounts of both macrominerals (7,308–9,160 mg · 100 g^?1dwt; Na, K, Ca) and trace elements (263–1,594 mg · 100 g^?1dwt; Fe, Ni, Mn, Cu, Co) than have been reported for edible land plants. C. sinuosa had the highest amount of Ca, Fe, and a considerable content of Na was measured in P. pavonica.     

ANTIFEEDING DEFENSE IN BALTIC MACROALGAE: INDUCTION BY DIRECT GRAZING VERSUS WATERBORNE CUES1

The prevalence of antigrazing defense induction and the cues triggering induction in marine macroalgae are generally not well understood. We examined the capacity of defense and the mechanisms of regulation in five common perennial macroalgal species from the Baltic Sea, Furcellaria lumbricalis (Huds.) J. V. Lamour., Delesseria sanguinea (Huds.) J. V. Lamour., Phyllophora pseudoceranoides (S. G. Gmel.) Newroth et A. R. A. Taylor, Fucus serratus L., and Fucus evanescens C. Agardh. Specifically, we investigated whether direct feeding and/or waterborne cues from feeding on neighboring conspecifics decreased the palatability of the tested algae. Direct feeding by the local isopod Idotea baltica triggered the induction of chemical defense in Fur. lumbricalis, D. sanguinea, P. pseudoceranoides, F. serratus, and F. evanescens. Conversely, we did not find any evidence for waterborne cues associated with feeding to trigger defense induction in neighboring conspecifics.     

RESTRICTION ENDONUCLEASE ANALYSIS OF RIBOSOMAL DNA SEQUENCE VARIATION IN LAMINARIA (PHAEOPHYTA)1

The taxonomy and evolutionary relationships of species in the genus Laminaria are poorly understood. Previous studies have demonstrated significant plasticity of morphological characters used to describe taxa, and interfertility has been reported among putative species. We analyzed nuclear ribosomal DNA (rDNA) sequence variation in eight species of Laminaria (L. agardhii Kjell., L. digitata (Huds.) Lamour., L. groenlandica Rosenv. [sensu Druehl 1968], L. longicruris De la Pyl., L. longipes Bory, L. saccharina (L.) Lamour., L. setchellii Silva, and L. yezoensis Miyabe) to elucidate evolutionary relationships in this genus. Restriction maps were constructed using a small subunit rDNA probe from Costaria costata (Turn.) Saunders, an rDNA repeat from the nematode Caenorhabditis elegans, and 11 hexameric restriction endonucleases in an annealing analysis of genomic DNA. Laminaria rDNA restriction maps were compared to each other and to that of the outgroup taxon, C. costata. rDNA restriction maps of Laminaria species and C. costata were similar. Restriction fragment length polymorphisms mapped to both the coding regions and the nontranscribed spacer of rDNA. Laminaria species were distinguished with this method. The restriction maps of L. agardhii, L. saccharina, and L. longicruris were identical, supporting a previous hypothesis that these species are conspecific. Comparison of restriction maps of Laminaria species suggested that the generic subdivision of Sections Simplices and Digitatae may be invalid.     

Divergent strategies in pre‐ and postzygotic reproductive isolation between two closely related Dianthus species

Quantifying the relative contribution of multiple isolation barriers to gene flow between recently diverged species is essential for understanding speciation processes. In parapatric populations, local adaptation is thought to be a major contributor to the evolution of reproductive isolation. However, extrinsic postzygotic barriers assessed in reciprocal transplant experiments are often neglected in empirical assessments of multiple isolation barriers. We analyzed multiple isolation barriers between two closely related species of the plant genus Dianthus, a genus characterized by the most rapid species diversification in plants reported so far. Although D. carthusianorum L. and D. sylvestris Wulf. can easily be hybridized in crossing experiments, natural hybrids are rare. We found that in parapatry, pollinator‐mediated prezygotic reproductive isolation barriers are important for both D. carthusianorum (0.761) and D. sylvestris (0.468). In contrast to D. carthusianorum, high hybrid viability in D. sylvestris (–0.491) was counteracted by strong extrinsic postzygotic isolation (0.900). Our study highlights the importance of including reciprocal transplant experiments for documenting extrinsic postzygotic isolation and demonstrates clearly divergent strategies and hence asymmetric pre‐ and postzygotic reproductive isolation between closely related species. It also suggests that pollinator‐mediated and ecological isolation could have interacted in synergistic ways, further stimulating rapid speciation in Dianthus.     

Rhizoid production in excised Dictyota dichotoma

Excised segments of fronds of Dictyota dichotoma (Huds.) Lamour. show a marked basipetal increase in rhizoid production when grown in culture. Rhizoid production is inhibited by bright light and apparently enhanced by red light (λ 600–690 mμ).     

Interspecific hybridization between diploid species of Lotus (Leguminosae)

An interspecific hybridization study has been carried out between seven diploid species of Lotus (L. alpinus Schleich., L. japonicus (Regel) Larsen, L. filicaulis Dur., L. schoelleri Schweinf., L. krylovii Schischk. and Serg., L. tenuis Waldst. et Kit., and L. corniculatus var. minor Baker) closely related to L. corniculatus L. A total of 139 interspecific hybrids were produced in 16 combinations of the 7 species. Nine of these crosses were produced for the first time and four were obtained by means of embryo-culture. The growth habit, number of florets per umbel, flower color expression, HCN reaction and 15 metrical traits were compared between parents and hybrids. The relative case with which some hybrids were produced suggested that during the early evolutionary history of the genus species diversification could have originated through interspecific hybridization and subsequent gene differentiation. In some crosses, the hybrids resembled one parent more closely than the other. This close morphological affinity between the hybrids and one of their parents would make it extremely difficult to detect such hybrids in natural populations and probably aceounts for the prevailing belief that there is little or no hybridization in nature.     

HYBRIDIZATION AND INTROGRESSION IN THE GRASS GENUS ELYMUS

Brown , W. V., and G. A. Pratt . (U. Texas, Austin.) Hybridization and introgression in the grass genus Elymus. Amer. Jour. Bot. 47 (8) : 669–676. Illus. 1960.—The production of artificial F₁ hybrids that produce some seed between E. virginicus and E. canadensis, E. virginicus and E. interruptus, and E. canadensis and E. interruptus proves that similar plants found in nature are true hybrids. The artificial hybrids constituted the basis of comparison in an analysis of natural local populations in the Austin region. Analysis by scatter diagrams indicates that there is introgression of genes of some species into the genomes of others through the development of hybrid swarms. In the area studied the great variability of virginicus is due to the introgression of canadensis and, possibly, interruptus genes. Such hybridization and subsequent introgression have occurred many times and in many places and are still taking place. It is likely that the named varieties of canadensis and virginicus may be introgressant types that are the results of hybridizations between those species and others that occur sympatrically in Eastern United States.     

BIODIVERSITY OF CORALLINE ALGAE IN THE NORTHEASTERN ATLANTIC INCLUDING CORALLINA CAESPITOSA SP. NOV. (CORALLINOIDEAE,RHODOPHYTA)1

The Corallinoideae (Corallinaceae) is represented in the northeastern Atlantic by Corallina officinalis L.; Corallina elongata J. Ellis et Sol.; Haliptilon squamatum (L.) H. W. Johans., L. M. Irvine et A. M. Webster; and Jania rubens (L.) J. V. Lamour. The delimitation of these geniculate coralline red algae is based primarily on morphological characters. Molecular analysis based on cox1 and 18S rRNA gene phylogenies supported the division of the Corallinoideae into the tribes Janieae and Corallineae. Within the Janieae, a sequence difference of 46–48 bp (8.6%–8.9%) between specimens of H. squamatum and J. rubens in the cox1 phylogeny leads us to conclude that they are congeneric. J. rubens var. rubens and J. rubens var. corniculata (L.) Yendo clustered together in both phylogenies, suggesting that for those genes, there was no genetic basis for the morphological variation. Within the Corallineae, it appears that in some regions, the name C. elongata has been misapplied. C. officinalis samples formed two clusters that differed by 45–54 bp (8.4%–10.0%), indicating species‐level divergence, and morphological differences were sufficient to define two species. One of these clusters was consistent with the morphology of the type specimen of C. officinalis (LINN 1293.9). The other species cluster is therefore described here as Corallina caespitosa sp. nov. This study has demonstrated that there is a clear need for a revision of the genus Corallina to determine the extent of “pseudocryptic” diversity in this group of red algae.     

广东丽虫兆属一新种（弹尾纲：爪虫兆科）

记述广东弹尾纲 1 新种广东丽虫兆Callyntrura (Javaphysa) guangdon gensis sp. nov.,该新种与C. (J.) javana Yosii,1992 在上唇和下唇上比较相似,但是它们在体色、齿节刚毛、头部 V0 大毛、胸部第2节毛序有较大的区别。     

The butterfly Danaus chrysippus (L.) in East Africa comprises polyphyletic, sympatric lineages that are, despite behavioural isolation, driven to hybridization by female-biased sex ratios

Mitochondrial and nuclear DNA information was analysed among four subspecies of the African Queen butterfly, Danaus (Anosia) chrysippus sensu lato (s.l.), along with four other Danaus species drawn from all three subgenera (D. (Danaus) plexippus, D. (Salatura) genutia, D. (A.) gilippus, D. (A.) eresimus) and two outgroup species from the same tribe, Tirumala septentrionis and Amauris niavius. A mitochondrial phylogeny derived from the 12S rRNA (347 bp) and COI (537 bp) loci indicates two very distinct haplotypes for subspecies D. (A.) c. dorippus, dorippus‐1 and dorippus‐2. Interestingly, dorippus‐1, on the one hand, and all other D. (A.) chrysippus haplotypes, on the other, are the most distantly related clades within the genus and have different most recent ancestors from different subgenera, though sharing the common ancestor of the monophyletic genus. A phylogeny based on the EF1‐α nuclear locus (400 bp) shows that the two well‐separated mitochondrial lineages of dorippus are identical for this gene and reciprocally monophyletic to the other D. (A.) chrysippus lineages. Thus, nuclear and cytoplasmic phylogenies are not only discordant, but also suggest that both D. (A.) chrysippus s.l. and subspecies dorippus are polyphyletic. Paradoxically, four African subspecies, chrysippus‐orange, chrysippus‐brown, alcippus and dorippus, though substantially vicariant, hybridize extensively in East Africa wherever the ranges of two or more of them overlap. Linkage disequilibrium, and hence sexual isolation, in sympatry between colour (nuclear) genes and unlinked mitochondrial (cytoplasmic) loci is consistent across populations and therefore indicates the operation of positive natural selection. Together with data from previous experimental and field work, our results suggest that extensive hybridization occurs among once allopatric or parapatric lineages, that are now nascent species. We deduce that hybridism among lineages in sympatry is currently enforced, in the face of assortative mate choice, by a bacterial symbiont, Spiroplasma, a male‐killer that forces females in female‐biased populations to pair with heterotypic males. In discussion we emphasize that neither D. (A.) chrysippus s.l. as presently circumscribed, nor its component clades, conform to any established concept of species. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 86 , 117–131.     

Deltocyathiidae,an early‐diverging family of Robust corals (Anthozoa,Scleractinia)

Kitahara, M.V., Cairns, S.D., Stolarski, J. & Miller, D.J. (2012). Deltocyathiidae, an early‐diverging family of Robust corals (Anthozoa, Scleractinia). —Zoologica Scripta, 00, 000–000. Over the last decade, molecular phylogenetics has called into question some fundamental aspects of coral systematics. Within the Scleractinia, most families composed exclusively by zooxanthellate species are polyphyletic on the basis of molecular data, and the second most speciose coral family, the Caryophylliidae (most members of which are azooxanthellate), is an unnatural grouping. As part of the process of resolving taxonomic affinities of ‘caryophylliids’, here a new ‘Robust’ scleractinian family (Deltocyathiidae fam. n.) is proposed on the basis of combined molecular (CO1 and 28S rDNA) and morphological data, accommodating the early‐diverging clade of traditional caryophylliids (represented today by the genus Deltocyathus). Whereas this family captures the full morphological diversity of the genus Deltocyathus, one species, Deltocyathus magnificus, is an outlier in terms of molecular data, and groups with the ‘Complex” coral family Turbinoliidae. Ultrastructural data, however, place D. magnificus within Deltocyathiidae fam. nov. Unfortunately, limited ultrastructural data are as yet available for turbinoliids, but D. magnificus may represent the first documented case of morphological convergence at the microstructural level among scleractinian corals. Marcelo V. Kitahara, Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, S.P. 11600‐000, Brazil. E‐mail: kitahara@usp.br     

Active, Irreversible Accumulation of Extreme Levels of H(2)SO(4) in the Brown Alga, Desmarestia

The brown algae Desmarestia ligulata var. ligulata (Lightf.) Lamour., and D. viridis (Mull.) Lamour., accumulate H₂SO₄ until their average internal pH is 0.5 to 0.8. A related species, D. aculeata (L.) Lamour., does not accumulate acid. The H₂SO₄ accumulation is accompanied by a reduction in the K⁺ and Cl⁻ content, presumedly to maintain osmotic balance. Measurements of the membrane potential and H⁺ and SO₄²⁻ concentrations indicate that both ions are accumulated in the vacuole against their electrochemical potential gradients.

The internal pH remains constant in all three species over the growing season, despite striking changes in the algal morphology. The pH is not affected by periods of darkness of up to 34 hours. Sulfate accumulated in the vacuoles appears to be trapped there since incubation of D. ligulata for up to 10 days in sulfate-free medium resulted in little loss of either vacuolar sulfate or H⁺. Although the uptake of H₂SO₄ into the vacuole must require energy, the maintenance of the vacuolar H₂SO₄ may be due to the impermeability of the tonoplast, with little necessity for continued expenditure of energy.

     

Phylogeny of woodcreepers of the genus Lepidocolaptes (Aves,Furnariidae), a widespread Neotropical taxon

Arbeláez‐Cortés, E., Navarro‐Sigüenza, A. G. & García‐Moreno J. (2012). Phylogeny of woodcreepers of the genus Lepidocolaptes (Aves, Furnariidae), a widespread Neotropical taxon. —Zoologica Scripta, 41, 363–373. Phylogeny of woodcreepers of the genus Lepidocolaptes (Aves, Furnariidae), a widespread Neotropical taxon. The phylogeny of the genus Lepidocolaptes was reconstructed based on three mitochondrial DNA regions and one nuclear DNA intron, using Bayesian analysis. A general pattern of diversification among the lowland species followed by the diversification of highland species, and a close relationship among montane species with the two Atlantic Forest endemics, seem to depict the history of this genus. Results also showed that the two Mesoamerican species are sister‐taxa with high support. Finally, our data also suggest the existence of previously unknown intraspecific genetic structure within some taxa, especially among populations of Lepidocolaptes souleyetii.     

Hybridisation and lack of prezygotic barriers between Phymata pennsylvanica and americana

1. The persistence of both geographical and reproductive boundaries between related species poses a fundamental puzzle in biology. Reproductive interactions between species can have a substantial impact on the maintenance of a boundary, potentially contributing to its collapse (e.g. via hybridisation) or facilitating reproductive isolation (e.g. via reinforcement). 2. The degree to which two parapatric insect species in the genus Phymata are reproductively isolated was evaluated and several mechanisms that could contribute to the maintenance of species boundaries were assessed. 3. Behavioural assays showed no indication of species‐assortative mating, nor any fecundity costs associated with heterospecific mating. Thus, there was no evidence of prezygotic mechanisms of reproductive isolation between the two species. 4.In laboratory crosses, it was found that the two species were indeed capable of producing viable F1 hybrids. Morphologically, these hybrids were phenotypically intermediate to the two parental species, and similar to the phenotypes seen in natural populations thought to occur in a hybrid zone. F1 hybrids did not show reduced viability, although there was some suggestion of ‘hybrid breakdown’, evident from the lower viability observed for progeny of ‘natural hybrids’. 5. Collectively, we show that despite genetically based morphological differences between species, P. americana and pennsylvanica can, and probably do hybridise. More studies are needed to understand the mechanisms that maintain the distinct phenotypes and geographical ranges of these species, despite the considerable potential for introgression.     

Karyological notes on another eight species of Achillea (Asteraceae) from Turkey

The chromosome number and morphology in eight species of the sections Ptarmica (Mill.) W. D. J. Koch, Anthemoideae (DC.) Heimerl, Arthrolepis Boiss., Santolinoideae (DC.) Heimerl and Achillea of the genus Achillea L. (Asteraceae) were investigated using karyological techniques. Sample plants and seeds of A. biserrata M. Bieb., A. fraasii var. troiana Aschers. & Heimerl, A. multifida (DC.) Boiss., A. brachyphylla Boiss. & Hausskn., A. pseudaleppica Hub.-Mor., A. cretica L., A. latiloba Ledeb. ex Nordm., and A. kotschyi Boiss. subsp. kotschyi) were collected from natural habitats in 2003 and 2004. The chromosome number found in seven species was 2n = 18, while only A. kotschyi had 2n = 36. All chromosomes had median point (M), median region (m), and submedian (sm) centromers. In addition, only A. biserrata species had one subterminal (st) chromosome. An increase in asymmetry was not observed in the karyotypes of the species studied. None of the studied species had any B chromosomes.     

Six new species of the genus Dicranosepsis Duda (Diptera, Sepsidae) from Vietnam, with a revised key to the species

The flies of the genus Dicranosepsis from Vietnam were investigated and classified taxonomically. Six new species (D. longa sp. nov., D. kurahashii sp. nov., D. monoseta sp. nov., D. sinuosa sp. nov., D. barbata sp. nov., and D. vietnamensis sp. nov.) are described and illustrated. Dicranosepsis is redefined and a revised key to the species is also provided.     

CYTOGENETICS OF AGROPYRON FERGANENSE AND ITS HYBRIDS WITH SIX SPECIES OF AGROPYRON,ELYMUS, AND SITANION

Meiosis and mode of reproduction are described in Agropyron ferganense Drob., a perennial forage grass from Central Asia. This species is diploid (2n = 14); it exhibits normal meiosis and reproduces by cross-pollination. Hybrids were produced between A. ferganense and six species with known genome formulas: 1) North American A. spicatum (Pursh) Scribn. & Smith, an SS diploid (2n = 14), 2) Middle Eastern A. libanoticum Hack., an SS diploid (2n = 14), 3) North American A. dasystachyum (Hook.) Scribn., an SSHH tetraploid (2n = 28), 4) Eurasian A. caninum (L.) Beauv., an SSHH tetraploid (2n = 28), 5) North American Sitation hystrix (Nutt.) J. G. Smith, an SSHH tetraploid (2n = 28), and 6) South American Elymus patagonicus Speg., an SSHHHH hexaploid (2n = 42). Almost complete chromosome pairing in the A. ferganense x A. spicatum and A. libanoticum hybrids demonstrated that A. fergenanse is an SS diploid, but it is genetically isolated from the other SS diploids because of high sterility in the F₁ hybrids. S-genome diploids form a network of species that extend from the Middle East through Central Asia to western North America. Frequent occurrence of seven univalents and seven bivalents at metaphase I in the triploid hybrids of A. ferganense x A. dasystachyum, A. caninum and S. hystrix was consistent with the proposed genome formulas of SS for A. ferganense, SSHH for the three tetraploid species, and SSH for the hybrids. Chromosome pairing was highly variable in the A. ferganense x E. patagonicus hybrids; however, some cells had almost complete bivalent pairing, an expected observation in an SSHH hybrid from a cross between an SS diploid (A. ferganense) and an SSHHHH hexaploid (E. patagonicus). Various options were considered concerning the appropriate generic classification of the S-genome diploids, which are now commonly placed in Agropyron. The inclusion of these species in the genus Eiytrigia, as advocated by some Soviet taxonomists, appears to be a reasonable decision.