Some osteological differences between the blennioid fishes Limnichthys polyactis and L. rendahli,with comments on other species of Creediidae

Abstract

The two endemic species of New Zealand Limnichthys differ in several osteological characters. L. polyactis differs from L. rendahli in having a rayed dorsal margin of the opercle (cf. entire), little or no gap between the lower limb of the coracoid and the pelvis (cf. wide gap), one epural (cf. two), and narrow posterior neural and haemal spines (cf. wide spines). Comments are given on some characters in the other 10 recognised named species of Creediidae. Squamicreedia obtusa is removed from the Creediidae, and is provisionally placed in the Percophididae.     

New species of bark beetles from the Rovno amber (Insecta: Coleoptera: Scolytidae)

Two new species of bark beetles are described from the Late Eocene Rovno amber. Xylechinus mozolevskae sp. nov. (Hylesininae: Tomicini) is the first fossil representative of this genus, differing from recent species in having large triangular scales along the suture. Taphramites rovnoensis sp. nov. (Scolytinae: Dryocoetini) differs from the closest species, T. gnathotrichus from Baltic amber, in the presence of short thin hairs on the elytra.     

Experimental sympatry suggests geographic isolation as an essential reproductive barrier between two sister species of Pedicularis

Although mechanical isolation mediated by shared pollinators has been considered as a classic model of pollinator-mediated floral isolation in Pedicularis, a superdiverse genus in Hengduan Mountains, southwest China, there has been no empirical study of interspecific pollen flow between closely related species. We examined reproductive barriers at six different stages between Pedicularis cranolopha and Pedicularis tricolor, two sister species. The two sister species were geographically isolated from each other based on our field survey and the records of herbarium specimens. Translocation experiments showed that flowering phenology partly overlapped and bumblebee pollinators did not discriminate between flowers of the two species. Bumblebee interspecific moves could mediate interspecific pollination as traced using fluorescent powder, in which pollen analogs placed on one species were transferred to the stigmas of the other species in experimental plots containing both species. Heterospecific pollen tubes grew in the style as well as conspecific pollen in hand-pollination experiments. Reciprocal hybridization between the two species could produce (partially) viable seeds, suggesting weak post-pollination barriers. Our results showed that geographic isolation was an important barrier of two species, and the total reproductive isolation between two species was incomplete when without geographical isolation. The formation of Big Snow Mountains could introduce an important pre-zygotic reproductive barrier between the two sister species of Pedicularis; such geographical isolation could be responsible for allopatric speciation, giving a clue to understanding the rapid radiation on mountain areas.     

Conservation priorities for forest-floor invertebrates of the southeastern half of Madagascar: evidence from two land-snail clades

Leaf litter and soil of tropical forests harbour some of Earth's most diverse, most endangered, yet least understood biological communities. How well do east-southeast Madagascar's reserves protect this resource? A preliminary answer is provided by the landsnail genera Cyclophoridae Boucardicus and Charopidae n. gen., as represented by 3680 specimens in 64 species, collected 1990–1993 from 129 stations in 26 transects, with nine reserves included. These two genera qualify as indicator/target taxa because they are endemic, species-rich, well-defined clades, sensitive to environmental degradation, with species readily identifiable by shells alone. Indices of diversity and endemism were used to rank 12 bioclimate-latitude regions by priority for conservation/collection. The higher-priority regions generally have some forest nominally conserved, of which the lowland-rainforest reserves of Manombo, Kianjavato, and Betampona are especially rich. A crucial exception, however, is the highest-priority region: the coastal-montane rainforests to the north of Tolagnaro (Fort Dauphin), which are completely unprotected and are rapidly being destroyed. (Andohahela Reserve hes westward, where diversity and endemism are 60% and 20% lower, respectively, so it conserves less than a fourth of the general region's endemic diversity.)     

The effects of high and low fluoride diets on the frequencies of sister chromatid exchanges

A recent report suggests that fluoride has mutagenic activity in mice. To examine the potential clastogenic effect of ingested fluoride, we examined the frequencies of baseline SCE and mitomycin C induced SCE as well as baseline chromosomal aberrations and cell-cycle kinetics in mice raised on high and low fluoride diets. The lack of significant differences in any of these parameters between the two groups of animals indicates that dietary fluoride is not clastogenic and supports the continued use of water fluoridation.     

Chloroplast DNA variation in the cultivated and wild olive taxa of the genus Olea L.

Polymorphism in the lengths of restriction fragments of the whole cpDNA molecule were studied in 15 taxa (species or subspecies) of the genus Olea. From restriction analysis using nine endonucleases, 28 site mutations and five length polymorphisms were identified, corresponding to 12 distinct chlorotypes. From a phenetic analysis based on a Nei’s dissimilarity matrix and a Dollo parsimony cladistic analysis using, as an outgroup, a species of the genus Phillyrea close to Olea, the ten taxa of section Olea were distinguished clearly from the five taxa of section Ligustroides which appear to posses more ancestral cpDNA variants. Within the section Ligustroides, the tropical species from central-western Africa, Olea hochtetteri, showed a chlorotype which differed substantially from those of the other four Olea taxa growing in southern Africa, supporting a previous assessment according to which O. hochtetteri may have been subjected to a long period of geographical isolation from the other Olea taxa. Within the Olea section, three phyla were identified corresponding to South and East Africa taxa, Asiatic taxa, and a group including Saharan, Macaronesian and Mediteranean taxa, respectively. On the basis of cpDNA variation, the closest Olea taxa to the single Mediterranean species, Olea europaea, represented by its very predominant chlorotype, observed in both wild and cultivated olive, were found to be Olea laperrinei (from the Sahara), Olea maroccana (from Maroccan High Atlas) and Olea cerasiformis (from Macaronesia). These three taxa, which all share the same chlorotype, may have a common maternal origin. Received: 5 December 1999 / Accepted: 30 December 1999     

Systematic revision,molecular phylogeny and biogeography of the antlion tribe Acanthoplectrini (Neuroptera: Myrmeleontidae: Dendroleontinae), with emphasis on the Oriental lineage

The tribe Acanthoplectrini (Myrmeleontidae: Dendroleontinae) includes a group of antlion genera widely distributed across the Australasian and Oriental regions. The intergeneric and interspecific relationships between or within the Australian and Oriental lineages of this tribe as well as their historical biogeography remain largely unexplored. Here, we present a molecular phylogenetic and biogeographic analyses of Acanthoplectrini to infer the diversification history of this tribe, with emphasis on the Oriental lineage. Both the Oriental and Australian lineages are monophyletic and recovered as sister groups. Ancestral area reconstruction suggests that the ancestor of Acanthoplectrini might have been once widely distributed from Indochina to Australia and then split into the Oriental and Australian lineages during the early-Miocene. Our analyses recovered northeastern Indochina and south China as the ancestral range of the Oriental Acanthoplectrini. During the mid-Miocene to the mid-Pliocene, orographic events such as the rising of mountain ranges (including the Himalayas) and the formation of major islands in southeastern Asia triggered several dispersal and vicariance events in the Oriental Acanthoplectrini, driving their speciation. We revise the classification of the Oriental Acanthoplectrini, establishing the new genus Paralayahima gen. n. , which is recovered sister to Layahima Navás. Moreover, we describe four new species of Layahima, Layahima aspoeckorum sp. n. , Layahima monba sp. n. , Layahima lhoba sp. n. and Layahima xinliae sp. n. , and we reinstate two previously synonymized species, Layahima melanocoris (Yang) stat. rev. and comb. n. and Layahima nebulosa Navás stat. rev.