Mass mortality of macrobenthic communities in the lagoon of Hikueru atoll (French Polynesia)

Epibenthic macrofauna communities (corals, molluscs, echinoderms, and macroalgae) were investigated at Hikueru Atoll, Tuamotu Archipelago. The very low diversity and abundance that we observed (1 coral genus, and 2 mollusc, 1 echinoderm, and 17 macroalgal species) is likely to be the result of a mass mortality event that occurred 18 months earlier. Hydrological surveys suggest that this high mortality was the result of a major dystrophic crisis. Other atoll lagoons in the Tuamotu Archipelago have also been affected by high mortalities in the past, but Hikueru appears to have been the most frequently and intensely affected. The present study confirms that mass mortalities associated with phytoplankton blooms may be one of the major disturbances affecting coral reef ecosystems. Accepted: 14 May 2000     

A taxonomic study of the Rana narina complex, with description of three new species (Amphibia: Ranidae)

A morphometric and electrophoretic survey was conducted to examine taxonomic relationships among eight population samples of the Rana narina complex from the Ryukyu Archipelago of Japan and Taiwan. Five discrete morphotypes are differentiated, and these showed considerable genetic differentiation from each other. From the available information, each of the five morphotypes is judged to represent a species, and three are described as new. Rana utsunomiyaorum sp. nov. and R. supranarina sp. nov. are sympatric in Ishigakijima and Iriomotejima islands of the Yaeyama Group, and differ from the other members by having a shorter hindlimb. Rana utsunomiyaorum is the smallest in the complex, while R. supranarina is the largest. Rana amamiensis sp. nov . occurs on Amamioshima and Tokunoshima islands of the Amami Group and, like R. narina from Okinawajima of the Okinawa Group, has a long hindlimb; it differs from the latter species by having a larger body and relatively small tympanum. These two species differ from R. swinhoana from Taiwan by having a narrower disk on the third finger. A key to known species of the complex is given. Further, syslematics of the R. narina complex within Rana , body size in the two sympatric species, and sexual dimorphism found in this complex are discussed.     

Phylogeography of Arabis serrata (Brassicaceae) in the Japanese Archipelago based on chloroplast DNA variations

Arabis serrata (Brassicaceae), a perennial plant widely distributed along the Japanese Archipelago, occurs in various habitats: for example, limestone zones, serpentine barrens, volcanic soils, and roadsides. It likely survived by adapting to its surrounding environment, resulting in great morphological and ecological variation. In this study, we performed a phylogeographic analysis to examine past changes in the distribution of A. serrata following climate oscillations during the Pleistocene. To cover most of A. serrata's range, leaves were collected from eight to ten individuals randomly selected from each of 37 populations in the Japanese Archipelago. Two chloroplast noncoding regions of the samples were amplified and sequenced: trnT(GGU)‐psbD and trnH(GUG)‐psbA spacers. Twenty‐five haplotypes were detected and distinguished by 31 substitutions. Four main haplotypes were observed in many populations distributed throughout the Japanese Archipelago. According to the genetic boundaries detected using the Monmonier algorithm, A. serrata is clustered into four groups, each including several populations: Hokkaido Island, northern mainland Honshu, central Japan, and western Japan. The boundaries, however, were not robust because all genetic parameters did not support the differentiation among groups. These results indicate the absence of an obvious geographic structure in the distribution of A. serrata, suggesting that this species has experienced a rapid range expansion in postglacial times.     

Benthic marine flora in the Tuscan Archipelago. A first contribution: Isles of Capraia,Elba, Formiche di Grosseto,Giglio, Scoglio d'Africa,Montecristo and Giannutri

Abstract

Benthic marine flora of Tuscan Archipelago has been studied. Several samples were collected along five islands and some rocks. This paper is a compendium of new and already published data, in which 267 species, varieties, forms and stadia of algae and seagrasses are listed: 5 Bangiophyceae, 182 Florideophyceae, 45 Phaeophyceae, 6 Chlorophyceae, 28 Bryopsidophyceae, 1 Angiospermae.     

A review of the distribution of hydrothermal vent communities along the northern Mid-Atlantic Ridge: dispersal vs. environmental controls

Hydrobiologia - Until 1985, seven vent fields were described from the Mid-Atlantic Ridge (MAR). An eighth field, Mount Saldanha (36° N), discovered in 1998, showed unusual geological and...     

Pollen morphology and systematics of Burseraceae

The Burseraceae are a medium‐sized family in which 18 genera are currently recognised. They are the subject of a long‐term project to describe the pollen morphology from light, scanning electron and transmission electron microscopy. The pollen morphology of tribe Protieae has been published, as well as an account of the pollen of the African taxa in the family. Pollen data for the other two tribes, Bursereae and Canarieae, are more or less complete. The pollen of all the genera have been examined, with the exception of the recently described Pseudodacryodes Pierlot for which, currently, there is no pollen material available. This paper summarises the results.

There is considerable variation in exine and aperture features between, and occasionally within, the genera and 14 major pollen types are defined, including two previously undescribed types: ‘Canarium oleiferum’ and ‘Canarium gracile’. The distribution of pollen characteristics throughout the family is compared with previously published tribal and subtribal groupings, as well as with current ideas of generic relationships from molecular analyses. Comparisons show notable congruence of pollen data with molecular data. To some extent pollen morphology is different for each of the subtribes. Nevertheless, there are some notable exceptions, for example, the pollen of Garuga and Boswellia are remarkably similar, although Garuga has been included, somewhat tenuously, in tribe Protieae, and Boswellia is included in tribe Bursereae, subtribe Boswelliinae. In a recent molecular tree Garuga and Boswellia appear to be closely related, and this supports the conclusion, based on several macromorphological characters as well as pollen, that Garuga should be transferred to tribe Bursereae.