A SURVEY OF BLOOD PARASITES OF BIRDS IN THE MASCARENE ISLANDS, INDIAN OCEAN: WITH DESCRIPTIONS OF TWO NEW SPECIES AND TAXONOMIC DISCUSSION

A survey was carried out on the prevalence of blood parasites in birds in the Mascarene Islands. Smears from 357 birds of 25 species in 12 families were examined, of which 150 (42%) were found to harbour blood parasites. The most common parasites were Leucocytozoon ; a new species, L. zosteropis , is described from the Grey White-eye Zosterops borbonica mauritiana. This parasite was observed in smears from 68 birds of three species: Z. borbonica, Z. chloronothos and Z. olivacea. Other species of Leucocytozoon identified were L. fringillinarum from fodies, sparrows and a bulbul and L. marchouxi from two doves.
Haemoproteus was found only in domestic pigeons Columba livia and identified as H. columbae. Plasmodium relictum, P. vaughani and an unidentified species with elongate gametocytes were found in Zosterops , and Plasmodium sp. of low infection observed in other hosts. Trypanosoma mayae is redescribed from the House Sparrow Passer domesticus and the Mauritius Fody Foudia rubra , and considered to be a valid species. A new species of trypanosome, Trypanosoma phedinae , is described from the Malagasy Swallow Phedina b. borbonica. Other birds were found to harbour low infections of unidentified species of trypanosomes. A small number of birds were infected with Atoxoplasma , haemogregarines and Rickettsia-like organisms. An unidentified organism with a predilection for eosinophils was observed in several Mascarene Swiftlets Collocalia francica.
The results are discussed in relation to the possible effects of the parasites on the birds of the Mascarene Islands and comparisons made with the results of similar surveys on other Indian Ocean Islands.     

Geographic origin and taxonomic status of the invasive Privet, Ligustrum robustum (Oleaceae), in the Mascarene Islands, determined by chloroplast DNA and RAPDs

Information concerning the area of origin, genetic diversity and possible acquisition of germplasm through hybridisation is fundamental to understanding the evolution, ecology and possible control measures for an introduced invasive plant species. Among the most damaging of alien plants that are invading and degrading native vegetation in the Mascarene Islands of the Indian Ocean is the Tree Privet, Ligustrum robustum. Exact information about the geographic source of introduced material of this species is lacking, in part because Ligustrum is a taxonomically difficult genus. Native material of L. robustum ssp. walkeri from Sri Lanka, L. robustum ssp. robustum from northeastern India, and the closely related L. perrottetii from southern India was compared with introduced material from La Réunion and Mauritius using chloroplast DNA RFLP markers and random amplified polymorphic DNA (RAPDs). Sri Lankan and introduced material was monomorphic for the same cpDNA haplotype that was absent from south and northeast Indian Ligustrum. Sri Lankan and introduced material was also clearly distinguished from Indian Ligustrum by RAPDs. It was concluded that material introduced and established in the Mascarene Islands is derived from the Sri Lankan subspecies L. robustum ssp. walkeri. No geographic structuring of genetic variation within Sri Lanka was detected for this taxon, so the location(s) within Sri Lanka from which introduced material is derived could not be pinpointed. RAPDs indicate that L. robustum ssp. walkeri in Sri Lanka is more similar to south Indian L. perrottetii than to northeast Indian L. robustum ssp. robustum. Moreover, RAPDs showed that introduced material in La Réunion has undergone little or no loss of genetic diversity since introduction. However, there was no evidence that it is introgressed with germplasm from two other alien Ligustrum species present on La Réunion.     

Zur verlorenen Taubenwelt der Insel Réunion – Neue Erkenntnisse über ausgerottete Vertreter der Ordnung Columbiformes auf der Inselgruppe der Maskarenen

Since the beginning of the influence of the fauna of the Mascarene Islands as a result of activities by Europeans, various members of Columbiformes have become extinct on Réunion Island. The erection of an obviously involved species of the former family Raphidae proved to be erroneous, indeed, but nevertheless it was assumed that there were up to four different endemic members of Columbidae that vanished from the said island. Inquiries by the help of both historical and modern literature showed that on Réunion Island overall “only” three indigenous pigeon species were wiped out: Nesoenas duboisi, Alectroenas sp., and one more form of the former genus that because of the lack of sufficient subfossil bone remains cannot be definitely identified.     

Ecogeographic survey of the genus Coffea in the Mascarene Islands

An ecogeographic survey is required for the development of a strategy for the conservation and use of plant genetic resources. An herbarium-based ecogeographic survey is presented, supplemented by detailed field surveys of wild Coffea species in the Mascarene Islands. The geographical and ecological distribution of the different Coffea species in the Mascarene Islands, principally in Mauritius, is determined, and an assessment is made of the IUCN conservation status of native Coffea species. Ecogeographic data were collated from herbarium specimens from four major herbaria holding collections of Mascarene Coffea . The geography, ecology, phenology and conservation status of the Coffea species from Mauritius are discussed.     

Molecular biology,phytochemistry and bioactivity of three endemic Aloe species from Mauritius and Réunion Islands

Introduction – Aloe tormentorii, A. purpurea and A. macra are used as multipurpose folk medicines in Réunion and Mauritius Islands and are mistaken for the introduced Aloe vera. Objective – To compare the phytochemical, antimicrobial and DNA profiles of Aloe endemic to Mauritius and Réunion with the profiles of A. vera. Methodology – Leaf extracts of these Aloe species were analysed using standard phytochemical screening techniques, TLC and by HPLC. These extracts were also assayed for antimicrobial activity using microdilution techniques. Genetic diversity was studied using RAPD markers. Results – Phytochemical and antimicrobial assays and RAPD analysis showed that Mascarene Aloe species were very different from A. vera. Conclusion – This study is the first report highlighting the differences between Aloe sp.p from Mascarene and Aloe vera at the metabolic and genomic level. Copyright © 2010 John Wiley & Sons, Ltd.     

Tristyly in the endangered Mascarene Island endemic Hugonia serrata (Linaceae)

Tristyly is a rare floral polymorphism known to occur in only five flowering plant families. One unresolved and potential additional case of tristyly concerns the genus Hugonia in the Linaceae. Here we confirm the existence of tristyly in the genus by reporting floral measurements made on Hugonia serrata Lam., an extremely rare species endemic to the Mascarene Islands of La Réunion and Mauritius in the southern Indian Ocean. We conducted an extensive search of all natural habitats on La Réunion Island where the species had been previously reported. Twenty-eight individuals were found, of which nine were in flower. Of the nine flowering individuals five had long-styled flowers with the stigmas placed above the two levels of anthers, three had intermediate length styles with the stigmas placed between the two anther levels, and one had stigmas placed below the two anther levels, i.e., three floral morphs could be identified based on the sequence of stigma and anther positions. Reciprocity and precision indices calculated for sexual organ length in each morph confirm that this variation is well within the range of values observed by previous workers on other tristylous species in other families. Our empirical data confirm the existence of tristyly in the genus Hugonia, thereby raising the number of known families in which tristyly occurs to six. Pollen size, pollen number, and anther length increased slightly with stamen length, but the low number of plants precludes statistical tests of these trends. A bibliographic survey suggests that tristyly may occur in several other species of the genus.     

The role of geography and ecological opportunity in the diversification of day geckos (Phelsuma)

We examine the effects of ecological opportunity and geographic area on rates of species accumulation and morphological evolution following archipelago colonization in day geckos (genus Phelsuma) in the Indian Ocean. Using a newly generated molecular phylogeny for the genus, we present evidence that these geckos likely originated on Madagascar, whereas colonization of three archipelagos in the Indian Ocean, the Seychelles, Mascarene, and Comoros Islands has produced three independent monophyletic radiations. We find that rates of species accumulation are not elevated following colonization but are roughly equivalent on all three isolated archipelagos and on the larger island of Madagascar. However, rates of species accumulation have slowed through time on Madagascar. Rates of morphological evolution are higher in both the Mascarene and Seychelles archipelagos compared to rates on Madagascar. This negative relationship between rate of morphological evolution and island area suggests that ecological opportunity is an important factor in diversification of day gecko species.     

A revision of <Emphasis Type="Italic">Foetidia</Emphasis> (Lecythidaceae subfamily Foetidioideae)

Seventeen species of Foetidia are recognized; one from East Africa, two from the Mascarene Islands and the remaining fourteen from Madagascar. A key to all the species is provided for the first time.     

Ancient mitochondrial DNA and morphology elucidate an extinct island radiation of Indian Ocean giant tortoises (Cylindraspis).

Ancient mitochondrial DNA sequences were used for investigating the evolution of an entire clade of extinct vertebrates, the endemic tortoises (Cylindraspis) of the Mascarene Islands in the Indian Ocean. Mitochondrial DNA corroborates morphological evidence that there were five species of tortoise with the following relationships: Cylindraspis triserrata ((Cylindraspis vosmaeri and Cylindraspis peltastes) (Cylindraspis inepta and Cylindraspis indica)). Phylogeny indicates that the ancestor of the group first colonized Mauritius where speciation produced C. triserrata and the ancestor of the other species including a second sympatric Mauritian form, C. inepta. A propagule derived from this lineage colonized Rodrigues 590 km to the east, where a second within-island speciation took place producing the sympatric C. vosmaeri and C. peltastes. A recent colonization of Réunion 150 km to the southwest produced C. indica. In the virtual absence of predators, the defensive features of the shells of Mascarene tortoises were largely dismantled, apparently in two stages. 'Saddlebacked' shells with high fronts evolved independently on all three islands. This and other features, such as a derived jaw structure and small body size, may be associated with niche differentiation in sympatric species and may represent a striking example of parallel differentiation in a large terrestrial vertebrate. The history of Mascarene tortoises contrasts with that of the Galápagos, where only a single species is present and surviving populations are genetically much more similar. However, they too show some reduction in anti-predator mechanisms and multiple development of populations with saddlebacked shells.     

Systematics of the Pacific monkey‐faced bats (Chiroptera: Pteropodidae), with a new species of Pteralopex and a new Fijian genus

The fruit‐bat genus Pteralopex comprises the monkey‐faced bats, a group of six endangered species found only in old‐growth forests on certain islands in the south‐west Pacific (the Solomon Islands and Fiji). The taxonomy of the genus is reviewed in detail and updated accordingly. Two ‘cryptic’ biological species are shown to occur in sympatry on both Bougainville and Choiseul in the northern Solomon Islands (corresponding to Pteralopex anceps Andersen, 1909 and a previously undescribed species) and each is accordingly described and reviewed. A new genus (Mirimiri) is erected for the Fijian monkey‐faced bat (formerly Pteralopex acrodonta), which differs greatly both morphologically and genetically from species of Pteralopex in the Solomon Islands. Ecomorphological differences between sympatric Pteralopex species are briefly reviewed, including potential differences in functional morphology and feeding ecology. Geographic patterns of occurrence and future survey priorities for monkey‐faced bats are also discussed.     

Variation among strains of Xanthomonas campestris pv. vasculorum from Mauritius and other countries based on fatty acid analysis

Fatty acid profiling was used to study variation amongst strains of Xanthomonas campestris pv. vasculorum (Xcv). They could be divided into five groups using cellular fatty acid profiles. Group A strains represent a new and little known taxon and all came from plants of broom bamboo (Thysanolaena maxima) from Mauritius. Group B strains included the Xcv pathotype reference strain and were from palms, broom bamboo and sugarcane from Mauritius, Reunion and Australia. Group C contained southern African and Malagasy strains from sugarcane and maize, together with X. campestris pv. holcicola strain. No Mascarene strains fell into this group. Group D strains isolated from sugarcane, maize and royal palm (Roystonea regia) were from Mauritius and Reunion, the earliest known strains coming from Réunion. These groups represented in the Mascarene Islands possibly belong to three different Xanthomonas species. A further Group E comprised one Xcv strain (NCPPB 182) from Puerto Rico, one X. vasicola pv. holcicola strain plus 6 other unclassified Xanthomonas strains causing red stripe disease symptoms in sugarcane. Three of these groups occur on Mauritius and two occur on Réunion. Group B strains originally caused serious problems in noble canes. As resistant interspecific hybrids were introduced, group D strains appeared in Mauritius possibly being introduced from Reunion but having similar host ranges within the Gramineae and Palmae. The findings that 3 of these groups (A, B, D) can cause gumming disease in a grass species (T. maxima) and that 2 of them (B, D) also cause gumming disease in sugar cane (Gramineae) and palms (Palmae) is unusual.     

Brittle stars (Echinodermata: Ophiuroidea) from La Réunion and the systematic position of Ophiocanops Koehler, 1922

The ophiuroid fauna of La Réunion, Indian Ocean, is still incompletely known. We report 13 different species from coral reefs, including five new records and a probably undescribed species of Amphioplus , which increases the number of ophiuroids known from La Réunion to 25. The most important find consists of three individuals of a previously unknown representative of the genus Ophiocanops . Originally placed in Ophiomyxidae, its systematic position has long been debated, with some authors advocating a placement with the otherwise extinct Palaeozoic Oegophiurida, based on the absence of several skeletal characters. The new species, O. multispina sp. nov. , shows intermediate characters between its previously only known congener, O. fugiens , and the ophiomyxid Renetheo felli . The three species appear to represent a line of taxa with progressively reduced skeleton instead of an ancient condition. We propose to transfer Ophiocanops back to the Ophiomyxidae, to synonymize Renetheo with Ophiocanops , and to invalidate the Ophiocanopidae, for which there is no autapomorphy-based support. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 545–560.     

Ubiquity of Sicyopterus lagocephalus (Teleostei: Gobioidei) and phylogeography of the genus Sicyopterus in the Indo-Pacific area inferred from mitochondrial cytochrome b gene

Sicyopterus lagocephalus is a Gobiidae Sicydiinae (Teleostei) thought to inhabit Indo-Pacific island rivers from Comoros Islands in the Indian Ocean to Australs Islands (French Polynesia) in the Pacific Ocean. Its biological cycle comprises a marine planctonic larval phase of several months allowing it to migrate from island to island, but the other species of the genus, with such a larval stage, have generally a more restricted range and are often endemic. To understand the organisation of a species with such a wide distribution, mtDNA cytochrome b sequences were amplified for 55 specimens of this genus covering most of its distribution range together with six close endemic species and other gobiids used as outgroups. The main result is the confirmation of the ubiquity of S. lagocephalus that occurs over a range of 18,000 km in the Indian and Pacific Oceans. Two clades were identified within this species, one clustering most of French Polynesian haplotypes and the other clustering most of Mascarene (including Comoros) haplotypes. The overall pattern of distribution and phylogenetic relationship suggests that the lineages leading to endemic species originated earlier than S. lagocephalus. This latter seems to be a secondary migrant species, having colonised both Indian and Pacific Oceans with a few exceptions, situated at the border of the range (Madagascar, Marquesas, Rapa). According to the results, the phylogeny of the Sicyopterus group, the age of the different lineages and the past history of the colonisation of the Indo-Pacific islands are discussed.     

Key to the genus Pentamyzus Hille Ris Lambers (Homoptera, Aphididae), with a description of a new species from the Falkland Islands

ABSTRACT. A key to the apterous viviparous females of the genus Pentamyzus is given and the host plants of the four known species are discussed. P. tenuis sp.n., which exhibits a highly specialized grass-feeding morphology, is described from Poa alopecurus in the Falkland Islands.     

Can invasion patches of Acacia mearnsii serve as colonizing sites for native plant species on Réunion (Mascarene archipelago)?

There is need for documenting the long-term effects of plant invasions at the landscape scale. We investigated the possible catalytic effect of invasive Acacia mearnsii De Wild. on the colonization of rural landscapes by native plant species on Réunion Island (Mascarene Archipelago, Indian Ocean). Data were recorded from 182 circular plots of 50 m² within a set of 48 large invasion patches, aged from 1 to 48+ years. Only eighteen native plant species were present in the invaded patches and these in only 21 of the 48 patches. The Acacia invasion patches colonized by native flora were older and closer to the closest forest remnant. Most invasion patches colonized by native species were located <200 m from forest remnants. Results are consistent with studies on colonization rates of nonindigenous forest plantations, which increase with age and decrease with distance to seeds sources. Yet, the rate of Acacia invasion patches colonized by native flora remained very low compared to studies on the colonization of exotic plantations in other tropical countries. We conclude that invasion patches of Acacia mearnsii are poor colonizing sites for native plant species. Allelopathy is suspected as one of the strongest factors, which prevent this colonization.     

The phylogeny of Halgerda (Opisthobranchia, Nudibranchia) with the description of a new species from Okinawa

This paper proposes a refined hypothesis of evolution for the tropical Indo-Pacific nudibranch genus Halgerda . Numerous specimens from 31 species were examined anatomically and literature from four additional species was reviewed, bringing to 33 the ingroup taxa. Fifty-three characters were considered from these examinations. The outgroup Asteronotus was used to polarize the characters. The phylogeny obtained from the analysis of the characters supports the hypothesis that Halgerda is a monophyletic group. A species previously placed with the genus Sclerodoris is examined and determined to be a member of the genus Halgerda . Phylogenetic analysis places this species, H. paliensis , as a basal member of the genus . Halgerda paliensis appears to be restricted to the Hawaiian Islands. Specimens previously identified as Sclerodoris paliensis from the Marshall Islands actually represent H. dalanghita Fahey & Gosliner, 1999. A new species, Halgerda onna , is described and presented as the sister taxon to a basal member of the genus. A range and depth extension of a previously described species, H. malesso , is presented. The present phylogeny is then compared to previous studies, in particular those of Fahey & Gosliner (1999a,b) .     

Natural colonization or introduction? Phylogeographical relationships and morphological differentiation of house geckos (Hemidactylus) from Madagascar

Several house gecko species of the genus Hemidactylus are almost cosmopolitan lizards, with distributions that have probably been shaped by natural transoceanic dispersal as well as by more recent human introductions. Here we revise the Hemidactylus populations of Madagascar and compare them genetically with populations from other sites in the Indian Ocean region. Morphological data strongly confirm the occurrence of three Hemidactylus species on Madagascar: Hemidactylus frenatus , distributed along the western coast of Madagascar; H. platycephalus , restricted to the north-west and the widespread H. mercatorius that occurs throughout the island, including coastal areas at sea level as well as big cities (Antananarivo, Fianarantsoa) at altitudes of 1200–1300 m above sea level. Analyses of partial sequences of the 16S rRNA gene in 46 Hemidactylus specimens from Madagascar, East Africa, South Asia, and the Comoro and Mascarene archipelagos demonstrated the presence of a fourth species, H. brooki, on the Mascarenes (Réunion, Rodrigues, and Mauritius) and Comoros (Moheli). The Malagasy populations of H. platycephalus were genetically uniform and differentiated from the African and Comoroan specimens studied. H. frenatus had a relatively low genetic differentiation over the whole region with no recognizable phylogeographical structure, indicating more recent colonizations or introductions. In contrast, H. mercatorius showed a strong phylogeographical structure of haplotypes, with two distinctly different lineages in Madagascar. Moreover, all Malagasy specimens differed strongly from the single African specimen included. This indicates that populations of H. mercatorius in Madagascar have a long history that predates human settlement.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 115–130.