Survey of the Mosquitoes (Diptera: Culicidae) of Mayotte

A transversal survey of immature mosquitoes was conducted on Mayotte Island (France) in the Comoros Archipelago, western Indian Ocean, with the aim to inventory the Culicidae and to document inter-species relationships in different habitats. In total 420 habitats were sampled for larvae and/or pupae mosquitoes, resulting in more than 6,000 specimens. Forty species belonging to 15 genera were collected, with eight taxa integrated for the first time to the Mayotte mosquito list. The most frequently recorded species were Stegomyia aegypti, St. albopicta, Anopheles gambiae and Eretmapodites subsimplicipes, the first three species being known vectors of viruses and parasites transmitted to humans. Mean species richness in habitats ranged from 1.00 to 3.29, with notable differences between habitats. For example, water-filled axils of banana leaves, tree-holes and crab-holes had low species richness, while cut bamboo, water pools, abandoned tires and marsh and swamp water had notably higher species richness. Twenty-seven mosquito species belonging to 12 genera were routinely collected (in ≥20% of at least one type of larval habitat) suggesting that multiple species play a role in the biocenosis of these aquatic habitats. Multispecies association was observed in 52% of the habitats. The co-occurrence of up to six species belonging to five genera was recorded in a single habitat. The mosquitoes of Mayotte show notable biogeographical affinities to those of Madagascar, as compared to the African continent. These two potential source areas are nearly equidistant from Mayotte, which in turn indicates biased dispersal from east to west. Our findings suggest that with relatively short-term intensive sampling in different habitats, it is possible to approach exhaustive species inventories based on collection of larvae. Mayotte, with its modest elevation range and land surface, has a notable species richness of mosquitoes with 45 well-documented species belonging to 15 genera.     

Ontogeny of Feeding Behavior of Eulemur fulvus in the Dry Forest of Mayotte

Captive data show that juvenile mammals usually reproduce the diet of the adult. However, it is not known whether, in natural environments, the process of feeding maturation varies according to available foods and to adult choices. I examined the feeding ontogeny of Mayotte brown lemurs (Eulemur fulvus), a presumed introduced species, from birth to 12 mo old in the southern dry forest of Mayotte. The study focused on activities and diets of 4 mothers and their juveniles from 2 groups in 1999 and 2000. In 2001, we also observed 2 other dyads from each group for 2 mo (March/April). I assessed plant phenology in each group's home range. There are 4 phases of feeding ontogeny: (1) the 3 mo following birth are characterized by lactation, early bouts of exploration, and consumption; (2) the next 2 mo are characterized by feeding and social weaning; (3) during the sixth and seventh mo, the daily feeding activity rhythms of the mother and her juvenile are synchronized and diets largely overlap; (4) at 10–12 mo of age, the feeding juvenile is closer to other group members than to its mother. During their first year of life, especially before being weaned, juveniles eat several food items that are not ingested by their mothers. It appeared that the progressive overlap in dietary items and feeding synchrony between mother and juvenile depends on several types of leaming. There is a correlation between the availability of particular food resources with high nutritional quality and timing of reproduction and infant maturation.     

Assessing ecological status with diatoms DNA metabarcoding: Scaling-up on a WFD monitoring network (Mayotte island,France)

Diatoms are excellent ecological indicators of water quality because they are broadly distributed, they show high species diversity and they respond rapidly to human pressures. In Europe, the Water Framework Directive (WFD) gives the legal basis for the use of this indicator for water quality assessment and its management. Several quality indices, like the Specific Polluosensitivity Index (SPI), were developed to assess the ecological quality status of rivers based on diatom communities. It is based on morphological identifications and count of diatom species present in natural biofilms using a microscope. This methodology requires high taxonomic skills and several hours of analysis per sample as 400 individuals must be identified to species level. Since several years, a molecular approach based on DNA metabarcoding combined to High-Throughput Sequencing (HTS) is developed to characterize species assemblages in environmental samples which is potentially faster and cheaper. The ability of this approach to provide reliable diatom inventories has been demonstrated and its application to water quality assessment is currently being improved. Despite optimization of the DNA metabarcoding process with diatoms, few studies had yet extended it at the scale of a freshwater monitoring network and evaluated the reliability of its quality assessment compared to the classical morphological approach.In the present study we applied DNA metabarcoding to the river monitoring network of the tropical Island Mayotte. This island is a French département since 2011 and the WFD has to be applied. This offered the opportunity to scale up the comparison of molecular and morphological approaches and their ability to produce comparable community inventories and water quality assessments. Benthic diatoms were sampled following WFD standards in 45 river sites in 2014 and 2015 (80 samples). All samples were submitted in parallel to the molecular and the morphological approaches. DNA metabarcoding was carried out using Genelute DNA extraction method, rbcL DNA barcode and PGM sequencing, while microscopic counts were carried out for the classical methodology. Diatom community structures in terms of molecular (OTUs) and of morphological (species) were significantly correlated. However, only 13% of the species was shared by both approaches, with qualitative and quantitative variation due to i) the incompleteness of the reference library (82% of morphological species are not represented in the database), ii) limits in taxonomic knowledge and iii) biases in the estimation of relative abundances linked to diatom cell biovolume. However, ecological quality status assessed with the molecular and morphological SPI values were congruent, and little affected by sequencing depth. DNA metabarcoding of diatom communities allowed a reliable estimation of the quality status for most of the rivers at the scale of the full biomonitoring network of Mayotte Island.     

The annual cycle and breeding behaviour of the Mauritius Fody Foudia rubra

Safford, R.J. 1997. The annual cycle and breeding behaviour of the Mauritius Fody Foudia rubra. Ostrich 68 (24): 58–67.

The Mauritius Fody Foudia rubra, a highly endangered species of weaver (Ploceidae) endemic to Mauritius, was studied from 1989–1993. The plumage, various display postures (typical of the family), and seven adult and two juvenile vocalisations are described. The diet consisted of insects, nectar and fruit. Males were in breeding plumage, and breeding took place, between late August and early April, although severe weather in February 1992 terminated breeding activity early. The species appeared to be monogamous and was suspected to maintain a long-term pair bond. Pairs occupied exclusive territories of not less than 0.9 ha. Both sexes built the nest from the outset, but only the female lined it. Between breeding attempts, some pairs habitually started but then abandoned one or more nests. Clutch sizes of two to four were recorded, three being the norm. Incubation and brooding were carried out by the female; the male joined in feeding the young after daytime brooding ceased. Juvenile dependency appeared to last around two weeks after which the young were ousted from the territory. The potential productivity of up to three broods per pair per year was not achieved by any pair studied because of poor nesting success. A complete moult followed breeding. Territorial defence continued throughout the year, and no evidence for seasonal movements was seen. Two behavioural features seem unexpected: 1) male nest invitation and nest advertisement behaviour appeared to be absent; 2) females participated from the outset of nest-building (including prospecting). These could be explained by the existence of a long-term pair bond, which needs to be confirmed but would not be surprising in a species that remains on territory all year. Hypotheses that could be tested to find a mechanism responsible for the unusual features of the fody are suggested. In comparison with other fodies studied, the breeding behaviour most resembled that of the Seychelles Fody F. sechellarum (also a monogamous, non-graminivorous omnivore that breeds in solitary pairs in evergreen forest). The annual cycle was similar to that of other native passerines and most other fody taxa.     

Threats to the tropical island dragonfly fauna (Odonata) of Mayotte, Comoro archipelago

The dragonfly fauna of the 374 km² island of Mayotte in the western Indian Ocean comprises some widespread African species and some Comoro endemics, and is a biodiversity hotspot. This dragonfly assemblage is under threat from increasing human impact as it creeps up the water courses from the periphery of the island towards the centre. Among these impacts are indigenous tree removal and replacement growth by alien vegetation. An even greater impact and threat is detergent input into streams. The intensity of this impact is so great that the streams and rocks become white. To date, although often the wings and bodies of odonates become stained white with detergent, the dragonfly assemblage appears remarkably tolerant of this impact. However, there is differential impact, with loss of island endemic species in the most impacted areas. In contrast, the geographically widespread and eurytopic species continue to thrive in these impacted areas, at least in the short term. It is urgent to change people's water-usage behaviour, both for their benefit and for the endemic dragonfly assemblage.     

Cathemerality in the Mayotte brown lemur (Eulemur fulvus): seasonality and food quality

In past decades, cathemerality--as defined by Tattersall [1987]--has been documented in two primate families: Cebidae and Lemuridae. In the Lemuridae, in particular the genus Eulemur, cathemeral activity seems to be a regular behavioural trait. Nevertheless, ultimate and proximate determinants responsible for this behaviour remain unclear. In this study, in a dry and deciduous forest on Mayotte (Comoro Archipelago), activities of 4 female brown lemurs (Eulemur fulvus fulvus) were recorded by focal animal sampling during the daylight period and by scan sampling on their respective groups during the night. Horizontal distances travelled by females and groups were measured using GPS. During the daylight period, food intakes were estimated in grams by extrapolation of counting of mouthfuls after weighing a large sample of plant parts eaten. Crude protein, crude lipid, soluble sugar and crude fibre were analyzed for each seasonal reconstituted diet. Records of temperature and rainfall were supplied by a local meteorological station. Observations confirmed cathemerality in the Mayotte brown lemur as reported by Tattersall in 1977. During the dry season, the animals increased their nocturnal activity--substantially increasing the time devoted to feeding and moving overall, but especially at night--and were less active during the daylight period. The quality of their diet in the dry season was poorer than that in the wet season, with soluble sugar content and protein content decreasing and fibre content increasing slightly. As a result, Mayotte brown lemurs may need to extend their foraging activity over the 24-hour cycle to balance nutritional requirements.     

Isolation and Characterization of New Leptospira Genotypes from Patients in Mayotte (Indian Ocean)

Background

Leptospirosis has been implicated as a severe and fatal form of disease in Mayotte, a French-administrated territory located in the Comoros archipelago (southwestern Indian Ocean). To date, Leptospira isolates have never been isolated in this endemic region.

Methods and Findings

Leptospires were isolated from blood samples from 22 patients with febrile illness during a 17-month period after a PCR-based screening test was positive. Strains were typed using hyper-immune antisera raised against the major Leptospira serogroups: 20 of 22 clinical isolates were assigned to serogroup Mini; the other two strains belonged to serogroups Grippotyphosa and Pyrogenes, respectively. These isolates were further characterized using partial sequencing of 16S rRNA and ligB gene, Multi Locus VNTR Analysis (MLVA), and pulsed field gel electrophoresis (PFGE). Of the 22 isolates, 14 were L. borgpetersenii strains, 7 L. kirschneri strains, and 1, belonging to serogoup Pyrogenes, was L. interrogans. Results of the genotyping methods were consistent. MLVA defined five genotypes, whereas PFGE allowed the recognition of additional subgroups within the genotypes. PFGE fingerprint patterns of clinical strains did not match any of the patterns in the reference strains belonging to the same serogroup, suggesting that the strains were novel serovars.

Conclusions

Preliminary PCR screening of blood specimen allowed a high isolation frequency of leptospires among patients with febrile illness. Typing of leptospiral isolates showed that causative agents of leptospirosis in Mayotte have unique molecular features.     

Plants Consumed by Eulemur fulvus in Comoros Islands (Mayotte) and Potential Effects on Intestinal Parasites

The study of self-medication among animals—zoopharmacognosy—is founded on observations that suggest that wild animals use plants with specific biological properties that may be beneficial to them. To verify whether self-vermifugation occurs among Eulemur fulvus in the wild, we studied their feeding behavior in both the dry and humid forests of Mayotte (Comoros Islands). We used the focal individual sampling method over an annual cycle. We conducted a complementary study during the 2-mo mating season, via the scan sampling method (at 10-min intervals). Among the 29 plant species brown lemurs consumed, we tested 16 in vitro as antiparasitic agents on 3 experimental parasite models (Rhabditis pseudoelongata, Trichomonas vaginalis, Entamoeba invadens). We obtained crude extracts to be tested after 2 successive chemical extractions (ethyl acetate and methanol), and 7 of them, belonging to 4 different plant species, showed an antiparasitic property: lemurs consumed Annona squamosa and Mimusops comorensis in large amounts, but ingested Ixora cremixora and Syzygium jambos sporadically. The 4 plants were active on the flagellate but only one of them (Ixora cremixora) also demonstrated antinematode properties. Humans use 2 of the plants as intestinal antiparasitic agents in traditional medicine and include numerous other plants in the diet. The relative lake of amoebas and flagellates in stools of Eulemur fulvus may be related to the consumption of plants with antiprotozoal properties. Nevertheless, in the absence of specific behavior that could be linked to a voluntary therapeutic action during our study, self-vermifugation in Eulemur fulvus remains elusive.     

Examination of the Bacterial Biodiversity of Coastal Eroded Surface Soils from the Padza de Dapani (Mayotte Island)

To better understand microbial populations present in atypical soil environments, and to discern any relations between these environments and their bacterial communities, we examined the “Padza de Dapani” on the island of Mayotte off the east coast of Africa. This area is not a true (hot) desert, but resembles one in many places due to extensive soil erosion. We collected surface soil samples from five different sites of the Padza de Dapani in Mayotte. We examined bacterial biodiversity using pyrosequencing of PCR-amplified 16S V1–V3 rDNA sequences from total extracted DNA. Our results show that in the acidic (pH 4.6–6), oligotrophic (organic carbon; 0.1–0.7 g/kg of soil) and mineralized (Fe: 18 g/100 g; Al: 12 g/100 g) Dapani Padza soil samples, members of the Actinobacteria and Proteobacteria phyla dominated the bacterial communities, as was also observed in samples from Saudi Arabia hot desert sands.

Interestingly, members belonging to the genera Acinetobacter, Arthrobacter and Bacillus were also found to be very abundant in our samples. These were also seen in hot Asian deserts sand samples, such as those from the Gobi (Mongolia) and Taklamaken (China) deserts, thus possibly pointing to microbial populations characteristic of denuded soils.     

The systematic status of the genus bletilla (Orchidaceae)

The genusBletilla has been variously placed in the major classifications of the Orchidaceae. This study attempts to provide a better understanding of the relationships of this genus and to clarify its systematic position. A survey is provided of the taxonomic assignments ofBletilla in major classifications of the Orchidaceae, and morphological comparisons are made of species chosen to represent the generaBletilla, Arethusa, andBletia. Chromosome numbers reported forBletilla andBletia are summarized, and confirmatory counts of 2n =32 are reported forBletilla striata andB. striata f.gebina. A preliminary report is provided on intergeneric crossing studies. It was found thatBletilla consistently shows greater similarity toBletia than toArethusa. It is suggested, therefore, thatBletilla be removed from the subtribe Arethusinae and placed nearBletia in the Bletiinae.     

The threatened status of groupers (Epinephelinae)

The marine environment has traditionally been considered to be resilient to human impacts. However, concern over growing threats to marine biodiversity has led to a renewed effort to assess and quantify risks to marine species. This study assesses threats to the subfamily Epinephelinae of the Serranidae (groupers), a commercially and ecologically important group of predatory fish which are heavily exploited throughout their range. Eighty-five tropical species of the subfamily are examined in detail and classified according to 1996 IUCN Red List categories. Thirty-seven species (43.5%) are considered Threatened, of which two (Cromileptes altivelis and Epinephelus akaara) are Endangered, and the remaining 35 are Vulnerable. Thirty-four species (40%) are listed as Lower Risk and do not appear to be under immediate threat. Fourteen species (16.5%) are Data Deficient. Most of the threatened species are wide ranging. Large range size and the production of abundant, dispersive offspring are characteristics of groupers that have previously been considered to make them unlikely candidates for extinction. However, rapidly intensifying fisheries employing habitat-destructive gears now encompass vast areas of the tropics, putting many species at risk. Members of the genera Epinephelus and Mycteroperca were found to be particularly at risk, probably due to their large body sizes, long life-span and late reproduction.     

The status of Asarum marmoratum (Aristolochiaceae)

Asarum marmoratum Piper, a species with marbled leaves from southern Oregon and northern California, differs fromA. hartwegii. S. Wats. in many respects, and should be recognized as distinct. The species is described, illustrated, and compared to the four other western North American species ofAsarum in a synoptic key.     

The status of Clarkia australis (Onagraceae)

Clarkia australis and C. virgata grow on the western slope of the central Sierra Nevada of California. Clarkia australis was established to accommodate populations of C. virgata from south of the Tuolumne River that could not be successfully hybridized to populations north of the river. Although the species is maintained in the new Jepson Manual, its validity has been questioned because only two populations were originally tested, and they had no useful morphological traits that distinguished them from C. virgata. We report here the results of a large program of interpopulation hybridizations that show that C. australis is distinct and that its reproductive isolation from C. virgata is complete and absolute and reflects a compatibility block that apparently causes abortion of hybrid seeds in early development. Both species include populations north and south of the Tuolumne River and, in general, those of C. australis occupy higher elevations. Morphologically, the species are extremely similar though the mean values of several dimensions of the petals are different. However, significant variation among their populations has the consequence that, at present, the only certain way to assign particular populations to species is to test their compatibility with previously tested populations.     

Incidence and survival of childhood cancer in the French islands of Reunion and Mayotte (2005–2011)

The aim of this study is to describe childhood cancer incidence and survival in the French islands of Reunion and Mayotte for the period 2005–2011. Data were taken from the population-based Cancer Registry of Reunion Island. All incident cases of malignant tumours and benign tumours of the Central Nervous System diagnosed between 2005 and 2011 in children under the age of 15 and living in Reunion or Mayotte were included. A total of 236 cases were registered (176 in Reunion, 60 in Mayotte). Age-standardised incidence rates (ASRs, world standard) for all cancers were 125.0 and 101.8 per million for Reunion and Mayotte, respectively. ASRs for the main cancer groups were lower than those described in mainland France for the same period. The 5-year overall survival rate for all patients was 78.5% (95%CI 71.9- 83.7), slightly lower than that reported in mainland France.     

The impact of zooplankton status on the management of Lake Kinneret (Israel)

Monthly averages of standing stock wet biomass of zooplankton in Lake Kinneret (Israel) varied between 11 and 76 g m^–2 during 1969–1981, with the exception of two months. Averaged contributions of different groups were: Cladocera 58%, Copepoda 35% and Rotifera 7%. Total standing crop wet biomass is highest during January–June, averages varied between 35 and 50 g m^–2, and decreases during summer–fall (23–36 g m^–2). The winter biomass of Cladocera fluctuated between 22 and 35 g m^–2 and dropped to a range of 9–23 g m^–2 in summer, whereas copepod biomass varied very little around an average of 18 g (ww) m^–2 with the exception of low values from April to June. The stock biomass of Rotifera is relatively high during winter floods season (December-March) whilst in summer it is very low.Young stages of fish in Lake Kinneret feed mostly on zooplankton and zoobenthic forms. The most abundant fish in the Kinneret ecosystem, Mirogrex terraesanctae terraesanctae, also feed on zooplankton at the adult stage throughout the year, and herbivorous fish consume zooplankton during the summer when lake plankton resources are limited.The summer ecosystem of Lake Kinneret is characterised as a steady state type, in which the impact of the zooplankton-chain is of great importance. Increase of predation pressure on zooplankton by fish can disequilibrate the balanced trophic relations existing between nannoplankton production and zooplankton grazing capacity. Such a situation can lead to organics accumulation as nannoplankton blooms, resulting in water quality deterioration. Management options aimed at preventing collapse of zooplankton populations are discussed.     

The influence of ethanol on the functional status of GABA(A) receptors

Gamma aminobutyric acid (GABA) is one of the main inhibitory neurotransmitters in the mammalian brain. Its effects are realized via GABA_A, GABA_B, and GABA_C receptors. GABA_A is the most abundant type of GABA receptors. It consists of six classes of subunits, , , , , , and . Acute and chronic exposures to ethanol are accompanied by changes in structure and function of GABA_A receptors. These changes may be a basis for altered behavior seen in alcoholism.     

The present status of the genus Pseudotorellia Florin (Ginkgophyta)

An account is given of the present state of Pseudotorellia Florin (Ginkgophyta). The necessity to limit the use of this generic name to leaves, which have been studied with regard to their microscopical characters, is particularly emphasized. Pseudotorellia comprises at present seven valid species from Spitzbergen, East Greenland, Sweden, Poland, and the U.S.S.R. (Kazakhstan, Uzbekistan, and the Bureja basin in the Soviet Far East). The range of the species is Rhaetic to Lower Cretaceous. No remains of the genus are known from the Southern Hemisphere.     

The status of Homo heidelbergensis (Schoetensack 1908)

The species Homo heidelbergensis is central to many discussions about recent human evolution. For some workers, it was the last common ancestor for the subsequent species Homo sapiens and Homo neanderthalensis; others regard it as only a European form, giving rise to the Neanderthals. Following the impact of recent genomic studies indicating hybridization between modern humans and both Neanderthals and "Denisovans", the status of these as separate taxa is now under discussion. Accordingly, clarifying the status of Homo heidelbergensis is fundamental to the debate about modern human origins.