Seasonal variability of bull and tiger shark presence on the west coast of Reunion Island, western Indian Ocean

2015 ◽  
Vol 37 (2) ◽  
pp. 199-208 ◽  
Author(s):  
A Blaison ◽  
S Jaquemet ◽  
D Guyomard ◽  
G Vangrevelynghe ◽  
T Gazzo ◽  
...  
Keyword(s):  
Indian Ocean ◽  
West Coast ◽  
Seasonal Variability ◽  
Western Indian Ocean ◽  
Tiger Shark ◽  
Reunion Island ◽  
The West ◽  
Réunion Island

New insights into the reproductive biology of the tiger shark Galeocerdo cuvier and no detection of polyandry in Reunion Island, western Indian Ocean

2020 ◽  
Vol 71 (10) ◽  
pp. 1301 ◽  
Author(s):  
Agathe Pirog ◽  
Hélène Magalon ◽  
Thomas Poirout ◽  
Sébastien Jaquemet
Keyword(s):  
Indian Ocean ◽  
Reproductive Biology ◽  
Population Biology ◽  
Western Indian Ocean ◽  
Analysis Of Covariance ◽  
Tiger Shark ◽  
Reunion Island ◽  
Frequency Distributions ◽  
Galeocerdo Cuvier ◽  
Réunion Island

The reproductive biology of the tiger shark Galeocerdo cuvier remains poorly documented because it is difficult to obtain data on a sufficient number of mature individuals to conduct appropriate analyses and thus to adequately investigate its population biology. In this study, the reproductive traits of 150 individuals caught during a shark control program in Reunion Island (western Indian Ocean), including five gravid females, were investigated. Specific microsatellite loci were used to investigate the occurrence of polyandry. The total length (TL) of the studied individuals was 130–415cm for males and 175–429cm for females. Sizes at maturity were estimated at 278.5cm for males and 336cm for females. Although the length–weight relationships differed between both sexes (analysis of covariance (ANCOVA): intercept, n=49, F1,45=0.95, P=0.34; slope, n=49, F1,45=8.39, P=0.01), the TL–frequency distributions did not differ significantly. Parturition likely occurs during the warm season, in December–January. No evidence of genetic polyandry was detected, and this supports recently published results. This absence of polyandry in the species likely reflects both a long reproductive cycle and a specific reproductive behaviour related to the oceanic nature of the tiger shark. These results are valuable for improving conservation and management plans for this species.

scholarly journals Bat coronavirus phylogeography in the Western Indian Ocean

2019 ◽  
Author(s):  
Léa Joffrin ◽  
Steven M. Goodman ◽  
David A. Wilkinson ◽  
Beza Ramasindrazana ◽  
Erwan Lagadec ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Phylogenetic Analyses ◽  
Strong Association ◽  
Western Indian Ocean ◽  
Reunion Island ◽  
High Genetic Diversity ◽  
Soil Fertilization ◽  
Réunion Island ◽  
History Of ◽  
Bat Coronavirus

AbstractBats provide key ecosystem services such as crop pest regulation, pollination, seed dispersal, and soil fertilization. Bats are also major hosts for biological agents responsible for zoonoses, such as coronaviruses (CoVs). The islands of the Western Indian Ocean are identified as a major biodiversity hotspot, with more than 50 bat species. In this study, we tested 1,013 bats belonging to 36 species from Mozambique, Madagascar, Mauritius, Mayotte, Reunion Island and Seychelles, based on molecular screening and partial sequencing of the RNA-dependent RNA polymerase gene. In total, 88 bats (8.7%) tested positive for coronaviruses, with higher prevalence in Mozambican bats (20.5% ± 4.9%) as compared to those sampled on islands (4.5% ± 1.5%). Phylogenetic analyses revealed a large diversity of α- and β-CoVs and a strong signal of co-evolution between CoVs and their bat host species, with limited evidence for host-switching, except for bat species sharing day roost sites.ImportanceThis is the first study to report the presence of coronaviruses (CoVs) in bats in Mayotte, Mozambique and Reunion Island, and in insectivorous bats in Madagascar. Eight percent of the tested bats were positive for CoVs, with higher prevalence in continental Africa than on islands. A high genetic diversity of α- and β-CoVs was found, with strong association between bat host and virus phylogenies, supporting a long history of co-evolution between bats and their associated CoVs in the Western Indian Ocean. These results highlight that strong variation between islands does exist and is associated with the composition of the bat species community on each island. Future studies should investigate whether CoVs detected in these bats have a potential for spillover in other hosts.

scholarly journals Modelling with stakeholders to integrate biodiversity into land-use planning – Lessons learned in Réunion Island (Western Indian Ocean)

2010 ◽  
Vol 25 (11) ◽  
pp. 1413-1427 ◽  
Author(s):  
Erwann Lagabrielle ◽  
Aurélie Botta ◽  
Williams Daré ◽  
Daniel David ◽  
Sigrid Aubert ◽  
...  
Keyword(s):  
Land Use ◽  
Indian Ocean ◽  
Land Use Planning ◽  
Western Indian Ocean ◽  
Lessons Learned ◽  
Reunion Island ◽  
Réunion Island

English Private Trade on the West Coast of India, c. 1680–c. 1740

Itinerario ◽  
2014 ◽  
Vol 38 (2) ◽  
pp. 51-73 ◽  
Author(s):  
Timothy Davies
Keyword(s):  
Indian Ocean ◽  
West Coast ◽  
Western Indian Ocean ◽  
East India Company ◽  
The West ◽  
Trade Networks ◽  
West Coast Of India ◽  
The Indian Ocean ◽  
English East India Company ◽  
Indian Ocean World

This article explores the private trade networks of English East India Company merchants on the west coast of India during the first half of the eighteenth century. Existing studies of English private trade in the Indian Ocean have almost exclusively focused on India's eastern seaboard, the Coromandel Coast and the Bay of Bengal regions. This article argues that looking at private trade from the perspective of the western Indian Ocean provides a different picture of this important branch of European trade. It uses EIC records and merchants' private papers to argue against recent metropolitan-centred approaches to English private trade, instead emphasising the importance of more localised political and economic contexts, within the Indian Ocean world, for shaping the conduct and success of this commerce.

scholarly journals Integrating conservation, restoration and land-use planning in islands—An illustrative case study in Réunion Island (Western Indian Ocean)

2011 ◽  
Vol 101 (2) ◽  
pp. 120-130 ◽  
Author(s):  
Erwann Lagabrielle ◽  
Mathieu Rouget ◽  
Thomas Le Bourgeois ◽  
Karine Payet ◽  
Laurent Durieux ◽  
...  
Keyword(s):  
Land Use ◽  
Indian Ocean ◽  
Land Use Planning ◽  
Western Indian Ocean ◽  
Illustrative Case ◽  
Reunion Island ◽  
Réunion Island ◽  
Illustrative Case Study

scholarly journals Electrical structure of Plaine des Sables caldera, Piton de la Fournaise volcano (Reunion Island)

1997 ◽  
Vol 40 (2) ◽  
Author(s):  
P. A. Schnegg
Keyword(s):  
Electrical Properties ◽  
Indian Ocean ◽  
Hot Spot ◽  
Western Indian Ocean ◽  
Conducting Layer ◽  
Reunion Island ◽  
Shield Volcano ◽  
Final Model ◽  
Piton De La Fournaise ◽  
Réunion Island

An Audio Magnetotelluric (AMT) profile has been carried out across the Plaine des Sables, a former caldera of the active Piton de la Fournaise volcano, Reunion Island. Located in the Western Indian Ocean, between the Mascarene and Madagascar basins, this basaltic shield volcano originates from the activity of a hot spot. Our aim was to determine the internal structure of the volcano, in particular the shallow electrical properties of an area extending between the old and the new caldera rims. Although several teams had already conducted AMT work in this region a few years ago, there was a need for more a detailed, in depth survey. Our final model displays a noticeable slope of the Plaine des Sables basement oriented toward the present Fournaise summit. This slope is interpreted as resulting from successive landslides toward the ocean. We conclude that this dipping, electrically good conducting layer, probably belongs to the flat layering of an older caldera.

scholarly journals A giant squid (Architeuthis dux) off Reunion Island, western Indian Ocean: the greatest giant ever?

2017 ◽  
Vol 98 (8) ◽  
pp. 2087-2093
Author(s):  
Evgeny V. Romanov ◽  
Sebastien Jaquemet ◽  
Lara Puetz
Keyword(s):  
Indian Ocean ◽  
Western Indian Ocean ◽  
Allometric Equation ◽  
Mantle Length ◽  
Reunion Island ◽  
The South ◽  
Giant Squid ◽  
Réunion Island ◽  
Comparable Size

A freshly dead individual of the giant squidArchiteuthis dux, presumably mutilated by a predator of bigger or comparable size, is reported from the south-western Indian Ocean in proximity to Reunion Island. The species was identified from body and beak morphology and validated genetically. The dorsal mantle length (DML) estimated from beak measurements (lower rostral length, LRL) varied between 2153 and 3060 mm depending on the allometric equation used. TheArchiteuthis duxindividual described here is the biggest giant squid ever reported for the region.

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