scholarly journals Flatfoot in Africa, the cirripede Chthamalus in the west Indian Ocean

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11710
Author(s):  
Noa Simon-Blecher ◽  
Avi Jacob ◽  
Oren Levy ◽  
Lior Appelbaum ◽  
Shiran Elbaz-Ifrah ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Cryptic Species ◽  
Morphological Characteristics ◽  
West Indian ◽  
Western Indian Ocean ◽  
Rocky Intertidal ◽  
Morphological Data ◽  
The West ◽  
African Species ◽  
West Indian Ocean

Barnacles of the genus Chthamalus are commonly encountered rocky intertidal shores. The phylogeography of the different species in the Western Indian Ocean is unclear. Using morphological characteristics as well as the molecular markers mitochondrial cytochrome oxygenase subunit I (COI) and the nuclear sodium-potassium ATPase (NaKA), we identified four clades representing four species in the Western Indian Ocean and its adjacent seas. Among these species, a newly identified species, Chthamalus barilani, which was found in Madagascar, Zanzibar and Tanzania. Chthamalus from the coasts of Tanzania and Zanzibar is identified morphologically as C. malayensis, and clusters with C. malayensis from the Western Pacific and the Indo Malayan regions. C. malayensis is regarded as a group of four genetically differentiated clades representing four cryptic species. The newly identified African clade is genetically different from these clades and the pairwise distances between them justify the conclusion that it is an additional cryptic species of C. malayensis. This type of genetic analyses offers an advantage over morphological characterization and allowed us to reveal that another species, C. barnesi, which is known from the Red Sea, is also distributed in the Arabian Sea and the Persian Gulf. We could also confirm the presence of the South African species C. dentatus in the Mozambique channel. This represents the Northeastern limit of C. dentatus, which is usually distributed along the coast of southern Africa up to the Islands of Cape Verde in West Africa. Altogether, based on a combination of morphology and genetics, we distinct between four clusters of Chthamalus, and designate their distribution in the West Indian Ocean. These distinctions do not agree with the traditional four groups reported previously based merely on morphological data. Furthermore, these findings underline the importance of a combining morphological and genetics tools for constructing barnacle taxonomy.

scholarly journals Molecular Ecology of Coral Reef Microorganisms in the Western Indian Ocean coast of Kenya

2020 ◽  
Author(s):  
Sammy Wambua ◽  
Hadrien Gourlé ◽  
Etienne de Villiers ◽  
Oskar Karlsson ◽  
Nina Wambiji ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Coral Reefs ◽  
High Throughput Sequencing ◽  
Molecular Ecology ◽  
West Indian ◽  
Western Indian Ocean ◽  
Sediment Layer ◽  
The West ◽  
Kenyan Coast ◽  
West Indian Ocean

AbstractCoral reefs face increased environmental threats from anthropomorphic climate change and pollution, from agriculture, industries and tourism. They are economically vital for many people worldwide, and harbour a fantastically diverse ecosystem, being the home for many species of fish and algae. Surprisingly little is known about the microbial communities living in and in the surrounding of coral reefs. Here we employ high throughput sequencing for investigating the bacteria living in the water column and upper sediment layer in close proximity to coral reefs on the Kenyan coast of the West Indian Ocean. We show that while the read-level taxonomic distribution of bacteria is similar with ones obtained from 16S metabarcoding, whole metagenome sequencing provides valuable functional insights not available with 16S metabarcoding. We find evidence of pollution, marked by the presence of Vibrio and more importantly the presence of antibiotic resistance notably to vancomycin, that we attribute to the use of avoparcin in agriculture. Additionally, 175 bacterial genomes not previously sequenced were discovered.Our study is the first whole-metagenome study from the West Indian Ocean, provides a much-needed baseline to study microbes surrounding coral reefs under different conditions as well as the microbiome of coral reefs.

scholarly journals Delivery of halogenated very short-lived substances from the West Indian Ocean to the stratosphere during Asian summer monsoon

2017 ◽  
Author(s):  
Alina Fiehn ◽  
Birgit Quack ◽  
Helmke Hepach ◽  
Steffen Fuhlbrügge ◽  
Susann Tegtmeier ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Interannual Variability ◽  
Summer Monsoon ◽  
Asian Monsoon ◽  
Asian Summer Monsoon ◽  
Source Region ◽  
West Indian ◽  
The West ◽  
West Indian Ocean ◽  
Asian Summer

Abstract. Halogenated very short-lived substances (VSLS) are naturally produced in the ocean and emitted to the atmosphere. When transported to the stratosphere, these compounds can have a significant influence on the ozone layer and climate. During a research cruise on RV Sonne in the subtropical and tropical West Indian Ocean in July and August 2014, we measured the VSLS, methyl iodide (CH3I) and for the first time bromoform (CHBr3) and dibromomethane (CH2Br2), in surface seawater and the marine atmosphere to derive their emission strengths. Using the Lagrangian transport model Flexpart with ERA-Interim meteorological fields, we calculated the direct contribution of observed VSLS emissions to the stratospheric halogen burden during Asian summer monsoon. Furthermore, we compare the in situ calculations with the interannual variability of transport from a larger area of the West Indian Ocean surface to the stratosphere for July 2000–2015. We found that the West Indian Ocean is a strong source region for CHBr3 (910 pmol m−2 h−1), very strong for CH2Br2 (930 pmol m−2 h−1), and average for CH3I (460 pmol m−2 h−1). The atmospheric transport from the tropical West Indian Ocean surface to the stratosphere experiences two main pathways. On very short timescales, especially relevant for the shortest-lived compound CH3I (3.5 days lifetime), convection above the Indian Ocean lifts oceanic air masses and VSLS towards the tropopause. On a longer timescale, the Asian summer monsoon circulation transports oceanic VSLS towards India and Bay of Bengal, where they are lifted with the monsoon convection and reach stratospheric levels in the southeastern part of the Asian monsoon anticyclone. This transport pathway is more important for the longer-lived brominated compounds (17 and 150 days lifetime for CHBr3 and CH2Br2). The entrainment of CHBr3 and CH3I from the West Indian Ocean to the stratosphere during Asian summer monsoon is less than from previous cruises in the tropical West Pacific Ocean during boreal autumn/early winter, but higher than from the tropical Atlantic during boreal summer. In contrast, the projected CH2Br2 entrainment was very high because of the high emissions during the West Indian Ocean cruise. The 16-year July time series shows highest interannual variability for the short-lived CH3I and lowest for the long-lived CH2Br2. During this time period, a small increase of VSLS entrainment from the West Indian Ocean through the Asian monsoon to the stratosphere is found. Overall, this study confirms that the subtropical and tropical West Indian Ocean is an important source region of halogenated VSLS, especially CH2Br2, to the troposphere and stratosphere during the Asian summer monsoon.

scholarly journals Four new species of Acalypha L. (Euphorbiaceae, Acalyphoideae) from the West Indian Ocean Region

PhytoKeys ◽  
2020 ◽  
Vol 140 ◽  
pp. 57-73
Author(s):  
Iris Montero-Muñoz ◽  
Geoffrey A. Levin ◽  
José M. Cardiel
Keyword(s):  
New Species ◽  
Indian Ocean ◽  
Western Indian Ocean ◽  
Molecular Evidence ◽  
Indian Ocean Region ◽  
The West ◽  
Ocean Region ◽  
West Indian Ocean ◽  
Conservation Assessments ◽  
First Time

Four new species of Acalypha (Euphorbiaceae, Acalyphoideae) from the Western Indian Ocean Region, based on morphological and molecular evidence, are described, illustrated, and mapped. Acalypha gillespieae sp. nov., A. leandrii sp. nov. and A. nusbaumeri sp. nov. are endemic to Madagascar, and A. mayottensis sp. nov. is known only from Mbouzi islet (Mayotte), in the Comoros Archipelago. We also describe for the first time in Acalypha the presence of membranous or chartaceous perules covering the axillary buds. Preliminary conservation assessments of the new species are also provided.

Population subdivision in the tropical spiny lobster Panulirus ornatus throughout its Indo-West Pacific distribution

2016 ◽  
Vol 74 (3) ◽  
pp. 759-768 ◽  
Author(s):  
Bhargavi Yellapu ◽  
Andrew Jeffs ◽  
Stephen Battaglene ◽  
Shane D. Lavery
Keyword(s):  
Indian Ocean ◽  
Western Australia ◽  
Spiny Lobster ◽  
Haplotype Diversity ◽  
West Indian ◽  
Population Subdivision ◽  
Effective Population ◽  
The West ◽  
West Pacific ◽  
West Indian Ocean

Many marine species with Indo-West Pacific distributions have been found to have a considerable level of genetic population structuring across this broad region. We investigated mitochondrial DNA diversity throughout the extensive range of the commercially valuable ornate spiny lobster, Panulirus ornatus, which has an unusually lengthy larval period that can last up to six months. In this study, 298 specimens were sampled from 17 locations covering the West Indian Ocean, Western Australia, Southeast Asia, and the Northwest and Southwest Pacific. Based on sequencing of a 461 bp fragment of mitochondrial control region, we found high levels of haplotype diversity (H = 0.99) and overall significant population differentiation (Φst = 0.113, P < 0.001). The West Indian Ocean and Western Australia populations were the most genetically divergent, with little differentiation among the remaining Southeast Asian and West Pacific populations. The Western Australia population showed evidence of being a peripherally isolated population, with significantly lowered effective population size, likely due to the prevailing ocean currents. The present results indicate that genetically distinct stocks of P. ornatus are present in the wild and that historical and present day biogeographic phenomena have likely influenced this population structure. The presence of these divergent stocks has major implications for both management of fisheries and aquaculture breeding programs for this valuable species.

Sign in / Sign up

Export Citation Format

Share Document