Restricted gene flow among western Indian Ocean populations of the mangrove whelk Terebralia palustris (Linnaeus, 1767) (Caenogastropoda: Potamididae)

ABSTRACTBackgroundBonefishes are cryptic species indiscriminately targeted by subsistence and recreational fisheries worldwide. The roundjaw bonefish, Albula glossodonta is the most widespread bonefish species in the Indo-Pacific and is listed as vulnerable to extinction by the IUCN’s Red List due to anthropogenic activities. Whole-genome datasets allow for improved population and species delimitation, which – prior to this study – were lacking for Albula species.ResultsWe generated a high-quality genome assembly of an A. glossodonta individual from Hawai‘i, USA. The assembled contigs had an NG50 of 4.75 Mbp and a maximum length of 28.2 Mbp. Scaffolding yielded an NG50 of 14.49 Mbp, with the longest scaffold reaching 42.29 Mbp. Half the genome was contained in 20 scaffolds. The genome was annotated with 28.3 K protein-coding genes. We then analyzed 66 A. glossodonta individuals and 38,355 SNP loci to evaluate population genetic connectivity between six atolls in Seychelles and Mauritius in the Western Indian Ocean. We observed genetic homogeneity between atolls in Seychelles and evidence of reduced gene flow between Seychelles and Mauritius. The South Equatorial Current could be one mechanism limiting gene flow of A. glossodonta populations between Seychelles and Mauritius.ConclusionsQuantifying the spatial population structure of widespread fishery species such as bonefishes is necessary for effective transboundary management and conservation. This population genomic dataset mapped to a high-quality genome assembly allowed us to discern shallow population structure in a widespread species in the Western Indian Ocean. The genome assembly will be useful for addressing the taxonomic uncertainties of bonefishes globally.

Download Full-text

Highly restricted gene flow between disjunct populations of the skunk clownfish (Amphiprion akallopisos) in the Indian Ocean

Marine Ecology ◽

10.1111/maec.12357 ◽

2016 ◽

Vol 38 (1) ◽

pp. e12357 ◽

Cited By ~ 8

Author(s):

Filip Huyghe ◽

Marc Kochzius

Keyword(s):

Gene Flow ◽

Indian Ocean ◽

Restricted Gene Flow ◽

Disjunct Populations ◽

The Indian Ocean ◽

Amphiprion Akallopisos

Download Full-text

Expansion of the mangrove species Rhizophora mucronata in the Western Indian Ocean launched contrasting genetic patterns

Scientific Reports ◽

10.1038/s41598-021-84304-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ludwig Triest ◽

Tom Van der Stocken ◽

Dennis De Ryck ◽

Marc Kochzius ◽

Sophie Lorent ◽

...

Keyword(s):

Gene Flow ◽

Indian Ocean ◽

Large Scale ◽

Geographic Distance ◽

Western Indian Ocean ◽

Coastal Current ◽

Rhizophora Mucronata ◽

East African ◽

Mangrove Species ◽

Mozambique Channel

AbstractEstimates of population structure and gene flow allow exploring the historical and contemporary processes that determine a species’ biogeographic pattern. In mangroves, large-scale genetic studies to estimate gene flow have been conducted predominantly in the Indo-Pacific and Atlantic region. Here we examine the genetic diversity and connectivity of Rhizophora mucronata across a > 3,000 km coastal stretch in the Western Indian Ocean (WIO) including WIO islands. Based on 359 trees from 13 populations and using 17 polymorphic microsatellite loci we detected genetic breaks between populations of the (1) East African coastline, (2) Mozambique Channel Area (3) granitic Seychelles, and (4) Aldabra and northern Madagascar. Genetic structure, diversity levels, and patterns of inferred connectivity, aligned with the directionality of major ocean currents, driven by bifurcation of the South Equatorial Current, northward into the East African Coastal Current and southward into the Mozambique Channel Area. A secondary genetic break between nearby populations in the Delagoa Bight coincided with high inbreeding levels and fixed loci. Results illustrate how oceanographic processes can connect and separate mangrove populations regardless of geographic distance.

Download Full-text

Phylogeography of two marine predators, giant trevally (Caranx ignobilis) and bluefin trevally (Caranx melampygus), across the Indo-Pacific

Bulletin of Marine Science ◽

10.5343/bms.2019.0114 ◽

2021 ◽

Vol 97 (2) ◽

pp. 257-280

Author(s):

Jessica R Glass ◽

Scott R Santos ◽

John SK Kauwe ◽

Brandon D Pickett

Keyword(s):

Gene Flow ◽

Western Indian Ocean ◽

Genetic Connectivity ◽

Restricted Gene Flow ◽

Nucleotide Polymorphisms ◽

Central Pacific ◽

Geographic Population ◽

Marine Predators ◽

Management Measures ◽

Critical Components

For economically valuable marine fishes, identifying biogeographic barriers and estimating the extent of gene flow are critical components of fisheries management. We examined the population genetic structure of two commercially important reef-associated predators, the giant trevally ( Caranx ignobilis) and bluefin trevally (Caranx melampygus). We sampled 225 individuals and 32,798 single nucleotide polymorphisms (SNPs) of C. ignobilis, and 74 individuals and 43,299 SNPs of C. melampygus. Analyses of geographic population structure indicate the two species display subtly different phylogeographic patterns. Caranx ignobilis comprises two to three putative populations—one in the Central Pacific, one inhabiting the Western Pacific and Eastern Indian oceans, and one in the Western Indian Ocean—with some restricted gene flow between them. Caranx melampygus shows evidence of restricted gene flow from Hawaii to the West Pacific and Indian oceans, as well as limited genetic connectivity across the Indo- Pacific Barrier. Both species exhibit patterns characteristic of other large, reef-associated predators such as deepwater snappers and the great barracuda. This study contributes to ongoing assessments of the role of the Indo-Pacific Barrier in shaping patterns of phylogeography for large reef-associated fishes. Furthermore, by identifying putative populations of C. ignobilis and C. melampygus in the Central Pacific, our findings serve to improve future management measures for these economically important, data-limited species, particularly in light of historic and contemporary overfishing in Hawaii.

Download Full-text

Gene flow and genetic structure of Sicyopterus lagocephalus in the south-western Indian Ocean, assessed by intron-length polymorphism

Journal of Experimental Marine Biology and Ecology ◽

10.1016/j.jembe.2007.05.015 ◽

2007 ◽

Vol 349 (2) ◽

pp. 223-234 ◽

Cited By ~ 19

Author(s):

Thierry B. Hoareau ◽

Pierre Bosc ◽

Pierre Valade ◽

Patrick Berrebi

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

Indian Ocean ◽

Length Polymorphism ◽

Western Indian Ocean ◽

Intron Length ◽

The South ◽

Intron Length Polymorphism

Download Full-text

Editorial Introduction

The Journal of Indian Ocean World Studies ◽

10.26443/jiows.v4i1.68 ◽

2020 ◽

Vol 4 (1) ◽

pp. 1

Author(s):

Editors of the JIOWS

Keyword(s):

Nineteenth Century ◽

Indian Ocean ◽

Western Indian Ocean ◽

Late Nineteenth Century ◽

Fourth Volume ◽

History Of ◽

The Indian Ocean ◽

Complex Relationships ◽

Indian Ocean World ◽

Shed Light

The editors are proud to present the first issue of the fourth volume of the Journal of Indian Ocean World Studies. This issue contains three articles, by James Francis Warren (Murdoch University), Kelsey McFaul (University of California, Santa Cruz), and Marek Pawelczak (University of Warsaw), respectively. Warren’s and McFaul’s articles take different approaches to the growing body of work that discusses pirates in the Indian Ocean World, past and present. Warren’s article is historical, exploring the life and times of Julano Taupan in the nineteenth-century Philippines. He invites us to question the meaning of the word ‘pirate’ and the several ways in which Taupan’s life has been interpreted by different European colonists and by anti-colonial movements from the mid-nineteenth century to the present day. McFaul’s article, meanwhile, takes a literary approach to discuss the much more recent phenomenon of Somali Piracy, which reached its apex in the last decade. Its contribution is to analyse the works of authors based in the region, challenging paradigms that have mostly been developed from analysis of works written in the West. Finally, Pawelczak’s article is a legal history of British jurisdiction in mid-late nineteenth-century Zanzibar. It examines one of the facets that underpinned European influence in the western Indian Ocean World before the establishment of colonial rule. In sum, this issue uses two key threads to shed light on the complex relationships between European and other Western powers and the Indian Ocean World.

Download Full-text