Occurrence and distribution of ascidians in Vizhinjam Bay (south west coast of India)

Abdul, Jaffar Ali H.; Sivakumar, V.

doi:10.1016/j.jembe.2006.10.041

Cited by 10 publications

(2 citation statements)

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“…This species was first recorded outside its introduced range in Bizerte (Tunisia) in the early 1960s [46] , but has since been recorded all over the western Mediterranean Sea and adjacent Atlantic Ocean region [47] , [48] . Subsequently, this species was detected in California in 1986 [49] , on the NE Atlantic coast in 1994 [50] , [51] , in South Africa in 2000 [52] , in New Zealand in 2003 [53] , in India in 2006 [54] , and recently in Japan (T. Nishikawa, pers. comm.).…”

Section: Methodsmentioning

confidence: 99%

Tracking Invasion Histories in the Sea: Facing Complex Scenarios Using Multilocus Data

et al. 2012

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In recent years, new analytical tools have allowed researchers to extract historical information contained in molecular data, which has fundamentally transformed our understanding of processes ruling biological invasions. However, the use of these new analytical tools has been largely restricted to studies of terrestrial organisms despite the growing recognition that the sea contains ecosystems that are amongst the most heavily affected by biological invasions, and that marine invasion histories are often remarkably complex. Here, we studied the routes of invasion and colonisation histories of an invasive marine invertebrate Microcosmus squamiger (Ascidiacea) using microsatellite loci, mitochondrial DNA sequence data and 11 worldwide populations. Discriminant analysis of principal components, clustering methods and approximate Bayesian computation (ABC) methods showed that the most likely source of the introduced populations was a single admixture event that involved populations from two genetically differentiated ancestral regions - the western and eastern coasts of Australia. The ABC analyses revealed that colonisation of the introduced range of M. squamiger consisted of a series of non-independent introductions along the coastlines of Africa, North America and Europe. Furthermore, we inferred that the sequence of colonisation across continents was in line with historical taxonomic records - first the Mediterranean Sea and South Africa from an unsampled ancestral population, followed by sequential introductions in California and, more recently, the NE Atlantic Ocean. We revealed the most likely invasion history for world populations of M. squamiger, which is broadly characterized by the presence of multiple ancestral sources and non-independent introductions within the introduced range. The results presented here illustrate the complexity of marine invasion routes and identify a cause-effect relationship between human-mediated transport and the success of widespread marine non-indigenous species, which benefit from stepping-stone invasions and admixture processes involving different sources for the spread and expansion of their range.

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Section: Methodsmentioning

confidence: 99%

Tracking Invasion Histories in the Sea: Facing Complex Scenarios Using Multilocus Data

et al. 2012

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“…The solitary ascidian Microcosmus squamiger was first described in a study of Australian samples undertaken by Michaelsen (1927), and is considered to be native to this region (Kott, 1985; Monniot et al ., 2001) where it lives in open, undisturbed habitats. However, this animal has spread throughout the world and has been detected as an introduced species in locations such as the west coast of North America (Lambert & Lambert, 1998; Lambert & Lambert, 2003), South Africa (Monniot et al ., 2001), the east coast of Africa (Monniot, 2002), the south coast of India (Abdul & Sivakumar, 2007), along the Atlantic Iberian Peninsula coast (Naranjo & García‐Gómez, 1994; Turon et al ., 2007), Madeira and the Canary Islands (Turon et al ., 2007) and the Mediterranean Sea (Monniot, 1981; Naranjo et al ., 1996; Mastrototaro & Dappiano, 2005; Zenetos et al ., 2005; Turon et al ., 2007). In its introduced range, the species is usually found in harbours and marinas (Lambert & Lambert, 1998; Lambert & Lambert, 2003; Ranasinghe et al ., 2005), but it can spread to adjacent habitats as well, altering local benthic communities as it forms dense populations (Turon et al ., 2007).…”

Section: Introductionmentioning

confidence: 99%

Phylogeography of the widespread marine invader Microcosmus squamiger (Ascidiacea) reveals high genetic diversity of introduced populations and non‐independent colonizations

Rius¹,

Pascual

Turon

2008

Diversity and Distributions

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The spread of non‐indigenous species into new marine habitats represents an increasing threat to global diversity. Genetic techniques provide basic understanding of the invasion processes. The ascidian Microcosmus squamiger is considered to be native to Australia, having been spread worldwide via transoceanic vessels. It has successfully invaded artificial and natural habitats where it has become a pest. We studied phylogeography and genetic structure of 12 M. squamiger populations, including samples from its native range (Australia) and introduced populations from the Indian, Pacific, and Atlantic oceans, as well as the Mediterranean Sea. We amplified 574 bp of the mitochondrial COI gene in 258 individuals and found a total of 52 haplotypes. A haplotype tree revealed two main groups of haplotypes. The relative frequency of each group of haplotypes, multidimensional scaling, and analysis of molecular variance showed important differences between the western Australia localities and the remaining ones (eastern Australia and introduced populations). Furthermore, we found that the colonization of the different areas by M. squamiger has not occurred independently, as many introduced populations shared some low frequency alleles. A nested clade analysis showed a global pattern of restricted gene flow with isolation by distance, although we found episodes of long‐distance dispersal in some clades. A contiguous range expansion was detected between Australian populations. We conclude that M. squamiger is native to Australia and has most likely expanded its range of distribution sequentially through worldwide shipping, especially from the harbours of the more populated eastern Australia. In introduced populations, we found a high genetic diversity which suggests enhanced invasive potential. Consequently, there is a need to control this species, as it outcompetes local biota and is an economic threat.

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Distribution and invasiveness of a colonial ascidian, Didemnum psammathodes, along the southern Indian coastal water

Jaffar¹,

Akram²,

Arshan³

et al. 2016

Oceanologia

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Occurrence and distribution of ascidians in Vizhinjam Bay (south west coast of India)

Cited by 10 publications

References 0 publications

Tracking Invasion Histories in the Sea: Facing Complex Scenarios Using Multilocus Data

Tracking Invasion Histories in the Sea: Facing Complex Scenarios Using Multilocus Data

Phylogeography of the widespread marine invader Microcosmus squamiger (Ascidiacea) reveals high genetic diversity of introduced populations and non‐independent colonizations

Distribution and invasiveness of a colonial ascidian, Didemnum psammathodes, along the southern Indian coastal water

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