Phylogeography of Petrolisthes armatus, an invasive species with low dispersal ability

Abstract

Theoretically, species with high population structure are likely to expand their range, because marginal populations are free to adapt to local conditions; however, meta-analyses have found a negative relation between structure and invasiveness. The crab Petrolisthes armatus has a wide native range, which has expanded in the last three decades. We sequenced 1718 bp of mitochondrial DNA from native and recently established populations to determine the population structure of the former and the origin of the latter. There was phylogenetic separation between Atlantic and eastern Pacific populations, and between east and west Atlantic ones. Haplotypes on the coast of Florida and newly established populations in Georgia and South Carolina belong to a different clade from those from Yucatán to Brazil, though a few haplotypes are shared. In the Pacific, populations from Colombia and Ecuador are highly divergent from those from Panamá and the Sea of Cortez. In general, populations were separated hundreds to million years ago with little subsequent gene flow. High genetic diversity in the newly established populations shows that they were founded by many individuals. Range expansion appears to have been limited by low dispersal rather than lack of ability of marginal populations to adapt to extreme conditions.

Habitat provided by native species facilitates higher abundances of an invader in its introduced compared to native range

“…This is predicted to result in shifts in body size and higher reproductive output, and therefore higher fitness, in the introduced compared to native range 44,45 . Indeed, another invasive porcelain crab, P. armatus, has a smaller size at first reproduction and increased reproductive output in invasive populations on the southeastern coast of the USA compared to native populations in Brazil 46,47 , although it is unlikely that P. armatus on the southeastern coast of the USA came from Brazil 48 . We do not know whether invasive P. elongatus have higher fitness, Table 1.…”

Sexual system, reproductive cycle and embryonic development of the red-striped shrimp Lysmata vittata, an invader in the western Atlantic Ocean

“…Lastly, in addition to environmental factors that may affect larval survival (e.g., salinity, temperature, food availability), the time required for the development of planktonic decapods is another relevant factor to the invasion of new territories. The dissemination patterns of populations of sessile or sedentary marine organisms are directly related to their dispersal ability [59]. Moreover, decapod crustaceans disperse more commonly during the planktonic larval stages, naturally as well as during invasions.…”

Marine species formation along the rise of Central America: The anomuran crab Megalobrachium

“…Atlantic and Pacific populations of Cytb, 18S and H3 of four individuals, two from each side of the Panama Isthmus, were newly sequenced. 16S rDNA (GenBank accession numbers , , and ) and COI (GenBank accession numbers , , and ) sequences of the same individuals were taken from a previous study by Hiller and Lessios (). Petrolisthes armatus shows the least transisthmian divergence of all porcellanids sampled to date (Hiller et al, ; Hiller & Lessios, ) and is thus likely to have been separated during the final stages of isthmus completion, 3 Ma (Coates & Obando, ; O'Dea et al, ).…”

“…16S rDNA (GenBank accession numbers , , and ) and COI (GenBank accession numbers , , and ) sequences of the same individuals were taken from a previous study by Hiller and Lessios (). Petrolisthes armatus shows the least transisthmian divergence of all porcellanids sampled to date (Hiller et al, ; Hiller & Lessios, ) and is thus likely to have been separated during the final stages of isthmus completion, 3 Ma (Coates & Obando, ; O'Dea et al, ). However, Montes et al () have suggested that after 12.5 Ma only narrow water passages connected the eastern Pacific and the Caribbean.…”

“…These species, known as geminates‚ (Jordan, ) resemble each other morphologically to a degree that suggests that they belong to sister clades separated by the isthmus. Morphological porcellanid geminates are so similar that in some cases they can only be distinguished at the larval stage, or by molecular comparisons (Gore, ; Hiller et al, ; Stillman & Reeb, ), and in some cases they are not granted specific status (Hiller et al, ; Hiller & Lessios, ). This morphological similarity provides a first hint that a great deal of porcellanid speciation in American waters was triggered by the rise of the Isthmus of Panama.…”