From the mountains to the sea: phylogeography and cryptic diversity within the mountain mullet, Agonostomus monticola (Teleostei: Mugilidae)

Abstract

Aim The mountain mullet, Agonostomus monticola, is a diadromous fish widespread throughout Middle America, occurring in rivers along the Atlantic and Pacific slopes, as well as in the West Indies. Based on the disjunct distribution of this species, it has been hypothesized that this fish may represent more than one taxon. The purpose of this study was to conduct a robust phylogeographical analysis of A. monticola across its range, using mitochondrial and nuclear markers. We aimed to investigate the potential for cryptic diversity and the time‐scale of divergence in an effort to elucidate biogeographical episodes within Middle America in relation to the evolutionary history of Agonostomus monticola. Location North and Middle America, including the West Indies. Methods Mitochondrial and nuclear sequence data (cyt b, S7‐1) from individuals throughout the range of the species were analysed phylogenetically using maximum‐likelihood methodology. The oldest known fossil mullet was used as a calibration to investigate divergence times for clades within A. monticola. Results Results indicate four distinct lineages within the known range of A. monticola that largely correspond to oceanic basins (Caribbean, Gulf of Mexico, Pacific‐A, Pacific‐B). Divergence time estimates indicate early to mid‐Miocene divergences for all four A. monticola clades, with Oligocene to Miocene divergences of internal nodes. Main conclusions These findings are congruent with geological hypotheses regarding movement of the Chortís block, as well as recent studies on the age of beginning emergence of the Panama Arc.

Occurrence of a Colorful Prejuvenile Mountain Mullet (Agonostomus monticola) in Brackish Water of Montserrat, Lesser Antilles

“…The resulting COI sequence from the Montserrat mullet was identical to 3 Mountain Mullet sequences available in Genbank (Cuba: FN545593 and FN545594, and Guadeloupe: JQ060146). Consequently, this latter finding confirms that the Montserrat specimen belongs to the Caribbean clade as defined by McMahan et al (2013) and as expected from the geographic location of the island.…”

“…McMahan et al (2013) found 4 distinct lineages within the Mountain Mullet, roughly corresponding to ocean basins: an Eastern Mexico form, a Caribbean form, and 2 forms in the Pacific Ocean. Mountain Mullet has often been described as catadromous (e.g., Fievet et al 2001), but its condition has been questioned (Gilbert and Kelso 1971, Loftus et al 1984, Cruz 1987.…”

Complete mitochondrial genomes of three Neotropical sleeper gobies: Eleotris amblyopsis, E. picta and Hemieleotris latifasciata (Gobiiformes: Eleotridae)

“…This marine-derived and diadromous component comprises five families (Ariidae, Atherinidae, Gerridae, Eleotridae, and Gobiidae) that, despite representing an important fraction of the diversity of this Neotropical assemblage, is considerably understudied (McMahan et al 2013;Galv an-Quesada et al 2016); particularly relative to the other taxa in the region such as poeciliids and cichlids that have been the focus of many systematic and biogeographic studies (e.g. Martin and Bermingham 1998;Perdices et al 2005;Alda et al 2013;Marchio and Piller 2013;McMahan et al 2017).…”

Assessing population-level morphometric variation of the Mountain Mullet Agonostomus monticola (Teleostei: Mugilidae) across its Middle American distribution

“…One such group is the genus Agonostomus, which includes A. monticola (Bancroft, 1834), A. telfairii Bennett, 1832and A. catalai Pellegrin, 1932(cf. Harrison, Howes, 1991Thomson, 1997;McMahan et al, 2013). Within the genus, A. monticola is the most widespread species, occurring along both sides of the American continent from the Yaqui river in Sonora, México (Hendrickson et al, 1980) including drainages in Baja California Sur (Follett, 1960;Ruiz-Campos et al, 2002) to Colombia; on the Atlantic slope, it is distributed from Florida (USA) (Contreras-Balderas, 1972;García-DeLeón et al, 2005) to Venezuela as well as the islands of the West Indies (Castro-Aguirre et al, 1999;Miller, 2005).…”

“…They recovered a non-monophyletic Agonostomus, and demonstrated the existence of multiple lineages within the widespread A. monticola. Later, McMahan et al (2013) conducted a phylogeographic study of A. monticola based also on molecular data (mitochondrial and nuclear) and recovered four lineages, with origins from the late to middle Miocene (14.7 to 7.0 million years).…”