An Example of How Barcodes Can Clarify Cryptic Species: The Case of the Calanoid Copepod Mastigodiaptomus albuquerquensis (Herrick)

Abstract

BackgroundThe freshwater calanoid Mastigodiaptomus is a genus with high richness in the Americas and is composed of nine species, seven recorded in Mexico and four that are apparently endemic to small areas. Mastigodiaptomus albuquerquensis is a common, widely distributed species ranging from the southern USA to Central America. This species can be easily identified by a notable butterfly-like sclerotization on the basis of the right fifth leg of males. Nevertheless, morphological differences observed among populations throughout this species distributional range have led to the description of several related species or subspecies, such as M. albuquerquensis patzcuarensis from Lake Pátzcuaro in the Central Plateau of Mexico.MethodsGenetic results based on barcodes, morphology based on scanning electron and light microscopy images, and morphometric analyses were used to describe cryptic species within the M. albuquerquensis complex.ResultsThe morphological analyses coincided partially with the genetic markers, suggesting the existence of at least two sibling species: M. albuquerquensis s. str. and M. patzcuarensis. A third species was genetically separated but was morphologically indistinguishable from the M. patzcuarensis group.ConclusionsHidden diversity has been a major problem in establishing real patterns of species distribution and genetic acquisition from megadiverse hotspots such as Mexico, where the Nearctic and the Neotropical regions of the Americas meet. Barcodes can help taxonomists to reveal and formally name these new species. Here, we describe two of three potential species highlighted by the use of barcodes: M. albuquerquensis s. str. in the northern semi-desert and M. patzcuarensis on the Central Plateau at more than 2000 m above sea level.

A new species of Mastigodiaptomus Light, 1939 from Mexico, with notes of species diversity of the genus (Copepoda, Calanoida, Diaptomidae)

“…A segment of the COI gene was amplified using the LCOI490 and HCO2198 primers or the Zplank primers, as suggested by Folmer et al (1994) and Prosser et al (2013), respectively. The preparation of the PCR 12.5 µL PCR reaction mixture and visualization of PCR products was performed as described by Gutiérrez-Aguirre et al (2014) and Montiel-Martínez et al (2008). Sequence analysis was carried out at the Chetumal Node of the MEXBOL (El Colegio de la Frontera Sur).…”

“…Additionally, a search of GenBank and the public data of the Barcode of Life Data System (BOLD) produced sequences of Mastigodiaptomus albuquerquensis , Mastigodiaptomus patzcuarensis , Mastigodiaptomus cf. albuquerquensis (accession numbers for BOLD and GenBank in Gutiérrez-Aguirre et al 2014), Mastigodiaptomus texensis , Mastigodiaptomus cf. nesus, Mastigodiaptomus montezumae , Mastigodiaptomus cf. reidae, and Mastigodiaptomus reidae (accession numbers for BOLD and sampled site are shown in Table 1). …”

“…Bowman (1986) recognized morphologically similar species within the Mastigodiaptomus genus using differences in the integument of prosomal wings and fifth legs of both sexes. Empirical evidence gathered from several species of freshwater crustaceans has shown that these morphological differences are consistent with reproductive isolation (Alekseev et al 2006), genetic differentiation (Quiroz-Vázquez and Elías-Gutiérrez 2009; Gutiérrez-Aguirre et al 2014), or both when they are probed (Montiel-Martínez et al 2008). …”

“…Recent studies of this genus in the Neotropical region have added new species of these diaptomids (Gutiérrez-Aguirre and Cervantes-Martínez 2013) or the morphological and genetic analysis have produced recognition of species such as Mastigodiaptomus patzcuarensis (Kiefer, 1938) (Gutiérrez-Aguirre et al 2014). Currently ten species of Mastigodiaptomus are known: Mastigodiaptomus purpureus (Marsh, 1907), Mastigodiaptomus texensis (M. S. Wilson, 1953), Mastigodiaptomus amatitlanensis (M. S. Wilson, 1941), Mastigodiaptomus albuquerquensis (Herrick, 1895), Mastigodiaptomus patzcuarensis (Kiefer, 1938), Mastigodiaptomus montezumae (Brehm, 1955), Mastigodiaptomus nesus Bowman, 1986, Mastigodiaptomus maya Suárez-Morales & Elías-Gutiérrez, 2000, Mastigodiaptomus reidae Suárez-Morales & Elías-Gutiérrez, 2000, and Mastigodiaptomus suarezmoralesi Gutiérrez-Aguirre & Cervantes-Martínez, 2013.…”

Eurytemora carolleeae in the Laurentian Great Lakes revealed by phylogenetic and morphological analysis

“…Sequences of the mitochondrial cytochrome oxidase I (COI) gene have been shown to be very useful for distinguishing calanoid and harpacticoid copepods including cryptic and sibling species in biogeographic studies (Gutierrez-Aguirre et al, 2014; Laakmann et al, 2013; Miracle et al, 2013; Peterson et al, 2013). Previous genetic analyses of the COI gene in Eurytemora populations described specimens from the Great Lakes as belonging to an Atlantic clade of E. affinis (Lee and Frost, 2002; Winkler et al, 2008).…”