Although attempts to understand Central American freshwater fish provincialism date to the 1960s, early efforts lacked the wealth of distributional data now available. Biogeographic work on Central American freshwater fishes has been largely descriptive and regional, and lacked a broader synthesis. Here we use parsimony analysis of endemicity (PAE) to elucidate faunistic relationships between major drainages and to delineate areas of endemism. We then perform a Brooks parsimony analysis (BPA) on the resulting areas. The PAE recovered a primary division between four Pacific and six Atlantic slope areas of endemism. In contrast, the BPA recovered two Central American geographic clades, one sharing a history with North America and the other with South America. Fish diversity is uneven across Central America, with greater diversity in areas adjacent to the more species‐rich regions of North and South America. In northern and nuclear Central America, the paucity of ostariophysan freshwater fishes such as catfishes and characins (groups that dominate adjacent regions) contrasts with high species richness of poeciliids and cichlids. Results of this study are consistent with Myer's hypothesis that poeciliids and cichlids dispersed to Northern or Nuclear Middle America early in the Cenozoic, long before the Plio‐Pleistocene rise of the Isthmus of Panama.

The biogeographical patterns of the obligate freshwater fishes of Nuclear Middle America, a region that expands from southern Guatemala to northern Nicaragua, are described herein. Historically, three broad ichthyological provinces have been assigned to Nuclear Middle America: the Usumacinta, and the San Juan in the Atlantic slope and the ChiapasNicaragüense in the Pacific slope. With the use of correspondence analysis and unweighted pair group method with arithmetic mean cluster analysis of a presence/absence matrix of 76 obligate freshwater fishes, we identified four ichthyological provinces in Nuclear Middle America: (1) the Honduras and Guatemala Caribbean Highlands Province, (2) the Honduras and Nicaragua Mosquitia Province, (3) the Chiapas-El Salvador-Nacaome Province, and (4) the Choluteca and Nicaragua Pacific Province. Differences between provinces in species composition and species turnover between provinces were tested by analysis of similarity, the calculation of beta-diversity indices and an indicator species analysis. We then further characterized each province by identifying the number of endemics and classifying species according to their salinity tolerance. The most striking patterns of Nuclear Middle America freshwater fish distribution are its paucity of primary freshwater fishes and limited numbers of endemics. The four ichthyological provinces are distinct as indicated by the ANOSIM and beta-diversity analysis, although one province showed low beta-diversity values. These results suggest that, despite of the active geological history that characterized the region, there has been limited isolation of species in any given province, and historical drainage connectivity has been high.

We document patterns of coordinated dispersal over evolutionary time frames in heroine cichlids and poeciliine live-bearers, the two most species-rich clades of freshwater fishes in the Caribbean basin. Observed dispersal rate (DO) values were estimated from time-calibrated molecular phylogenies in Lagrange+, a modified version of the ML-based parametric biogeographic program Lagrange. DO is measured in units of “wallaces” (wa) as the number of biogeographic range-expansion events per million years. DO estimates were generated on a dynamic paleogeographic landscape of five areas over three time intervals from Upper Cretaceous to Recent. Expected dispersal rate (DE) values were generated from alternative paleogeographic models, with dispersal rates proportional to target area and source-river discharge volume, and inversely proportional to paleogeographic distance. Correlations between DO and DE were used to assess the relative contributions of these three biogeographic parameters. DO estimates imply a persistent dispersal corridor across the Eastern (Antillean) margin of the Caribbean plate, under the influence of prevailing and perennial riverine discharge vectors such as the Proto–Orinoco–Amazon river. Ancestral area estimation places the earliest colonizations of the Greater Antilles and Central America during the Paleocene–Eocene (ca. 58–45 Ma), potentially during the existence of an incomplete Paleogene Arc (∼59 Ma) or Lesser Antilles Arc (∼45 Ma), but predating the GAARlandia land bridge (∼34–33 Ma). Paleogeographic distance is the single best predictor of DO. The Western (Central American) plate margin did not serve as a dispersal corridor until the Late Neogene (12–0 Ma), and contributed relatively little to the formation of modern distributions.

No abstract

In recent years great strides have been made for improving our understanding of the evolutionary relationships among neotropical cichlids, particularly within the clade Heroini and its crown clade the herichthyins. Most phylogenetic studies have largely converged on congruent topologies for relationships among species and major lineages within the herichthyins. One major aspect missing from previous studies of these cichlids is a formal taxonomic revision, including the redefining of genera. Based on analysis of 52 species and three mitochondrial and two nuclear loci, we generate a Bayesian phylogeny for the herichthyin cichlids, and formally revise the taxonomy for genera within this clade using morphological features. Eight new genera are recognized and a key to all 16 genera of herichthyin cichlids is also presented.Key words: cichlid, revision, Mexico, Central America, morphology ResúmenGrandes pasos se han dado en años recientes en la mejora de nuestro conocimiento de las relaciones evolutivas entre ciclidos Neotropicales, particularmente dentro del clado Heroini. En el clado corona de Heroini están los herichthyins. Los estudios filogenéticos más recientes, han coincidido ampliamente con topologías congruentes para definir las relaciones entre especies y linajes mayores en este clado. La falta de una revisión taxonómica formal de estos ciclidos, es un gran vacío que han dejado estudios anteriores, incluyendo la redefinición de géneros. Basados en un muestreo taxonómico completo y un set de datos molecular casi-completo, nosotros generamos una filogenia para el grupo de ciclidos conocido como los herichthyins, y revisamos formalmente la taxonomía de cada género en este clado usando caracteres morfológi-cos. Una clave para los 16 géneros de ciclidos herichthyinos es también presentada.

–  Movement and dispersal patterns are key biological processes across a range of organisational levels. The Fundulus notatus species complex includes several species with similar ecological niches that exhibit broadly overlapping ranges. We conducted a mark–recapture study on two of the most widely distributed members of this species complex to improve our understanding of their movement and habitat use. A population of F. notatus was studied between June and August of 2008 and 2009 in Cahokia Creek, a small tributary of the Mississippi River in Illinois, along with a parallel study of Fundulus olivaceus between May and July of 2009 in Big Creek, a tributary of the Pascagoula River in Mississippi. Fish were recaptured approximately weekly, and habitat variables were measured. Estimated daily movement rates varied significantly both between locations and between years. Fundulus olivaceus in Big Creek moved <1 m per day, while F. notatus in Cahokia Creek in 2009 moved nearly 23 m per day. The distribution of movements was strongly leptokurtic in all three data sets. Differences in movement rates were attributed to significant differences in population size and habitat characteristics. Our data did not support the hypothesis that populations consist of distinct mobile and resident components. Instead, individual fish went through periods of little or no movement followed by extensive movement (consistent with the home range shift model of fish movement). We discuss the implications these results have for contact zone dynamics between these two species.

The freshwater fishes of Honduras were surveyed for a period of four years (2005–2008). Surveys were supplemented with both literature and museum collection reviews. Our results show that there are at least 172 species of fishes inhabiting Honduran mainland and insular freshwater systems, 166 native and six exotic. Primary freshwater fish diversity was low, with only eigth species (4.8%). The remaining species were either secondary freshwater (47 species, 28.3%) or peripheral (111 species, 66.9%). This checklist includes 36 new records for Honduras, and 12 range expansions. Nine species were found to be endemic; however, just two of them (Amphilophus hogaboomorum and Theraps wesseli) are already described. The depauperate primary freshwater fishes fauna of Honduras (8) is congruent with low primary freshwater fishes diversity found in the region between the Usumacinta River and the Nicaraguan great lakes. Although many previously unsampled regions of Honduras were visited as part of this project, there are a variety of remote areas that remain unstudied. While this paper contributes much to the understanding of the distribution and diversity of Honduran freshwater fishes, it is likely that much diversity there remains undocumented.

Aim: The processes that generate biodiversity occur at finer scales than are often studied, particularly in freshwater systems of the northern Neotropics. We investigate whether fine-scale biogeographic patterns are present within the larger Grijalva-Usumacinta Area of Endemism (AoE)-a region in Middle America where nearly 60% of freshwater fishes are endemic-and if present-day river basins are single historical units. Location: Northern Central America and southern Mexico.