Biology subjects

Matamoros, W. A.

Publications and source records attributed to Matamoros, W. A..

3 recordsLinked to original sources

bioRxiv2026

Diversifying the Northern Neotropics: Phylogenomics and Evolutionary History of the Early-Diverging Herichthyine Cichlids Thorichthys and Trichromis

Among Neotropical cichlids the tribe Heroini exhibits substantial ecological diversity and is one of the dominant fish groups across northern Neotropical riverscapes. The majority of studies on heroine cichlids have focused on macroevolutionary patterns but the role of geological and ecological factors shaping lineage diversification within the tribe remains poorly understood. Here we used ultraconserved elements (UCEs) to infer a taxonomically complete and geographically comprehensive phylogenomic framework of the early-diverging herichthyine sister genera Thorichthys and Trichromis and to comparatively investigate their evolutionary and biogeographic histories. All our phylogenomic hypotheses support the monophyly of both genera and two species subgroups within Thorichthys. Our results provide evidence of a) unrecognized diversity within Trichromis salvini, b) uncertainty in species boundaries in Thorichthys, and c) the first report of ghost introgression in fishes of the northern Neotropics. Additionally, our results demonstrate the importance of the Papaloapan and Coatzacoalcos watersheds for fish diversification in the region. Finally, we show patterns consistent with ecological divergence during the evolution of this group, particularly among sympatric species. Altogether, these patterns suggest that lineage diversification in northern Neotropical cichlids has been driven by the interaction of geological restructuring, climatic and sea-level oscillations, and heterogeneous ecological pressures.

evolutionary biology↗

bioRxiv2023

Biogeography of Greater Antilleans freshwater fishes, with a review of competing hypotheses

In biogeography, vicariance and long-distance dispersal are often characterized as competing scenarios. However, they are related concepts, both relying on reciprocal illumination from geological, ecological, and phylogenetic evidence. This can be illustrated for freshwater fishes, which may immigrate to islands when freshwater connections are temporarily present (vicariance), or by unusual means when oceanic gaps are crossed (long-distance dispersal). Marine barriers have a strong filtering effect, limiting immigrants to those most capable of oceanic dispersal. The roles of landspans and oceanic dispersal are being debated for freshwater fishes of the Greater Antilles. We review three active hypotheses (Cretaceous vicariance, GAARlandia, long-distance dispersal) and propose long-distance dispersal to be an appropriate null model due to a lack of reciprocal illumination for landspan hypotheses. Greater Antillean freshwater fishes have six potential source bioregions (defined from faunal similarity): Northern Gulf of Mexico, Western Gulf of Mexico, Maya Terrane, Chortis Block, Eastern Panama, and Northern South America. Faunas of the Greater Antilles are composed of taxa immigrating from many of these bioregions, but there is strong compositional disharmony between island and mainland fish faunas (>90% of the species are cyprinodontiforms, compared to <10% in Northern Gulf of Mexico and Northern South America, and [≤]50% elsewhere), consistent with a hypothesis of long-distance dispersal. Ancestral area analysis indicates there were 16 or 17 immigration events over the last 51 my, 14 or 15 of these by cyprinodontiforms. Published divergence estimates and evidence available for each immigration event suggest they occurred at different times and by different pathways, possibly with rafts of vegetation discharged from rivers or washed to sea during storms. If so, ocean currents likely provide critical pathways for immigration when flowing from one landmass to another, but create dispersal barriers when flowing perpendicular between landmasses. In addition to high salinity tolerance, cyprinodontiforms (collectively) display a variety of adaptations that could enhance their ability to live with rafts (small body size, viviparity, low metabolism, amphibiousness, diapause, self-fertilization). These adaptations likely also helped immigrants establish island populations after arrival and persist long term thereafter. Cichlids may have used a pseudo bridge (Nicaragua Rise) to reach the Greater Antilles, persisting only on the largest islands (Cuba, Hispaniola). Gar (Lepisosteidae) may have crossed the Straits of Florida to Cuba, a relatively short crossing that is not a barrier to gene flow for several cyprinodontiform immigrants. Indeed, widespread distributions of Quaternary migrants (Cyprinodon, Gambusia, Kryptolebias), within the Greater Antilles and among neighbouring bioregions, imply long-distance dispersal is not necessarily inhibitory for well-adapted species, even though it appears to be virtually impossible all other freshwater fishes.

evolutionary biology↗

bioRxiv2023

Historical biogeography of New World Killifishes (Cyprinodontiformes: Funduloidea) recapitulates geographical history in the Gulf of Mexico watershed

We reconstructed the phylogenetic relationships of superfamily Funduloidea with a synthesis of its biogeographic history. We used DNA sequences from five genes for 135 species, with four fossil calibrations, to generate a time-calibrated phylogeny. We estimated diversification rates, ancestral areas (Nearctic or Neotropical), and ancestral habitat (coastal or upland), for each node. Our results suggest that Funduloidea originated in the Late Cretaceous and diversified from Late Paleocene to present at a uniform rate, except Cyprinodontidae expressed an accelerated rate of speciation ~11.02 Ma. Neither viviparity, marine-to-freshwater transition, consistently accelerated speciation. Funduloidea has a coastal origin, but invaded inland many times. Funduloidea phylogeny indicates, sea-level falls isolate coastal populations, but increase island accessibility and climatic cooling facilitates invasions of temperate species into the tropics. For continental lineages, ancient river drainages accord with lineage distributions, including enigmatic disjunctions in Goodeidae and Fundulus. Niche shifts occurred from estuaries to open coasts and from forests to grasslands. Antiquity, adaptability, and dynamic geography can explain Funduloidea diversity. Combined environmental and phylogenetic data unveil the history of the Gulf of Mexico watershed. Phylogeny suggests there was diversification by barrier displacement and coastal speciation pump. Overall, speciation time, transitions to freshwater, dispersal, vicariance, adaptive radiation, and viviparity contributed to total diversification.

zoology↗