Background: Fish classifications, as those of most other taxonomic groups, are being transformed drastically as new molecular phylogenies provide support for natural groups that were unanticipated by previous studies. A brief review of the main criteria used by ichthyologists to define their classifications during the last 50 years, however, reveals slow progress towards using an explicit phylogenetic framework. Instead, the trend has been to rely, in varying degrees, on deep-rooted anatomical concepts and authority, often mixing taxa with explicit phylogenetic support with arbitrary groupings.
View Article and Find Full Text PDFThe structure of the caudal skeleton of extant teleost fishes has been interpreted in two different ways. In a diural interpretation, a caudal skeleton is composed of two centra articulated with one to six hypurals. Most subsequent authors have followed this interpretation.
View Article and Find Full Text PDFThe vast darkness of the deep sea is an environment with few obvious genetic isolating barriers, and little is known regarding the macroevolutionary processes that have shaped present-day biodiversity in this habitat. Bioluminescence, the production and emission of light from a living organism through a chemical reaction, is thought to occur in approximately 80 % of the eukaryotic life that inhabits the deep sea (water depth greater than 200 m). In this study, we show, for the first time, that deep-sea fishes that possess species-specific bioluminescent structures (e.
View Article and Find Full Text PDFThe tree of life of fishes is in a state of flux because we still lack a comprehensive phylogeny that includes all major groups. The situation is most critical for a large clade of spiny-finned fishes, traditionally referred to as percomorphs, whose uncertain relationships have plagued ichthyologists for over a century. Most of what we know about the higher-level relationships among fish lineages has been based on morphology, but rapid influx of molecular studies is changing many established systematic concepts.
View Article and Find Full Text PDFThe Genome 10K project aims to sequence the genomes of 10,000 vertebrates, representing approximately one genome for each vertebrate genus. Since fishes (cartilaginous fishes, ray-finned fishes and lobe-finned fishes) represent more than 50% of extant vertebrates, it is planned to target 4,000 fish genomes. At present, nearly 60 fish genomes are being sequenced at various public funded labs, and under a Genome 10K and BGI pilot project.
View Article and Find Full Text PDFThe recent rise in speed and efficiency of new sequencing technologies have facilitated high-throughput sequencing, assembly and analyses of genomes, advancing ongoing efforts to analyze genetic sequences across major vertebrate groups. Standardized procedures in acquiring high quality DNA and RNA and establishing cell lines from target species will facilitate these initiatives. We provide a legal and methodological guide according to four standards of acquiring and storing tissue for the Genome 10K Project and similar initiatives as follows: four-star (banked tissue/cell cultures, RNA from multiple types of tissue for transcriptomes, and sufficient flash-frozen tissue for 1 mg of DNA, all from a single individual); three-star (RNA as above and frozen tissue for 1 mg of DNA); two-star (frozen tissue for at least 700 μg of DNA); and one-star (ethanol-preserved tissue for 700 μg of DNA or less of mixed quality).
View Article and Find Full Text PDFBackground: Invasive species are a serious problem in ecosystems, but are difficult to eradicate once established. Predictive methods can be key in determining which areas are of concern regarding invasion by such species to prevent establishment [1]. We assessed the geographic potential of four Eurasian cyprinid fishes (common carp, tench, grass carp, black carp) as invaders in North America via ecological niche modeling (ENM).
View Article and Find Full Text PDFWe infer the phylogenetic relationships of finescale shiners of the genus Lythrurus, a group of 11 species of freshwater minnows widely distributed in eastern North America, using DNA sequences from the ND2 (1047 bp), ATPase8 and 6 (823 bp), and ND3 (421 bp) mitochondrial protein-coding genes. The topologies resulting from maximum parsimony, Bayesian, and maximum likelihood tree building methods are broadly congruent, with two distinct clades within the genus: the L. umbratilis clade (L.
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