Macroevolutionary role reversals in the earliest radiation of bony fishes.

The evolution of jaws is hypothesized to have fueled radiations among vertebrates, contributing to their overwhelming success in the present day. Past work shows rapid early expansion of diversity in jaw structure in many lineages; however, the evolutionary dynamics underlying this pattern are unclear and hindered by the lack of a robust comparative framework. Here, using a macroevolutionary approach, we explore the diversification of lower jaws in early bony fishes, a major contributor to this initial radiation.

The lower jaw of Devonian ray-finned fishes (Actinopterygii): Anatomy, relationships, and functional morphology.

Actinopterygii is a major extant vertebrate group, but limited data are available for its earliest members. Here we investigate the morphology of Devonian actinopterygians, focusing on the lower jaw. We use X-ray computed tomography (XCT) to provide comprehensive descriptions of the mandibles of 19 species, which span the whole of the Devonian and represent roughly two-thirds of all taxa known from more than isolated or fragmentary material.

Ancient climate changes and relaxed selection shape cave colonization in North American cavefishes.

Extreme environments serve as natural laboratories for studying evolutionary processes, with caves offering replicated instances of independent colonizations. The timing, mode and genetic underpinnings underlying cave-obligate organismal evolution remain enigmatic. We integrate phylogenomics, fossils, palaeoclimatic modelling and newly sequenced genomes to elucidate the evolutionary history and adaptive processes of cave colonization in the study group, the North American Amblyopsidae fishes.

Colonization Dynamics Explain the Decoupling of Species Richness and Morphological Disparity in Syngnatharian Fishes across Oceans.

AbstractA clear longitudinal gradient in species richness across oceans is observed in extant marine fishes, with the Indo-Pacific exhibiting the greatest diversity. Three non-mutually-exclusive evolutionary hypotheses have been proposed to explain this diversity gradient: time for speciation, center of accumulation, and in situ diversification rates. Using the morphologically disparate syngnatharians (seahorses, dragonets, goatfishes, and relatives) as a study system, we tested these hypotheses and additionally assessed whether patterns of morphological diversity are congruent with species richness patterns.

Evolutionary innovation accelerates morphological diversification in pufferfishes and their relatives.

Evolutionary innovations have played an important role in shaping the diversity of life on Earth. However, how these innovations arise and their downstream effects on patterns of morphological diversification remain poorly understood. Here, we examine the impact of evolutionary innovation on trait diversification in tetraodontiform fishes (pufferfishes, boxfishes, ocean sunfishes, and allies).

The impact of paleoclimatic changes on body size evolution in marine fishes.

Body size is an important species trait, correlating with life span, fecundity, and other ecological factors. Over Earth's geological history, climate shifts have occurred, potentially shaping body size evolution in many clades. General rules attempting to summarize body size evolution include Bergmann's rule, which states that species reach larger sizes in cooler environments and smaller sizes in warmer environments, and Cope's rule, which poses that lineages tend to increase in size over evolutionary time.

Cerogobius petrophilus (Perciformes: Gobiidae), a new gobiid genus and species from the Red Sea.

A new genus and species of cryptobenthic goby, Cerogobius petrophilus is described from the Red Sea based on nine specimens not exceeding 2.5 cm in total length, collected from a stone-rubble habitat at Thuwal, Saudi Arabia, at depths of 8-15 m. It was also observed underwater at the southern tip of Ras Mohammed and Marsa Alam in Egypt.

Comparison of cryptobenthic reef fish communities among microhabitats in the Red Sea.

Knowledge of community structure within an ecosystem is essential when trying to understand the function and importance of the system and when making related management decisions. Within the larger ecosystem, microhabitats play an important role by providing inhabitants with a subset of available resources. On coral reefs, cryptobenthic fishes encompass many groups and make up an important proportion of the biodiversity.