Adaptive radiation of gobies in the interstitial habitats of gravel beaches accompanied by body elongation and excessive vertebral segmentation

Abstract

Background: The seacoasts of the Japanese Arc are fringed by many gravel beaches owing to active tectonic uplift and intense denudation caused by heavy rainfall. These gravel beaches are inhabited by gobies of the genus Luciogobius that burrow into the gravel sediment and live interstitially. Although their habitat and morphology (e. g., reduced fins, elongated, scale-less body, and highly segmented vertebral column) are highly unusual among fishes, little is known on how their morphological evolution has facilitated the colonization of interstitial habitats and promoted extensive diversification. We conducted thorough sampling of Luciogobius and related species throughout Japan, and performed molecular phylogenetic analysis to explore the patterns of morphological evolution associated with gravel beach colonization.

Multigene phylogeny reveals convergent evolution in small interstitial catfishes from the Amazon and Atlantic forests (Siluriformes: Trichomycteridae)

“…Although members of most trichomycterid subfamilies have been reported to live associated to river bottom substrate, only members of the Glanapteryginae, Sarcoglanidinae and Microcambevinae have shown specialised burrowing habits (Costa, ; Costa et al, ; Nico & de Pinna, ; Schaefer et al, ; Zuanon & Sazima, ), often acquiring uncommon morphological features, some of which are consistent with the morphological changes reported to be adaptations to the interstitial lifestyle independently acquired by diverse lineages of both vertebrates and invertebrates (Adriaens et al, ; Giere, ; Wagner et al, ; Yamada et al, ). These morphological adaptations include minute body size, body elongation, loss of skin pigmentation and reduction of appendages (Adriaens et al, ; Giere, ), all occurring in some lineage of those three subfamilies (Baskin, Pinna, Provenzano, & Schaefar, ; Costa & Bockmann, ; de Pinna, ; Schaefer et al, ).…”

“…Sand‐dwelling trichomycterids are similar to many other psammophilic Neotropical fishes in possessing translucent body and small adult size (Zuanon, Bockmann, & Sazima, ). On the other hand, interstitial trichomycterids exhibit uncommon morphology that has convergently occurred in cryptobenthic fishes (Wagner et al, ; Yamada, Sugiyama, Tamaki, Kawakita, & Kato, ), including elongate eel‐shaped body with numerous vertebrae and reduction or absence of eye and fins (Costa & Bockmann, ; de Pinna, ; de Pinna & Kirovsky, ; Schaefer, Provenzano, Pinna, & Baskin, ). Similar adaptations to interstitial life convergently occurred in so different lineages of marine interstitial teleost fishes such as clingfishes (Wagner et al, ) and gobies (Yamada et al, ).…”

Multi‐locus sequence data reveal a new species of coral reef goby (Teleostei: Gobiidae: Eviota), and evidence of Pliocene vicariance across the Coral Triangle

“…A segment of the mitochondrial gene cytochrome c oxidase subunit I ( coi ) was amplified and sequenced using the primers GOBYL6468 and GOBYH7696 (Thacker, ). The nuclear locus protease III ( Ptr ) was also sequenced using the primers PtrF2 and PtrR2 (Yamada et al , ). The PCRs for both genes used Promega GoTaq Hot Start Master Mix (http://www.promega.com) and a thermal profile that consisted of 95° C, followed by 35 cycles of 40 s at 95° C, 40 s at 54° C and 90 s at 72° C with a single extra extension period of 5 min at 72° C. Purification and sequencing of PCR products were performed by Beckman Coulter Genomics (http://www.beckmangenomics.com).…”

Phylogeographical Analysis of a Cold-Temperate Freshwater Fish, the Amur Sleeper (Perccottus glenii) in the Amur and Liaohe River Basins of Northeast Asia

“…Due to the lack of fossil data, we assumed a mutation rate of 1.35% per million years per lineage for Cyt b, which has been obtained for freshwater gobioid fishes in northeast Asia based on well-dated geological events (Sota et al, 2005). This molecular rate has also been used in other studies of gobioid fishes from northeast Asia (e.g., Yamada et al, 2009;Kokita and Nohara, 2011). Finally, a calibrated Cyt b tree was constructed using the expansion growth coalescent prior and a strict molecular clock.…”