Extreme dentition does not prevent diet and tooth diversification within combtooth blennies (Ovalentaria: Blenniidae)

Abstract

The dentition of fishes can be quite striking and is often correlated with a specific diet. Combtooth blennies have long incisiform oral teeth, unlike most actinopterygians. It has been suggested that the long tooth morphology is an adaptation for detritivory, but given the diversity of diets (detritus, coral polyps, polychaetes, and pieces of other fishes), are blenny teeth indeed monomorphic? Or does tooth variation associated with diet still exist at this extreme? To explore tooth and diet diversification, we used a new phylogenetic hypothesis of Blenniidae, measured tooth shape, number, and mode of attachment, and quantified blenniid diet. The ancestral diet of blennies contained detritus and diversified into many different diets, including almost exclusively detritivory. Our results reveal a dental cline that may be constrained by tooth shape, but has not prevented diet diversification. Ancestral state reconstruction of tooth morphologies suggests that the ancestor of blennies had many unattached teeth and featured transitions to fewer attached teeth, with several transitions back to attached or unattached teeth. The dentition of blenniids is not monotypic; rather it is diverse and small changes in tooth shape are accompanied by changes in size, number, attachment, and often diet.

DNA reconciles morphology and colouration in the drunk blenny genusScartichthys(Teleostei: Blenniidae) and provides insights into their evolutionary history

“…This molecular phylogeny confirmed the monophyly of the genus Scartichthys. Molecular evidence (Hundt et al, 2014;Hundt & Simons, 2018) confirmed that Scartichthys was sister to Ophioblennius as formerly hypothesized by Williams (1990) using morphological data. Interestingly, a minimal divergence between S. crapulatus and S. viridis was retrieved, questioning whether this divergence was of the order of inter or intraspecific divergence and paralleling the concern expressed by Stepien (1990) regarding the validity of S. crapulatus.…”

“…CC-BY-NC-ND 4.0 International license available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint this version posted February 22, 2021. ; https://doi.org/10.1101/2021.02.22.432327 doi: bioRxiv preprint 6 Finally, the recent phylogeny of blenniids (Hundt & Simons, 2018) represents the first attempts to reconstruct the evolutionary history of Scartichthys including one representative of the four currently valid species based on five nuclear markers (refer to Supplementary Figure S1 in Hundt & Simons (2018)). This molecular phylogeny confirmed the monophyly of the genus Scartichthys.…”

Co‐evolution of cleaning and feeding morphology in western Atlantic and eastern Pacific gobies

“…This action is enacted by fishes that specialize in scraping algae or detritus off rocks and possess similar stockade‐like dentitions (Parenti and Maciolek ; Streelman and Albertson ; Bellwood et al. ; Hundt and Simons ). Freshwater stream gobies of the Stenogobius group (formerly subfamily Sicydiinae; Thacker and Roje ; Agorreta et al.…”

“…Functionally, cleaning involves the dislodging of firmly attached objects from a substratum. This action is enacted by fishes that specialize in scraping algae or detritus off rocks and possess similar stockade-like dentitions (Parenti and Maciolek 1993;Streelman and Albertson 2006;Bellwood et al 2014;Hundt and Simons 2018). Freshwater stream gobies of the Stenogobius group (formerly subfamily Sicydiinae; Thacker and Roje 2011;Agorreta et al 2013) are exemplar analogs to dedicated cleaners due to their tightly packed rows of elongate teeth and inferior mouths (Parenti and Maciolek 1993).…”

Opsin gene evolution in amphibious and terrestrial combtooth blennies (Blenniidae)

“…Combtooth blennies are small (< 10 cm) scaleless fish that 94 are commonly found in many shallow tropical and warm water marine habitats, including 95 coral reefs, estuaries, mangroves, tide pools, and sometimes on land (Hundt et al 2014a, 96 Hundt and Simons 2018). They comprise one of the most diverse percomorph families 97 consisting of 400 described species (58 genera; fishbase.org) that fall into 13 phylogenetic 98 clades (Hundt et al 2014a, Hundt andSimons 2018). Within the Salariini division of 99 blennies, amphibious behaviour is common, and more than twenty species in at least three 100 genera exhibit a highly terrestrial lifestyle (Ord and Cooke 2016).…”