Bruno F. Simões

University of Plymouth | UoP · School of Biological and Marine Sciences

The photopigment-encoding visual opsin genes that mediate colour perception show great variation in copy number and adaptive function across vertebrates. An open question is how this variation has been shaped by the interaction of lineage-specific structural genomic architecture and ecological selection pressures. We contribute to this issue by inv...

Australian scincid lizards in the sister-genera Lerista and Ctenotus are a prominent system for understanding adaptation in the transition from surface to fossorial life. The approximately 205 species in this group exhibit extreme diversity in morphology and ecology. Lerista and Ctenotus both include diurnal and surface-active species that are full...

Color vision is mediated by ancient and spectrally distinct cone opsins. Yet, while there have been multiple losses of opsin genes during the evolution of tetrapods, evidence for opsin gains via functional duplication is extremely scarce. Previous studies have shown that some secondarily marine elapid snakes have acquired expanded "UV-blue" sensiti...

Snakes comprise nearly 4,000 extant species found on all major continents except Antarctica. Morphologically and ecologically diverse, they include burrowing, arboreal, and marine forms, feeding on prey ranging from insects to large mammals. Snakes are strikingly different from their closest lizard relatives, and their origins and early diversifica...

Molecular genetic data have recently been incorporated in attempts to reconstruct the ecology of the ancestral snake, though this has been limited by a paucity of data for one of the two main extant snake taxa, the highly fossorial Scolecophidia. Here we present and analyse vision genes from the first eye transcriptomic and genome-wide data for Sco...

Many ambush-foraging snakes move their tails to entice prey within striking range (‘caudal luring’). During ontogeny, the conspicuous hues of caudal lures change to match the cryptic patterning of the body/head. This coincides with decreased luring behaviour and reflects the trade-off between prey acquisition and camouflage as the snake grows. Aust...

Snakes are descended from highly visual lizards [1] but have limited (probably dichromatic) color vision attributed to a dim-light lifestyle of early snakes [2, 3, 4]. The living species of front-fanged elapids, however, are ecologically very diverse, with ∼300 terrestrial species (cobras, taipans, etc.) and ∼60 fully marine sea snakes, plus eight...

We examined lens and brille transmittance, photoreceptors, visual pigments, and visual opsin gene sequences of viperid snakes with and without infrared-sensing pit organs. Ocular media transmittance was high in both groups. Contrary to previous reports, both small and large single cones occur in pit vipers. Non-pit vipers differ from pit vipers in...

The Pig-footed Bandicoot, Chaeropus ecaudatus, an extinct arid-adapted bandicoot, was named in 1838 based on a specimen without a tail from the Murray River in New South Wales. Two additional species were later named, C. castanotis and C. occidentalis, which have since been synonymised with C. ecaudatus. Taxonomic research on the genus is rather di...

We examined lens and brille transmittance, photoreceptors, visual pigments, and visual opsin gene sequences of viperid snakes with and without infrared-sensing pit organs. Ocular media transmittance was high in both groups. Contrary to previous reports, both small and large single cones occur in pit vipers. Non-pit vipers differ from pit vipers in...

Dermal phototaxis has been reported in a few aquatic vertebrate lineages spanning fish, amphibians and reptiles. These taxa respond to light on the skin of their elongate hind‐bodies and tails by withdrawing under cover to avoid detection by predators. Here, we investigated tail phototaxis in sea snakes (Hydrophiinae), the only reptiles reported to...

Through their unique use of sophisticated laryngeal echolocation bats are considered sensory specialists amongst mammals and represent an excellent model in which to explore sensory perception. While several studies have shown that the evolution of vision is linked to ecological niche adaptation in other mammalian lineages, this has not yet been fu...

Poster on tail phototaxis in sea snakes. Abstract: Non-visual photoreception, i.e light detection not involved in image forming vision, is best known among marine invertebrates, but far fewer examples have been described among vertebrates. Olive sea snakes, Aipysurus laevis, are the only snakes reported to show non-visual phototaxis and this unique...

The long history and great ecological and morphological diversity of reptiles (all amniotes except mammals and birds) is matched by their visual system diversity. Although less known than in other amniotes, visual pigments have been studied in all extant reptile orders except Sphenodontia. There have been no additions to the five visual pigments pr...

Much of what is known about the molecular evolution of vertebrate vision comes from studies of mammals, birds and fish. Reptiles (especially snakes) have barely been sampled in previous studies despite their exceptional diversity of retinal photoreceptor complements. Here we analyse opsin gene sequences and ocular media transmission for up to 69 sp...

In 1934, Gordon Walls forwarded his radical theory of retinal photoreceptor ‘transmutation’. This proposed that rods and cones used for scotopic and photopic vision, respectively, were not fixed but could evolve into each other via a series of morphologically distinguishable intermediates. Walls' prime evidence came from series of diurnal and noctu...

The dominant hypothesis for the evolutionary origin of snakes from 'lizards' (non-snake squamates) is that stem snakes acquired many snake features while passing through a profound burrowing (fossorial) phase. To investigate this we examined the visual pigments and their encoding opsin genes in a range of squamate reptiles, focusing on fossorial li...

We analysed the phylogenetic relationships between M. d. daubentonii and M. d. nathalinae based on 1,010 bp of the cytochrome b mtDNA gene. The inference based on molecular phylogenetics methods shows that these two morphotypes correspond to two mitochondrial groups within the Iberian Peninsula. Our results also support the model of ‘refugia within...

Holarctic Chrysoperla carnea is a complex of sibling species known as "carnea complex", whose unique courtship songs prevent them from interbreeding in nature and lead C. Henry in 2003 to describe C. agilis. Its geographic range is westerly limited by Madeira and Azores archipelagos. The insular biogeographic paths linking the two archipelagos, led...

Holarctic Chrysoperla carnea is a complex of sibling species known as the "Chrysoperla carnea complex", whose diverse courtship songs have led to the recognition of several cryptic species, including C. agilis Henry et al. 2003. The geographic range of C. agilis is westerly limited by Madeira and Azores. The climatic diffe-rences between the two ar...