The Evolution of Eyes in the Bivalvia: New Insights*

  title={The Evolution of Eyes in the Bivalvia: New Insights*},
  author={Brian R Morton},
Abstract: Two types of multi-cellular eyes have been identified in the Bivalvia. Paired cephalic eyes occurring internally above the anterior end of the ctenidia are seen only in representatives of the Arcoidea, Limopsoidea, Mytiloidea, Anomioidea, Ostreoidea, and Limoidea. These eyes, comprising a pit of photo-sensory cells and a simple lens, are thought to represent the earliest method of photoreception. Many shallow-water marine, estuarine, and freshwater bivalves also possess simple… 
Development of the pallial eye in Nodipecten nodosus (Mollusca: Bivalvia): insights into early visual performance in scallops
Whereas the pallial eyes from adult scallops are a complex visual system based on a mirror mechanism to form a focused image on the retina, early eye condition suggests a simple degree of directional photoreception, with no spatial vision.
Hard to get, easy to lose: Evolution of mantle photoreceptor organs in bivalves (Bivalvia, Pteriomorphia)
The observed patterns suggest that eye evolution in pteriomorphians might have evolved in association with light‐guided behaviors, such as phototaxis, body posture, and alarm responses, in lineages that shift to burrowing lifestyles and deep‐sea habitats.
Three-dimensional reconstructions of pallial eyes in Pectinidae (Mollusca: Bivalvia)
It is shown how morphological characteristics such as the hyperbolic shape of the lens can be overlooked if only single sections are investigated and how three-dimensional reconstructions of microtome sections enable the comparison of whole eyes and structures in contrast to single-section analysis.
The ectopic compound ommatidium-like pallial eyes of three species of Mediterranean (Adriatic Sea) Glycymeris (Bivalvia: Arcoida). Decreasing visual acuity with increasing depth?
Comparison eye dimensions suggest a hypothesised trend in eye size differences in relation to depth to be valid, which will be the differences in abilities to create a summed image and thereby reduce visual acuity.
On the Evolutionary Significance of the Mantle Margin in Pteriomorphian Bivalves
The present work discusses how the mantle margin can be used as a model for investigating the evolution of the marine epifaunal benthos as many species in this community have undergone similar selective pressures and developed comparable morphological adaptations, such as ciliated tentacular organs.
Photoreception and the Polyphyletic Evolution of Photoreceptors (with Special Reference to Mollusca)*
It is proposed that the evolutionary pathway of photoreceptors reflects two different, successive processes: the (monophyletic?) differentiation ofPhotoreception as such, mediated by a specific transcription factor gene (such as Pax-6 or sine oculis) and the genetic information of that induction factor (normative unit for photoreception).
Mantle margin morphogenesis in Nodipecten nodosus (Mollusca: Bivalvia): new insights into the development and the roles of bivalve pallial folds
Analysis of the mantle margin of the scallop Nodipecten nodosus shows that the middle mantle fold forms from the outer surface of the inner fold after metamorphosis and that the initial unfolded mantle margin may represent a common condition among bivalves.


The function of pallial eyes within the Pectinidae, with a description of those present in Patinopecten yessoensis
  • B. Morton
  • Environmental Science
    Geological Society, London, Special Publications
  • 2000
Abstract The structure of the pallial, ectopic eye of Patinopecten yessoensis is described and shown to be of the typical pectinid form, located on the middle mantle fold. The cornea is, however, a
The fine structure of the pallial eyes of Laternula truncata (Bivalvia: Anomalodesmata: Pandoracea)
The structure of the pallial eyes of Laternula truncata (Lamarck 1818) has been studied using the light and electron microscopes. The eye is complex and can be- considered to be- the most advanced
The biology and functional morphology of Minnivola pyxidatus (Bivalvia: Pectinoidea)
Unusually, the labial palps of Minnivola pyxidatus are fused to the mantle and visceral mass, preventing their collapse in the mantle cavity and thus maintaining particle selection efficiency.
The biology and functional morphology of Arca noae (Bivalvia: Arcidae) from the Adriatic Sea, Croatia, with a discussion on the evolution of the bivalve mantle margin
The inner/middle mantle fold of A. noae, possibly representative of simpler, more primitive conditions, may have differentiated into distinct folds in other recent representatives of the Bivalvia.
Functional morphology of Bathyarca pectunculoides (Bivalvia: Arcacea) from a deep Norwegian fjord with a discussion of the mantle margin in the Arcoida
Abstract Bathyarca pectunculoides (Scacchi, 1834), a small Atlantic species, most noticeably possesses posterior extensions of the inner mantle folds which serve as simple siphons channelling
Toward Developing Models to Study the Disease, Ecology, and Evolution of the Eye in Mollusca*
An overview of molluscan eye research is provided from these two perspectives: eye researchers whose interests involve the development, physiology, and disease of the eye and malacologists who study the complete organism in its natural environment.
Laternula truncata (Lamarck) is a highly specialized member of a somewhat diverse assemblage of bivalves, the Anomalodesmata. It is found buried in coarse sand on the seaward side of mangrove
Functional morphology and development of veliger larvae of the European oyster, Ostrea edulis Linné
Study of body and shell in a growth series revealed many structures and patterns of development previously poorly known or unknown: the presence of four ciliary bands on the velum, not three, and the heel-first development of the foot, with medial ciliation of the toe preceding complete ciliation.
Development and Larval Morphology of the Spiny Scallop, Chlamys hastata
The early life history of Chlamys hastata, the spiny scallop, from spawning through metamorphosis to a benthic juvenile is described using light and electron microscopy, with an interlocking crown and groove feature on the larval denticles.