Fine structure of complex ocelli of a cubomedusan, Tamoya bursaria Haeckel

Yamasu, Terufumi; Yoshida, Masao

doi:10.1007/bf00219415

Cited by 90 publications

(50 citation statements)

References 9 publications

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“…Photoreceptive organs in Cnidaria have diverse structures, not only between species but within the same species. The cubozoan that we have been investigating, Tridpedalia cystophora, has four equally spaced sensory structures (called rhopalia) dangling from a stalk and situated within open cavities surrounding the bell (Conant 1897, Laska and Hundgen, 1982, Pearse and Pearse, 1978, Yamasu and Yoshida, 1976 (Fig. 3).…”

Section: Cubozoan Eyes With Special Reference To Tripedaliamentioning

confidence: 99%

“…The complex eyes of jellyfish show striking similarities in overall structure with the camera-type eye of vertebrates even though they differ in numerous anatomical details. In addition to a cellular lens and cornea, adult cubomedusan jellyfish eyes have ciliated photoreceptors, as do vertebrate eyes, rather than the rhabdomeric (microvillar) photoreceptors generally populating invertebrates (Eakin, 1962, Yamasu andYoshida, 1976). Eakin believed from electron microscopic evidence that there was "a common ancestry of the taxa bearing light-sensitive cilia" (Eakin, 1979); however, close examination of diverse groups shows that the presence of ciliary or rhabdomeric photoreceptors is not neatly divided among species (Arendt and Wittbrodt, 2001).…”

Section: Cubozoan Eyes With Special Reference To Tripedaliamentioning

confidence: 99%

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Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems

Piatigorsky

Kozmík²

2004

Int. J. Dev. Biol.

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Cnidaria are the most basal phylum containing a well-developed visual system located on specialized sensory structures (rhopalia) with eyes and statocyts. We have been exploring the cubozoan jellyfish, Tripedalia cystophora. In addition to containing simple photoreceptive ocelli, each rhopalium in Tridedalia has a large and small complex, camera-type eye with a cellular lens containing three distinct families of crystallins which apparently serve non-lenticular functions. Thus, Tridpedalia recruited crystallins by a gene sharing strategy as have mollusks and vertebrates. Tripedalia has a single Pax gene, PaxB, which encodes a structural and functional Pax 2/5/8-like paired domain as well as an octapeptide and Pax6-like homeodomain. PaxB binds to and activates Tripedalia crystallin promoters (especially J3-crystallin) and the Drosophila rhodopsin rh6 gene in transfection tests and induces ectopic eyes in Drosophila. In situ hybridization showed that PaxB and crystallin genes are expressed in the lens, retina and statocysts. We suggest from these results that an ancestral PaxB gene was a primordial gene in eye evolution and that eyes and ears (mechanoreceptors) may have had a common evolutionary origin. Thus, the numerous structural and molecular features of Tridpalia rhopalia indicate that ancient cubozoan jellyfish are fascinating models for evo/devo insights into eyes and other sensory systems.

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Section: Cubozoan Eyes With Special Reference To Tripedaliamentioning

confidence: 99%

Section: Cubozoan Eyes With Special Reference To Tripedaliamentioning

confidence: 99%

Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems

Piatigorsky

Kozmík²

2004

Int. J. Dev. Biol.

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“…Tripedalia cystophora uses its visual system to detect the light shafts but it cannot see the copepods themselves, and would forage readily in empty light shafts (Buskey, 2003). The visual system of all box jellyfish is distributed at four sensory clusters, called rhopalia ( Fig.1A), each carrying six eyes (Claus, 1878;Conant, 1898;Berger, 1900;Laska and Hündgen, 1982;Yamasu and Yoshida, 1976). Each rhopalium contains one lens eye looking upward (upper lens eye), one lens eye looking obliquely downwards (lower lens eye), one pair of lens-less pit eyes looking upward (pit eyes) and one pair of slit-shaped lens-less eyes looking obliquely downward (slit eyes).…”

Section: Introductionmentioning

confidence: 99%

Visual control of steering in the box jellyfishTripedalia cystophora

Petie

Garm

Nilsson

2011

Journal of Experimental Biology

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SUMMARYBox jellyfish carry an elaborate visual system consisting of 24 eyes, which they use for driving a number of behaviours. However, it is not known how visual input controls the swimming behaviour. In this study we exposed the Caribbean box jellyfish Tripedalia cystophora to simple visual stimuli and recorded changes in their swimming behaviour. Animals were tethered in a small experimental chamber, where we could control lighting conditions. The behaviour of the animals was quantified by tracking the movements of the bell, using a high-speed camera. We found that the animals respond predictably to the darkening of one quadrant of the equatorial visual world by (1) increasing pulse frequency, (2) creating an asymmetry in the structure that constricts the outflow opening of the bell, the velarium, and (3) delaying contraction at one of the four sides of the bell. This causes the animals to orient their bell in such a way that, if not tethered, they would turn and swim away from the dark area. We conclude that the visual system of T. cystophora has a predictable effect on swimming behaviour.

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“…For example, Cubozoa (known as ''box jellyfish'') have camera-type eyes with cornea, lens, and retina; unexpectedly, the cubozoan retina has ciliated PRCs that are typical for vertebrate eyes (7)(8)(9). Cubomedusae are active swimmers that are able to make directional changes in response to visual stimuli (10).…”

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confidence: 99%

Assembly of the cnidarian camera-type eye from vertebrate-like components

Kozmík

Růžičková

Jonasova

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

118

113

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Animal eyes are morphologically diverse. Their assembly, however, always relies on the same basic principle, i.e., photoreceptors located in the vicinity of dark shielding pigment. Cnidaria as the likely sister group to the Bilateria are the earliest branching phylum with a well developed visual system. Here, we show that cameratype eyes of the cubozoan jellyfish, Tripedalia cystophora, use genetic building blocks typical of vertebrate eyes, namely, a ciliary phototransduction cascade and melanogenic pathway. Our findings indicative of parallelism provide an insight into eye evolution. Combined, the available data favor the possibility that vertebrate and cubozoan eyes arose by independent recruitment of orthologous genes during evolution.T he assembly of diverse animal eyes requires two fundamental building blocks, photoreceptors and dark shielding pigment. The function of photoreceptors is to convert light (stream of photons) into intracellular signaling. The photoreceptor cells (PRCs) are classified into two distinct types: rhabdomeric, characteristic of vision in invertebrate eyes; and ciliary, characteristic of vision in vertebrate eyes (1). In both ciliary and rhabdomeric PRCs, the seven-transmembrane receptor (opsin) associates with retinal to constitute a functional photosensitive pigment. Each photoreceptor type uses a separate phototransduction cascade. Rhabdomeric photoreceptors employ r-opsins and a phospholipase C cascade, whereas ciliary photoreceptors use c-opsins and a phosphodiesterase (PDE) cascade (2, 3). In general, the dark pigment reduces photon scatter and orients the direction optimally sensitive to light. The biochemical nature of the dark pigment appears more diverse than the phototransduction cascades used by the PRCs. Vertebrate eyes use melanin as their exclusive dark pigment. However, among invertebrates, pterins constitute the eye pigment in the polychaete Platynereis dumerilii (4), pterins and ommochromes are accumulated in eyes of Drosophila (5), and melanin is found rarely such as in the inverse cup-like eyes of the planarian, Dugesia (6).Cnidaria, the likely sister group to the Bilateria, constitute the earliest branching phylum containing a well developed visual system. For example, Cubozoa (known as ''box jellyfish'') have camera-type eyes with cornea, lens, and retina; unexpectedly, the cubozoan retina has ciliated PRCs that are typical for vertebrate eyes (7-9). Cubomedusae are active swimmers that are able to make directional changes in response to visual stimuli (10). The cubozoan jellyfish, Tripedalia cystophora (Fig. 1A), has four sensory structures called rhopalia that are equally spaced around the bell. In addition to two camera-type lens containing eyes at right angles to one another, each rhopalium has two pit-shaped and two slit-shaped pigment cup eyes (Fig. 1B). Thus, with six eyes located on each rhopalium, Tripedalia has 24 eyes altogether. Because the visual fields of individual eyes of the rhopalium partly overlap, Tripedalia (like other Cubomedusae) has an al...

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Fine structure of complex ocelli of a cubomedusan, Tamoya bursaria Haeckel

Cited by 90 publications

References 9 publications

Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems

Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems

Visual control of steering in the box jellyfishTripedalia cystophora

Assembly of the cnidarian camera-type eye from vertebrate-like components

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