Genome assembly and transcriptomic analyses of the repeatedly rejuvenating jellyfish Turritopsis dohrnii.

Only two hydromedusan species, Turritopsis dohrnii and T. sp., have exhibited experimental multiple-repeat life cycle reversion in the laboratory, which can be artificially induced by various means such as incubation with CsCl, heat shock, and mechanical damage with needles.

Three-dimensional measurement for spherical and nonspherical shapes of contact lenses.

In recent years, with the development of precise lathe-cutting equipment, special shaped contact lenses (CL) have been crafted. However, while it is possible to manufacture such a lens, its shape evaluation has not been well-established. We conducted a basic optical experiment using special lenses to measure a spherical lens and nonspherical mold.

Measurement algorithm for real front and back curved surfaces of contact lenses.

The optical measurement algorithm for the real front and back surfaces of contact lenses from their center to periphery accurately and simultaneously is proposed. It is an algorithm that makes light incident vertically along the curved surfaces of contact lenses under the condition that the difference of curvature radii between the front and back surfaces is small enough within the NA of the optical probe. For this purpose, we adopted time-domain optical coherence tomography (OCT) with translation and rotation mechanisms.

De Novo Assembly of the Transcriptome of Turritopsis, a Jellyfish that Repeatedly Rejuvenates.

In most animals, aging is an irreversible process; however the species Turritopsis sp. has been observed to undergo a rejuvenation process as many as 14 times. In the present study, we used multiplexed RNA libraries to obtain the transcriptome from four developmental stages (St) of Turritopsis sp.

Early Cambrian pentamerous cubozoan embryos from South China.

Background: Extant cubozoans are voracious predators characterized by their square shape, four evenly spaced outstretched tentacles and well-developed eyes. A few cubozoan fossils are known from the Middle Cambrian Marjum Formation of Utah and the well-known Carboniferous Mazon Creek Formation of Illinois. Undisputed cubozoan fossils were previously unknown from the early Cambrian; by that time probably all representatives of the living marine phyla, especially those of basal animals, should have evolved.

Evolutionary meaning of non-synchronous medusa release and spawning in the most advanced bivalve-inhabiting hydrozoan, Eugymnanthea japonica.

Circadial spawning times of medusa of the bivalve-inhabiting hydrozoans Eugymnanthea japonica Kubota and Eutima japonica Uchida are confirmed to be morning (possibly sunrise) for the former species and night for the latter. Eugymnanthea, with small, short-lived, univoltine medusae, seems to have evolved from a form similar to Eutima japonica, with larger, longer-lived, multivoltine medusae; the morning spawning of medusae in Eugymnanthea may therefore be a newly evolved trait. Medusa release from polyps and spawning of medusae are not synchronous in Eugymnanthea japonica.

Tiny sea anemone from the Lower Cambrian of China.

Background: Abundant fossils from the Ediacaran and Cambrian showing cnidarian grade grossly suggest that cnidarian diversification occurred earlier than that of other eumetazoans. However, fossils of possible soft-bodied polyps are scanty and modern corals are dated back only to the Middle Triassic, although molecular phylogenetic results support the idea that anthozoans represent the first major branch of the Cnidaria. Because of difficulties in taxonomic assignments owing to imperfect preservation of fossil cnidarian candidates, little is known about forms ancestral to those of living groups.

The olfactory receptor gene repertoires in secondary-adapted marine vertebrates: evidence for reduction of the functional proportions in cetaceans.

An olfactory receptor (OR) multigene family is responsible for the well-developed sense of smell possessed by terrestrial tetrapods. Mammalian OR genes had diverged greatly in the terrestrial environment after the fish-tetrapod split, indicating their importance to land habitation. In this study, we analysed OR genes of marine tetrapods (minke whale Balaenoptera acutorostrata, dwarf sperm whale Kogia sima, Dall's porpoise Phocoenoides dalli, Steller's sea lion Eumetopias jubatus and loggerhead sea turtle Caretta caretta) and revealed that the pseudogene proportions of OR gene repertoires in whales were significantly higher than those in their terrestrial relative cattle and also in sea lion and sea turtle.

Occurrence and detrimental effects of the bivalve-inhabiting hydroid on juveniles of the Japanese scallop in Funka Bay, Japan: relationship to juvenile massive mortality in 2003.

In November 2003, we first observed prevalent occurrence of a hydroid, , on soft body tissues of age zero Japanese scallop () juveniles cultured in large areas of Funka Bay, Hokkaido. The occurrence coincided with massive death of juvenile scallops. A major objective was to clarify ecological relationships between the symbionts, and to infer the relationship between symbiosis and the massive mortality.