Effects of salinity and temperature on the larval development of a sesarmid crab Neosarmatium trispinosum Davie (Crustacea: Brachyura: Sesarmidae) from mangrove swamp in Okinawa Island, Japan

The larval development of the semiterrestrial sesarmid mangrove crab Neosarmarium trispinosum was studied under laboratory conditions at salinities 0-35%o and constant temperatures of 20-30°C. The larval development consists of five zoeal stages and a megalopa. Larvae survived to the first crab stage at salinities between 15 and 35%o with different percentages. At 0, 5 and 10%o, the larvae died within 12-18 hours without moulting to subsequent stages. The highest survival rate was recorded at 20-25%o and 25-30°C with shortest development duration to the first crab stage ranging from 24-28 days. At the highest salinity (35%o), survival rate was gradually decreased with increasing development duration. There were significant differences (P<O.Ol) found in the development period among the tested salinities. Results of this study suggest that the larvae of N. trispinosum develop in estuarine water and recruit to the mangrove swamp at the megalopa stage, where they spend the rest of their lives

Population structure of the grapsid crab, Helice tridens latimera (PARISI) in the Taiho mangrove, Okinawa, Japan

Grapsid crab Helice tridens latimera inhabiting mangroves, seashores as well as muddy and rocky areas. Ovigerous females were observed from December to May. Juveniles appeared in July and from December to April. In the laboratory they reached 9.50 mm in carapace width 4 months after hatching. It is likely that spawning of this crab occurs throughout the year

Larval development of a semi terrestrial mangrove sesarmine crab Chasmagnathus convexus (Crustacea: Decapoda: Brachyura: Grapsidae) reared in laboratory

Four zoeal stages and one megalopal stage were identified in laboratory reared semiterrestrial mangrove sesarmine crab Chasmagnathus convexus. At an average salinity and temperature of 20±1% and 19.2±0.2°C, the megalopa was attained 24 days after hatching. Morphologically, the first zoae of C. convexz1s is very similar to those of other species of the genus Chasmagnathus as well as species of the genus Helice, in that view all share the following characteristics: lateral spine on the carapace, three pairs of setae on the posterior margin of the telson furca, one plus five setae on the endopod of the maxillule, and two plus two setae on the endopod of the maxilla. The differences between the first zoea and megalopa of and those of its congeners are discussed

Fabrication of disk-shaped, deuterated resorcinol/formaldehyde foam target for laser–plasma experiments

Resorcinol/formaldehyde (RF) foam resin is an attractive material as a low-density target in high-power laser–plasma experiments because of its fine network structure, transparency in the visible region, and low-Z element (hydrogen, carbon, and oxygen) composition. In this study, we developed disk-shaped RF foam and deuterated RF foam targets with 40–200 µm thickness and approximately 100 mg/cm3 density having a network structure from 100 nm to a few micrometers cell size. By deuteration, the polymerization rate was drastically slowed down owing to kinetic isotope effects. These targets were used in high-power laser experiments where a megaelectronvolt proton beam was successfully generated.Kaneyasu Y., Nagai K., Cadatal-Raduban M., et al. Fabrication of disk-shaped, deuterated resorcinol/formaldehyde foam target for laser–plasma experiments. High Power Laser Science and Engineering 9, e31 (2022); https://doi.org/10.1017/hpl.2021.15

Proof-of-principle experiment for laser-driven cold neutron source

The scientific and technical advances continue to support novel discoveries by allowing scientists to acquire new insights into the structure and properties of matter using new tools and sources. Notably, neutrons are among the most valuable sources in providing such a capability. At the Institute of Laser Engineering, Osaka, the first steps are taken towards the development of a table-top laser-driven neutron source, capable of producing a wide range of energies with high brightness and temporal resolution. By employing a pure hydrogen moderator, maintained at cryogenic temperature, a cold neutron ($$\le 25\hbox { meV}$$≤25meV) flux of $$\sim 2\times 10^3\hbox { n/cm}^2$$∼2×103n/cm2/pulse was measured at the proximity of the moderator exit surface. The beam duration of hundreds of ns to tens of \upmu \hbox {s}μsis evaluated for neutron energies ranging from 100s keV down to meV via Monte-Carlo techniques. Presently, with the upcoming J-EPoCH high repetition rate laser at Osaka University, a cold neutron flux in orders of $$\sim 1\times 10^{9}\hbox { n/cm}^2/\hbox {s}$$∼1×109n/cm2/sis expected to be delivered at the moderator in a compact beamline

Atyid shrimps (Crustacea: Decapoda: Caridea) of the Ryukyu Islands, southern Japan, with descriptions of two new species

10.1080/00222930601084049Journal of Natural History4038-402123-2172JNAH

Report on a collection of freshwater shrimps (Crustacea: Decapoda: Caridea) from the Philippines, with descriptions of four new species

Raffles Bulletin of Zoology542245-27