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Oka S.,Ocean Expo Research Center | Higashiji T.,Okinawa Churaumi Aquarium
Ichthyological Research

Development of eggs and larvae of the big roughy Gephyroberyx japonicus are described on the basis of specimens reared in captivity. Spherical eggs (diameter 1. 26-1. 35 mm) with a single oil globule were pelagic. Newly hatched larvae (2. 8-3. 1 mm in body length, BL) had strong linear pigmentation on the head and trunk. The mouth opened at ca. 3. 5 mm BL; thereafter the yolk was absorbed. Notochord flexion started at ca. 4. 5 mm BL when body depth increased rapidly, and melanophores spread to all of the body. Notochord flexion was completed at ca. 5. 0 mm BL. Head spination and pelvic fins began to develop during the flexion stage. © 2012 The Ichthyological Society of Japan. Source

Suzuki K.,Rakuno Gakuen University | Noda J.,Rakuno Gakuen University | Yanagisawa M.,Ocean Expo Research Center | Kawazu I.,Ocean Expo Research Center | And 4 more authors.
Biological Trace Element Research

The aim of this study was to evaluate the reliability of direct determination of trace and major element concentrations in plasma samples from wild (six hawksbill, nine green, and nine loggerhead) and captive sea turtles (25 howksbill, five green, and three loggerhead) in Okinawa, Japan. The particle induced X-ray emission method allowed detection of 23 trace and major elements (Al, As, Br, Ca, Cl, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Ni, P, Pb, S, Se, Si, Sr, Ti, Y, and Zn). The wild sea turtles were found to have high concentrations of As and Pb in plasma compared with captive, but there were no significant changes in the Al and Hg concentrations. Loggerhead sea turtles were found to have significantly higher accumulation of As and Pb in plasma in comparison to other species. These findings may be useful when adjusting environmental and species-related factors in severely polluted marine ecosystems. Our results indicate that measuring the plasma As and Pb concentrations in wild sea turtles might be of help to assess the level of pollution in marine ecosystems, keeping in mind that loggerhead sea turtles had been shown to have higher levels of As and Pb in plasma. © 2011 Springer Science+Business Media, LLC. Source

Isomura N.,Okinawa National College of Technology | Baba Y.,Okinawa National College of Technology | Baba Y.,Okinawa Churaumi Aquarium | Nagata S.,Ocean Expo Research Center | And 2 more authors.
Marine Biology Research

Reproductive success via sexual reproduction is a key factor in restoring and maintaining populations of branching corals. It is crucial to consider the relationship between genetic similarity and reproductive success when restoring branching acroporids because these corals have characteristics such as fragmentation and localized recruitment. In this study, we examined the relationship between genetic similarity (as measured by amplified fragment length polymorphisms) and reproductive success of Acropora intermedia in 2009 and 2010, at Okinawa, southern Japan. There was a significant negative relationship between fertilization rate and genetic similarity. However, there was no significant relationship between genetic similarity and planula survivorship. Based on these findings and the characteristics of A. intermedia, asexual reproduction may decrease genetic diversity and promote inbreeding in the population. © 2013 Copyright Taylor and Francis Group, LLC. Source

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