Newly Collected Specimens of the Sleeper Eleotris acanthopoma (Teleostei: Eleotridae) from French Polynesia Indicate a Wide and Panmictic Distribution in the West and South Pacific.

v. ill. 23 cm.QuarterlyThe morphology of Eleotris acanthopoma collected from Moorea in French Polynesia is described. This is the first record of this species from French Polynesia, greatly expanding the known range, which was previously only considered to extend from southern Japan to New Caledonia. Nucleotide sequences of the mitochondrial ND5 gene of several Eleotris species and related genera indicate that E. acanthopoma from Moorea belongs to the same lineage as E. acanthopoma from Japan and the Philippines. Despite being separated by a distance of approximately 10,000 km, two of the specimens from Moorea and one from the Philippines had identical nucleotide sequences. Results of this study indicate that extensive dispersal occurs during the pelagic larval stage of this species

Newly discovered habitat of a threatened goby, Acanthogobius insularis (Perciformes: Gobiidae), in southern part of Okinawa-jima Island, Japan

Acanthogobius insularis Shibukawa and Taki (1996) is a threatened goby species, previously known to be restricted to estuaries on Amami-oshima Island and northern part of Okinawa-jima Island. However, we found this species in two estuaries in the southern part of Okinawa-jima Island (Toyosaki and Manko), which are separated from their habitats in the northern part of the island by approx. 60 km of coral reefs. Morphologies of four specimens collected in Toyosaki and Manko examined in the present study correspond to the original description of A. insularis. This study reports that Toyosaki is the southernmost habitat of this species based on specimens. Because it is thought that A. insularis move to unknown spawning habitats in winter and because only one individual has been found in Manko, it is necessary to understand the habitats that these newly discovered small populations use, in their entirety

Biogeography and evolution of the Carassius auratus-complex in East Asia

<p>Abstract</p> <p>Background</p> <p><it>Carassius auratus </it>is a primary freshwater fish with bisexual diploid and unisexual gynogenetic triploid lineages. It is distributed widely in Eurasia and is especially common in East Asia. Although several genetic studies have been conducted on <it>C. auratus</it>, they have not provided clear phylogenetic and evolutionary descriptions of this fish, probably due to selection bias in sampling sites and the DNA regions analysed. As the first step in clarifying the evolutionary entity of the world's <it>Carassius </it>fishes, we attempted to clarify the phylogeny of <it>C. auratus </it>populations distributed in East Asia.</p> <p>Results</p> <p>We conducted a detailed analysis of a large dataset of mitochondrial gene sequences [<it>CR</it>, 323 bp, 672 sequences (528 sequenced + 144 downloaded); <it>CR </it>+ <it>ND4 </it>+ <it>ND5 </it>+ <it>cyt b</it>, 4669 bp in total, 53 sequences] obtained from <it>C. auratus </it>in East Asia. Our phylogeographic analysis revealed two superlineages, one distributed mainly among the Japanese main islands and the other in various regions in and around the Eurasian continent, including the Ryukyus and Taiwan. The two superlineages include seven lineages with high regional specificity that are composed of endemic populations indigenous to each region. The divergence time of the seven lineages was estimated to be 0.2 million years ago (Mya) by a fossil-based method and 1.0-1.9 Mya by the molecular clock method. The antiquity and endemism of these lineages suggest that they are native to their respective regions, although some seem to have been affected by the artificial introduction of <it>C. auratus </it>belonging to other lineages. Triploids of <it>C. auratus </it>did not form a monophyletic lineage but were clustered mostly with sympatric diploids.</p> <p>Conclusions</p> <p>The results of the present study revealed the existence of two superlineages of <it>C. auratus </it>in East Asia that include seven lineages endemic to each of the seven regions examined. The lack of substantial genetic separation between triploids and diploids indicates that triploids are not composed of a single independent lineage. The ancient origins and evolutionary uniqueness of the seven lineages warrant their conservation. An overall phylogenetic framework obtained from the present study will be of use for estimating the phylogenetic relationships of <it>Carassius </it>fishes on the Eurasian continent.</p

Diel and Seasonal Occurrence Patterns of Drifting Fish Larvae in the Teima Stream, Okinawa Island.

v. ill. 23 cm.QuarterlyDrifting fish larvae were collected with a plankton net in the lower reaches of a freshwater area of the Teima Stream, Okinawa Island, Japan, during 24 hr periods each month from June 1998 to October 1999 (except July 1998). Newly hatched larvae of several gobioid and two pipefish species were collected, and their morphology was described. The larval occurrences suggested that most species spawn mainly from spring to fall, with some Rhinogobius species spawning in winter. Larvae of all fishes occurred predominantly during hours after dusk throughout the year. It is suggested that larvae of amphidromous fishes spawned in freshwater streams on Okinawa Island begin to drift soon after hatching at dusk and complete their exit from freshwater areas into the estuary and sea by midnight

Pelagic Larval Duration and Settlement Size of Apogonidae, Labridae, Scaridae, and Tripterygiidae Species in a Coral Lagoon of Okinawa Island, Southern Japan.

v. ill. 23 cm.QuarterlyPelagic larval duration and settlement sizes in species of Apogonidae, Labridae, Scaridae, and Tripterygiidae in a coral lagoon in southern Japan were examined. Sampling was conducted monthly from July 2004 to June 2005 in the coral lagoon and channel of the Oh-do Beach on Okinawa Island, Japan. Pelagic larval duration was estimated by the number of otolith increments. Mean standard length at settlement of apogonids ranged from 7.7 to 13.9 mm, and mean pelagic larval duration ranged from 14.0 to 30.6 days (14 species, 418 individuals). In labrids, mean standard length at settlement and pelagic larval duration varied greatly (mean standard length: 5.4–11.0 mm; pelagic larval duration: 18–57 days, four species, four individuals). Scarids showed consistent mean standard length at settlement and pelagic larval duration (mean standard length: 7.1–7.6 mm; pelagic larval duration: 29–42 days, five species, 25 individuals). In tripterygiids, pelagic larval duration was more consistent (range: 18–29 days, mean: 22.2e2.1 days), but mean standard length at settlement ranged from 7.8 to 10.3 mm (six species, 32 individuals). These results suggest that the pelagic larval duration of Apogonidae and Tripterygiidae (nonpelagic egg spawning) is shorter than that of Labridae and Scaridae (pelagic egg spawning), and the dispersal strategy of labrids and scarids may include wider dispersal than that of apogonids and tripterygiids

Distribution of the alien freshwater fishes in the Ryukyu Archipelago

琉球大学21世紀COEプログラム主催　国際ワークショップ 「生物多様性と侵略的外来種 : 世界各地の事例からの教訓」, 日時：2008年11月1日, 会場：琉球大学法文学部講義棟大講義室, 発行元：琉球大学21世紀COEプログラ

PELAGIC LARVAL DURATIONS AND LARVAL DISPERSAL OF AMPHIDROMOUS SLEEPER, ELEOTRIS

琉球大学21世紀プログラム「サンゴ礁島嶼系の生物多様性の総合解析」平成17年度成果発表会（平成18年3月6日開催）　会場：琉球大学大学会館3