Koichi Shibukawa

A revision of the gobiid fish genus Odontamblyopus (Gobiidae: Amblyopinae)

Abstract The Indo-West Pacific gobiid genus Odontamblyopus Bleeker is defined and revised. Odontamblyopus is unique within the Amblyopinae in having free and silklike pectoral-fin rays. Odontamblyopus comprises four species: O. lacepedii, distributed from southern China to Taiwan, Korea, and Japan; O. roseus, distributed along the west coast of India; O. rubicundus, ranging from the east coast of India to Myanmar; and O. tenuis, known only from Pakistan and Myanmar. A key to species is provided. Figures and descriptions of each species are also given. Odontamblyopus has often been confused with Taenioides; the two genera are compared and characters to distinguish them are provided. The phylogeny and biogeography of Odontamblyopus are discussed.

An online database on freshwater fish diversity and distribution in Mainland Southeast Asia

Mainland Southeast Asia, the region that includes Cambodia, Laos, Thailand, Vietnam and Peninsular Malaysia, is known for its high diversity of freshwater fishes (e.g., Myers et al. 2000; Dudgeon 2005; Kang et al. 2009). Recently, however, intensive exploitation pressures have been threatening this biodiversity. While some studies on fish fauna of the region have been made (e.g., Taki 1974; Rainboth 1996; Kottelat 2000; Vidthayanon and Premcharoen 2002), most have been of limited duration and geographical range, and the full extent of the effect of this exploitation on the fish diversity is not fully understood. The main obstacles standing in the way of a proper understanding of the threats to this biodiversity and determining the means to alleviate them have been hindered by several factors: one is a general shortage of trained scientists in the region proficient in fish taxonomy; another is that exchanges of the results of the taxonomical studies done by scientists in the region are few and far between. And finally there is a general lack of awareness of the significance of species diversity in ecosystems. Beginning in 2007, the Nagao Natural Environment Foundation (NEF), from Japan, has been working to improve this situation in the Mekong-Chao Phraya region, the results of which are presented in a new online database, ‘‘Fishes of Mainland Southeast Asia (FiMSEA)’’ (Fig. 1; URL: http://ffish.asia). Since the outset of the project, the NEF has worked in collaboration with a number of counterpart institutions in the region, namely: Can Tho University (Vietnam), The Inland Fisheries Research and Development Institute

Redescription of the gobiid fish genus Pseudotrypauchen (Gobiidae : Amblyopinae) and its significance in amblyopine phylogeny

The Indo–West Pacific gobiid genus Pseudotrypauchen is defined and redescribed. Pseudotrypauchen comprises one species,P. multiradiatus, known only from India, Malaysia, and Sumatra. A figure and description of this species are given. Pseudotrypauchen is unique within the Amblyopinae in having short, compressed, and gently rounded teeth in the outermost row on jaws, and in having the first two pterygiophores of the second dorsal fin separated by a neural spine. The latter character is unique within the subfamily. Owing to their shared possession of (1) free and silk-like pectoral-fin rays, and (2) a high pectoral-fin ray count, Odontamblyopus is a more likely candidate as sister group to Pseudotrypauchen than any other member of the Amblyopinae. Other relationships of Pseudotrypauchen are discussed.

A new gobiid fish,Acanthogobius insularis, from the Ryukyu Islands, Japan

A new gobiid species,Acanthogobius insularis, is described from 88 specimens collected from Amami-oshima Island and Okinawa Island, Ryukyu Islands, southern Japan. The species is distinguished from its congeners by the combination of dorsal and anal fin ray counts, vertebral counts, cephalic sensory system patterns and coloration.

Impacts of Dams and Global Warming on Fish Biodiversity in the Indo-Burma Hotspot

Both hydropower dams and global warming pose threats to freshwater fish diversity. While the extent of global warming may be reduced by a shift towards energy generation by large dams in order to reduce fossil-fuel use, such dams profoundly modify riverine habitats. Furthermore, the threats posed by dams and global warming will interact: for example, dams constrain range adjustments by fishes that might compensate for warming temperatures. Evaluation of their combined or synergistic effects is thus essential for adequate assessment of the consequences of planned water-resource developments. We made projections of the responses of 363 fish species within the Indo-Burma global biodiversity hotspot to the separate and joint impacts of dams and global warming. The hotspot encompasses the Lower Mekong Basin, which is the world’s largest freshwater capture fishery. Projections for 81 dam-building scenarios revealed progressive impacts upon projected species richness, habitable area, and the proportion of threatened species as generating capacity increased. Projections from 126 global-warming scenarios included a rise in species richness, a reduction in habitable area, and an increase in the proportion of threatened species; however, there was substantial variation in the extent of these changes among warming projections. Projections from scenarios that combined the effects of dams and global warming were derived either by simply adding the two threats, or by combining them in a synergistic manner that took account of the likelihood that habitat shifts under global warming would be constrained by river fragmentation. Impacts on fish diversity under the synergistic projections were 10–20% higher than those attributable to additive scenarios, and were exacerbated as generating capacity increased—particularly if CO2 emissions remained high. The impacts of dams, especially those on river mainstreams, are likely to be greater, more predictable and more immediately pressing for fishes than the consequences of global warming. Limits upon dam construction should therefore be a priority action for conserving fish biodiversity in the Indo-Burma hotspot. This would minimize synergistic impacts attributable to dams plus global warming, and help ensure the continued provision of ecosystem services represented by the Lower Mekong fishery.

Review Of The Shrimp-Associated Goby Genus Lotilia (Actinopterygii: Perciformes: Gobiidae), With Description Of A New Species From The West Pacific

The Indo-West Pacific gobiid fish genus Lotilia, symbiotically associated with alpheid shrimps, is reviewed. The genus comprises two species, viz. L. graciliosa Klausewitz, 1960 and L. klausewitzi sp. nov., the latter of which is described herein based on 11 specimens (including seven type specimens) from Japan, Australia and the Bismark Archipelago. Lotilia klausewitzi, previously misidentified as L. graciliosa in the West Pacific, is readily distinguished from L. graciliosa by having the following features, in addition to some minor differences in the sensory-papillae configuration on the cheek: cephalic sensory canals and associated pores present (vs. absent in L. graciliosa); 7+6=13 branched caudal-fin rays (vs. 7+7=14); pale area on dorsum from snout to dorsoanterior part of body relatively long, extending posteriorly to, or beyond, base of fifth spine of first dorsal fin (vs. extending posteriorly to around base of third or fourth spine); a faint, relatively small dark grayish brown spot at center of first dorsal fin behind third or fourth spine, and its paler margin usually absent or obscure (vs. conspicuous ocellated black spot with vivid pale margin at center of first dorsal fin, extending anteriorly beyond third spine); and a submarginal row of black spots on caudal fin (vs. absent). Geographic records based on the specimens examined and underwater photographs indicate that L. graciliosa appears to be restricted to the Red Sea and its adjacent areas, whereas L. klausewitzi is widely found in the West Pacific. Lotilia is re-diagnosed, and L. graciliosa is re-described based on five specimens including the holotype.

A Redescription of the Eel Goby Trypauchenopsis (Gobiidae: Amblyopinae) with Comments on Relationships

The gobioid genus Trypauchenopsis and type species, T. intermedia, are redescribed based on examination of 485 specimens (including the holotype) from various localities in the Indo-West Pacific. The genus is unique in possessing forked middle radials of the ultimate dorsal- and anal-fin pterygiophores, no pleural ribs or only a single pleural rib on the ultimate precaudal vertebra, and caducous, cutaneous, short barbel-like processes scattered on the head. Two species that had been referred to the genus Taenioides (T. jacksoni and T. limicola) are now placed in the synonymy of Trypauchenopsis intermedia. Trypauchenopsis has often been confused with Taenioides or Brachyamblyopus; these three genera along with Gymnoamblyopus, Odontamblyopus, and Pseudotrypauchen are compared and characters to distinguish them are provided. The relationships of Trypauchenopsis to these genera are also discussed.

Two new dwarfgobies of the genus Eviota from the Ryukyu Islands, Japan (Teleostei: Gobiidae).

Two species of dwarfgoby are described from the Ryukyu Islands, Japan. Eviota flebilis n. sp. belongs to cephalic sensory-pore system pattern 2 (lacking only IT pore), has a dorsal/anal fin-ray formula of 8/7, unbranched pectoral-fin rays, the 5th pelvic-fin ray 12.9% of the 4th, a distinctive narrow, red-orange line under the eye, and a dark vertical line at the caudal-fin base. Eviota specca n. sp. has a cephalic sensory-pore system pattern 1 (complete), has a dorsal/anal-fin formula of 8/8, the body heavily sprinkled with chromatophores, and a single dark spot on the upper pectoral-fin base.