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A new genus, Liusius, is established for the East Asian leucosiid crab Leucosia longimaculata Chen & Fang, 1991. The new genus differs from Leucosia s. str. and allied genera in having the shaft of the male first gonopod coiled eight times on its axis, bearing a distal setose lobe topped by a digitate process, and prominently swollen female vulvae opening distad. The molecular phylogenetic analysis of the 16S rDNA supports the morphological observations. The species is redescribed and illustrated.

The present study investigated the population of the xanthid brachyuran crab, Macromedaeus distinguendus (De Haan, 1835), at a toxic hydrogen sulfide, shallow hydrothermal vent area at Turtle Island, off northeastern Taiwan. This is the first record of this species from this extreme environment, and M. distinguendus is only the second brachyuran discovered in this area. The wet weight of male and female M. distinguendus varied from 0.11 to 1.22 g (mean ± standard deviation: 0.56 ± 0.39 g) and 0.06 to 0.62 g (0.37 ± 0.15 g), respectively. The wet weight: carapace width ratio was significantly correlated in both sexes. The local distribution patterns of M. distinguendus were different from those of the obligate hydrothermal crab Xenograpsus testudinatus N. K. Ng, J.-F. Huang & Ho, 2000 (Xenograpsidae) in this area. An analysis of resource use and habitat partitioning revealed that the two crab species were able to co-exist within the study area.

In 2009, the container ship Colombo Queen and the oil tanker W-O BUDMO grounded off Jialeshui and Houwan, respectively, in southern Taiwan. Water quality was monitored at each site to evaluate the environmental impact caused by the resulting oil spills. The results show that the PAHs, turbidity, and other nutrients increased shortly after oil spill, however levels of these parameters eventually returned to baseline levels. On the other hand, DO saturation, pH and chl. a decreased initially, reached maxima after 10days, and returned to the baseline levels after 14days. The chl. a concentration, pH and DO saturation fluctuated in a similar pattern at both sites during the oil spills, likely driven by algal blooms. In this study, we documented a full environmental recovery at coastal areas before, during and after the oil spills.

This study presents a rare sesarmid cavernicolous crab, Karstama boholano (Ng, 2002), from Taiwan. This genus and species are both new to Taiwan. We describe the diagnostic characteristics of the Taiwanese specimen and provide illustrations of the adult and first zoea, as well as photographs of an adult in its natural habitat. The identity was confirmed by the COI gene sequence and morphological data. In addition, the zoeal morphology and breeding ecology of the genus Karstama Davie and Ng, 2007 are reported for the first time.

Two species of brachyurans, Pariphiculus coronatus (Alcock & Anderson, 1894) and Pariphiculus agariciferus Ihle, 1918, family Iphiculidae, are reported from Taiwan for the first time. A key to the known species of the genus is presented.

The western Pacific pinnotherid crab, Fabia obtusidentata Dai, Feng, Song and Chen, 1980, which lives in the saucer scallop, Amusium (Pectinidae), is found not to belong to Fabia Dana, 1851 s. str. or Pinnotheres Bosc, 1802. In contrast to these two genera, F. obtusidentata possesses a carapace not having longitudinal grooves, a third maxilliped in which the dactylus is slender and inserted one-third from the proximal end of the conical propodus, and a prominently elongated right third ambulatory leg with a long dactylus. It is here referred to its own genus, Amusiotheres gen. nov. Pinnotheres hanumantharaoi Devi and Shyamasundari, 1989, from India, is also transferred to the new genus.

Six species of leucosiid crabs are recorded for the first time from Taiwan: Cryptocnemus obolus Ortmann, 1892, Myrine kessleri (Paul’son, 1875), Nucia speciosa Dana, 1852, Pseudophilyra intermedia Ihle, 1918, Philyra malefactrix (Kemp, 1915), and Euclosiana crosnieri (Chen, 1989). One species, Pyrhila carinata (Bell, 1855), is also recorded, for only the second time. Diagnostic characters as well as distributional information of these species are summarized in the present paper.

The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction and climate change.

The fiddler crabs, genus Uca Leach, 1814 (Decapoda, Ocypodidae) of Taiwan, including the offshore islands of Penghu (Pescadores), Kinmen (Quemoy), Matsu (Matzu), and Dongsha (Pratas), are revised, with the recognition of five subgenera and 15 species, viz. Uca (Austruca) Bott, 1973: U. lactea (De Haan, 1835), U. perplexa (H. Milne Edwards, 1837), U. triangularis (A. Milne-Edwards, 1873); U. (Gelasimus) Latreille, 1817: U. borealis Crane, 1975, U. jocelynae Shih, NaruseNg, 2010, U. tetragonon (Herbst, 1790), U. vocans (Linnaeus, 1758); U. (Paraleptuca) Bott, 1973: U. crassipes (White, 1847), U. splendida (Stimpson, 1858); U. (Tubuca) Bott, 1973: U. acuta (Stimpson 1858), U. arcuata (De Haan, 1835), U. coarctata (H. Milne Edwards, 1852), U. dussumieri (H. Milne Edwards, 1852), U. paradussumieri (Bott, 1973); and U. (Xeruca) Shih, 2015: U. formosensis Rathbun, 1921. Among them, U. acuta, U. paradussumieri, and U. vocans are confirmed to be distributed in Taiwan. Uca formosensis is endemic to Taiwan. The Uca species of the main islands of Japan are also listed. Four species (U. arcuata, U. lactea, U. crassipes and U. borealis) are known, but the recent additional records of U. perplexa and U. vocans need further confirmation. Except U. acuta, U. borealis, U. formosensis, U. lactea, and U. paradussumieri, other 10 Taiwanese species can be found from the Ryukyus too. Only one endemic species, U. boninensis, is reported from the Ogasawara (Bonin) Islands. A key to the 18 species of Uca found in East Asia is also provided in this study.

Four leucosiid species from Taiwan are presented. Ebalia nudipes Sakai, 1963, with its male first gonopod figured for the first time. Galilia petricola KomaiTsuchida, 2014, is recorded on the basis of a larger specimen, and distinguishing features with its only congener, G. narusei NgRicher de Forges, 2007, reappraised. Nursia rhomboidalis (Miers, 1879), previously known only from Japan, Korea, and mainland China, is also recorded from Taiwan. Myra fugax (Fabricius, 1798) is now formally recorded from Taiwan, and female characters identified to help separate the three known Taiwanese species of Myra.

Paralytic toxicity was detected by tetrodotoxin (TTX) bioassay in 41 specimens of four species of coral reef crabs collected from Kenting National Park, southern Taiwan from January 2003 to March 2004. The frequency of toxicity in Zosimus aeneus, Xanthias lividus, Actaeodes tomentosus (Xanthidae family) and Camposcia retusa (Majidae family) specimens was 93.3%, 100%, 46.7% and 66.7%, respectively. The average toxicity of crab specimens was 483 ± 225 (mean ± SD) mouse units (MU) for Z. aeneus, 51 ± 32 MU for X. lividus, 6 ± 5 MU for A. tomentosus, and 18 ± 11 MU for C. retusa. Each toxin of four species of crabs was extracted with acidic methanol, cleansed using a C18 solid-phase extraction column, filtered through a microcentrifuge filter and analyzed by HPLC, LC-MS and GC-MS. The toxins of Z. aeneus and X. lividus contained TTX (90%) and a small amount of gonyautoxins (10%), whereas those of A. tomentosus and C. retusa all mainly contained TTX, but no paralytic shellfish poison. Except for Z. aeneus and X. lividus, two species A. tomentosus and C. retusa were first recorded as toxic in Taiwan.

Tetrodotoxin was detected by tetrodotoxin (TTX) bioassay in 28 specimens of six species of xanthid crabs collected from Tunkang, southern Taiwan, in May 2004. The average toxicity of crab specimens was 347 ± 276 (means ± SD) mouse units (MU) for Demania cultripes, 59 ± 17 MU for Demania toxica, 324 ± 114 MU for Demania reynaudi, 214 ± 65 MU for Lophozozymus incisus, 184 ± 85 MU for Lophozozymus pictor and 611 ± 471 MU for Atergatopsis germaini. Each toxin of the six species of crabs was extracted with acidic methanol, cleansed using a C18 solid-phase extraction (SPE) column, filtered through a microcentrifuge filter and determined by LC-MS and GC-MS. The recovery of TTX was above 82.9% and the detection limit was 0.005 μg with LC-MS analysis. A linear equation was obtained between 0.03 and 3.0 μg of TTX. Analyses by LC-MS and GC-MS showed that these crab species all contained TTX. The paralytic shellfish poisons were not found. Among samples, D. cultripes, D. toxica and L. incisus are the first to be recorded as toxic in Taiwan.

[In recent collections from deep waters around Taiwan, numerous new records of brachyuran crabs were obtained for Taiwan. Thirty-one species are added to the known Taiwanese brachyuran fauna, including 13 new records of genera and two new records of families (Homolodromiidae and Cymonomidae). The established brachyuran crab fauna for Taiwan now stands at 604 species. Au cours de collectes recentes dans les eaux profondes autour de Taiwan, de nombreux signalements nouveaux de crabes Brachyoures ont ete obtenus. Trente et une especes sont ainsi ajoutees a la faune connue des Brachyoures de Taiwan, incluant 13 nouvelles citations de genres et deux nouvelles citations de familles (Homolodromiidae et Cymonomidae). La faune des Brachyoures de Taiwan s'eleve maintenant a 604 especes., In recent collections from deep waters around Taiwan, numerous new records of brachyuran crabs were obtained for Taiwan. Thirty-one species are added to the known Taiwanese brachyuran fauna, including 13 new records of genera and two new records of families (Homolodromiidae and Cymonomidae). The established brachyuran crab fauna for Taiwan now stands at 604 species. Au cours de collectes recentes dans les eaux profondes autour de Taiwan, de nombreux signalements nouveaux de crabes Brachyoures ont ete obtenus. Trente et une especes sont ainsi ajoutees a la faune connue des Brachyoures de Taiwan, incluant 13 nouvelles citations de genres et deux nouvelles citations de familles (Homolodromiidae et Cymonomidae). La faune des Brachyoures de Taiwan s'eleve maintenant a 604 especes.]

[Two species of Pilumnus, P. orbitospinis Rathbun, 1911, and P. spinulus Shen, 1932, are newly recorded from Taiwan. Two new species, Pilumnus chani and Typhlocarcinops yui, are also described. Pilumnus chani is similar to P. ikedai Takeda & Miyake, 1968, from Japan, but can easily be distinguished by its frontal margin being lined with rounded granules, blunter anterolateral teeth and relatively longer ambulatory legs. Typhlocarcinops yui is allied to T.canaliculata Rathbun, 1909, from Thailand, but can be separated by the cleft anterolateral margin of its carapace and the distinctive form of its male first pleopod. Deux especes de Pilumnus, P.orbitospinis Rathbun, 1911, et P.spinulus Shen, 1932, sont citees comme nouvelles pour Taiwan. Deux nouvelles especes, Pilumnus chani et Typhlocarcinops yui, sont egalement decrites. Pilumnus chani ressemble a P. ikedai Takeda & Miyake, 1968 du Japon, mais peut facilement etre distinguee par son bord frontal marque par une ligne de granules arrondis, des dents anterolaterales plus emoussees et des pattes ambulatoires relativement plus longues. Typhlocarcinops yui est apparente a T. canaliculata Rathbun, 1909, de Thailande, mais peut en etre separe par le bord anterolateral incise de la carapace et la forme distinctive de son premier pleopode mâle., Two species of Pilumnus, P. orbitospinis Rathbun, 1911, and P. spinulus Shen, 1932, are newly recorded from Taiwan. Two new species, Pilumnus chani and Typhlocarcinops yui, are also described. Pilumnus chani is similar to P. ikedai Takeda & Miyake, 1968, from Japan, but can easily be distinguished by its frontal margin being lined with rounded granules, blunter anterolateral teeth and relatively longer ambulatory legs. Typhlocarcinops yui is allied to T.canaliculata Rathbun, 1909, from Thailand, but can be separated by the cleft anterolateral margin of its carapace and the distinctive form of its male first pleopod. Deux especes de Pilumnus, P.orbitospinis Rathbun, 1911, et P.spinulus Shen, 1932, sont citees comme nouvelles pour Taiwan. Deux nouvelles especes, Pilumnus chani et Typhlocarcinops yui, sont egalement decrites. Pilumnus chani ressemble a P. ikedai Takeda & Miyake, 1968 du Japon, mais peut facilement etre distinguee par son bord frontal marque par une ligne de granules arrondis, des dents anterolaterales plus emoussees et des pattes ambulatoires relativement plus longues. Typhlocarcinops yui est apparente a T. canaliculata Rathbun, 1909, de Thailande, mais peut en etre separe par le bord anterolateral incise de la carapace et la forme distinctive de son premier pleopode mâle.]

The fiddler crabs, genus Uca Leach, 1814 (Decapoda, Ocypodidae) of Taiwan, including the offshore islands of Penghu (Pescadores), Kinmen (Quemoy), Matsu (Matzu), and Dongsha (Pratas), are revised, with the recognition of five subgenera and 15 species, viz. Uca (Austruca) Bott, 1973: U. lactea (De Haan, 1835), U. perplexa (H. Milne Edwards, 1837), U. triangularis (A. Milne-Edwards, 1873); U. (Gelasimus) Latreille, 1817: U. borealis Crane, 1975, U. jocelynae Shih, Naruse & Ng, 2010, U. tetragonon (Herbst, 1790), U. vocans (Linnaeus, 1758); U. (Paraleptuca) Bott, 1973: U. crassipes (White, 1847), U. splendida (Stimpson, 1858); U. (Tubuca) Bott, 1973: U. acuta (Stimpson 1858), U. arcuata (De Haan, 1835), U. coarctata (H. Milne Edwards, 1852), U. dussumieri (H. Milne Edwards, 1852), U. paradussumieri (Bott, 1973); and U. (Xeruca) Shih, 2015: U. formosensis Rathbun, 1921. Among them, U. acuta, U. paradussumieri, and U. vocans are confirmed to be distributed in Taiwan. Uca formosensis is endemic to Taiwan. The Uca species of the main islands of Japan are also listed. Four species (U. arcuata, U. lactea, U. crassipes and U. borealis) are known, but the recent additional records of U. perplexa and U. vocans need further confirmation. Except U. acuta, U. borealis, U. formosensis, U. lactea, and U. paradussumieri, other 10 Taiwanese species can be found from the Ryukyus too. Only one endemic species, U. boninensis, is reported from the Ogasawara (Bonin) Islands. A key to the 18 species of Uca found in East Asia is also provided in this study.

Paralytic toxicity was detected by tetrodotoxin (TTX) bioassay in four and five specimens of new toxic xanthid crab Xanthia lividus collected from Lanyu, south-east Taiwan in April 1999 and Hsiaoliuchiu south-west Taiwan in November 1999, respectively. The average toxicity of crab specimens collected from Lanyu and Hsiaoliuchiu was 230 ± 94 (mean ± SD) mouse units (MU) and 241 ± 114 MU, respectively. The toxin was partially purified by YM-1 membrane ultrafiltration and Bio-Gel P-2 column chromatography. Electrophoresis, high-performance liquid chromatography and gas chromatography–mass spectroscopy analyses showed that the crab toxin was composed mainly of tetrodotoxin (83%), as well as a small amount of gonyautoxin 1-4 (17%).

The toxicity of the gastropod Nassarius glans was investigated. This gastropod was implicated in an incident of food paralytic poisoning on Tungsa Island, Taiwan, in April 2004. Six victims consumed both digestive glands and muscle. These tissues contained high concentrations of toxin; their highest toxicity scores were 2,048 and 2,992 MU/g, respectively, based on the tetrodotoxin (TTX) bioassay. The toxin was purified from these gastropods and analyzed by high-performance liquid chromatography, which revealed TTX and related compounds 4-epi TTX and anhydro-TTX; paralytic shellfish poisons were not found. The urine and blood samples from patients were cleansed using a C 18 Sep-Pak cartridge column and 3,000 molecular weight cutoff Ultrafree microcentrifuge filters, and the eluate was filtered and analyzed by liquid chromatography and mass spectrometry. The detection limit for TTX was 1 ng/ml. The standard curves were linear in the range 30 to 600 ng/ml for urine and 1 to 30 ng/ml for blood. TTX was detected in all urine samples but in only three of four blood samples tested. Thus, the causative agent of gastropod food poisoning was identified as TTX.

Four leucosiid species from Taiwan are presented. Ebalia nudipes Sakai, 1963, with its male first gonopod figured for the first time. Galilia petricola Komai & Tsuchida, 2014, is recorded on the basis of a larger specimen, and distinguishing features with its only congener, G. narusei Ng & Richer de Forges, 2007, reappraised. Nursia rhomboidalis (Miers, 1879), previously known only from Japan, Korea, and mainland China, is also recorded from Taiwan. Myra fugax (Fabricius, 1798) is now formally recorded from Taiwan, and female characters identified to help separate the three known Taiwanese species of Myra.

A new species of a strikingly coloured xanthid crab of the genus Neoliomera Odhner, 1925, is described from coral reefs in Guam, Taiwan, and the Hawaiian Islands. The new species is allied to N. pubescens (H. Milne Edwards, 1834), and N. demani Forest & Guinot, 1961, but differs in the form of the carapace armature, frontal margin, structure of the chela, proportions of the ambulatory merus and the form of the male first gonopod. Neoliomera demani is also recorded from Taiwan for the first time and aspects of its taxonomy are discussed.

A new species of obligate coral symbiont crab of the genus Cymo de Haan, 1833 (Brachyura: Xanthidae) is described from the Indonesian Anambas Islands in the South China Sea. The species is allied to C. deplanatus A. Milne-Edwards, 1873, but is easily distinguished by a suite of carapace, cheliped, male abdominal and gonopod characters. A revised key to the genus Cymo is presented.