Due to insufficient morphological diagnostic characters in larval fishes, it is easy to misidentify them and difficult to key to the genus or species level. The identification results from different laboratories are often inconsistent. This experiment aims to find out, by applying DNA barcoding, how inconsistent the identifications can be among larval fish taxonomists. One hundred morphotypes of larval fishes were chosen as test specimens. The fishes were collected with either larval fish nets or light traps in the northern, southern and northwestern waters of Taiwan. After their body lengths (SL) were measured and specimen photos were taken, all specimens were delivered, in turn, to five laboratories (A–E) in Taiwan to be identified independently. When all the results were collected, these specimens were then identified using COI barcoding. Out of a total of 100 specimens, 87 were identified to the family level, 79 to the genus level and 69 to the species level, based on the COI database currently available. The average accuracy rates of the five laboratories were quite low: 80.1% for the family level, 41.1% for the genus level, and 13.5% for the species level. If the results marked as “unidentified” were excluded from calculations, the rates went up to 75.4% and 43.7% for the genus and species levels, respectively. Thus, we suggest that larval fish identification should be more conservative; i.e., when in doubt, it is better to key only to the family and not to the genus or species level. As to the most misidentified families in our experiment, they were Sparidae, Scorpaenidae, Scombridae, Serranidae and Malacanthidae. On the other hand, Mene maculata and Microcanthus strigatus were all correctly identified to the species level because their larvae have distinct morphology. Nevertheless, barcoding remains one of the best methods to confirm species identification.

The red drums, Sciaenops ocellatus, are predatory marine fish from Atlantic American coast. They were introduced to Taiwan for aquaculture purpose in 1987 and have been reported in the wild along the southwest coast of Taiwan since 1998. Their current distribution is on the western coast of Taiwan and the Matsu Islands of Fujian Province where there are sand and mud bottoms. However, the discontinuous populations of Taiwan and Matsu indicated different sources of introduction. The facts that there are consecutive records of red drums for 7 years including every single month, at multiple localities, and the fish’s larger size all point to their survival in the wild. The mechanisms of their introductions are probably the escapes from net cages as well as the deliberate releases to improve fisheries and for religious activities. This paper documents for the first time a marine fish has invaded and established in coastal water off western Taiwan and the Indo-West Pacific. The ecological impact of red drums on the local fish community is still unknown and calls for further studies.

Annotated checklist of eels (orders Anguilliformes and Saccopharyngiformes) from Taiwan

A new species of gudgeon, Microphysogobio xianyouensis, is described from Mulan River in Fujian Province, southeastern China. M. xianyouensis appears to be closely related to M. brevirostris (Günther, 1868) of Taiwan. However, it can be well distinguished based on a combination of meristics, morphometric measurements, color pattern and molecular data. A molecular phylogenetic analysis of species of Microphysogobio from southeastern China and Taiwan based on concatenated mitochondrial Cyt b and D-loop genes is presented and tree topology strongly supports that M. xianyouensis as a distinct species and sister to M. brevirostris. Our molecular evidence agreed with Bănărescu's proposed taxonomic viewpoint, the tree topology reveals that the type species of the genus Huigobio, H. chenhsienensis, is nested within several valid species of Microphysogobio, and Huigobio is confirmed to be a junior synonym of the genus Microphysogobio.