Two new species of Rhinogobius (Gobiiformes: Oxudercidae) from Palawan, Philippines, with their phylogenetic placement

Two new species of Rhinogobius found in streams on central part of Palawan Island, Philippines are described. The two new species, Rhinogobius estrellae and Rhinogobius tandikan share unique transverse rows of sensory papillae on the cheek with Rhinogobius similis Gill, 1859, but differ from the latter in fin ray counts, arrangement of the scales, etc. The two new species are distinguished from each other by the pectoral-fin ray count, the longitudinal- and predorsal-scale counts, and colouration of the body. Rhinogobius estrellae new species and R. tandikan new species have been found allopatrically in a stream within Malatgao River system flowing into the Sulu Sea and in the Cayulo River flowing into the South China Sea, respectively. The Malatgao River system is the southernmost habitat of the genus Rhinogobius. Rhinogobius similis had been considered as the only member of the most basal lineage of this genus, but our mitochondrial genome analysis suggested that the two new species are additional members of this lineage. They are considered to be relicts of their common ancestor with R. similis, which probably had a wider distribution.

Rhinogobius houheensis, a new species of freshwater goby (Teleostei: Gobiidae) from the Houhe National Nature Reserve, Hubei province, China

A new freshwater goby, Rhinogobius houheensis, is described based on 40 specimens in a freshwater stream from the Houhe National Nature Reserve, Hubei Province, China. The new species can be distinguished from all its congeneric species by the following combination of characters: thee first dorsal fin rays VI, the second dorsal fin rays I/9-I/10; anal fin rays I/7-I/8; pectoral-fin rays 16–17; longitudinal scale series 37–40; transverse scales 12–14; predorsal scale series 0; and vertebrae counts 12+18=30. The first three spinous rays in the first dorsal fin are colored with two dark-blue stripes and one black spot in alive.

A new species of Rhinogobius (Pisces: Gobiidae), with analyses of its DNA barcode

The genus Rhinogobius Gill 1859 is widely distributed in fresh waters along the Western Pacific coast of tropical and temperate Asia. A new species, Rhinogobius maxillivirgatus, is described from Anhui Province in Eastern China. This species can be differentiated from all congeners by a combination of the following characters: up to 6 longitudinal brown to black stripes along the side of the body; pectoral-fin rays modally 14; predorsal scale series 5–9; lateral scale series 28–30; transverse scale series 6–7; branchiostegal membrane with about 20 red round spots in males; and 2 black oblique stripes parallel along the upper jaw on the anterior portion of the cheek. Analyzing sequences of cytochrome c oxidase subunit I revealed that the new species is closely related to, but distinct, from Rhinogobius wuyanlingensis.

A new species of Metzia (Cypriniformes: Cyprinidae) from Northern Laos

A new cyprinid fish, Metzia bounthobi, is described on the basis of 18 specimens (including 10 specimens in type series)from the Mekong River basin in Phongsaly and Luang Prabang Provinces, northern Laos. The species is distinguishedfrom congeners by having the following diagnostic traits: 18–20 branched anal-fin rays (vs. 10–18 in the others); 49–55lateral-line scale rows (vs. 35–48); 33–36 predorsal scale rows (vs. 15–20); 20–22 circumpeduncular scale rows (vs.14–18); 8–10 gill rakers on outer surface of first gill arch (vs. 12–18). The new species also resembles species of Hemic-ulterella, Ischikauia and at least some species of Anabarilius, in sharing a sharp keel developed only between the base ofthe pelvic fin and anus, soft last unbranched dorsal-fin ray, and air bladder composed of two chambers; however, M.bounthobi differs in having a considerably rounded snout (vs. pointed in Hemiculterella, Ischikauia and Anabarilius),18–20 branched anal-fin rays (vs. 8–17 in Hemiculterella, Ischiakuia and Anabarilius), 49–55 lateral-line scale rows (vs.more than 58 in Ischikauia and Anabarilius, except for A. transmontana with 54–57), air bladder with rounded posteriorend (vs. posterior end with a small lobe at least in Hemiculterella) and 39–40 vertebrae (vs. 40–43, 42–43 and 43–48 in Hemiculterella, Ischikauia and Anabarilius, respectively).

Polypterus mokelembembe, a new species of bichir from the central Congo River basin (Actinopterygii: Cladistia: Polypteridae)

Polypterus mokelembembe sp. n. is described from the central Congo River basin. It is distinguished from all other Polypterus species except P. retropinnis, P. teugelsi and P. palmas palmas by its high predorsal scale count (32–37 vs. 11–28). It differs from P. teugelsi by having 57– 60 lateral line scales (vs. 63–65), from P. palmas palmas by a single large black blotch on the pectoral-fin base (vs. numerous small spots on the posterior part of the base), and from P. retropinnis by having a wider first dorsal-fin spine (6.4–8.1 vs. 4.6–6.1 % of HL), a smaller internostril distance (11.6–13.7 vs 14.3–18.0 % of HL), and fewer pectoral-fin rays (23–29 vs. 30– 34). Inasmuch as the type series (comprising three specimens) of Polypterus retropinnis Vaillant, 1899 is of mixed composition, and includes two specimens of P. mokelembembe, a lectotype is designated for P. retropinnis and a rediagnosis for that species is provided.