OSMERIFORMES / SALANGIDAEOSMERIFORMES – freshwater smelts
Classification of the osmeriform fishes is in a state of flux, anddrastic changes are still being made to the phylogenetic hypotheses even in the recent yearas. For example, following thephylogenetic hypothesis proposed by Johnson & Patterson (1996),Nelson (2006) placed the salangid fishes in the tribe Salanginiof the osmerid subfamily Osmerinae, together with Mallotus
villosus (Capelin). However, recent analyses of molecular phylogeny (e.g., Li et al., 2010) contradict Nelson's classification
within the Osmeriformes, and the Salangidae is currently
accepted as a distinct family by many researchers. Within theOsmeriformes, only the single family Salangidae was recorded
from the Mekong; the occurrence, however, probably represents
the result of introduction from the non-Mekong Basin of China.
The Salangidae comprises small paedomorphic fishes, having

a soft, elongate and transparent body (which turns to whitish
immediately after death); due to its general appearance, thesalangid fishes are commonly called "noodlefishes". Many of
the salangid fishes occur in the brackish estuaries and adjacentfreshwater areas or shallow coastal waters in the East Asiancountries, but some are restrictedly found in freshwaters throughall life stages. This family was revised taxonomically by Roberts(1984), but his Salangidae contained Sundasalanx, which is
now regarded as a clupeid genus (see p. 68). Subsequenly theintrafamilial classification was modified by Zhang et al. (2007)
and Fu et al. (2012). Seven genera and 20 species are currently
recognized in the Salangidae, and, of these, at least a single
species, Neosalanx brevirostris, is found in the IndochineseMekong, which was probably introduced.

ANeosalanx brevirostris (Pellegrin, 1923) Exotic
Family: Salangidae (FC: --)Size: 8.5 cm SL (Kottelat, 2001a: 143, as Neosalanx sp.).
Distribution: Mekong Basin in China (Yunnan), Laos, Thailand, and Cambodia (probably introduced from non-Mekong
Basin of China to the Yunnanese Mekong, and then widespreadin the other countries).
Notes: A medium-sized species of noodlefish, found in slowflowing, medium to large freshwater rivers.
Referring to W. J. Rainboth's personal communication, Kottelat(2000b: 88) reported a species of Neosalanx from the Bokeo Provinceof Laos, and suggested its possible introduction upriver in the basinin China. Subsequently Kottelat (2001a: 143) noted, "as Neosalanx
taihuensis has been widely introduced in China, its presence inthe Mekong Basin in northern Laos would not be impossible."
The photographed specimens shown here were collected fromSavannakhet of Laos (photos A and B) and of Kandal of Cambodia (C).
During our field surveys in 2007–2013, we collected many
specimens of noodlefishes from the Mekong Basin in southern Laos(Savannakhet Province), Thailand (Ubon Ratchathani Province),and Cambodia (Kandal Province); in particular, it appears to beestablished and commonly captured in the Mun River (a tributaryof the Mekong) around Ubon Ratchathani, Thailand (C. Grudpan,pers. obs.). Its relatively short snout and ca. 57 vertebrae indicatethat it can be identified as Neosalanx brevirostris of Roberts (1984).
Roberts' N. brevirostris contains Neosalanx tangkahkenii (asProtosalanx tangkahkenii) and N. taihuensis (as N. tangkahkeniitaihuensis) as junior synonyms. In their taxonomic review of thesalangid fishes, Zhang et al. (2007) recognized that N. tangkahkeii

snout relatively
short and pointed

small but distinct
adipose fin

B
57 total vertebraeC

as valid, and N. taihuensus (as well as N. pseudotaihuensis) is ajunior synonym of N. tangkahkeii. They, however, did not state
about taxonomic status on N. brevirostris, and thus we do not follow
their decision here. Note that Fu et al. (2012) regarded Neosalanx
as a synonym of Protosalanx.
Neosalanx brevirostris is an important fish in freshwater
fisheries in China (Liu, 2001, as N. taihuensis; Zhao et al., 2008,
as N. taihuensis), and, as noted by Kottelat (2000b: 88, 2001a:143, as N. taihuensis), it was artificially introduced to many placesof China since 1980's (Liu et al., 2000, as N. taihuensis; Liu, 2001,
as N. taihuensis).

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A and B) NUOL-P 1384 (photo: KS); C) IFREDI-P 3771 (photo: PT)body elongate, subtransparent when alive(turned to be whitish immediately after death)