MUGILIFORMES / MUGILIDAE

Fishes of the Mugiliformes, comprising only a single family
Mugilidae, are silvery active swimmers, and are commonly
found in coastal marine waters, brackish estuaries and adjacentfreshwaters from temperate to tropical regions worldwide.
Most of the mugilid fishes have a moderately elongatedand subcylindrical body, small and terminal mouth, 2 wellseparated dorsal fins, 4 slender pungent spines of the firstdorsal fin, pectoral fin high on the body, pelvic fin behind avertical line through base of the pectoral-fin, 1 spine and 5
segmented rays of the pelvic fin, and medium to large scales
on the head and body. Due to their great similarities in generalappearance, species identification of the mugillid fishes are
difficult for non-specialists. The details of jaws and scales, anddevelopment of an adipose eyefold are useful for identifying
genera/species of the mugilid fishes.
Generic classification of the mugilid fishes follows Senou
in Nakabo (1993, 2000, 2002) rather than Durand et al. (2012).
For example, according to Senou, well-known genera Liza andValamugil are considered to be junior synonyms of Chelon andMoolgarda, respectively, and Ellochelon is a distinct genus.
Senou's classification (in Nakabo, 2002) was subsequently largely
supported by recent molecular analysis (Durand et al., 2012).
Ghasemzadeh et al. (2004) described a new genus Paramugil,and placed 2 species (P. georgii and P. parmatus) in the genus.
Their decision was, however, not supported by the molecularphylogeny (Durand et al., 2012). On some discrepancies in thegenus-level classification between Senou in Nakabo (1996, 2000,2002) and Durand et al. (2012), see "Notes" of Chelon subviridis(p. 313) and Moolgarda perusii (p. 314).
Vidthayanon (2008) recorded the following 11 species ofthe mugilid fishes from the Mekong Delta: Chelon parmata,Chelon subviridis, Chelon planiceps (as C. tade), Ellochelon
vaigiensis, Moolgarda cunnesius, Mo. ophuysenii (as ophuyseni),
Mo. pedaraki, Mo. perusii, Mo. seheli, Mo speigleri, and Mugil
cephalus. One of these, Mo. ophuysenii, was regarded as a juniorsynonym of Mo. cunnesius by Harrison & Senou (1999), and,thus, the number of mugilid species hitherto recorded from theEllochelon vaigiensis (Quoy & Gaimard, 1825)
Family: Mugilidae (FC: 245)

Non-Mekong specimens of mullets (Bangpakong, Thailand, photo: KS)

MUGILIFORMES – mullets

Mekong is 10. Kottelat (1989a) also recorded Chelon melinoptera(as Liza melinoptera) from the Mekong, but the record is notincluded here; he noted that the mullet's systematics is "veryconfused and most of the records need confirmation." Six ofthese 10 species (viz., C. parmata, C. subviridis, E. vaigiensis,
Mo. cunniseus, Mo. pedaraki, and Mo. perusii) were collectedfrom the Mekong during our field surveys in 2007–2013; inthe Mekong, all these mullets were restrictedly found in theVietnamese region. In addition to these 6 species, Mo. seheli andMu. cephalus are also shown in this book, based on non-Mekong
specimens (from Phú Quốc Island and Hồ Chí Minh, Vietnam).

ASize: 60 cm TL (Harrison & Senou, 1999: 2094, as Liza vaigiensis).
Notes: A medium-sized species of mullets, commonly foundin shallow coastal marine waters; it frequently enters brachish
estuaries in particular in the early-life stages (juveniles andyoung). Ellochelon vaigiensis is not so common in the Mekong,but the young fish are sometimes sold at local markets aroundthe coastal region.
Ellochelon vaigiensis is a characteristic species, which isreadily distinguished from the other Mekong mullets by having
blackened pectoral fin, a short and deep caudal peduncle, and atruncate caudal fin tinged with yellow or yellowish orange. Its
blackened pectoral fin and yellowish caudal fin are vivid evenin small specimens, and the identification is very easy.
This species was frequently assigned to Chelon (or itssynonym, Liza) (e.g., Harrison & Senou, 1999), but Senou inNakabo (2002) regarded Ellochelon as a distinct genus, comprising only a single species E. vaigiensis.

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pectoral fin blackenedBcaudal fin truncate, tinged withyellow or yellowish orangeA) CTU-P 4585 (photo: HVM); B) CTU-P 4584 (photo: HVM)

Distribution: Mekong Basin in Vietnam; Indo-Pacific.

MUGILIDAE
Chelon subviridis (Valenciennes, 1836)
Family: Mugilidae (FC: 245)

ASize: 40 cm SL (Harrison & Senou, 1999: 2093, as Liza subviridis).
Distribution: Mekong Basin in Vietnam; Indo-Pacific.

Bmaxilla relatively stocky,curved sigmoidallyCanteroventral edge ofpreorbital kinked

head (whenmouth opens)ventral part of maxilla exposed
when mouth closed (vs. usuallyconcealed in similar genus
Moolgarda, pp. 314–315)

adipose eyefold
well-developed,
covering about
1/3 to 1/2 of irisDbody depth at origin of 1st
dorsal fin 22–30% of SL

body depth at origin ofanal fin 21–26 % of SLEF313A & E) CTU-P 2484 (photo: LXT); B) CTU-P 4969 (photo: HVM); C) one of CTU-P collection (Bến Tre, Vietnam, photo: KS); D) CTU-P 1433 (photo: LXT); F) CTU-P 2310 (photo: LXT)

Notes: A medium-sized species of mullets, commonly found inshallow coastal marine waters, brackish estuaries and adjacentfreshwater areas. This is the most common species of the mugilids found in the Vietnamese Mekong, and abundantly foundparticularly in the brackish estuaries.
Chelon is similar to Moolgarda and Mugil in general appearance, but differs in having a kinked anteroventral edge of thepreorbital (vs. slightly concave or nearly straight in Moolgarda
and Mugil), maxilla relatively stocky and curved sigmoidally,
with its posteroventral part that is visible when the mouth isclosed (vs. maxilla slender and straight or weakly curved, with
its posteroventral part not clearly visible when the mouth iscloesd in Moolgarda and Mugil), and ctenoid scales with a nonmembranous hind margin (vs. with a membranous hind margin
in Moolgarda) (see also p. 317).
The genus-level classification follows Senou in Nakabo (1993,2000, 2002), who regarded the genus Liza as a junior synonymof Chelon. Based on the molecular phylogeny, Durand et al.
(2012) concurred Senou in Nakabo (1993, 2000, 2002) on theChelon-Liza synonymy. Durand et al. (2012), however, applied
the generic name Planiliza for the Indo-West Pacific subclade,whereas Chelon for the Atlantic and Mediterranean subclade.
Since these 2 subclades form a single clade (see figs 1–2 ofDurand et al., 2012), we here lump these together into a single
genus Chelon, as Senou in Nakabo (1993, 2000, 2002) did. The
third subclade (named as a new genus Parachelon by Durand etal., 2012), composed of a single species grandispuamis, is a sistergroup of Chelon + Planiliza of Durand et al. (2012), and thus canbe also placed in Chelon herein recognized; actually, for example,Harrison (2016) assigned the species to Chelon (as Liza), together
with the species of Chelon of Durand et al. (2012).
Of the 3 species of Chelon hitherto recorded from the Mekong(viz., C. parmata, C. planiceps, and C. subviridis), C. subviridis
is distinguished from the other 2 by having moderately slenderbody, and its depth at origin of anal fin is 21–24% (perhaps
up to 26%) of SL (vs. 29–33 and 19–20 in C. parmata and C.
planiceps, respectively) (Harrison & Senou, 1999, as species ofLiza). Chelon subviridis is also similar to C. macrolepis and C.
melinoptera, the other common Indo-Pacific species expected(but not yet recorded) from the Mekong estuaries, but has amore-developed adipose eyefold, covering 1/3 to 1/2 of iris in
specimens larger than 10 cm SL (vs. absent or poorly developed
as a narrow rim around the eye in the latter 2 species).
Considerable variations in the head and body shape (e.g.,shape of snout and body depth) and coloration are found within
the Mekong specimenes of Chelon subviridis (see photographs).
According to the key to species of mullets in the Western-Central
Pacific region by Harrison & Senou (1999, as a species of Liza),
however, all of these specimens can be identified as C. subviridis;
this identification was provisionally confirmed by H. Senou(Kanagawa Prefectural Museum of Natural History, Odawara,Japan), although he also suggested that these specimens possibly
contain more than a single species.

MUGILIDAE
Chelon parmata (Cantor, 1849)
Family: Mugilidae (FC: 245)A

Size: 30 cm TL (Harrison & Senou, 1999: 2093, as Liza parmata).
Distribution: Mekong Basin in Vietnam; Western Pacific.
Notes: A relatively small-sized species of mullets, found inshallow coastal marine waters and brackish estuaries. The
photographed specimen shown here is a small young, collectedfrom a mangrove creek at Bạc Liêu, Vietnam.
Its extremely deep body readily distinguishes Chelon parmata
from the other mugillids in the Mekong. Chelon melinoptera,
which is also expected from the Mekong (but not yet recordedthere), may have a similar deep body (depth at anal-fin origin
23–29% of SL), but differs in having more gill raker counts(45–59 vs. 30–45 in C. parmata) (Harrison & Senou, 1999).
Based on the phylogenetic analysis of morphological characters, Ghasemzader et al. (2004) placed 2 mullet species in their
new genus Paramugil; these are P. parmatus and P. georgii (known
only from Australia). However, recent molecular analysis did notagree with their classification; for example, in the phylogenetic
tree made by Durand et al. (2012), P. parmatus is deeply nested
within the Indo-Pacific clade of their Planiliza + Chelon. We thus
assign this species to Chelon (see also "Notes" of C. subviridis, p.
313).

Moolgarda perusii (Valenciennes, 1836)
Family: Mugilidae (FC: 245)
Size: 25 cm TL (Harrison & Senou, 1999: 2106, as Valamugil
perusii).

body depth at origin of 1st
dorsal fin 30–37% of SL

body depth at origin of
anal fin 29–33 % of SL

CTU-P 2561 (photo: LXT)

adipose eyefold
absent or poorly
developed as
rim around eye

Distribution: Mekong Basin in Vietnam; Indo-West Pacific.

314A

distinct dark spot at dorsal
end of pectoral-fin baseorigin of second dorsal fin well behinda vertical through anal-fin origin

B

31–35 longitudinal scales
second dorsal and anal finswell scaled on almost allparts (see text)
16 circumpeduncular scales

C small young

CTU-P 4548 (photo: HVM); B) CTU-P 4547 (photo: HVM); C) CTU-P 3087 (photo: LXT).

Notes: A relatively small-sized species of mullets, found in shallow coastal marine waters and brackish estuaries; it is commonlyseen at the local markets around the coastal region.
Moolgarda can be distinguished from Chelon and Mugil byhaving a membranous hind margin of scales on the body (vs.
body scales are weak ctenoid, without a membranous hind margin
in Chelon and Mugil), a weakly curved maxilla (the posterior
part of which is usually concealed when the mouth is closed vs.
visible when the mouth is closed in Chelon), and a preorbitalwith weakly concaved (rather than kinked) anteroventral edge
and a non-pointed posteriventral tip (vs. anteroventral edge iskinked in Chelon, anteroventrgal edge is nearly straight andposteroventral tip is pointed in Mugil) (see also p. 317).
Durand et al. (2012) considered Moolgarda as nomen dubium,and did not use the name in their revision of the mugilid genera.
On the other hand, Senou in Nakabo (1993, 2000, 2002) statedthat the type species is undoubtedly the same species as M. seheli;
Kottelat (2013c) referred the Senou's opinion, and indicatedthat the figured holotype of M. pura keyed out as M. seheli or
possibly M. buchanani of Harrison & Senou (1999). Following
Senou in Nakabo (1993, 2000, 2002) and Kottelat (2013c) (exceptfor status of Crenimugil), we use Moolgarda as the genus namefor the species belonging to a clade composed of Osteomugil +Crenimugil of Durand et al. (2012).
Moolgarda perusii differs from the other Mekong congeners(viz., M. pedaraki, M. cunnesius, and M. seheli) in fewer counts oftransverse and circumpeduncular scales, and well scaled second
dorsal and anal fins. See also the key to species of Moolgarda in
the Western-Central Pacific given by Harrison and Senou (1999,as Valamugil).

MUGILIDAE
Moolgarda cunnesius (Valenciennes, 1836)
Family: Mugilidae (FC: 245)
Size: 14 cm SL (Harrison & Senou, 1999: 2103, as Valamugil
cunnesius).
Notes: A small-sized species of mullets, found in shallow
coastal marine waters and brackish estuaries.
Moolgarda cunnesius is similar to Moolgarda engeli (notshown in this book, but is expected from the Mekong) and M.
perusii (left page) by having usually 16 circumpeduncular scales(vs. usually 19 or 20 in M. seheli and M. pedaraki, below) andthe origin of the second dorsal fin well behind the anal-fin origin(vs. almost opposite), but has 37–43 longitudinal scales (vs. 30–36 in M. engeli and M. perusii). The other congener M. speigleri,also recorded from the Mekong (Vidthayanon, 2008), has similarcounts of the scales, although it differs in having fewer gill rakers
on the lower limb of the first gill arch (35–45 vs. 62–75 in M.
cunnesius), and well scaled second dorsal and anal fins (vs. only
the anterior and basal parts of the fins are scaled) (Harrison &Senou, 1999, as species of Valamugil).

small young
origin of second dorsal fin well behinda vertical through anal-fin origin
37–43 longitudinal scales

small young
16 circumpeduncular scales

CTU-P 1466 (photo: LXT)

Distribution: Mekong Basin in Vietnam; Indo-West Pacific.

A small young

Moolgarda seheli (Forsskål, 1775)

Distribution: Mekong Basin in Vietnam; Indo-Pacific.
Notes: A relatively small-sized species of mullets, found inshallow coastal marine waters, brackish estuaries and adjacentfreshwater areas. Vidthayanon (2008) recorded this species fromthe Mekong Delta, but, during our field surveys in 2007–2013,
we could not confirm this from the region. The photographed
specimen (small young) shown here was collected from Phú QuốcIsland, off the western coast of the Mekong Delta in Vietnam,
where this species appears to be common.
Moolgarda seheli resembles M. pedaraki (below) in having
18–20 (usually 19 or 20) circumpeduncular scales (vs. usually
16 in the other Mekong congeners) and almost opposite second
dorsal and anal fins (vs. origin of the second dorsal fin distinctly
behind the origin of the anal fin). Moolgarda seheli can be
distinguished from the M. pedaraki by a slightly higher count of
longitudinal scales (36–42 vs. 32–37 in M. pedaraki), a longer
snout (usually 18% or more of head length vs. 14–19%), andweakly falcate second dorsal and anal fins (vs. falcate in adult)(Harrison & Senou, 1999, as species of Valamugil).

origin of second dorsal fin above or slightlybehind a vertical through anal-fin origin
36–42 longitudinal scales

B small young
18–20 circumpeduncular scales

AMoolgarda pedaraki (Valenciennes, 1836)
Family: Mugilidae (FC: 245)
Size: 50 cm SL (Harrison & Senou, 1999: 2102, as Valamugil
buchanani).
Distribution: Mekong Basin in Vietnam; Indo-Pacific.
Notes: A medium-sized species of mullets, found in shallow
coastal marine waters and brackish estuaries. Moolgarda buchanani (or Valamugil buchanani, originally described as Mugil
buchanani Bleeker, 1853) is a synonym (Senou in Nakabo,
2000, 2002, 2013). See "Notes" of a similar congener M. seheli(above).

origin of second dorsal fin above or slightly
behind a vertical through anal-fin origin
32–37 longitudinal scales

B small young (preserved)

second dorsal and anal fintall and falcate in adult

18–20 circumpeduncular scales

315A) Non-Mekong specimen, IFREDI-P 6128 (Koh Kong, Cambodia, photo: PT); B) 1 ofCTU-P 4041 (photo: KS); B)

Size: 25 cm TL (Harrison & Senou, 1999: 2106, as Valamugilseheli).

A) CTU-P 4218 (photo: LXT); B) CTU-P 4217 (photo: LXT)

Family: Mugilidae (FC: 245)

MUGILIDAE
A

Mugil cephalus Linnaeus, 1758

B

Family: Mugilidae (FC: 245)
Size: 91 cm TL (Harrison & Senou, 1999: 2096).

Notes: A medium to large-sized species of mullets, found incoastal marine waters, brackish estuaries and adjacent freshwater
areas. Mugil cephalus is a famous cosmopolitan fish, but is lessabundant in the tropics (Bhatia & Wongratana, 1974; Harrison &Senou, 1999). Wongratana et al. (1984) discovered 3 preserved
specimens of M. cephalus from Songkhla Lake, a brackish
water lake in the southern part of the peninsular Thailand, andnoted "The appearance of only three specimens during the longsearch for the fish is therefore due to its rarity in Thai waters."
Subsequently Vidthayanon (2008: 162, fig. 221) recorded thisspecies from the Mekong Delta, with a note, "Uncommon inSoutheast Asian markets." During our field surveys in 2007–2013, we could not find any specimens of M. cephalus from theMekong; photographed specimen shown here was purchased at afish market in Hồ Chí Minh City, Vietnam.
Mugil is somewhat similar to Chelon (pp. 313–314) andMoolgarda (pp. 314–315) in general appearance, but can bedistinguished by having, e.g., an extensive adipose eyefold in
adult (vs. usually less extensive, marginal or absent in Chelonand Moolgarda) and a nearly straight maxilla extending ventrally
to a point just behind the corner of rictus (vs. downwardly curved
and extending well beyond the corner of rictus).

dark blue spot at upper
base of pectoral finC
usually 8 (rarely 9) softanal-fin rays in adultadipose eyefold
greately developed,
etensively coveringover iris in adult

D lateral view of headmaxilla nearly straight,
extending ventrally to a point
just behind coner of rictus

316

E ventral view of headA) Marketed fish, including CTU-P 5399 (bottom one of large mullets) (Hồ Chí Minh City, Vietnam, photo: KS); ; B–F) CTU-P 5399 [photo: HVM (B and C) and KS (D–F)]

Distribution: Mekong Basin in Vietnam; tropical, subtropicaland temperate regions worldwide.

MUGILIDAE
Comparison of 3 similar-looking mugilid genera in the Mekong
Many of the mugilid fishes found in the Mekong represent
similar-looking appearances, and their identification may
be difficult for non-taxonomists in many cases, except for afew distinctive species, e.g., Ellochelon vaigiensis (p. 312).
Examples include Chelon, Moolgarda, and Mugil. Although
Mugil appears to be uncommon in the Mekong, fishes of theother 2 genera are abundantly seen around the estuarine area inthe Vietnamese Mekong. Some selective characters, which areuseful in identification of these genera (viz., details of mouth
region and scale morphology), are shown below.
Two additional similar-looking mugilid genera, Crenimugil and Oedalechilus, are also found in the Phú QuốcIsland of Vietnam (off the western coast of the Mekong Delta)
and the coastal area of western Cambodia, but, considering
their habitat preference, mullets of these genera are hardly
expected from the Mekong.

Chelonpreorbital

maxilla distinctly curved, and its posterior
end exposed when mouth closed
corner of mouth opening well above
a level of posterior tip of maxilla

scales ctenoid

Moolgarda
preorbital

maxilla only a slightly curved, and its
posterior end usually hidden underpreorbital bone when mouth closed
corner of mouth opening well above
a level of posterior tip of maxilla

scales cycloid

Mugil
preorbital

maxilla nearly straight, and its posterior
end hidden under preorbital bone whenmouth closed
corner of mouth opening at alevel of posterior tip of maxilla

scales ctenoid

317