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今天在 水世界 看到了这个 老板娘说叫千手观音，很感兴趣，上网查了点东西，可能是这个Polynemus aquilonaris或者Polynemus dubius，中文名不明。 要1000多，花地据说开价也要700，还是偶有而已。
上面的几张是转的观赏鱼之家上的 下面的是些查到的东东，转自Threadfins of the World一书。
Diagnostic Features: A medium-sized species. Body depth at first dorsal-fin origin 23 to 26% (mean 25%) of standard
length; head length 24 to 29% (mean 26%) of standard length. Snout pointed; occipital profile nearly straight. Posterior
margin of maxilla extending well beyond level of posterior margin of adipose eyelid; upper-jaw length 10 to 12% (mean 11%)
of standard length, approximately equal to caudal-peduncle depth [10 to 12% (mean 11%) of standard length]; depth of
posterior margin of maxilla [2 to 3% (mean 3%) of standard length] slightly less than eye diameter [3 to 4% (mean 3%) of
standard length]; lip on lower jaw well developed, dentary teeth restricted to dorsal surface; teeth villiform in broad bands on
vomer, palatines and ectopterygoids. Posterior margin of preopercle serrated. First dorsal fin with VIII spines, all spine
bases of similar thickness; second dorsal fin with I spine and 15 to 19 (mode 16) soft rays; anal fin with III spines and 11 to 13
(mode 12) soft rays, anal-fin base less than second dorsal-fin base; pectoral fin with 15 to 17 (mode 16) rays (all rays
unbranched), its length 34 to 41% (mean 37%) of standard length, posterior tip just short of or extending slightly beyond level
of anal-fin origin; pectoral filaments 7; first pectoral filament shortest, not reaching to level of posterior tip of pelvic fin; second
pectoral filament extending slightly beyond or not reaching to level of posterior tip of pelvic fin; third pectoral filament
extending beyond (rarely just short of) level of posterior tip of pelvic fin; fourth pectoral filament extending beyond level of
anal-fin origin or level of posterior base of anal fin; fifth pectoral filament extending beyond level of posterior tips of caudal-fin
lobes; sixth, usually longest, its length 260 to 371% (mean 308%) of standard length, and seventh pectoral filaments longer
than other filaments, extending well beyond posterior tips of caudal-fin lobes; caudal fin deeply forked, upper and lower
caudal-fin lobes not filamentous, upper caudal-fin lobe 39 to 44% (mean 43%) and lower lobe 33 to 41% (mean 38%) of
standard length. Pored lateral-line scales 80 to 86 (mode 81); lateral line simple, extending from upper end of gill opening to
mid-distal margin of caudal-fin membrane; scale rows above lateral line 6 to 8 (mode 7), below 13 to 17 (mode 14). Gillrakers
9 to 11 (mode 10) on upper limb, 16 to 18 (mode 17) on lower limb, 25 to 29 (mode 27) total. Vertebrae 10 precaudal and 15
caudal; supraneural bones 2. Swimbladder not apparent or present (varying in size less than about 23% of standard length).
Colour: Head and body greyish silver dorsally, silver ventrally; anterior margin of first dorsal fin and posterior margin of
second dorsal fin blackish, remaining parts translucent; pectoral fin translucent; base of pectoral filaments white, becoming
blackish on posterior tips; base and posterior margin of pelvic fin white, remaining parts translucent; posterior margin of anal
fin translucent, remaining parts white; posterior margin of caudal fin translucent, remaining parts white. Geographical Distribution: Currently known from the Chao Phraya River system (Thailand), Mekong River
system below the Khone waterfalls of Lao People's Democratic Republic (Cambodia, southernmost of Lao
People's Democratic Republic and southern Viet Nam), and Lake Tonle Sap and related rivers (Cambodia)
(Fig. 137). Two specimens (NSMT-P 21772, 21776, 133 to 138 mm standard length), collected from the Chao
Phraya River at Nakhon Sawan, Thailand, represent the northernmost reliable record of the species. Polynemus aquilonaris is currently known from Indochina, whereas a related species, P. dubius, is
distributed in rivers on the Malay Peninsula, Sumatra and Kalimantan. The distributions of both species are most likely to be as relics, and are consistent with the location of Sundaland during the last Pleistocene glacial period. According to Bornbusch and Lundberg (1989),
Sundaland was drained by several major river systems, at least 2 of which may have participated in faunal mixing. These included the South Indo-China River and North Sunda River which are now restricted to drainages on Indochina, and Malay Peninsula, Sumatra and
Kalimantan, respectively, following submergence of Sundaland owing to increased sea levels. The present distributional ranges of P. aquilonaris and P. dubius indicate that they evidently originated in the South Indo-China and North Sunda rivers, respectively. Habitat and Biology: Occurs on sandy or muddy bottoms in fresh-water rivers and estuaries. The species feeds on
crustaceans, small fishes and benthic organisms. Gonad examinations (based on 12 specimens) of the species by the
author revealed that the species should be considered as probably having separate sexes (hermaphroditism not present). Size: Maximum standard length at least 16 cm (Motomura, 2003a).
Interest to Fisheries: Esteemed as a food fish at least along the Chao Phraya and Mekong rivers, and Lake Tonle Sap. The
species has been often exported to Japan as an aquarium fish.
Local Names: CAMBODIA: Trey pream sor; LAO PEOPLE’S DEMOCRATIC REPUBLIC: Jin.
Literature: Motomura (2003a).
Remarks: Polynemus aquilonaris previously identified as P. dubius or P. longipectoralis (e.g. Rainboth, 1996; Kottelat,
2001), has recently been described as a new species by Motomura (2003a).
Larger specimens (over about 110 mm standard length) of Polynemus aquilonaris collected from Lake Tonle Sap had a
fleshy lip on the upper jaw, smaller specimens (less than about 100 mm standard length) from the lake and all those from
other localities having a relatively thin lip. Apart from the lip condition in larger specimens, however, the 2 forms were difficult
to distinguish between because their meristic characters and proportional measurements fully overlapped. Therefore, the
difference in lip condition between the 2 forms is considered to represent geographical variation. More studies of the 2 forms
of P. aquilonaris are needed to assess whether the 2 represent separate subspecies like P. melanochir dulcis and P. m.
melanochir or not.
Although P. aquilonaris is very similar to P. dubius, the former can be clearly distinguished from the latter by having higher
counts of pored lateral-line scales [80 to 86 (mode 81) versus 69 to 79 (mode 78) in P. dubius] and scale rows below the
lateral line [14 to 17 (mode 14, rarely 13 or 17) versus 13 (rarely 12) in P. dubius], and lower counts of gillrakers [9 to 11
(mode 11) in upper series, 16 to 18 (mode 17) in lower and 25 to 29 (mode 27) total versus 11 to 13 (mode 12), 18 to 21
(mode 18) and 29 to 33 (mode 30), respectively]. Furthermore, P. aquilonaris differs from P. dubius in having a slightly
higher second dorsal-fin soft ray counts (15 to 19 versus 14 to 16 in P. dubius) and lower pectoral-fin ray counts (15 to 17
versus 16 to 18).
Diagnostic Features: A medium-sized species. Body depth at first dorsal-fin origin 23 to 28% (mean 24%) of standard
length; head length 25 to 27% (mean 26%) of standard length. Snout pointed; occipital profile nearly straight. Posterior
margin of maxilla extending well beyond level of posterior margin of adipose eyelid; upper-jaw length 11 to 13% (mean 11%)
of standard length, approximately equal to caudal-peduncle depth [11 to 13% (mean 11%) of standard length]; depth of
posterior margin of maxilla [3 to 4% (mean 3%) of standard length] slightly greater than eye diameter [2 to 3% (mean 3%) of
standard length]; lip on lower jaw well developed, dentary teeth restricted to dorsal surface; teeth villiform in broad bands on
vomer, palatines and ectopterygoids. Posterior margin of preopercle serrated. First dorsal fin with VIII spines, all spine
bases of similar thickness; second dorsal fin with I spine and 14 to 16 (mode 16) soft rays; anal fin with III spines and 12 soft
rays, anal-fin base less than second dorsal-fin base; pectoral fin with 16 to 18 (mode 16) rays (all rays unbranched), its
length 30 to 40% (mean 37%) of standard length, posterior tip just short of or extending slightly beyond level of anal-fin origin;
pectoral filaments 7; first pectoral filament shortest, not reaching to level of posterior tip of pelvic fin; second pectoral filament
extending slightly beyond or not reaching to level of posterior tip of pelvic fin; third pectoral filament extending beyond (rarely
just short of) level of posterior tip of pelvic fin; fourth pectoral filament extending beyond level of anal-fin origin or level of
posterior base of anal fin; fifth pectoral filament extending beyond level of posterior tips of caudal-fin lobes; sixth, usually
longest, its length 264 to 312% (mean 293%) of standard length, and seventh pectoral filaments longer than other filaments,
extending well beyond posterior tips of caudal-fin lobes; caudal fin deeply forked, upper and lower caudal-fin lobes not
filamentous, upper caudal-fin lobe 35 to 50% (mean 42%) and lower lobe 33 to 47% (mean 39%) of standard length. Pored
lateral-line scales 69 to 79 (mode 78); lateral line simple, extending from upper end of gill opening to mid-distal margin of
caudal-fin membrane; scale rows above lateral line 6 to 8 (mode 7), below 12 or 13 (mode 13). Gillrakers 11 to 13 (mode 12)
on upper limb, 18 to 21 (mode 18) on lower limb, 29 to 33 (mode 30) total. Vertebrae 10 precaudal and 15 caudal; supraneural bones 2. Swimbladder not apparent. Colour: (preserved specimens) Head and body grey dorsally, pale silver ventrally; anterior margin and posterior tip of first dorsal fin blackish, remaining parts yellowish silver; posterior margins of second dorsal, anal and caudal fins translucent, remaining
parts pale yellow; pectoral fin and filaments translucent or white without melanophores; pelvic fin pale yellow.
Geographical Distribution: Currently known from the Kangsar and Muar rivers (western Malaysia in Malay Peninsula), Musi and Batanghari rivers (southeastern Sumatra, Indonesia), and Sampit and Barito rivers (southern Kalimantan, Indonesia) (Fig. 139).
Habitat and Biology: Occurs on sandy or muddy bottoms in fresh-water rivers and estuaries. Feeds on crustaceans, small fishes and benthic organisms. Size: Maximum standard length at least 18 cm (Motomura, 2003a).
Interest to Fisheries: Unknown. Local Names: None known. Literature: Motomura (2003a). Remarks: P. dubius was described by Bleeker (1854) on the basis of Bleeker’s (1851a, 1852) descriptions of a species
originally believed by him to represent P. longifilis (true P. longifilis Cuvier in Cuvier and Valenciennes, 1829b has recently
been regarded as a junior synonym of P. paradiseus; see Motomura et al., 2002b). Although P. dubius has been regarded as
a valid species (e.g. Kottelat et al., 1993; Randall and Lim, 2000), P. longipectoralis has also been regarded as a valid
species by many researchers (e.g. Chevey, 1932; Kottelat, 1989, 2001; Talwar and Jhingran, 1991; Mishra and Krishnan,
1993), but without comparisons of each nominal species. Weber and de Beaufort (1922), Myers (1936) and Rainboth (1996)
regarded both species as valid, the first-mentioned believing P. dubius and their new species, P. longipectoralis, to be
distinguished by the number of lateral-line scales [stated as 67 in P. dubius (based on a single specimen) versus 84 in
P. longipectoralis (based on the holotype), but in fact 79, according to examination of that specimen by the author]. The
diagnostic characters (seven pectoral filaments, 8 spines in the first dorsal fin, 79 pored lateral-line scales, 13 scale rows
below lateral line, vomer with villiform teeth and posterior portion of the maxilla less than orbit diameter) found in the holotype
of P. longipectoralis are consistent with those of specimens of P. dubius. Therefore, P. longipectoralis is regarded as a
junior synonym. Rainboth (1996) also distinguished between the 2 nominal species by the number of lateral-line scales (65-67 in P. dubius
versus 80-85 in P. longipectoralis). However, his P. longipectoralis is in fact P. aquilonaris (see account of P. aquilonaris).
Myers (1936) distinguished the 2 nominal species by the number of first dorsal-fin spines (7 in P. dubius versus 8 in
P. longipectoralis). However, P. dubius, including the holotype of P. longipectoralis, in fact has 8 spines in the first dorsal
fin. Polynemus hornadayi and P. paradiseus are the only polynemid species with 7 spines in the first dorsal fin. Polynemus dubius is easily distinguished from P. kapuasensis and P. multifilis by having 7 pectoral filaments (13 to 16 in
the latter). Polynemus melanochir dulcis and P. m. melanochir lack villiform teeth on the vomer and have black
pigmentation on (usually) more than half of the posterior margin of the pectoral fins, whereas P. dubius has villiform
vomerine teeth and lacks black pigmentation on the pectoral fins. Furthermore, P. dubius differs from both of the above
subspecies in having longer pectoral-fin rays [34 to 40% (mean 37%) of standard length in P. dubius versus 31 to 35% (mean
33%) in P. m. dulcis and 30 to 35% (mean 32%) in P. m. melanochir] and pectoral filaments [longest filament 264 to 312%
(mean 293%) of standard length in P. dubius versus 128 to 153% (mean 141%) and 141 to 193% (mean 159%),
respectively]. Comparisons of P. dubius with P. aquilonaris are given in the account of the latter. 有空我再慢慢翻译
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