Discussion
Recently, the advent of Scanning Electron Microscopy (SEM) has unveiled
numerous new features of teleost scales, enriching ichthyological
research (De Lamater and Courtenay, 1973; Hughes, 1981; Jawad, 2005;
Teimori, 2016). These advancements have significantly expanded our
understanding of fish scales, enhancing their utility in fish taxonomy
and phylogeny. Despite this progress, many fish groups including the
species studied here, remain insufficiently characterized in terms of
their scale features (Esmaeili and Gholami, 2011; Ferrito et al., 2009). In light of this, the present lepidological study aims to
identify key micro-characteristics of scales that facilitate species
identification and resolve taxonomic ambiguities among endemicSchizothorax species.
General morphology and Scale surface microstructures
Key scales
Scales are found in nearly all significant fish groups and exhibit a
wide range of differences in their shape, structure, and development
(Sire et al., 2009). Fish scales generally fall into four primary
categories: placoid (found in cartilaginous fishes), ganoid (present in
sturgeons and gars), cosmoid (seen in lungfishes of the Ceratodidae
family and some fossil species), and elasmoid, which include cycloid and
ctenoid scales and are predominantly found in teleost fishes (Esmaeiliet al., 2019; Wainwright, 2019). The diversity of scales across
different fish groups makes them highly valuable for various
ichthyological studies, including systematics (Poulet et al.,2004; Jawad, 2005; Gholami et al., 2013), ontogeny (Sire, 1986),
and phylogeny (Robert, 1993). Cycloid scales, in particular, are found
in various fish groups, including those in the order Cypriniformes.
Being a cypriniform fish, the general type of scale inSchizothorax plagiostomus was cycloid. Detailed studies of
cycloid scales have been conducted on several other Cypriniformes, such
as Capoeta damascina (Valenciennes, 1842), Catla catla(Hamilton-Buchanan, 1822), Hypophthalmichthys molitrix(Valenciennes, 1844), Rutilus frisii (Nordmann, 1840), andTor putitora (Hamilton-Buchanan, 1822) (Esmaeili et al.,2007, 2012; Esmaeili and Gholami, 2011). Additionally, the presence of
such scales has been documented in cyprinodontoid fishes, includingCyprinodon variegatus (Cyprinodontidae) and Lamprichthys
tanganicanus (Poecilidae) (Rosen and Bailey, 1963).
In the current study, two type of scale shapes i.e., polygonal and
circular/cordate were observed. However, a study on the scale surface
topography of Garra sharq from the Arabian Peninsula revealed
that the cycloid scales of this cyprinid exhibited various shapes,
including circular (true circular, cordate, and discoidal), polygonal
(hexagonal), and oval (true oval) across different regions and three
size groups of the fish, with the circular type being the most
prevalent. Other research on fish scales has examined both inter- and
intra-species variation in overall scale shape (Echreshavi et
al., 2021; Gholami et al., 2013; Sadeghi et al., 2021;
Teimori et al., 2017). For instance, mullid fish scales have been
reported to include intermediate (calyx), polygonal (hexagonal), and
oval shapes. Al Jufaili et al. (2021) found various shapes in the
scales of A. jayakari, such as polygonal (hexagonal and
pentagonal), circular/discoid, oval/elliptical, and
quadrilateral/square, across different size groups and body parts. It is
hypothesized that the shape plasticity of scales may help reduce
friction drag in fishes while swimming.
One of the detailed features of scales examined by SEM is the focus. The
focus is formed during the initial stages of scale development and
ontogeny. While typically located centrally on the scale, its position
can vary, appearing in the anterior, posterior, antero-central, or
postero-central parts (Echreshavi et al., 2021; Sadeghi et
al., 2021). In Schizothorax plagiostomus, the focus was
generally distinct, round and antero-centrally positioned. Additionally,
the sculpture of the focus area was smooth. Variation in focus shape has
been observed across different fish species, including the mullids,
where five types were identified: rectangular (Upenus doriae),
circular (U. tragula), round (U. sundaicus), wide round
(U. vittatus), and semi-round (Mulloidichthys
vanicolensis) (Echreshavi et al., 2021). Some species, like
those in the genus Sardinella, lack an obvious and distinct
focus, whereas other clupeid fishes have a clear focus, leading to
systematic classification challenges. There appears to be a correlation
between the scale morphology of Sardinella and its molecular
identity (Dizaj et al., 2020; Wang et al., 2022),
underscoring the importance of scale features in fish identification.
A distinctive feature of cycloid scales is the presence of concentric
lines (circuli) and radial grooves (radii) in the anterior field of the
scale (Schultze, 2016). In Schizothorax plagiostomus, the circuli
in the posterior field were discontinuous, while those in the lateral
field were continuous. In the anterior field, the circuli were closely
spaced, with an average intercircular space of 14.91 μm and an average
of 24 circuli. The circuli were convex in shape and smooth due to the
absence of lepidonts. Previous studies on cycloid scales have suggested
that these scales help reduce friction between the fish body and its
aquatic environment (Muthuramalingam et al., 2020; Wainwright,
2019). Consequently, for Schizothorax species inhabiting
fast-flowing coldwater hillstreams and rivers, this feature likely
provides an evolutionary advantage for surviving in such extreme
environments.
In the scales of Schizothorax plagiostomus, three types of
radii—primary, secondary, and tertiary were observed, with primary
radii being the most numerous. The average number of radii was 11, and
their width in the anterior field was 9.70 μm. According to Johalet al. (2006), the variation in the number of radii is associated
with the nutritive conditions of the fish; a higher number of radii
corresponds to better nutritional status and indicates scale
flexibility. The number of radii also depends on the scale’s location on
the fish’s body, showing no significant relationship with the overall
scale size (Esmaeili and Gholami, 2011). Additionally, the presence of
primary, secondary, and tertiary radii is considered a growth phenomenon
(Alkaladi et al., 2013) and is less influenced by the fish’s
genetic characteristics (Lippitsch, 1990). Radii may appear in various
fields: only anterior, as in pickerels (Esox); only posterior, as in
shiners (Notropis); both anterior and posterior, as in suckers
(Catostomidae) and R. frisii (Leuciscidae); or in all four
fields, as in barbs (Barbus) (Esmaeili et al., 2012; Esmaeili and
Gholami, 2011). However, scales of studied Schizothorax
plagiostomus displayed a distinct tetra-sectioned form due to the
presence of radii in all four fields (anterior, posterior, and
laterals). This tetra-sectioned form has also been reported for the
scales of G. rossica (Esmaeili et al., 2012) and G.
sharq (Echreshavi et al., 2022). This feature may be considered
a distinguishing characteristic for the genus Garra, as such an
architectural design is not observed in other cyprinid fishes, such asRutilus frisii, Capoeta damascina, and Tor putitora(Esmaeili et al., 2007; Esmaeili and Gholami, 2011; Johalet al., 1999).
Lateral line scales
Several detailed studies have investigated the morphology and topology
of lateral line scales, highlighting their potential use in fish
classification (Kaur and Dua, 2004). Research by Mekkawy et al.(1999) and Matondo et al. (2010) identified the channel openings
in the lateral line scales as a distinct and interesting feature. These
scales have been utilized to demonstrate their potential in fish
taxonomy and classification. Key features such as the canal’s position,
alignment (straight or oblique), and perforations (anterior, posterior,
or lateral) are crucial for fish classification (Delamater and
Courtenay, 1973; Tandon and Johal, 1983). In Schizothorax
plagiostomus, lateral line scales consist of four parts: anterior,
posterior, and two lateral regions. Unlike other scales, these lack
focus and instead feature a channel running along the anterior-posterior
axis, with two openings—an anterior opening, which is wider, and a
posterior opening. The lateral line canal resembles a long tube with
irregular boundaries. SEM examination of the lateral line scales inSchizothorax plagiostomus revealed a straight, central canal
originating from the upper margin of the posterior region and extending
to the anterior region. The average length of the lateral line canal was
1.52 mm, and the anterior opening measured 354.61 μm.
Conclusion
This study offers a detailed analysis of the scale morphology and
microstructures of Schizothorax plagiostomus using Scanning
Electron Microscopy (SEM). Key findings include polygonal shaped scales
with tetra-sectioned configuration, presence of smooth circuli (i.e.,
without lepidonts), small sized round focus and lateral line scales
which lack focus. This study underscores the importance of scale
morphology in ichthyological research and reaffirms the utility of SEM
in uncovering microstructural scale features critical for species
identification and resolving taxonomic ambiguities.
Acknowledgements
We would like to acknowledge the Central Research Facility Centre
(CRFC), National Institute of Technology-Srinagar for providing the
Scanning Electron Microscopy (SEM) facility.
Conflict of interest
The authors declare that there is no conflict of interest.
Agassiz, L. (1833). Recherches sur les poissons fossiles…:
Histoire de lorded des Ganoïdes (Vol. 2). Petitpierre.
Al Jufaili, S. M., Masoumi, A. H., Esmaeili, H. R., Jawad, L., &
Teimori, A. 2021. Morphological and microstructural characteristics of
scales in longnose goby Awaous jayakari (Teleostei: Gobiidae):
Light and scanning electron microscopy approaches. Microscopy
Research and Technique , 84 (12): 3128-3149.
Alkaladi A, Harabawy, ASA and Mekkawy IAA. 2013. Scale Characteristics
of Two Fish Species, Acanthopagrus bifasciatus (Forsskal, 1775)
and Rhabdosargus sarba (Forsskal, 1775) from the Red Sea at
Jeddah, Saudi Arabia. Pakistan Journal of Biological Sciences ,16 : 362-371.
Batts, B. S. 1964. Lepidology of the adult pleuronectiform fishes of
Puget Sound, Washington. Copeia , 666-673.
Bhat, F.A., Yousuf, A.R., Balkhi, M.H., Mahdi, M.D. and Shah, F.A. 2010.
Length-weight relationship and morphometric characteristics ofSchizothorax spp. in the River Lidder of Kashmir. Indian J.
Fish ., 57 : 73-76.
Braeger, Z., Staszny, A., Mertzen, M., Moritz, T., & Horvath, G. 2017.
Fish scale identification: from individual to species-specific shape
variability. Acta Ichthyologica et Piscatoria , 47 (4):
331-338.
DeLamater, E. D., & Courtenay Jr, W. R. 1974. Fish scales as seen by
scanning electron microscopy. Biol Sci 37 , 141-149.
Dey, S., Biswas, S. P., Dey, S. and Bhattacharyya, S. P., 2014. Scanning
electron microscopy of scales and its taxonomic application in the fish
genus Channa . Microsc. Microanal , 20 : 1188–1197.
Dulce-Amor, P.M., M.A.J. Torres, S.R.M. Tabugo, and C.G. Demayo, 2010.
Describing variations in scales between sexes of the yellows triped
goatfish, Upeneus vittatus Forskål, 1775) Perciformes: Mullidae.Egyptian Academic Journal of Biological Sciences, 21 :
37-50.
Echreshavi, S., Al Jufaili, S. M., & Esmaeili, H. R. 2022. Imaging
scale surface topography of an endemic cyprinid fish, Garra sharq from the Arabian Peninsula: An integrated optical light and scanning
electron microscopy approach. Acta Zoologica , 104 (4):
657-676.
Echreshavi, S., Esmaeili, H. R., Teimori, A., Safaie, M., & Owfi, F.
2021. Hidden morphological and structural characteristics in scales of
mullid species (Teleostei: Mullidae) using light and scanning electron
digital imaging. Microscopy Research and
Technique , 84 (11): 2749-2773.
Echreshavi, S., Esmaeili, H. R., Teimori, A., Safaie, M., & Owfi, F.
2021. Hidden morphological and structural characteristics in scales of
mullid species (Teleostei: Mullidae) using light and scanning electron
digital imaging. Microscopy Research and
Technique , 84 (11): 2749-2773.
Esmaeili HR and Gholami Z. 2011. Scanning electron microscopy of the
scale morphology in Cyprinid fish, Rutilus frisii kutum Kamenskii, 1901 (Actinopterygii: Cyprinidae). Iranian J. Fish.
Sci ., 10 : 155-166.
Esmaeili HR, Ansari TH and Teimori A 2007. Scale structure of cyprinid
fish, Capoeta Damascina (Valenciennes in Cuvier and Valenciennes,
1842) using Scanning Electron Microscope (SEM). Iranian Journal of
Science and Technology , Transaction A, 31, No. A3. Printed in the
Islamic Republic of Iran.
Esmaeili HR, Gholamifard A, Zarei N and Arshadi A. 2012. Scale structure
of a cyprinid fish, Garra Rossica (Nikol’skii, 1900) using
scanning electron microscope (SEM). Iranian Journal of Science &
Technology , 4 : 487-492.
Esmaeili HR, Khaefi R, Sayyad Zadeh G, Tahami, MS, Parsi B and
Gholamifard A. 2014. Scale Surface Microstructure and scale size in
three Mugilid fishes (Teleostei, Mugilidae) of Iran from three different
habitats. IUFS Journal of Biology , 73 (1): 31-42.
Esmaeili, H. R., Zarei, F., Vahed, N. S., & Masoudi, M. 2019. Scale
morphology and phylogenetic character mapping of scale-surface
microstructures in sixteen Aphanius species (Teleostei:
Aphaniidae). Micron , 119 :39-53.
Farooq, I., Bhat, F. A., Balkhi, M. H., Shah, T. H., Bhat, B. A., Qadri,
S., … & Ganie, P. A. 2019. Reproductive and breeding biology ofSchizothorax labiatus , a snow trout found in River Jhelum,
Kashmir. Journal of Environmental Biology , 40 (3):
291-294.
Ferrito, V., Corsaro, M., & Tigano, C. 2003. Scale surface morphology
in Lebias , Goldfuss, 1820 (Teleostei:
Cyprinodontidae). Journal of Natural History , 37 (12):
1529-1534.
Ferrito, V., Pappalardo, A. M., Fruciano, C., & Tigano, C. 2009.
Morphology of scale lepidonts in the genus Aphanius (Teleostei,
Cyprinodontidae) using SEM. Italian Journal of
Zoology , 76 (2); 173-178.
Gholami, Z., Teimori, A., Esmaeili, H. R., Schulz-Mirbach, T., &
Reichenbacher, B. 2013. Scale surface microstructure and scale size in
the tooth-carp genus Aphanius (Teleostei, Cyprinodontidae) from
endorheic basins in Southwest Iran. Zootaxa , 3619 (4):
467-490.
Goodrich, E. S. 1907. On the scales of fish, living and extinct, and
their importance in classification. Proceedings of the Zoological
Society of London , 77 (4): 751-773.
Goodrich, E. S. 1909. Subgrade 3. Osteichthyes. A Treatise on
Zoology, Part IX, Vertebrata Craniata (First Fascicle: Cyclostomes and
Fishes), pp. 210–229. Adam and Charles Black, London.
Gu, H. R., Wan, Y. F., Yang, Y., Ao, Q., Cheng, W. L., Deng, S. H., …
& Wang, Z. J. 2019. Genetic and morphology analysis among the
pentaploid F1 hybrid fishes (Schizothorax wangchiachii♀× Percocypris
pingi♂) and their parents. animal , 13 (12): 2755-2764.
Hughes, D. R. 1981. Development and organization of the posterior field
of ctenoid scales in the Platycephalidae. Copeia , 596-606.
Hussain, S., Bhat, F. A., Maqsood, H. M., Balkhi, M. H., Majid, I., &
Najar, A. M. 2018. Present status of breeding biology ofSchizothorax niger in Dal Lake Kashmir. Journal of
Entomology and Zoology Studies , 6 (6): 930-935.
Jawad, L. A. 2005. Comparative scale morphology and squamation patterns
in triplefins (Pisces: Teleostei: Perciformes:
Tripterygiidae). Tuhinga , 16 (1): 137-168.
Jawad, L. A., & Al‐Jufaili, S. M. 2007. Scale morphology of greater
lizardfish Saurida tumbil (Bloch, 1795) (Pisces:
Synodontidae). Journal of Fish Biology , 70 (4):
1185-1212.
Johal, M. S., Esmaeili, H. R., & Sharma, M. L. 2006. Scale structure of
a cobitid fish, Cobitis linea (Heckel, 1849) using different
modes of SEM. Current Science , 91 (11): 1464-1466.
Kaur, N. & Dua, A. 2004. Species specificity as evidenced by scanning
electron microscopy of fish scales. Curr. Sci., 87 :
692-696.
Kaur, R., & Dua, A. 2015. Colour changes in Labeo rohita (Ham.) due to
pigment translocation in melanophores, on exposure to municipal
wastewater of Tung Dhab drain, Amritsar, India. Environmental
toxicology and pharmacology , 39 (2), 747-757.
Kobayasi, H. 1953. Comparative studies of the scales in Japanese
freshwater fishes, with special reference to phylogeny and
evolution. Japanese Journal of Ichthyology , 2 (6):
246-260.
Kullander, S. O., Fang, F., Delling, B., & Ahlander, E. 1999. The
fishes of the Kashmir Valley. River Jhelum, Kashmir Valley.
Impacts on the aquatic environment. Swedmar, Göteborg , 99-167.
Lagler, K. F. 1947. Lepidological studies 1. Scale characters of the
families of Great Lakes fishes. Transactions of the American
Microscopical Society , 66 (2): 149-171.
Lanzing, W. J. R., & Higginbotham, D. R. 1974. Scanning microscopy of
surface structures of Tilapia mossambica (Peters)
scales. Journal of Fish Biology , 6 (3): 307-310.
Lin, Y., An, M., & Jiang, H. 2010. Study on morphological differences
among three Schizothorax species. Guizhou Agricultural Sciences ,10 : 121-126.
Lippitsch, E. 1990. Scale morphology and squamation patterns in cichlids
(Teleostei, Perciformes): A comparative study. Journal of Fish
Biology , 37 (2): 265-291.
Liu, W. T., Zhang, Y., Li, G. Y., Miao, Y. Q., & Wu, X. H. 2008.
Structure and composition of teleost scales from snakehead Channa argus
(Cantor)(Perciformes: Channidae). Journal of Fish
Biology , 72 (4): 1055-1067.
Matondo, D. A. P., Torres, M. A. J., Tabugo, S. R. M., & Demayo, C. G.
2010. Describing variations in scales between sexes of the yellowstriped
goatfish, Upeneus vittatus (Forskål, 1775) (Perciformes:
Mullidae). Egyptian Academic Journal of Biological Sciences, B.
Zoology , 2 (1): 37-50.
Mekkawy, I. A. A., Shehata, S. M. A., Saber, S. A., & Osman, A. G. M.
1999. Scale characteristics of five species of genus Epinephelus (Family
Serranidae) from the Red Sea Egypt. Journal of Basic and Applied
Zoology , 30 :71-102.
Muthuramalingam, M., Puckert, D. K., Rist, U., & Bruecker, C. 2020.
Transition delay using biomimetic fish scale arrays. Scientific
Reports , 10 (1): 14534.
Nie, Z. L., Wei, J., Ma, Z. H., Zhang, L., Song, W., Wang, W. M., &
Zhang, J. 2014. Morphological variations of Schizothoracinae species in
the Muzhati River. Journal of applied
ichthyology , 30( 2): 359-365.
Poulet, N., Reyjol, Y., Collier, H. 2005. Does fish scale morphology
allow the identification of populations at a local scale? A case study
for rostrum dace Leuciscus leuciscus burdigalensis in River Viaur
(SW France). Aquat. Sci. 67 , 122–127.
Purrafee Dizaj, L., Esmaeili, H. R., & Teimori, A. 2022. Comparative
otolith morphology of clupeids from the Iranian brackish and marine
resources (Teleostei: Clupeiformes). Acta
Zoologica , 103 (1), 29-47.
Raffealla.N, Nath BR. 2020. Comparative study of fish scale using
scanning electron microscopy in two Cyprinid fishes
(Neolissochilus hexagonolepis and Neolissochilus
hexastichus ) found in Meghalaya, North-East India. International
journal of Life Sciences , 8 (1): 77-82.
Roberts, C. D. 1993. Comparative morphology of spined scales and their
phylogenetic significance in the Teleostei. Bulletin of marine
science , 52 (1): 60-113.
Rosen, D. E., & Bailey, R. M. 1963. The poeciliid fishes
(Cyprinodontiformes): their structure, zoogeography, and systematics.Bulletin of the AMNH , 126, article 1.
Sabbah, N., Teimori, A., & Hesni, M. A. (2020). Digital light
microscopy to characterize the scales of two goatfishes (Perciformes;
Mullidae). Microscopy Research and Technique , 84 (2):
180-191.
Sadeghi, R., Esmaeili, H. R., Teimori, A., Ebrahimi, M., &
Gholamhosseini, A. 2021. Comparative ultrastructure and ornamentation
characteristics of scales in gobiid species (Teleostei: Gobiidae) using
the scanning electron microscope. Microscopy Research and
Technique , 84 (6): 1243-1256.
Sadeghi, R., Esmaeili, H. R., Teimori, A., Ebrahimi, M., &
Gholamhosseini, A. 2021. Comparative ultrastructure and ornamentation
characteristics of scales in gobiid species (Teleostei: Gobiidae) using
the scanning electron microscope. Microscopy Research and
Technique , 84 (6): 1243-1256.
Schultze, H. P. (2016). Scales, enamel, cosmine, ganoine, and early
osteichthyans. Comptes Rendus Palevol , 15 (1-2): 83-102.
Sire, J. Y. (1986). Ontogenic development of surface ornamentation in
the scales of Hemichromis bimaculatus (Cichlidae). Journal
of Fish Biology , 28 (6): 713-724.
Sire, J. Y., Donoghue, P. C., & Vickaryous, M. K. 2009. Origin and
evolution of the integumentary skeleton in non‐tetrapod
vertebrates. Journal of anatomy , 214 (4): 409-440.
Sunder, S. 1979. A review on the biological studies of Schizothoracids
in J &K state and elsewhere in India and their Cultural
possibilities. Recent Researchers in Coldwater Fisheries ,
152-171.
Tandon, K. K., & Johal, M. S. 1983. Study On Age and Growth of Tor
Putitora (Hamilton) As Evidenced by Scales. Indian Journal of
Fisheries , 30 (1); 171-174.
Teimori A. 2016. Scanning electron microscopy of scale and body
morphology as taxonomic characteristics of two closely related cyprinid
species of genus Capoeta Valenciennes, 1842 in southern Iran.Curr. Sci ., 111 : 1214-1219.
Teimori, A., Motamedi, M., & Golmakan, M. S. 2017. Combining
morphology, scanning electron microscopy, and molecular phylogeny to
evaluate the taxonomic power of scales in genus Nardo, 1827 (Teleostei:
Cyprinodontidae). Fisheries & Aquatic Life , 25 (2),
77-87.
Tzeng, W. N., Wu, H. F., & Wlckström, H. 1994. Scanning electron
microscopic analysis of annulus microstructure in otolith of European
eel, Anguilla anguilla. Journal of Fish Biology , 45 (3):
479-492.
Wainwright, D. K. (2019). Fish scales: morphology, evolution, and
function (Doctoral dissertation, Harvard University).
Wang, Q., Dizaj, L. P., Huang, J., Sarker, K. K., Kevrekidis, C.,
Reichenbacher, B., … & Li, C. 2022. Molecular phylogenetics of the
Clupeiformes based on exon-capture data and a new classification of the
order. Molecular Phylogenetics and Evolution , 175, 107590.
Wani, I. F., Bhat, F. A., Balkhi, M. H., Shah, T. H., Shah, F. A., &
Bhat, B. A. 2018. Study on gonadosomatic index (GSI) during the three
seasons (pre-spawning, spawning and post-spawning periods) ofSchizothorax niger Heckel in Dal Lake, Kashmir. Journal of
Pharmacognosy and Phytochemistry , 7 (6): 2132-2136.
Williamson, W. C. 1851. Investigations into the structure and
development of the scales and bones of fishes. Philosophical
Transactions of the Royal Society of London , 141 : 643-702.
Zahid H, Bano N, Masood Z, Ul-Ain M, Farooq RY and Razaq W. 2015. Scale
surface structure of Mugil cephalus (Teleostei; Mugilidae) using
Scanning Electron Microscopy (SEM). Biological Forum – An
International Journal , 7 (1): 1845-1848.
Zhang, D., Yu, M., Hu, P., Peng, S., Liu, Y., Li, W., … & Chen, L.
(2017). Genetic adaptation of Schizothoracine fish to the phased
uplifting of the Qinghai–Tibetan Plateau. G3: Genes, Genomes,
Genetics , 7 (4): 1267-1276.
Zhou, W., Apkarian, R., Wang, Z. L., & Joy, D. 2007. Fundamentals of
scanning electron microscopy (SEM). Scanning Microscopy for
Nanotechnology: Techniques and Applications , 1-40.
Zhou, X. J., Xie, C. X., Huo, B., Duan, Y. J., Yang, X., & Ma, B. S.
2015. Reproductive biology of Schizothorax waltoni (cyprinidae:
schizothoracinae) in the yarlung zangbo river in Tibet,
China. Environmental biology of fishes , 98 : 597-609.
Zutshi, D. P., & Gopal, B. 2000. State of biodiversity in lakes and
wetlands of Kashmir valley. Environment, biodiversity and
conservation, (ed.) Khan, MA APH Publishing Corporation New Delhi .