IJLSSR, VOLUME 2, ISSUE 4, JULY-2016:478-487

Research Article (Open access)

Study of the Morphometry and Meristic Analyses of Three Mystus species from the
Chandubi Beel, Kamrup District, Assam

Kamaljyoti Chakravorty1*, Dr. Janardan Pathak2, Dr. M M Goswami3
1Department of Zoology, B Borooah College (Gauhati University), Ulubari, Guwahati, (Assam), India
2Assistant Professor, Dept. of Zoology, B. Borooah College, India
3Professor, Dept. of Zoology, Gauhati University, India

*Address for Correspondence: Kamaljyoti Chakravorty, Department of Zoology, B Borooah College (Gauhati University), Ulubari,
Guwahati, (Assam), India

Received: 10 May 2016/Revised: 03 June 2016/Accepted: 26 June 2016

ABSTRACT- The morphometric and meristic analyses of three species of freshwater catfish, Mystus cavasius, Mystus vittatus and Mystus bleekeri of Chandubi beel, Assam were investigated. The morphometric characters vary effectively among the three different species making its application taxonomically significant. In terms of their total length, M. bleekeri is found to be the longest with 97.48 mm and M. vittatus is found to be the shortest with 83.9 mm. Moreover, M. vittatus has also shown an extension of their barbel length upto 74.6% of the total length. Such morphometric variations and advancements indicate the adaptive capability of the Mystus spp. over the varied geographical, climatic and nutritive factors in their habitat.
Key-words- Morphometry, Mystus vittatus, Mystus bleekeri, Mystus cavasius, Barbels, Dorsal spine

INTRODUCTION- Siluriformes is a diverse group of fish ranking second or third among the orders of vertebrate series. Although very little is known about the origin of the Siluriformes, the fossil records in Seymour island suggest their inhabitancy during Eocene age in the inland and coastal water of all the continents [1]. The earliest known fossil Siluriformes were in freshwater and marine deposits of late Cretaceous age. Due to their worldwide distribution, at present, the catfishes became a subject of great interest to ecologists and evolutionary biologists and are important in the study of biogeography.
Among more than 30 recognized families of Siluriformes, the South American Pimelodidae and the African-Asian Bagridae are the two largest families yet known. Bagridae is a family of catfish that includes about 250 species.
Most of the bagrid fishes are used as food and individuals of 6-9 cm are of high ornamental value [2].
Fishes of Bagridae family can be easily identified by their 4 pairs of well developed barbells covered by a layer of taste bud enriched epithelium [3].
Mystus spp. is one of the most easily available Bagrids in Assam. These small to medium sized catfishes are distributed throughout India, Pakistan, Bangladesh, Afghanistan and Nepal [4-5]. In course of time extensive studies on Mystus spp. contributed significantly to the identification of new species such as Mystus dibrugarensis [2] in upper brahmaputra basin. Many workers described different fish species with the help of morphometric measurements. For example the identification of Mystus cavasius [6] in Myanmar. Mystus ngasep was identified in Manipur [7]. Morphometry is an essential tool to provide a concept of size and shape of the specimens making their identification taxonomically significant. According to Sajina et al [8], A morphometric Trait proves to be the most frequently employed and cost effective method. Species, Populations and Races were separated in the past by morphometric analyses and even it is used for identifying different stocks of fish [9]. In fact, animals with the same morphometric characteristics are believed to belong to the same species [10]. The interactive effect of environment, selection and heredity on body shape and size of a species can study by morphometry [11].
However, extensive studies on Bagridae revealed dramatic changes in the taxonomic characters of the family in course of time. According to Nelson [12], the family is very different from that recognized in previous study. Therefore, in order to re-examine such changes morphometric analyses of the bagrids are still in progress. The present work is focused on comparing 11 fish specimens, collected from the Chandubi Beel, Assam, India based on their morphometric characters. The specimens are Mystus cavasius (3 specimens), Mystus vittatus (3 specimens), and Mystus bleekeri (5 specimens).

MATERIALS AND METHODS:

Collection of Specimens-
Specimens of Mystus vittatus, Mystus bleekeri and Mystus cavasius were collected from Chandubi wet-land, Kamrup district, Assam, India with the help of local fishermen using different types of nets.
Collected fishes were brought to the laboratory and preserved in 10% formalin solution in containers.

Experimental Work- The meristic and morphometric characters were measured using Vernier caliper (Least count = 0.01 mm), magnifying glasses, needles and identified up to species level with the help of standard key and books (Day, 1878; Jayaram, 1999; Talwar and Jhingram, 1991).
The morphometric parameters measured from each species are as follows:

Total length- Straight measurement from the tip of the snout to the posterior end of the last vertebrae.

Standard length- Straight measurement from the tip of the snout to the posterior end of the last vertebrae.

Body depth at anus- The vertical distance from the dorsal margin of the body to the ventral margin of the body measured near the base of the pectoral fin near the anus.

Pre dorsal length- Straight-line measurement taken from the front of the snout to the insertion of the first ray of the dorsal fin.

Pre anal length- Straight-line measurement taken from the tip of the snout to the point of insertion of the anal fin.

Pre pelvic length- Straight-line measurement taken from the front of the snout to the insertion of the pelvic fin.

Pre pectoral length- Straight-line measurement taken from the front of the snout to the origin of the pectoral fin.

Length of dorsal fin base- Length of the insertion of the first fin to the insertion of the last of the dorsal fin.

Dorsal spine length- The entire length of the dorsal spine present near the dorsal fin.

Anal fin length- Length of the insertion of the first fin to the tip of the largest fin.

Pelvic fin length Length of the point of insertion of the fin to the tip of the longest fin.

Pectoral fin length- Straight-line measurement from the point of insertion of the fin to the end of the pectoral fin.

Caudal fin length- Straight-line measurement from the point of insertion of the fins to the end of the caudal fin.

Adipose fin base length- Length of the base of the adipose fin from its anterior to its posterior insertion.

Dorsal to adipose length- Straight-line measurement from the point of insertion of the last ray of the dorsal fin to the anterior insertion of the adipose fin.

Post adipose length- Straight-line measurement from the point of the post-erior insertion of the adipose fin to the base of the caudal fin flexure.

Caudal peduncle length- Straight-line measurement taken from the insertion of the anal fin to the caudal flexure.

Caudal peduncle depth- Vertical length taken from the dorsal margin to the ventral margin near the caudal flexure.

Head length- Straight-line measurement taken from the front of the snout to the origin of operculum.

Head width- The distance between the two widest points of the head.

Snout length- The distance between the upper jaw and the anterior margin of the orbit.

Eye diameter- Diameter of eye.

Interorbital distance- The space between the eyes; bones on the roof of the skull between the eyes.

Barbel length- The length of the barbells present in the fish:

  • Maxillary barbel length
  • Nasal barbel length
  • Inner Mandibular barbel length
  • Outer Mandibular barbel length

    The meristic counts used for the fishes are discussed as follows:

    Ray counts- Fins are the distinct structures attached to the body of a fish and are composed of mobile filaments. Conventional abbreviations for the various fins in the reporting of numbers of fin rays are as follows;

  • D dorsal
  • A anal
  • C caudal
  • P pectoral
  • P2 pelvic

    There are two basic types of fin rays, true spines and soft rays.

    True spines- These single, median structures are unbranched and lack joints. They usually occur in the anterior part of a single fin or in the anterior of two separate fins. All true spines are designated by upper roman numerals (I, II, III etc) whether they are stiff or flexible.

    Soft rays- These articulated structures are composed of numerous movable joints. The unbranched soft rays are des-ignated by lower case roman numerals (i, ii, iii etc). The branched soft rays are designated by Arabic numerals (1, 2, 3 etc).

    Direction of counts:
    Dorsal fin rays-
    These are counted back to front, i.e, the posterior most ray is counted as first ray and count is done towards anterior.

    Anal fin rays- These are counted front to back, i.e, the anterior most ray is counted as first ray and count is done towards posterior.

    Caudal fin rays- These are counted from the outermost ray to the inner most ray.

    RESULTS- The mean morphometric measures of M. vittatus, M. bleekeri and M. cavasius are presented in table I, table II and table III and their mean total lengths are 83.9 mm, 97.48 mm and 85.63 mm respectively. They have an adipose fin whose base length varies from 16.53 mm in M. vittatus to 23.63 mm in M. cavasius. The mean head lengths of M. vittatus, M. bleekeri and M. cavasius are found to be 15.53 mm, 17.5 mm and 13.93 mm whereas their mean head widths are 9.9 mm, 11.16 mm and 7.86mm respectively.
    The meristic counts depict the number of dorsal fin rays to be indifferent (7). However, the anal fin rays ranges from eight to nine in number.

    Table I - Morphometry of Mystus vittatus (mm) with average & SD

    Parameters Specimen 1 Specimen 2 Specimen 3 Average Standard deviation
    Total length 86.2 83.2 82.3 83.9 2.042057786
    Standard length 66.7 65 66.5 66.06667 0.929157324
    Body depth at anus 14.1 14 12.4 13.5 0.953939201
    Pre dorsal length 23 24.2 26.9 24.7 1.997498436
    Pre anal length 47.1 48 46.7 47.26667 0.665832812
    Pre pelvic length 34.4 34 34.6 34.33333 0.305505046
    Pre pectoral length 14.1 14.4 15.3 14.6 0.6244998
    Length of dorsal fin base 11 8.7 9.4 9.7 1.178982612
    Dorsal spine length 11 17 9.4 12.46667 4.00666112
    Anal fin length 12.5 12.2 12.1 12.26667 0.2081666
    Pelvic fin length 11 12 11 11.33333 0.577350269
    Pectoral fin length 13.6 12.4 13.4 13.13333 0.642910051
    Caudal fin length 17.4 14.2 15.4 15.66667 1.616580754
    Adipose fin base length 16.1 16.2 17.3 16.53333 0.665832812
    Dorsal to adipose length 5.1 4.2 3.7 4.333333 0.709459888
    Post adipose length 9.6 9.6 10.3 9.833333 0.404145188
    Caudal peduncle length 11.2 10.6 12.6 11.46667 1.026320288
    Caudal peduncle depth .1 7.1 7.4 7.2 0.173205081
    Head length 15.7 15.4 15.5, 15.53333 0.152752523
    Head width 10.2 10 9.5 9.9 0.360555128
    Snout length 6.1 5.2 5.9 5.733333 0.472581563
    Eye diameter 3.5 4 3.6 3.7 0.264575131
    Interorbital distance 9.3 9.5 9.3 9.366667 0.115470054
    Maxillary barbel length 65 61 62 62.66667 2.081665999
    Nasal barbel length 12 13 12 12.33333 0.577350269
    Inner mandibular barbel length 14 15 14 14.33333 0.577350269
    Outer mandibular barbel length 28 26 21 25 3.605551275


    Table II - Morphometry of Mystus bleekeri (mm) with average & SD

    Parameters Specimen 1 Specimen 2 Specimen 3 Specimen 4 Specimen 5 Average Standard deviation
    Total length 99 110.7 96.5 87.7 93.5 97.48 8.507761163
    Standard length 76.5 88.2 77.3 69.5 73.5 77 6.969218034
    Body depth at anus 16.6 17.5 14.6 15.6 13.6 15.58 1.549838701
    Pre dorsal length 31.2 35.3 27.3 27.6 26.4 29.56 3.693643188
    Pre anal length 52.1 62.6 54.4 49.6 54 54.54 4.889580759
    Pre pelvic length 39.5 44.1 36.7 36.5 35 38.36 3.596943147
    Pre pectoral length 17.7 20.2 15.4 15.5 18 17.36 1.993238571
    Length of dorsal fin base 11.5 12.2 10 9.2 10 10.58 1.229634092
    Dorsal spine length 10.6 15 10 9.6 9.4 10.92 2.326370564
    Anal fin length 15.5 12 13.2 13.6 12.1 13.28 1.420211252
    Pelvic fin length 14.2 14.4 11.6 11 12.4 12.72 1.527088734
    Pectoral fin length 17.3 17.1 14.2 13 13.4 15 2.055480479
    Caudal fin length 22.5 20.3 17.7 18 19.8 19.66 1.94242117
    Adipose fin base length 20.5 17.2 30.2 16 32.3 23.24 7.532131173
    Dorsal to adipose length 5.1 9.4 0.01 6.1 1.5 4.422 3.743650625
    Post adipose length 12.3 12.6 9 9 7.4 10.06 2.279912279
    Caudal peduncle length 14.1 15 18 10 15.6 14.54 2.92027396
    Caudal peduncle depth 9.4 9.7 8 8.2 6.8 8.42 1.167047557
    Head length 18.6 20.2 16.1 16.6 16 17.5 1.838477631
    Head width 11.5 14 10 10.8 9.5 11.16 1.761533423
    Snout length 6 5.6 6.2 5.5 7 6.06 0.598331012
    Eye diameter 3.6 4.1 4.2 4.4 4.2 4.1 0.3
    Interorbital distance 11.6 13.2 9.7 10.3 8.7 10.7 1.747855829
    Maxillary barbel length 67 80 56 57 59 63.8 10.03493896
    Nasal barbel length 13 15 6 13 9 11.2 3.633180425
    Inner mandibular barbel length 13 23 11 15 12 14.8 4.816637832
    Outer mandibular barbel length 31 35 24 24 22 27.2 5.540758071


    Table III - Morphometry of Mystus cavasius (mm) with average & SD

    Parameters Specimen 1 Specimen 2 Specimen 3 Average Standard deviation
    Total length 86.3 87.8 82.8 85.63333 2.56580072
    Standard length 59.4 67.2 62 62.86667 3.971565602
    Body depth at anus 9.2 12.7 12 11.3 1.852025918
    Pre dorsal length 18.2 23.7 23.2 21.7 3.041381265
    Pre anal length 40.4 46.8 49 45.44.467661581
    Pre pelvic length 25.3 32.5 30.2 29.33333 3.677408508
    Pre pectoral length 11.8 16.5 15 14.43333 2.400694344
    Length of dorsal fin base 6.5 8.8 8.6 7.966667 1.27410099
    Dorsal spine length 6 9 8.2 7.733333 1.553490693
    Anal fin length 9 11.4 11.6 10.66667 1.446835628
    Pelvic fin length 8.7 10.8 10.7 10.06667 1.18462371
    Pectoral fin length 8.8 12 11.3 10.7 1.682260384
    Caudal fin length 16.2 21 20 19.06667 2.532455988
    Adipose fin base length,/b> 20.1 25.3 25.5 23.63333 3.061590001
    Dorsal to adipose length 0.02 0.09 0.07 0.06 0.036055513
    Post adipose length 5.3 7.3 6.4 6.333333 1.00166528
    Caudal peduncle length 10.3 14.5 13.1 12.63333 2.138535324
    Caudal peduncle depth .4.3 6.1 5.6 5.333333 0.929157324
    Head length 11.9 15.2 14.7 13.93333 1.77857621
    Head width 6.7 8.8 8.1 7.866667 1.069267662
    Snout length 3.7 5.8 5 4.833333 1.059874206
    Eye diameter 3.9 4.4 4.3 4.2 0.264575131
    Interorbital distance 5.7 7.3 7.3 6.766667 0.923760431
    Maxillary barbel length 67 70 69 68.66667 1.527525232
    Nasal barbel length 6 10 10.1 8.7 2.338803113
    Inner mandibular barbel length 9 15 14 12.66667 3.214550254
    Outer mandibular barbel length 23 27 24 24.66667 2.081665999


    Table IV - Morphometry of Mystus vittatus (%) with average

    Parameters Specimen 1 Specimen 2 Specimen 3 Average
    Total length 100% 100% 100% 1
    Standard length 77.30%,/td> 78.10% 80.80% 0.787333
    Body depth at anus 16.30% 16.80% 15% 0.160333
    Pre dorsal length 26.70% 28% 32.70% 0.291333
    Pre anal length 54.60% 55.70% 56.70% 0.556667
    Pre pelvic length 39.90% 40.80% 42% 0.409
    Pre pectoral length 16.30% 17.30% 18.60% 0.174
    Length of dorsal fin base 12.70% 10.40% 11.40% 0.115
    Dorsal spine length 12.70% 19.70% 11.40% 0.146
    Anal fin length 14.50% 14.60% 14.70% 0.146
    Pelvic fin length 12.70% 14.40% 13.40% 0.135
    Pectoral fin length 15.70% 14.90% 16.30% 0.156333
    Caudal fin length 20.20% 17% 18.70% 0.186333
    Adipose fin base length 18.70% 19.50% 21% 0.197333
    Dorsal to adipose length 5.90% 5% 4.50% 0.051333
    Post adipose length 11.10% 11.50% 12.50% 0.117
    Caudal peduncle length 12.90% 12.74% 15.30% 0.136467
    Caudal peduncle depth 8.20% 8.50% 8.90% 0.085333
    Head length 18.20% 18.50% 18.80% 0.185
    Head width 11.80% 12% 11.50% 0.117667
    Snout length 7% 6.20% 7.10% 0.067667
    Eye diameter 4% 4.80% 4.30% 0.043667
    Interorbital distance 10.70% 11.40% 11.30% 0.111333
    Maxillary barbel length 75.40% 73.30% 75.30% 0.746667
    Nasal barbel length 13.90% 15.60% 14.60% 0.147
    Inner mandibular barbel length 16.20% 18% 17% 0.170667
    Outer mandibular barbel length 32.50% 31.20% 25.50%,/td> 0.297333


    Table V - Morphometry of Mystus bleekeri (%) with average

    Parameters Specimen 1 Specimen 2 Specimen 3 Specimen 4 Specimen 5 Mean
    Total length 100% 100% 100% 100% 100% 1
    Standard length 77.20% 79.60% 80.10% 79.20% 78.60% 0.7894
    Body depth at anus 16.70% 15.80% 15.10% 17.80% 14.50% 0.1598
    Pre dorsal length 31.50% 31.80% 28.30% 31.50% 28.20%,/td> 0.3026
    Pre anal length 52.60% 56.50% 56.40% 56.50% 57.70% 0.5594
    Pre pelvic length 39.90% 39.80% 38% 41.60% 37.40% 0.3934
    Pre pectoral length 17.90% 18.20% 16% 17.70% 19.20% 0.178
    Length of dorsal fin base 11.60% 11.02% 10.40% 10.50% 10.70% 0.10844
    Dorsal spine length 10.70% 13.50% 10.40% 10.90% 10% 0.111
    Anal fin length 15.60% 10.80% 13.60% 15.50% 12.90% 0.1368
    Pelvic fin length 14.30% 13% 12% 12.50% 13.20%,/td> 0.13
    Pectoral fin length 17.40% 15.40% 14.70% 14.80% 14.30% 0.1532
    Caudal fin length 22.70% 18.30% 18.30% 20.50% 21.20% 0.202
    Adipose fin base length 20.70% 15.50% 31.20% 18.80% 34.50% 0.2414
    Dorsal to adipose length 5.15% 8.50% 0% 6.90% 1.60% 0.0443
    Post adipose length 12.40% 11.40% 9.30% 10.20% 7.90% 0.1024
    Caudal peduncle length 14.20% 13.50% 18.60% 11.40% 16.70% 0.1488
    Caudal peduncle depth 9.50% 8.70% 8.30% 9.30% 7.30% 0.0862
    Head length 18.80% 18.20% 16.70% 18.90% 17.10% 0.1794
    Head width 11.60% 12.60% 10.40% 12.30% 10.20% 0.1142
    Snout length 6.06% 5.06% 6.42% 6.30% 7.50% 0.06268
    Eye diameter 3.60% 3.70% 4.30% 5.01% 4.50% 0.04222
    Interorbital distance 11.70% 11.90% 10% 11.70% 9.30% 0.1092
    Maxillary barbel length 67.70% 72.20% 58% 64.90% 63.10% 0.6518
    Nasal barbel length 13.10% 13.50% 6.20% 14.80% 9.60% 0.1144
    Inner mandibular barbel length 13.10% 20.70% 11.40% 17.10% 12.80% 0.1502
    Outer mandibular barbel length 31.30% 31.60% 24.90% 27.40% 23.50% 0.2774


    Table VI - Morphometry of Mystus cavasius (%) with average

    Parameters Specimen 1,/b> Specimen 2 Specimen 3 Mean
    Total length 100% 100% 100% 1
    Standard length 79% 76.50% 74.90% 0.768
    Body depth at anus 13.90% 14.40% 14.50% 0.142667
    Pre dorsal length 27.40% 26.90% 28.02% 0.2744
    Pre anal length 53.50% 53.30% 59.20% 0.553333
    Pre pelvic length 38.10% 37% 36.50% 0.372
    Pre pectoral length 17.80% 18.80% 18.10% 0.182333
    Length of dorsal fin base 9.80% 10% 10.40% 0.100667
    Dorsal spine length 9.04% 10.20% 9.90% 0.097133
    Anal fin length 13.60% 12.90% 14% 0.135
    Pelvic fin length 13.10% 12.30% 12.90% 0.127667
    Pectoral fin length 13.30% 13.70% 13.60% 0.135333
    Caudal fin length 24.40% 23.90% 24.10% 0.241333
    Adipose fin base length 30.30% 28.80% 30.80% 0.299667
    Dorsal to adipose length 0.00% 0.00% 0.00% 0.000007
    Post adipose length 7.90% 8.30% 7.70% 0.079667
    Caudal peduncle length 15.50% 16.50% 15.80% 0.159333
    Caudal peduncle depth 6.50% 6.90% 6.80% 0.067333
    Head length 17.90% 17.30% 17.70% 0.176333
    Head width 10.10% 10% 9.80% 0.099667
    Snout length 5.60% 6.60% 6.03% 0.060767
    Eye diameter 5.90% 5.01% 5.20% 0.0537
    Interorbital distance 8.60% 8.30% 8.80% 0.085667
    Maxillary barbel length 85.90% 85.40% 83.30% 0.848667
    Nasal barbel length 9.05% 11.40% 12.20% 0.108833
    Inner mandibular barbel length 10.50% 17.08% 16.90% 0.148267
    Outer mandibular barbel length 24.10% 30.70% 26.60% 0.271333


    Table VII Meristic counts of Mystus vittatus

    Parameters Specimen 1 Specimen 2 Specimen 3
    Dorsal fin (soft rays) 7 7 7
    Pectoral fin (soft rays) 7 8 8
    Pelvic fin (soft rays) 6 6 6
    Anal fin (soft rays) 8 9 9
    Caudal fin (soft rays) 18 18 18


    Table VIII Meristic counts of Mystus bleekeri

    Parameters Specimen 1 Specimen 2 Specimen 3 Specimen 4 Specimen 5
    Dorsal fin (soft rays) 7 7 7 7 7
    Pectoral fin (soft rays) 7 8 8 7 8
    Pelvic fin (soft rays) 6 6 6 6 6
    Anal fin (soft rays) 9 9 9 9 9
    Caudal fin (soft rays) 18 18 18 19 20


    Table IX Meristic counts of Mystus cavasius

    Parameters Specimen 1 Specimen 2 Specimen 3
    Dorsal fin (soft rays) 7 7 7
    Pectoral fin (soft rays) 7 7 8
    Pelvic fin (soft rays) 6 6 6
    Anal fin (soft rays) 9 9 10
    Caudal fin (soft rays) 20 21 19


    Photographs of the Specimens


    Photo plate 1 Mystus bleekeri



    Photo plate 2 Mystus cavasius



    Photo plate 3 Mystus vittatus


    DISCUSSION- The head lengths of Mystus spp. with respect to their total length is found to be nearly 18% whereas the head width is about 10% to that of their total length. Therefore, the Head width of dorsoventrally flattened head of the Mystus spp. is nearly half of their head length. The mouth bears four pairs of unequal barbels, among which the maxillary barbels are significantly longer in M. cavasius. Chattopadhyay et al (2014) have reported that the maxillary barbels have extended up to 60% of the total length in M. vittatus collected from Bolpur, West Bengal. However, the present. study has shown their extension up to 74.6% of the total length. The increase in the relative length could be an outcome of the gustatory arrangement in the body due to varied geographical, climatic and nutritive factors. Moreover, the Mystus spp. has shown eloquent interspecific variation. The mean Interorbital distance is significantly smaller inM. cavasius. In like manner, M. vittatus have shown a significantly shorter adipose fin base length.

    CONCLUSION- The Northeastern India is well known for its immense biodiversity yet fewer studies have been made so far on the aquatic living entities found here. Although the present study is confined to only three species of Mystus spp., still a convincing mass of information has been obtained. It was found that the Mystus spp. has evolved varied morphological characteristics depending upon their external environment. The Mystus spp. was found to have four pairs of barbells extending beyond their standard length, in some. Such gustatory outgrowths must ease their labour to trace their food in the water bodies. Moreover, the eloquent interspecific variations shown by the Mystus spp. could be a consequence of their adaptability to varied geographical and climatic environment and a strong reason for their ab-undance in the sub-continent. From this study, it is understood that Morphometry is not only a strong tool for the taxonomic identification of the organisms but also an essential tool to determine the variations among them.

    ACKNOWLEDGEMENT- I would like to express my special thanks of gratitude to the Assam Science Technology and Environmental Council (ASTEC) for their financial support, Dr. (Mrs.) Jolly Mazumder (H.O.D, Department of Zoology, B. Borooah College) as well as our principal Dr. S.N Barman for giving me the excellent opportunity to do this wonderful project.

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    Source of Financial Support: ASTEC, Assam Conflict of interest: Nil