International Journal of Zoology Studies ISSN: 2455-7269 Impact Factor: RJIF 5.14 www.zoologyjournals.com Volume 2; Issue 5; September 2017; Page No. 203-211 Morphometric analysis: A tool to identify green puffer fish Tetraodon fluviatilis (Hamilton, 1822) from the Digha coastal region, West Bengal, East coast of India * Rudra Prasad Nath, Jayanta Kumar Kundu Department of Zoology, Vidyasagar University, Midnapore, West Bengal, India Abstract Tetraodontidae is a family of primarily marine and estuarine fish of the order Tetraodontiformes but some of the species are confined to freshwater environments also. 70 specimens of Tetraodon fluviatilis (Hamilton, 1822), commonly known as green puffer fish were collected from the Digha coastal region, West Bengal (between 21°32´N to 22°40´N latitude and 88°05´E to 89°00´E longitude). Morphometric measurements and meristic counts of different size groups of the puffer fishes were studied. All the meristic counts remain constant with increasing body length. Keywords: Tetraodon fluviatilis, green puffer fish, morphometric measurements, meristic count Introduction The most important step of taxonomic research is proper identification of a species [1]. Morphometric measurements and meristic counts are known as simplest and genuine methods for the identification of a specimen which can be denoted as morphological systematics [2]. Morphometric studies are not only essential to realize the taxonomy but also the physiological condition of a species in an environment [3]. The shape and structures are unique to the species and the variations in its feature are probably related to the habit and habitat among the variants of this species [4]. Morphometric measurement is measurements of different external body parts of an organism and meristic counts mean anything that can be counted [5]. Genus Tetraodon is based on several phenotypic and osteological characters like laterally expanded sphenotic bone beyond frontal to form a broad flattened lobe, orbital roof scarcely arched, the lateral ethmoid not bent down before the eye, mesethmoid broad, upper lateral line not reaching end of tail, presence of 19 vertebrae, dermal ossifications of back bearing simple prickles, evenly scattered spines on either sides, dorsal fin maximally containing 16 fin rays; nasal organ is an elevated tube [6]. Morphological characters are phenotipically plastic and are influenced each year by the physical environment during spawning and early juvenile stages [7]. Morphometric and meristic study will provide a vigorous tool for measuring discreteness of the same species, therefore all such characters had most commonly used by several ichthyologists for the differentiation of fish species or geographically variants or populations [8]. The study of morphometric relationship can be helpful to identify any particular species or to determine that whether there is any similarity of characters or differences among their male and female fishes. In fish, morphometric characters represent one of the major keys for determining their systematic relationships, growth variability, ontogenetic trails and various other population parameters [8, 9, 10, 11]. Studies on morphometric and meristic characters might have also potential value in taxonomy, conservation and fisheries management [12, 13]. It can also be used to evaluate the influence of various environmental factors, availability of food items and spawning condition on fish [14]. So, morphometric characters are considered as suitable tools for the identification of any fish species, genera or stocks of fish, its habitat as well as the ecological conditions of sea, rivers, lakes etc. [15, 16, 17]. Present study describes the record of occurrence of the freshwater puffer fish, Tetraodon fluviatilis (Hamilton, 1822) from the Digha coastal region, West Bengal (between 21°32´N to 22°40´N latitude and 88°05´E to 89°00´E longitude). Materials and Methods Study Region Collection of Puffer fishes were made from the Digha coast (between 21°32´N to 21°45´N latitude and 87°32´E to 87°50´E longitude), in Purba Medinipur District, West Bengal, east coast of India. Three different fishing stations (Figure 1) of this coastal region which were Digha mohona, Sankarpur, Soula (Table 1). This sea coast is situated at the northern end of Bay of Bengal with low gradient and a shallow sand beach [18]. Survey has been carried out trawling and local fishing. Local fishing were made from this coastal region like Digha, Sankarpur, Mandarmoni, Soula, Junput, Rasulpur etc. Length of this coast line is almost 30 - 35 Kilometers. 203 International Journal of Zoology Studies Table 1: Three Fishing stations with GPS Location from where samples were collected periodically from Digha coast during this survey. S. No. Station 1 Station 2 Station 3 Station Name Digha mohona Sankarpur Soula GPS Location 21°37´N latitude and 87°32´E longitude 21°38´N latitude and 87°34´E longitude 21°44´N latitude and 87°50´E longitude Fig 1: Satellite image of study region and three fish landing centers (Station 1- Digha mohona, Station 2 - Sankarpur, Station 3 - Soula) along Digha coastal region, West Bengal, east coast of India. (Source – Google Earth) Sample Collection: Samples had been collected for three years (January, 2013 - January, 2016). Immediately after the collection, the fishes were photographed for their original colour and shape of puffer fish species. For the purpose of photograph “Nikon Coolpix L 24” was used, made by Nikon Corporation, Japan (14.0 Megapixel, 3.6 X optical zoom). After collection the samples were kept in different ice boxes according to their length and weight. Then the samples were brought to the laboratory and immediately washed. After transfer to the laboratory, the fishes were preserved in 10% neutralized formalin for identification up to the species level. For each specimen, total length (TL) was then measured along with all morphometric parameters by digital caliper to the nearest 0.1 mm, and body weight measured with an electronic balance to 0.01 g. Details of morphometric measurements and meristic counts were recorded along with their means and standard deviation, using SPSS (13.0) software [19]. Because of the variation in size of fish, morphometric data was statistically adjusted to permit comparative analysis in terms of shape independent of size. Terminology used in the morphological description of puffer fish shown in figure 2 [20, 21] . Total 70 fishes were divided into two groups according to their size. Group A: 2.0 - 5.99 cm (35 Specimens) Group B: 6.0 - 12.0 cm (35 Specimens) Fig 2: Process of taking morphometric measurements of Tetraodon fluviatilis (Hamilton, 1822) in which parameters are AK = Total length (TL) = Fork length (FL), AJ = Standard length (SL), GN = Body depth (BD), AC = Pre Orbital Length (POL), AB = Snout Length, CD = Orbital diameter (OD), AE = Head Length (HL), AH = Pre Dorsal Length (PDL), AF = Pre Pectoral Length (PPL), AM = Pre Anal Length (PAL), JK = Caudal fin length (CL), IL = Caudal fin height (CH). 204 International Journal of Zoology Studies Results and Discussions According to morphometric analysis the present specimens have greatest resemblance to the above descriptions based on: 1. Rosette shaped nasal organ is very prominent with spongy tissue. 2. Head length is almost 2.4 – 2.6 times greater than Snout length (Table 2 and Fig 1). 3. Standard length is almost 2.4 times greater than head length (Table 2 and Fig 1). 4. Inter – orbital space is convex, without a groove (Fig 3A). 5. Mouth is terminal, directed forwards (Fig 3A). 6. Three large yellowish dark patches encircled on back, middle patch is situated between pectoral fins, posterior patch in front of dorsal fin (Fig 3B). 3A 3B Fig 3: Lateral view (Fig 3A) and Dorsal view (Fig 3B) of Tetraodon fluviatilis (Hamilton, 1822) Meristic counts also show similarities with existing data provided by Dekkers i.e. dorsal fin ray 13 , pectoral fin ray 21, anal fin ray 11 (Table – 3). The meristic counts were independent of body size [5, 21, 22]. The correlation between different morphometric measurements of Tetraodon fluviatilis are given in Table 4. Table 2: Morphometric measurements (cm) of Juvenile (Group A) and Adult (Group B) Tetraodon fluviatilis (Hamilton, 1822) along with their mean and Standard Deviations. Parameters Total length (TL=FL) Standard length (SL) Body depth (BD) Pre orbital length (POL) Post orbital length of Head (PHL) Orbital diameter (OD) Head length (HL) Snout length (SnL) Pre Dorsal Length (PDL) Pre Pectoral Length (PPL) Pre Anal Length (PAL) Caudal fin length (CL) Caudal fin height (CH) Group - a 3.45 ± 0.2028 2.66 ± 0.1586 1.03 ± 0.0758 0.31 ± 0.0224 0.37 ± 0.0112 0.43 ± 0.0240 1.11 ± 0.0490 0.46 ± 0.0013 1.98 ± 0.1128 1.21 ± 0.1412 2.02 ± 0.1134 0.77 ± 0.0039 0.67 ± 0.0241 GROUP - B 9.57 ± 0.8797 7.68 ± 0.6145 3.16 ± 0.2113 0.81 ± 0.0019 1.13 ± 0.0578 0.69 ± 0.0257 2.61 ± 0.1396 1.06 ± 0.0658 5.54 ± 0.4789 2.99 ± 0.1656 5.43 ± 0.3212 2.05 ± 0.0112 2.93 ± 0.1112 Fig 4: Showing morphometric measurements of Juvenile (Group A) and Adult (Group B) Tetraodon fluviatilis (Hamilton, 1822). 205 International Journal of Zoology Studies Fig 5: Comparison of Morphometric measurements of Juvenile (Group A) and Adult (Group B) Tetraodon fluviatilis (Hamilton, 1822). Table 3: Meristic counts of adult and juvenile Tetraodon fluviatilis (Hamilton, 1822) Distribution Group Adults Juveniles Dorsal Fin rays 13 13 Meristic Counts Pectoral Fin rays Anal Fin rays 21 11 21 11 Caudal Fin rays 11 11 Fig 6: Meristic counts of adult and juvenile Tetraodon fluviatilis (Hamilton, 1822) Fig 7: Correlation curve of total length of Tetraodon fluviatilis (Hamilton, 1822) 206 International Journal of Zoology Studies Fig 8: Correlation curve of standard length of Tetraodon fluviatilis (Hamilton, 1822) Fig 9: Correlation curve of body depth of Tetraodon fluviatilis (Hamilton, 1822) Fig 10: Correlation curve of pre orbital length of Tetraodon fluviatilis (Hamilton, 1822) 207 International Journal of Zoology Studies Fig 11: Correlation curve of post orbital length of head of Tetraodon fluviatilis (Hamilton, 1822) Fig 12: Correlation curve of orbital diameter of Tetraodon fluviatilis (Hamilton, 1822) Fig 13: Correlation curve of head length of Tetraodon fluviatilis (Hamilton, 1822) 208 International Journal of Zoology Studies Fig 14: Correlation curve of snout length of Tetraodon fluviatilis (Hamilton, 1822) Fig 15: Correlation curve of pre dorsal length of Tetraodon fluviatilis (Hamilton, 1822) Fig 16: Correlation curve of pre pectoral length of Tetraodon fluviatilis (Hamilton, 1822) 209 International Journal of Zoology Studies Fig 17: Correlation curve of pre anal length of Tetraodon fluviatilis (Hamilton, 1822) Fig 18: Correlation curve of caudal fin length of Tetraodon fluviatilis (Hamilton, 1822) Fig 19: Correlation curve of caudal fin height of Tetraodon fluviatilis (Hamilton, 1822) 210 International Journal of Zoology Studies Table 4: Correlation between different morphometric measurements of Tetraodon fluviatilis (Hamilton, 1822) Total length (TL) = Fork length (FL), Standard length (SL), Body depth (BD), Pre Orbital Length (POL), Snout Length (SnL), Orbital diameter (OD), Head Length (HL), Pre Dorsal Length (PDL), Pre Pectoral Length (PPL), Pre Anal Length (PAL), Caudal fin length (CL), Caudal fin height (CH). SL-BD 0.373832 SL-POL -0.0794 SL-PHL -0.03768 SL-OD 0.401862 SL-HL 0.132841 SL-SnL -0.19538 Conclusion The morphometric measurements and meristic counts confirmed that the test organism is Tetraodon fluviatilis from the Digha coastal region of West Bengal, east coast of India. 12. Acknowledgement The authors are grateful to scientists of MARC, Digha, Regional Centre of ZSI, Dept. of Zoology, Vidyasagar University for giving valuable suggestions during this study. The authors are heartily thankful to Mr. Soumitra Samanta and local fishermen for constant support during this survey. References 1. Hazarika A, Borah U, and Bordoloi L. Studies on Morphometric Measurements and Meristic Counts of Hill Trout Barilius Bendelisis, Hamilton. From the River Buroi at the Boundary Areas of Assam and Arunachal Pradesh, India. Indian Journal of Fundamental and Applied Life Sciences. 2011; 1 (3):194-198. 2. Nayman N. Growth and Ecology of fish population. Journal of Animal Ecology. 1965; 20:201-219. 3. Cavalcanti MJ, Lopes PRD. Análise morfométrica multivariada de cinco species de Serranidae (Teleostei, Perciformes). Acta Biol. Leopoldensia. 1993; 15:53-64. 4. Manimegalai M, Karthikeyeni S, Vasanth S, Arul Ganesh S, Siva Vijayakumar T, Subramanian P. Morphometric Analysis – A Tool to Identify the Different Variants in a Fish Species E. maculatus. International Journal of Environmental Sciences. 2010; 1(4):481 -497. 5. Talwar PK, Jhingran AG. Inland fishes of India and adjacent countries. A. A. Balkema/Rotterdam. 1992, 11062. 6. Dekkers WJ. Review of the Asiatic fresh water puffers of the genus Tetraodon Linnaeus, 1758 Pisces, Tetraodontiformes, Tetraodontidae. Bijdragen tot der Dierkunde. 1975; 45:88-141. 7. Austin M. Morphometric separation of annual cohorts within mid– Atlantic bluefish, Pomatomus saltatrix, using discriminant function analysis. 1999; 97: 411-420. 8. Rohollah A, Rahbar M, Karimi JM. Comparative Survey of Morphometric-meristic Male and Female Anjak Fish (Schizocyprisbrucei, Annandale and Hora, 1920) of Hamoun Wetland in South East Iran. Middle-East Journal of Scientific Research. 2013; 14(5):620-623. 9. Lashari PK, Narejo NT, Mastoi AM, Mahar MA. Some morphometric characters and their relationship in carp, Cirrhinusreba from fishpond district Jacobabad, Sindh. Proceedings of Pakistan Congress of Zoology. 2004; 24:179-184. 10. Narejo NT. Morphometric characters and their relationship in Gudusiachapra (Hamilton) from Keenjhar lake (Distt: Thatta), Sindh. Pakistan Journal of Zoology. 2010; 42(1):101-104. 11. Dars BA, Narejo NT, Awan KP. Morphometric, meristic 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. SL-PDL 0.414556 SL-PPL 0.119951 SL-PAL 0.800419 SL-CL 0.158802 SL-CH 0.365595 characters and their relationships in Channapunctatus from River Indus near Jamshoro Sindh, Pakistan. Sindh University Research Journal (Science Series). 2012; 44(1):91-96. Motomura H, Paulin CD, Stewart AL. First records of Scorpaenaonaria (Scorpaeniformes: Scorpanidae) from the Southwestern Pacific Ocean and comparison with the Northern Hemisphere population. New Zealand journal of Marine and Freshwater Research. 2005; 39:865-880. Quist MC, Bower MR, Hubert WA, Parchman TL, MC Donald DB. Morphometric and meristic differences among bluehead suckers, flannelmouth suckers, white suckers, and their hybrids: Tools for the management of native species in the Upper Colorado River Basin. North American Journal of Fisheries Management. 2009; 29:460-467. Adeyemi SO. Length – Weight, Length – Length Relationship and Condition Factor of Synodontisresupinatus At Idah Area of River Niger, Nigeria. Production Agriculture and Technology (PAT). 2010; 6(2):85-90. Bagenal TB, Tesch AT. Conditions and growth patterns in fresh water habitats. Blackwell Scientific Publications, Oxford, 1978. Ismen A. Use of a discriminant function for the morphometric and meristic separation of Whiting Stocks, Merlangiusmerlanguseuxinus, along the Turkish Black Sea Coast. Turkish Journal of Zoology. 2001; 25:297304. Mekkawy IAA, Mohammad AS. Morphometrics and meristics of the three Epinepheline species, Cephalopholisargus (Bloch and Schneider, 1801), Cephalopholisminiata (Forsskal, 1775) and Variolalouti (Forsskal, 1775) from the Red Sea, Egypt. Journal of Biological Sciences. 2011; 11:10-21. Manna B, Goswami BBC. A checkl;ist of marine & esturine fishes of Digha , West Bengal, India. Mahasagar Bulletin of the National Institute of Ocenography. 1985; 18(4):489-499. Varadharajan D, Soundarapandian P, Dinakaran GK, Vijakumar G. Crab Fishery Resources from Arukkattuthurai to Aiyammpattinam, South East Coast of India. C. Res. J Biol. Sci. 2009; 1(3):118-122. Froese R, Pauly D. FishBase. http:// www. Fishbase.org, version, 2010. Dekkers WJ. Review of the Asiatic freshwater puffers of the genus Tetraodon Linnaeus, 1758. Pisces, Tetraodontiformes, Tetraodontidae. Bijdragen tot der Dierkunde. 1975; 45:88-141. Ram Krishan N, Tarana N. Analysis of morphometric character of Schizothorax richardsonii (Gray, 1832) from the Uttarkashi District of Uttrakhand State, India. Journal of Biological Sciences. 2010; 10(6):536-540. 211