Indian Journal of Geo Marine Sciences Vol. 47 (01), January 2018, pp. 60-66 A note on shallow water octocorallia from Nicobar Islands, India J. S. Yogesh Kumar1*, S. Geetha2, C. Raghunathan3 & R. Sornaraj2 1Marine Aquarium and Regional Centre, Zoological Survey of India, (Ministry of Environment, Forest and Climate Change), Government of India, Digha – 721428, West Bengal, India. 2Research Department of Zoology, Kamaraj College (Manonmaniam Sundaranar University), Thoothukudi – 628003, Tamil Nadu, India. 3Zoological Survey of India (Ministry of Environment, Forest and Climate Change), Government of India, M Block, New Alipore, Kolkata - 700 053,West Bengal, India. [E.mail: [email protected] ] Received 07 December 2015 ; revised 17 November 2016 Present study revealed the diversity of shallow water soft coral octocorallia (Helioporacea, Alcyonacea, Pennatulacea, Gorgonacea) in Nicobar group of Islands. The sampling made at 11 study sites with help of SCUBA diving to the depth of 5 to 30 m. A total 27 species were found in Nicobar Island. Of which the Alcyonacea was dominant group followed by Gorgonacea, Helioporacea and Pennatulacea at all the study sites which is contributed with result obtained based on Principal Component analysis, De-Treneded analysis and Ternary plot. Bray-Curtis cluster analysis resulted 75% similarity between the study sites in Nicobar Islands. [Key words: Soft coral, Octocorallia, diversity, Nicobar Islands, India] Introduction Nicobar Islands are situated in the Helioporacea (blue coral), Pennatulacea (sea southeast region of Bay of Bengal, between 60-10 pens), and Alcyonacea (soft corals, Stolonifera, N Lat. and 920 - 940 E Long. There are 22 islands gorgonians and telestacea) found in intertidal to in Nicobar group, of which 12 are inhabited. The abyssal depths around World Ocean from present communication deals with the octocoral tropical to polar seas1. distribution of Nicobar group of Islands. The The studies on the Indian octocoral taxonomy Octocoral belongs to the Anthozoan subclass were initiated by Hickson2,3 from Lakshadweep Octocorallia comprised of three orders: and Maldive, Pratt4 and Thomson TABLE 1 Areas surveyed in the Nicobar group of Islands for assessing the status of Octocorals. Name of the study sites Abbrevation Latitude Longitude Malacca MA N 09009.701” E 092050.128” Kakana KA N 09007.750” E 092048.678” Tamaloo TA N 09011.350” E 092049.498” Parka PA N 09011.203” E 092049.877” Car Nicobar Lapathy LA N 09013.978” E 092048.002” Nancowry NA N 08002.145” E 093033.117” Champian CH N 08001.718” E 093032.728” Kamota KM N 08002.183” E 093032.573” Munak (Alukiah) MU N 07059.806” E 093029.852” Nancowry Groups Trinket TR N 08003.352” E 093034.102” Great Nicobar Gandhi Nagar GN N 06051.056” E 093053.769” INDIAN J. MAR. SCI., VOL. 47, NO. 01, JANUARY 2018 61 and Handerson5,6 from Gulf of Mannar, Nicobar Islands. Followed by Rao and Kamala Sri Lankan coast at 1200 m depth. Thomson and Devi15 reported 54 species of soft corals from Simpson7 reported Octocorals from the collection Andaman and Nicobar Islands. of Royal Indian Marine Survey Ship in Indian Limited records of avilability on Ocean, while Thomas and George8,9,10 reported Pennatulacea only 9 species reported from India, gorgonian octocorals from Indian water. Van of which 6 species reported from the Gulf of Ofwegen and Vennam11 and Alderslade and Mannar16 and 3 species from Andaman and Shirwaiker12 Studied octocorals from Nicobar Island17. Altogether 171 species of Lakshadweep Islands. In west coast of India, gorgonian octocorals have been reported from Usha et al.13 found the distribution of octocorals Indian water18 among them 121 species from from the Gulf of Kachchh and Gujarat coast. southeast coast19 and 51 species identified from JayaSree et al.14 reported the occurrence and Andaman and Nicobar Islands Kumar et al.20. distribution of soft corals from Andaman and TABLE 2 List of octocorals species from Nicobar group of Islands Systematic Position MA KA TA PA LA NA CH KM MU TR GN Family: Helioporidae _ _ _ _ _ _ + + + + _ 1 Heliopora coerulea Family: Nidaliidae _ _ _ _ _ + _ + + + _ 2 Siphonogorgia media Family: Xeniidae _ _ _ _ _ _ _ _ _ _ + Heteroxenia 3 fuscescens Family: Tubiporidae _ + _ _ _ _ _ _ _ _ + 4 Tubipora musica Family: Alcyoniidae _ _ + + _ _ _ + + _ _ 5 Cladiella sp. 6 Lobophytum sp. + + + + + + + + + + + 7 Sinularia sp. + + + + + + + + + + + 8 Sarcophyton sp. + + + + + + + + + + + 9 Dendronephthya sp. _ + _ _ _ _ + + _ + _ Family: Gorgoniidae + _ _ _ + + + + + _ 10 Rumphella torta 11 Hicksonella princeps _ _ _ _ + _ _ _ _ _ _ Family: + _ _ _ _ _ + + + + _ Subergorgiidae 12 Annella mollis 13 Annella reticulate _ _ _ _ _ _ + _ _ _ _ 14 Subergorgia suberosa + _ _ _ _ + + + + + _ Family: Plexauridae _ _ _ _ _ _ + _ _ _ _ 15 Bebryce sirene Echinomuricea _ _ _ _ _ + _ _ + _ _ 16 indomalaccensis 17 Euplexaura amerea _ _ _ _ _ + _ + _ _ _ 18 Menella kanisa _ _ _ _ _ + + _ _ + _ Trimuricea + _ _ _ + _ _ _ _ + _ 19 caledonica Family: Melithaea _ _ _ _ _ + _ _ _ _ _ 20 Melithaea braueri 21 Melithaea caledonica + _ _ + _ _ + _ + _ + 22 Melithaea variabilis _ _ _ _ _ + _ _ _ _ _ Family: Isididae + + + + + + + + + + + 23 Isis hippuris Family: _ _ _ + _ _ _ + _ _ _ Virgulariidae 24 Virgularia mirabilis _ _ _ _ _ _ _ _ _ _ + Family: Pennatulidae Pteroeides 25 caledonicum 26 Pteroeides esperi _ _ _ _ _ _ _ _ _ + _ Family: Veretillidae _ _ _ _ _ _ _ _ _ + _ 27 Cavernularia pusilla +Present, - Absent 62 KUMAR et al.: OCTOCORALS OF NICOBAR ISLANDS FIGURE 1 Underwater pictures of some octocorals from the study site in Nicobar Islands (1.Heteroxenia fuscescens, 2. Sinularia sp., 3. Lobophytum sp., 4. Cladiella sp., 5. Sarcophyton sp., 6. Dendronephthya sp., 7. Heliopora coerulea, 8. Virgularia gustaviana, 9. Pteroeides esperi, 10. Siphonogorgia media, 11. Tubipora musica, 12. Rumphella torta, 13. Hicksonella princeps, 14. Melithaea caledonica, 15. Melithaea variabilis, 16. Melithaea braueri, 17. Isis hippuris, 18. Echinomuricea indomalaccensis, 19. Subergorgia suberosa, 20. Annella mollis. INDIAN J. MAR. SCI., VOL. 47, NO. 01, JANUARY 2018 63 Materials and Methods B The undersea survey using SCUBA gears have been conducted in 11 sites at Nicobar GorgonaceaKM group of Islands during 2009 to 2015 by using NA Helioporacea SCUBA diving. Line Intercept Transect (LIT) CH Pennatulacea 21 and Quadrate methods were used to investigate TR GN Alcyonacea the diversity and dispersion of the Octocorallia. LAPA MA KATA These specimens were identified based on the morphological characteristics and sclerite MU structure and preserved in 70% ethanol following Breedy22 and deposited in the National Zoological collection of ZSI, Port Blair. The FIGURE 2 Principal Component Analyses (PCA): A- Life form categories and B – Octocorals recorded in the Nicobar statistical analysis like Menhinick Diversity, groups of Islands. Shannon – Weiner Diversity, Pielou’s Evenness, Principal Component Analysis (PCA) scatter A Principal Component Analysis (PCA) diagram, De-trended correspondence analysis of different live form categories and genera of and Ternary plot were made using PAST octocoral and its contribution with respect to 23 software . study sites are presented in the Fig 2 A&B. The live coral cover was maximum at NA, KM and Results MU while dead coral cover was maximum in A total of 27 species of octocorals under 23 LA, GN, TA and the rubble was reported genera, 13 families were recorded from the maximum at the KA (Fig 2A). Diversity and Nicobar group of Islands (Table 2, Fig. 1). A distribution of octocorals were maximum at TR maximum number of species were recorded from and minimum at TA. Percentage of octocoral TR (14 sp.) and minimum at TA (5 sp.). The cover was varied between the study sites, for the Menhinick Diversity index was recorded as 4 order Helioporacea, Alcyonacea, Pennatulacea, highest at PA (1.5) while LA and CH (0.8) Gorgonacea. Among them alcyonacea was represented the lowest diversity of Octocorals. dominant at all the study sites whereas and The Shannon – Weiner Diversity index was pennatulacea was rare in four field sites (PA, maximum in KM (1.24) and minimum in MU NA, KM, GN). The distribution of Gorgonacea (0.57). The Simpson’s Diversity indices, KM and Helioporacea were maximum at KM and TR (0.68) was noted maximum and MU (0.29) respectively (Fig. 2B & Fig. 3). minimum and the Pielou’s Evenness index for species community ranged from 0.59 at MU to 0.91 at LA. A maximum number of individuals and percentage of cover reported in TR and minimum in TA (Table 3). A FIGURE 3 Percentage of octocoral cover in the study sites. 64 KUMAR et al.: OCTOCORALS OF NICOBAR ISLANDS 2.5 Nancowry Kamorta Malacca Champian Trinket Alukiah Lapathi Parka G.Nicobar Kakanna Tamaloo 2 Pennatulacea 1.5 0.96 1 0.92 0.5 Alcyonacea LA MU PA 0.88 GN KANA -2 -1.6 -1.2 -0.8 -0.4 KMCHTATRMA0.4 0.8 1.2 1.6 0.84 -0.5 Gorgonacea -1 Similarity 0.8 -1.5 0.76 -2 Helioporacea 0.72 FIGURE 4 De-Trended correspondence analysis based 0.68 Octocoral distribution between the study site in the Nicobar groups. 0.64 Helioporacea FIGURE 6 Bray-Curtis similarity cluster analysis under paired linkage for the Nicobar group of islands based on the species of octocoral. De-Treneded analysis clearly showed that alcyonacean diversity was highly significant and pennatulacea was nonsignificant between the 50 50 study sites (Fig.