International Journal of Zoology and Research (IJZR) ISSN 2278-8816 Vol. 3, Issue 4, Oct 2013, 23-30 © TJPRC Pvt. Ltd. THE ONCHIDIUM (GASTROPODA: PULMONATA: ONCHIDIIDAE: GENUS: ONCHIDIUM) OF THE URAN, WEST COAST OF INDIA PRADNYA PATIL & B. G. KULKARNI Department of Zoology, Institute of Science, Mumbai, Maharashtra, India ABSTRACT In India, Maharashtra state has a coastline of 720 km having all types of shores. Most of the available Reports are on macrobenthos diversity on coast of Maharashtra. It is mainly focused on diversity of mollusc like gastropod and pelecypoda. However, meagre data is available on diversity of Pulmonata gastropod on coast of Maharashtra. Due to such encroachment and reclamation, a species displacement has been reported on coast of Konkan. In recent years urbanization and industrialization in coastal belt of Konkan has resulted into modifications of topography of these areas. Present work on assessing diversity of Onchidium species on coast of Uran has been recorded three species of Onchidium. O. verruculatum, O. peronii, Platevindex species. The present investigation is the first report on diversity of Onchidium species on the coast of Uran. KEYWORDS: Diversity, O. verruculatum, O. peronii, Platevindex species INTRODUCTION Census of Marine Life (www.coml.org) programme proved that oceans have great diversity of life. 33 out of 34 major phyla are represented in the ocean, whereas only 15 phyla’s are presented on the land. Census of Marine Life also proved that every niche in marine ecosystem is occupied by the life. Although every oceanic country has participated in an international project of Census of Marine Life, a little attention has been paid on coast of India to measure the diversity of marine life. The Census of Marine Life established a baseline of marine life diversity, distribution, and abundance against which future change can be measured. Census of Marine Life aggregated more than 30 million of species; including 1,200 newly discovered and described species. Another 5,000 or more await formal description. Census of Marine Life created the Ocean Biogeographic Information System, the world’s largest online repository of geo-referenced data that nations can use to develop national and regional assessments and to meet their obligations to the Convention on Biological Diversity and other international commitments. Census of Marine Life collaborated with the Encyclopaedia of Life to complete ~ 90,000 marine species pages and provided and continues to serve as the marine component of the Global Biodiversity Information Facility. Census of Marine Life supported the World Register of Marine Species, which confirmed that excluding microbes approximately 250,000 valid marine species have been formally described in the scientific literature, with an estimated at least 750,000 more species remaining to be described. NaGISA (http://nagisa.cbm.usb.ve) the program for assessing diversity of near shore has executed many projects to assess diversity of intertidal zones. Reports of near shore diversity are available on webpage of NaGISA. Maharashtra has a coastline of 720 km having all types of shores. Reports are available on macrobenthos diversity on coast of Maharashtra. Among these reports of Parulekar et.al (1976), Parulekar (1981) Ingole et. al. (2002, 2009), Chhapgar (1958) Zingde (1999) Jaiswar and Kulkarni (2000), Shahnawaz et.al. (2006), Jaiswar et.al. (2007), Datta et.al. (2010), Balli et.al. (2011) are worth to mention here. Most of the available reports pertains to diversity of macrobenthos on coast of Maharashtra mainly focus on diversity of mollusc like gastropod and pelecypoda. However, meagre data is available on 24 Pradnya Patil & B. G. Kulkarni diversity of Pulmonata gastropod on coast of Maharashtra. (Awati and karandikar, 1948; Gopinadha et.al., 1980; Datta et.al., 2008). In recent years urbanization and industrialization in coastal belt of Konkan has resulted into modifications of topography of these areas. Due to such encroachment and reclamation a species displacement has been reported on coast of Konkan. (Khade and Mane 2012a,2012b,2012c).Therefore, present work on assessing diversity of Onchidium species on coast of Uran has been undertaken, to create a data base with respect to present circumstances of human settlement on coast of Uran. MATERIAL AND METHODS The selected sites were visited during low tide for collection of the Onchidium species. The animals collected manually from respective sites were washed with sea water and brought to the laboratory for taxonomical studies. The morphological characters of Onchidium are extremely variable within the populations, and therefore the diagnoses and identification keys are based on type specimens when available. The identification of Onchidium species was done as per reports of Fretter (1943); Awati and Karandikar (1948) and Dayrat (2009). The dorsal eyes morphology is used by many authors to distinguish between species. Table 1 shows the mainly characters used in the keys. Species Diversity Topography of Selected Sites A Preliminary survey of Uran coast was carried out to locate niche of Onchidium species. It has been noticed that usually marshy areas in mangrove zones are habituated by Onchidium species. Furthermore, population of Onchidium species was also recorded at rocky shore covered with mud near, marshy areas of mangroves. After thorough survey of Uran coast Site-I named as Pirwadi beach and Site - II called as Dookar khadi were selected for collection of Onchidium species Site-I Uran Pirwadi Geographically, Uran city (Latitude 180 50’ 20” N and Longitude 720 57’ 5” E) is located on the coast of Arabian Sea along the eastern shore of Mumbai harbour opposite to Colaba. Total length of Uran coast is approximately 16 km and it is marked by rocky, muddy and sandy substratum. Most of the coast is rocky towards the sea side and Marshy towards upper middle zone. Pirwadi site located 7 km away from Uran city. The moderate cover of mangrove exists at Pirwadi Site. Site II: Uran Dookar khadi Dookar creek of Uran city opens on one side into the sea near Bori is located at (Latitude: 18° 48' 20" N Longitude: 72° 59' 33" E). A dense cover of mangrove trees (Avicennia marina) is present in most of the creek. Presence of loamy mud substratum is one of the favourable factors for habitat of Onchidium species in this creek. Since the creek is in proximity of Uran city, it is used as dumping ground and therefore heaps of garbage is frequently seen on shore of the creek. During present survey three species of Onchidium were collected from both the sites during low tide. Among the three species Onchidium verruculatum was abundantly found at Site I where most of the area is marshy and of loamy substratum. During collection the animals were observed to creep on the substratum exposed to the atmosphere. Creeping trail of O. verruculatum was followed to locate the species. At the time of high tide it was observed that animals were hiding themselves in crevices of the rocks present on the shore. However, two animals of O. verruculatum found to follow each other in a straight line during copulation. Further, more than two animals were found in group showing courtship behaviour Juveniles of O. verruculatum found to hide in burrows of the fiddler crab. Although Onchidium peronii was The Onchidium (Gastropoda: Pulmonata: Onchidiidae: Genus: Onchidium) of the Uran, West Coast of India 25 available at both the Sites, the percentage of availability of O. peronii was maximum at Site II where mangroves (Avicennia marina) are abundant. It was observed that O. peronii camouflage with the substratum present near the mangroves. A group consist of 7-8 O. peronii was observed near the mangroves. The density of O. peronii was recorded right from upper part of intertidal zone to the lower part of intertidal zone. Platevindex species was collected from both the sites. However, at site I higher density of Platevindex species was observed than that at Site II. Platevindex species was also observed to live in a group of 5-6 animals. Since dorsal eyes are absent in Platevindex species it is not prominently seen against the background of substratum. Therefore, this species is to be collected after careful observation. It has been noticed that during dusk time Platevindex species density was higher at Site I. RESULTS Three species of Onchidium mainly collected from different sites were brought to the laboratory for morphological studies. Onchidium species were maintained under laboratory conditions in aquaria with sufficient sea water (25cm×25cmX25cm). External morphological characters were observed in fresh as well as in preserved specimens. The basic plan of morphological characters is found to be uniform in all three species of Onchidium. However, variations in certain morphological characters were noticed in all three species of Onchidium. The basic plan of morphology includes presence of mantle on the dorsal surface. The mantle is thickly covered with tubercles or body warts. These tubercles are in wide variety of form, size and structure ranging from minute granules to large protuberances scattered all over the dorsal surface. It has been noticed that tubercles located at posterior side of the mantle are irregularly branched and have in general a bushy appearance which are commonly known as ‘Gill trees’. Whereas, unbranched types of tubercles are flattened at their free end on which the mantle eyes are situated. Therefore, these tubercles are also called as ‘ocular papillae’. These mantle eyes either located singly or in groups consisting of two or more on each ocular tubercle. The largest ocular group observed to contain six eye spots. However, three to four eye groups were commonly observed. The fleshy elongated foot present on the ventral side of the body. The foot is surrounded by all the sides by peripheral extension of the mantle known as hyponotum. The hyponotum is distinguished as per its location into the right, left, front, and the hind hyponotum regions.