SHORT COMMUNICATION First report of Megodontolaimus coxbazari Timm, 1969 (Nematoda: Chromadorida) from the Indian coast Tridip Kumar Datta 1 & Alberto De Jesús Navarrete 2 & Susanta Kumar Chakraborty 3 & Anil Mohapatra 1 Received: 4 March 2015 /Revised: 19 January 2016 /Accepted: 21 January 2016 # Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg 2016 Abstract Free-living marine nematodes of the genus Megodontolaimus Timm, 1969 are represented by two spe- cies described from Bangladesh, namely M. coxbazari and M. sonadiae. The genus is characterized by six outer labial sensillae rather than labial papillae, as well as cresentic apophysis on the pharyngeal bulb, two-pronged dorsal tooth, single large ventral tooth and four cephalic sensilla. After more than four decades, M. coxbazari has been rediscovered from the intertidal coastal area of India for the first time as well as outside the type locality. M. coxbazari has one pair of alae along the body and a double oesophageal bulb similar to Timm’s description. The length of whole body, oesophagus, tail, and sensilla are within the range as described in the type materials. This report on the occurrence of such an interesting nema- tode adds relevance to biodiversity assessments. Keywords Intertidal . Meiobenthic nematode . Bay of Bengal . West Bengal Introduction Free-living marine nematodes are among the most diverse faunal groups in marine waters (Platt and Warwick 1980), usually represent 70-90 % of meiobenthic metazoans and play fundamental ecological roles (Austen 2004). Records from the coast of India are scant. In December 1964, Richard William Timm ( BFather Timm^) recorded free-living marine Chromadorids during a survey along the Cox’s Bazar and Sonadia Island, Bangladesh (then East Pakistan). These Chromadorids were distinguished from Hypodontolaimus de Man, 1886 by having cresentic apophysis on the dorsal side of the pharyngeal bulb along with two-pronged dorsal tooth and single large ventral tooth over dorsal. Based on these differ- ences, a new Genus, Megodontolaimus Timm, 1969, was erected. This comprises two species, M. coxbazari, an inhab- itant of fine silty-sand dominated sediments of coastal belts of Cox’s Bazar, and M. sonadiae, a nematode from the muddy soil of intertidal belts of Sonadia Island. In spite of being a member of subfamily Hypodontolaiminae, Megodontolaimus has six outer labial sensilla instead of labial papillae and four cephalic sensilla. Megodontolaimus coxbazari has a double oesophageal bulb and two longitudinal alae, where as M. sonadiae is smaller in size and possesses six alae and a single oesophageal bulb. No distributional records of this ge- nus are available from other parts of the world. The present paper reports M. coxbazari from India for the first time and provides some additional details on its morphology. Material and methods Sediment samples were collected by means of a hand- held corer from three intertidal areas of West Bengal coast: Sagar Island (21°38’ 1^N, 88°4’ 59^E), Tajpur Communicated by M. Schratzberger * Anil Mohapatra anil2k7@gmail.com 1 Marine Aquarium and Regional Centre, Zoological Survey of India, Digha, West Bengal, India 2 Department of Systematics and Aquatic Ecology, ECOSUR, Chetumal, Mexico 3 Department of Zoology, Vidyasagar University, Midnapore, West Bengal, India Mar Biodiv DOI 10.1007/s12526-016-0452-y