ISSN 2348-313X (Print) International Journal of Life Sciences Research ISSN 2348-3148 (online) Vol. 8, Issue 1, pp: (57-63), Month: January - March 2020, Available at: www.researchpublish.com
REDESCRIPTION OF ONYCHOCAMPTUS BENGALENSIS LANG, 1948 (COPEPODA, HARPACTICOIDA, LAOPHONTIDAE) - A NEW RECORD FROM ADYAR ESTUARY, INDIA A. Saboor *1, K. Altaff2 1
PG & Research Department of Zoology, The New College (Autonomous), Chennai 600014, India. 2
Department of Marine Biotechnology, AMET University, ECR, Chennai 603112, India. *
Corresponding author: Email Id: prof.saboor@gmail.com
Abstract: In 1998 a laophontid harpacticoid copepod Onychocamptus bengalensis was recorded for the first time in the plankton collections of Adyar Estuary, India. This species is redescribed for the first time with the aid of scanning electron microscopy and is compared with the existing descriptions. It is distinct from other species of the same genus by having leg 5 with exopod fused to baseoendopod. Keywords: Zooplankton, copepod, harpacticoid, estuary and taxonomy. I.
INTRODUCTION
It is quite common for coastal nekton to use estuaries as nursery grounds, where young growth stages can take advantage of the protection and abundant food. Since man often harvests such species offshore, the vital life history and energetic connections with the nearby estuary have not always been appreciated (Odum,1971). The role of harpacticoids in estuarine communities and food webs can be investigated only if their species are known. With regard to taxonomy, the harpacticoid species of the world are incompletely known. Moreover, their familial classification is also in a state of flux and many changes are likely to occur in the near future (Huys et al., 1996). Onychocamptus bengalensis Lang, 1948, which belongs to the family Laphontidae T. Scott, 1905, was formerly placed under the genus Laophonte by Sewell 1934 based on the presence of three inner setae on the end segment of leg3 endopod. Bayly & Williams (1966) reported its occurrence in Victorian and South Australian lakes. Hamond (1973) while studying the laophontids in saline lakes of southeast Australia noted that O. bengalensis was originally identified in India. Sewell, 1934 observed this species in the Salt Lakes of Calcutta, India. Later this species was reported by Krishnaswamy (1957) from the weeds collected at Cooum Estuary of Madras, India. Arunachalam and Nair (1988) found this species associated with the seagrass halophila ovalis in Ashtamudi Estuary, southwest coast of India. While analysing the planktonic fauna of the polluted Adyar Estuary of Madras, O. bengalensis was recorded as the dominant copepod species during 1998-1999. Saboor (2003) discussed that the alteration of physical extent of Adyar Estuary and the chemical nature of its water were due to the increasing urbanization in the surrounding mainland and a high influx of domestic sewage into the system and which resulted in the alteration of species dominance and diversity. As a detailed description of this species is lacking, it is redescribed for the first time with the aid of scanning electron microscopy.
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