Distribution of scolecithricidae (Copepoda: Calanoida) in the Indian Ocean

Abstract

Ecology and zoogeography of the frequently occurring and widely distributed planktonic copepods collected during the International Indian Ocean Expedition, Scolecithrix danae, Scolecithricella bradyi, S. tenuiserrata, S. abyssalis, Scaphocalanus curtus, S. echinatus, Scolecithricella dentata and S. ctenopus (family Scolecithricidae) are discussed in this paper. They were present in 82.0, 63.6, 49.1, 43.4, 35.1, 34.3, 34.0 and 31.7% of the stations and constituted 60.0, 6.5, 4.4, 3.6, 3.4, 3.7, and 5.1% of the total numbers of specimens of Scolecithricidae collected respectively. High density areas of S. danae were found scattered between 15 degrees N and 15 degrees S latitudes, especially along the African coast. S. bradyi and S. echinatus were found between 20 degrees N and 30 degrees S, S. ctenopus and S. tenuiserrata between 25 degrees N and 20 degrees S, S. dentata between 10 degrees N and 40 degrees S, S. abyssalis between 20 degrees N and 20 degrees S, and S. curtus between 25 degrees N and 30 degrees S. S. tenuiserrata, S. currtus, S. echinatus and S. dentata were inhabitants of subsurface and intermediate waters, S. danae, S. bradyi and S. ctenopus were surface and subsurface inhabitants and S. abyssalis, an abyssal species was occasionally migrating to the surface. Even though these species were widely distributed in the Indian Ocean, in general, S. danae, S. curtus and S. echinatus were most abundant in the equatorial waters, S. bradyi and S. dentata lived mainly south of the equator while S. tenuiserrata, S. abyssalis and S. ctenopus were found mainly north of the equator