During a routine visit to ‘Nasima Tirmizi Marine Research Station’ (NTMRS) at Sandspit, Karachi, specimens of a Cubozoan jellyfish Chiropsalmus buitendijki belonging to the order Chirodropida and Chirodropidae family, were collected. An earlier occurrence of this species at the same location was observed in the same season and reported by us. This family is of particular interest to science as it includes some of the most dangerous jellyfish. Another species, a large scyphozoan jellyfish Catostylus mosaicus, which belongs to the order Rhizostomeae and family Catostylidae, was netted alive from the Korangi Creek during a routine shore collection trip. The scyphozoan genus and species are both new records for the area. The rhizostome jellyfish are harvested for food the world over. A brief description of the species collected from Karachi waters (northern Arabian Sea) is given with notes on their distribution, ecology and habitat. The importance of jellyfish in fishery is also discussed.
