title: Timoides agassizii Bigelow, 1904, little-known hydromedusa (Cnidaria), appears briefly in large numbers off Oman, March 2011, with additional notes about species of the genus Timoides.
abstract: A bloom of the hydromedusan jellyfish, Timoides agassizii, occurred in February 2011 off the coast of Sohar, Al Batinah, Sultanate of Oman, in the Gulf of Oman. This species was first observed in 1902 in great numbers off Haddummati Atoll in the Maldive Islands in the Indian Ocean and has rarely been seen since. The species appeared briefly in large numbers off Oman in 2011 and subsequent observation of our 2009 samples of zooplankton from Sohar revealed that it was also present in low numbers (two collected) in one sample in 2009; these are the first records in the Indian Ocean north of the Maldives. Medusae collected off Oman were almost identical to those recorded previously from the Maldive Islands, Papua New Guinea, the Marshall Islands, Guam, the South China Sea, and Okinawa. T. agassizii is a species that likely lives for several months. It was present in our plankton samples together with large numbers of the oceanic siphonophore Physalia physalis only during a single month's samples, suggesting that the temporary bloom off Oman was likely due to the arrival of mature, open ocean medusae into nearshore waters. We see no evidence that T. agassizii has established a new population along Oman, since if so, it would likely have been present in more than one sample period. We are unable to deduce further details of the life cycle of this species from blooms of many mature individuals nearshore, about a century apart. Examination of a single damaged T. agassizii medusa from Guam, calls into question the existence of its congener, T. latistyla, known only from a single specimen.
authors.affiliation: Zoological Survey of India, New Alipore, Kolkata, India Marine Ecology/Biological Oceanography, Marine Science and Fisheries Centre (MSFC), Ministry of Fisheries Wealth (MoFW) Sultanate of Oman; Email: jasbose@gmail.com.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Purushothaman
authors.affiliation: Marine Ecology/Biological Oceanography, Marine Science and Fisheries Centre (MSFC), Ministry of Fisheries Wealth (MoFW) Sultanate of Oman; Email: unknown.
authors.forename: Lubna Al
authors.initials: LA
authors.lastname: Kharusi
authors.affiliation: Friday Harbor Laboratories and Department of Biology, University of Washington, 620 University Road, Friday Harbor, Washington 98250, U.S.A; Email: cemills@u.washington.edu.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Mills
authors.affiliation: Marine Ecology/Biological Oceanography, Marine Science and Fisheries Centre (MSFC), Ministry of Fisheries Wealth (MoFW) Sultanate of Oman; Email: unknown.
authors.forename: Hamed
authors.initials: H
authors.lastname: Ghielani
authors.affiliation: Marine Ecology/Biological Oceanography, Marine Science and Fisheries Centre (MSFC), Ministry of Fisheries Wealth (MoFW) Sultanate of Oman; Email: unknown.
authors.forename: Mohammad Al
authors.initials: MA
authors.lastname: Marzouki
mesh_terms: D000818:Animals; D037402:Hydrozoa / Q000033:anatomy & histology* / Q000502:physiology*; D019156:Indian Ocean; D009850:Oman; D011157:Population Dynamics