The rhizostome scyphozoan Cassiopea andromeda is referred to Cassiopeidae, an unusual family of so-called upside-down jellyfishes that comprises the single genus Cassiopea and six currently recognized species (Holland, et al, 2004). Circumtropical in distribution (Schembri et al., 2010), these species most often occur in shallow bays, intertidal sand, mangrove mudflats and lagoons (Browne, 1916).
The species has been recorded previously in India as C. andromeda var. maldivensis from Armara, Gulf of Kutch, Gujarat (Browne, 1916) and from Krusadai Island, Gulf of Mannar, Tamilnadu (Rao, 1931), and as C. andromeda from Madras (Menon 1930, 1936) and the Andaman Islands (Venkataraman et al. 2012). Gopalkrishnan (1970) reported Cassiopea sp. from Adatra, Gujarat, but provided no photographs or information on its morphology. Cassiopea andromeda has been implicated as an invasive or alien species worldwide (Özgür and Öztürk, 2008; Çevik, et al., 2006; Katsanevakis, 2011; Zenetos et al, 2005, 2011) and is referred as ecologically important species considering its invasive distribution (Heins et al, 2015).
The global phylogeography of Cassiopea spp. from the Pacific and Indian oceans was investigated by Holland et al. (2004) who provided molecular evidence of the cryptic nature of the genus and of problems raising with species identification based on morphological characters only.
Cassiopea andromeda is a carnivorous species that uses nematocysts to capture its prey. Nutrition is also obtained from photosynthetic dinoflagellate algae (zooxanthellae) present in the oral arms on the ventral side of the body. As with most scyphozoans, the life cycle of C. andromeda includes a sessile polypoid or scyphistoma stage eventually giving origin to the medusa stage through monodisk strobilation with a single ephyra developing by the oral part of the polyp (Heins et al, 2015).
Cassiopeid medusae were observed during 2013 at Arambhada, Gulf of Kutch (Fig. 1). Medusa and scyphistoma polyp specimens were tentatively identified as C. andromeda (sensu Holland et al 2004), based on descriptions of Mayer (1910) and with the support of D. K. Hofmann who confirmed morphology scyphistoma, type of budding and nematocysts are similar to C. andromeda (personal communication, 12 February 2015). Our report constitutes the first record of the scyphistoma of Cassiopea sp. in India, and the first record of the medusa from Gujarat since 1916. Following its discovery, the Wildlife Trust of India gave accounts of the species in news articles during 2014, reporting it from “India’s first jellyfish lake”.