André Carrara Morandini

Hydrocoryne iemanja (Cnidaria), a new species of Hydrozoa with unusual mode of asexual reproduction

Hydrocoryne iemanja sp. nov. was found in an aquarium, growing on rhodoliths ofcoralline algae collected on the south-eastern coast ofBrazil (20°40S 40°2W). The colonies were reared through maturity in the laboratory. Each colony had up to 7 sessile, long and thin monomorphic zooids, very extensible and flexible, arising from a chitinous, hard dark-brown plate with minute spines. Medusae budded from near the basai part of hydrocaulus, and were released in immature condition, acquiringfully developed interradial gonads 5-7 days after release. Asexual reproduction by longitudinal fission was observed on the hydrocaulus ofthepolyps, both for those in normal condition and those with injuries. Fission started at the oral region, extending aborally, with a new hard plate formed in the basai part of hydrocaulus. When fission reached the new hard plate, the new polyp detached, becomingfree and sinking to the bottom, starting a new colony. Detached polyps were morphologically indistinguishable from other polyps, being able to produce medusae. Mother and daughter polyps undertook subsequent fissions. This mode of longitudinal fission is distinct from other modes of longitudinal fission, a process knownfor afew species of cnidarians. Further studies ofthis process may shed light on the understanding ofthe evolutionary pathways in Cnidaria and animais. Hydrocoryne iemanja sp. nov. is distinguishable from its two congeners by the distinct marginal tentacles ofthe medusae-short and with a median nematocyst knob-an unambiguous character useful even for the identification ofnewly liberated medusae.

Asexual reproduction of Nausithoe aurea (Cnidaria, Scyphozoa, Coronatae) induced by sterile polystyrene dishes

, 2003). For the scyphozoan order Coronatae, the solitary polyps are hypothesized to strobilate under conditions of energy surplus, while colonial species tend to strobilate in determined periods (Werner, 1970). The strobilation process of the scyphozoans is a relevant morphological event that helps understanding the evolution and relationships of other taxonomic groups (see more in Berrill, 1949 and Collins

Jellyfish (Chrysaora lactea, Cnidaria, Semaeostomeae) aggregations in southern Brazil and consequences for human stings

The frequency of blooming is generating a world-wide discussion about medusae population explosions, mainly those associated with accidents. We report over 20,000 accidents caused by Chrysaora lactea (Scyphozoa) in the State of Parana (Brazil) during the austral summer of 2011-2012. Accidents were considered mild, but almost 600 cases were treated in emergency services, with either toxic and allergic reactions, some with systemic manifestations. We proposed non-exclusive hypotheses to explain this large number of cases.