The lack of an exumbrellar component to the crumple activation system contrasts with the situation found in hydromedusae
(Mackie and Passano, 1968; Mackie, 1975, 2004a; Spencer, 1975, 1978; Josephson and Schwab, 1979), in which an exumbrellar epithelial conducting system does initiate crumple responses.
of the New Zealand Oceanographic Institute (Hydrozoa, Cnidaria).
The velarium is an annular flap of swim muscle extending to the bell opening that serves to shape the aperature during a swim contraction, much like the velum in hydromedusae
(Gladfelter, 1972, 1973).
Individual adult hydromedusae
(n = 4, diameter = 13.
Key words: Hydromedusae
, Blackfordia virginica, morphological variations, Chiapas, Mexico.
The two invasive species were well known non-indigenous hydromedusae
Blackfordia virginica Mayer, 1910 and Moerisia inkermanica Paltschikowa-Ostroumova, 1925, found in different estuaries and harbors with intense shipping traffic along the south Atlantic coast (Genzano et al.
of the Atlantic Ocean and adjacent waters.
atlanticum, another hydromedusae
Olindias sambaquiensis has been observed mainly between autumn and spring.
A hypothesis on Mesozoic vicariance in Hydromedusae
Comparatively, the southwestern Atlantic has been better studied, with inventories of hydromedusae
(Ramirez & Zamponi, 1981; Bouillon, 1999; Migotto et al.
Morphology, swimming performance, and propulsive mode of six co-occurring hydromedusae
and water masses of the Indian Ocean.