Occurence of association between Phillorhiza punctata Von Lendelfeld, 1884 (Cnidaria: Scyphozoa) and fishes on the Paranaguá Bay, Paraná State, Brazil

Abstract

Many species of fishes have been found in association with drifting objects and a few factors to explain it are: attraction by food, negative phototaxis in response to shadow cast by the object, shelter from predators and use of the object as a spawning substrate. Symbiosis between certain species of young small fish and various sizes of pelagic jellyfish have attracted the attention of many observers, but little effort has been made to study this phenomenon. A review oh the literature indicated that fish representing 72 families have been found associated with drifting algae, flotsam and jellyfishes in the pelagic environment. The proposal os this study is to report the association between the Scyphomedusae Phyllorhiza puntacta and fishes in the Paranaguá Bay. Jellyfishes were collected using a sweep net (40 cm x 55 cm) with a 1 mm mesh. Aggregations of fish were dominated individually by five species in juvenille stages: Chloroscombrus chrysurus, Caranx bartholomaei, Trachinotus carolinus, Trachonotus falcatus, all carangids, and Sthephanolepis hispidus, a monacanthid. The Pearson coeficient showed small correlation between bell diamater, and number of fishes associated and between bell diamater and standard length of fishes. The association of fishes with drifting objects shall not be considered the only criterion of ecological importance, but they exert a huge influence in the ecosystem, being able to enhance growth and survival rates of small fishes.