Environment and life cycles influence distribution patterns of hydromedusae from austral South America.

MARQUES A. C; MIGOTTO; G. RODRIGUEZ; TRONOLONE; MIANZAN H.; GENZANO G. N.

MARINE BIOLOGY RESEARCH

TAYLOR & FRANCIS AS

Lugar: Londres; Año: 2017

1745-1000

We analysed hydromedusa assemblages of South America (from 22°S to 56°S and from 040°W to080°W), their association with water masses and the influence of the life cycle on medusadistributions. The geographic distribution of 130 species of hydromedusae was compiled fromliterature reports (62 publications between 1913 and 2012). Seven areas were defined: AtlanticMagellanic, Argentinean, Pacific intermediate zone, Pacific Magellanic, Peruvian?Chilean, SouthBrazilian and Oceanic. The variance of the species?environment relationship was explained bydepth and temperature. Distribution patterns of Atlantic hydromedusae are associated with neriticwater masses, supporting previously proposed biogeographical provinces. Assemblages on thePacific side of South America are under the influence of the Humboldt Current system, with abreak in species distribution around Chiloé Island. Only the oceanic assemblage contained thesame species in both the Pacific and Atlantic zones. We found that meroplanktonic medusaecontributed more to define the neritic assemblages, while the oceanic assemblage was betterdefined by holoplanktonic medusae. Therefore, our data suggest that meroplanktonichydromedusae appeared to be more restricted in distribution than holoplanktonic ones.