Trophic spectrum of Corymorphid hydroid polyps in the Bahía Blanca estuary (Southwestern Atlantic Ocean)

DUTTO; NAHUELHUAL; CARCEDO; GARCIA; CONTE; GENZANO G. N.; HOFFMEYER

Congreso; XVII Congreso Latinoamericano de Ciencias del Mar; 2017

Hydroids play important roles in bentho-pelagiccoupling processes in shallow marine ecosystemssince their great abundances and the high predation impact on a wide food spectrum, fromdetritus and benthic microplankton to egg and fish larvae (GILI and HUGHES 1995; OREJAS etal. 2013). The ecological significance of these benthic stages was particularly proved for colonialhydroid polyps (COMA et al. 1995; OREJAS et al. 2000; OREJAS et al. 2001; GENZANO 2005;GILI et al. 2008; OREJAS et al. 2013). Comparatively, trophic knowledge for solitary polyps isscarce and practically no data exists on the natural feeding of Corymorphiidae polyps. The recordin nature of these kind of polyps comprises a rare event, sometimes fortuitous (e.g. WATSON2008; VERVOORT 2009; GENZANO et al. 2009). Numerous polyps of Corymorpha januarii,however, have been observed in muddy-bottom channels of the Bahía Blanca Estuary inArgentina during late spring by local fisherman for more than 20 years. Our work aimed atdescribing a population of the conspicuous and solitary C. januarii polyp providing one of the firstapproaches to its feeding ecology.To this end, our objectives were to describe the zonation andthe main features of the population and its individuals, and to analyze the diet and the trophicpreference of C. januarii polyps.