DEMOGRAPHIC DYNAMICS OF THE COMMON DEMOSPONGE IRCINIA FELIX
Sponges are one of the principal benthic components of Caribbean coral reefs. Despite the fact that they have multiple functional roles, little is known about their demography and ecology. Here, we present a demographic study of the common demosponge Ircinia felix performed at Tamarindo Bay, Culebra, Puerto Rico. Preliminary studies comparing size structure of two populations within Tamarindo Bay, Tamarindo North (TN) and Tamarindo South (TS), indicate that sponges at TN are significantly larger than sponges at TS. These data served as baseline for the present comparative study in which we aim to determine whether such spatial differences in population size structure can be explained by differences in rates of survival, growth, and/or recruitment. Significant differences where only observed when comparing growth rates. The fact that rates of survival and recruitment where similar between localities may be the causal factor for the lack of significant difference in population growth rates (λ) which varied TN and TS (0.79 and 0.74, respectively). Interestingly, elasticity analyses suggest that the major contributor to λ at TN was survival of large sponges whereas at TS survival of small individuals contributed the most; suggesting that I. felix is able to adapt to site-specific environmental conditions by means of life history traits plasticity. We are currently conducting a study to determine if the noticeably high presence of gorgonians in TN in comparison to TS may be responsible for site-specific growth rates.
Rivera-Irizarry , F., University of Puerto Rico at Rio Piedras, Puerto Rico, firstname.lastname@example.org
Fonseca, J., Sociedad Ambiente Marino, Puerto Rico, email@example.com
Bruno-Laureano, Y., University of Puerto Rico at Rio Piedras, Puerto Rico, firstname.lastname@example.org
Mercado-Molina, A. E., Sociedad Ambiente Marino, Puerto Rico, email@example.com
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