Contribuições ecológicas de briozoários marinhos no Ceará: diversidade e interações com a epifauna bentônica incrustante

Abstract

The study of benthic communities is complex and can be influenced by numerous biotic and abiotic factors. This thesis is divided into two chapters. In Chapter 1, we investigated the biodiversity of bryozoan fauna in the Pecém Port area, identifying 21 species from 18 families, with the order Cheilostomatida being the most abundant. The dominant species were Biflustra marcusi, Licornia diadema, Celleporaria mordax, Catenicella uberrima, Savignyella lafontii, Schizoporella errata, and Arbopercula bengalensis. Other bryozoans, such as Smittoidea evelinae, Sinoflustra annae, Beania mirabilissima, Parasmittina winstonae, and Rhynchozoon phrynoglossum, showed lower recruitment on settlement plates, possibly due to substrate unsuitability (competition with inhibitory species, substrate composition, or environmental factors). In Chapter 2, we examined the composition of the epibenthic community in Pecém Port over three years of monitoring, including the presence of non-native species and their introduction status. The main fouling groups identified were Tunicata, Bryozoa, Mollusca, Cnidaria, Crustacea, Annelida, and Porifera, with tunicates, bryozoans, and bivalves being the most dominant. Species richness and abundance varied significantly with time and seasonality (p = 0.001). Using the Relative Biological Value Index (IVBr), we ranked the most ecologically significant species: Chordata (Didemnum psammatodes, Symplegma brakenielmi, Lissoclinum sp., Didemnidae (morphotype 2), Ascidia interrupta, Didemnidae (morphotype 1)), Mollusca (Crassostrea brasiliana), Bryozoa (B. marcusi, L. diadema, S. errata, A. bengalensis), Porifera (Demospongiae), Annelida (polychaetes Sedentaria), Cnidaria (Corydendrium parasiticum, Stragulum bicolor) and Arthropoda (Cirripedia). We also identified potential indicator species based on seasonality: dry season—Didemnidae (morphotype 1), B. marcusi, C. uberrima, A. interrupta, S. errata, and Phallusia nigra; rainy season—Didemnidae (morphotype 2) and Lissoclinum sp. Additionally, we assessed interactions between bryozoans and other fouling organisms, particularly ascidians. A total of 296 interactions involving A. bengalensis, B. marcusi, C. mordax, and S. errata were recorded, with the main competing taxa being colonial ascidians, cnidarians, bivalves, polychaetes, sponges, and barnacles (χ2 = 66.94; df = 48; p = 0.037). Bryozoans lost competitive interactions for space in 81% of cases (n = 227). Despite frequent interactions, no significant correlation was found between ascidian presence and bryozoan community structure (ρ = 0.0008; p = 0.996), with linear regressions indicating weak (positive and negative) relationships.