Use of Artificial Collectors to Obtain Oyster Seeds in Babitonga Bay, Santa Catarina, Brazil

Abstract

The aim of this study was to evaluate oyster seed settlement pattern in artificial collectors affixed along Babitonga Bay (26°28’S í 48°50’W), Santa Catarina state, Brazil. Artificial collectors were installed in the upper tidal range (supralittoral), in the line of intermediate variation of the tide (mesolittoral), and below the limit region of the low tide (infralittoral). A total of 7,579 seeds were obtained over a year, presenting clear variations of quantities and species according to the seasons, depths and collection sites. Among the total number of seeds collected, 284 were submitted to molecular analyses for species identification, among which 5.63% belonged to Crassostrea gasar, 16.9% to C. rhizophorae, 0.35% to C. gigas, 24.29% of Ostrea sp. and 52.81% to C. talonata. Species identification through morphological analysis is difficult because of the inherent polymorphism of shells. Results demonstrate that artificial collectors present a higher performance for the settlement of oyster species inappropriate for farm cultivation (C. talonata and Ostrea sp.). Moreover, C. talonata is an exotic species from Indo-Pacific seas recently confirmed along Brazilian coasts, and it already possesses a high recruitment rate in the estuarine region. This raises environmental and commercial concerns about the maintenance of the natural oyster population in Babitonga Bay.

Cryptic Marine Diversity in the Northern Arabian Gulf: An Integrative Approach Uncovers a New Species of Oyster (Bivalvia: Ostreidae), Ostrea oleomargarita

“…Ambiguous classification based on morphological characters is commonplace in oysters (e.g., [16,17,62,64,65]), and in most cases, a molecular approach allowed a straightforward systematic assessment of debated species [10,11]. Phylogenetic results unequivocally place O. oleomargarita within the subfamily Ostreinae.…”

The effect of density on the cultivation of the native mangrove oyster Crassostrea tulipa (Lamarck, 1819)

“…The farming of mangrove oyster species, however, still relies, almost exclusively, on the extraction of seeds from the wild by artificial collectors (Nalesso et al, 2008;Gardunho et al, 2012;Christo et al, 2016;Diadhiou & Ndour, 2017;Oliveira et al, 2018;Funo, 2019;Tureck et al, 2020). The implications of utilizing such a method involve the difficulty of correct species identification, including the high polymorphism of Crassostrea oysters in areas of sympatric occurrence (Reece et al, 2008), small capacity for seeds settlement by structure (ranging from ~5.000 to ~20.000 seeds, according to Galvão et al, 2009) and the likelihood of different seed ages attaching to the same structure.…”