Morphological variation in the atlantic genus Siderastrea (Anthozoa, Scleractinia)

Abstract

Siderastrea is a small genus of scleractinian corals, composed by zooxanthellate massive colonial forms. Besides contributing to the consolidation of the reef structure, represent a group with significant resistance to environmental stress. Until the 70's, its taxonomy was a complicated task, limited by the difficulty in identifying morphotypes. More recently, interspecific boundaries were redefined for 'Atlantic Siderastrea Complex'. However, despite new perspectives, including the occurrence of S. radians and S. siderea for Brazil, morphological patterns are still poorly studied and inconspicuous for several coastal areas. In order to characterize levels of intraspecific and interspecific morphological variation in S. stellata and S. radians, morphometric analysis were carried out in colonies from Bahia State coast. Samples were taken in Todos-os-Santos Bay and North Coast. We applied the Canonical Discriminate Analysis upon six corallite characters to evaluate the different levels of variation. The tests revealed that diameter of corallites, columella depth and number of septa varied among populations. Number of septa was the most important character for the species differentiation. Siderastrea stellata, with three different morphological patterns, was more variable than S. radians.

Predicted Shifts in the Distributions of Atlantic Reef-Building Corals in the Face of Climate Change

“…Three species of Siderastrea occur in the Atlantic (Siderastrea siderea, Siderastrea stellata, and Siderastrea radians) and constitute the "Atlantic Siderastrea complex" (Menezes et al, 2014). Siderastrea stellata was believed to be endemic to Brazil but was recently found in the Gulf of Mexico (Leão and Kikuchi, 2005;García et al, 2017).…”

“…Siderastrea stellata was believed to be endemic to Brazil but was recently found in the Gulf of Mexico (Leão and Kikuchi, 2005;García et al, 2017). On the Brazilian coast, S. radians occurs simultaneously with S. stellata, and are hard to distinguish in the field due to their similar morphology (Menezes et al, 2014). Thus, considering the coinciding environmental requirements shared by these two species, we decided to model S. stellata and S. radians as a single entity (hereafter, Siderastrea sp.…”

The true identity of Siderastrea glynni Budd & Guzmán, 1994, a highly endangered eastern Pacific scleractinian coral

“…A single-factor MANOVA test failed to demonstrate a significant difference among the siderastreid species with respect to all skeletal traits examined (F 3,17 = 2.2937, p = 0.1146). Other morphometric studies of Siderastrea species have demonstrated similar variation in these traits (e.g., Menezes et al 2014). Skeletal (Glynn 1974) d Sessile?…”

The forgotten reefs: benthic assemblage coverage on a sandstone reef (Tropical South-western Atlantic)

“…Sedimentation and turbidity affect benthic assemblages (Dutra et al , 2006; Castro et al , 2012) by selecting species most well-adapted to stress and consequently reducing the percentage of coverage and diversity of taxa known to be stress-sensitive, such as scleractinian corals (Fabricius, 2005; Silva et al ., 2013). For example, S. stellata , a species endemic to the South Atlantic, has been described to have large polyps (Menezes et al ., 2014) that are less susceptible to the effect of sediments (Lirman & Manzello, 2009). Furthermore, this coral species is very resistant to temperature, salinity variations and water turbidity (Costa et al ., 2008).…”