Taxonomic classification of the reef coral families Merulinidae, Montastraeidae, and Diploastraeidae (Cnidaria: Anthozoa: Scleractinia)

Abstract

Modern coral taxonomy has begun to resolve many long‐standing problems in traditional systematics stemming from its reliance on skeletal macromorphology. By integrating examinations of colony, corallite, and subcorallite morphology with the molecular sequence data that have proliferated in the last decade, many taxa spread across the scleractinian tree of life have been incorporated into a rigorous classification underpinned by greater phylogenetic understanding. This monograph focuses on one of the most challenging clades recovered to date – its disarray epitomized by the informal name ‘Bigmessidae’. This group of predominantly Indo‐Pacific species previously comprised families Merulinidae, Faviidae, Pectiniidae, and Trachyphylliidae, but in a recent study these have been incorporated within Merulinidae. We studied 84 living merulinid species by examining morphological traits at three different scales of coral skeletal structure − macromorphology, micromorphology, and microstructure − to construct a morphological matrix comprising 44 characters. Data were analysed via maximum parsimony and also transformed onto a robust molecular phylogeny under the parsimony and maximum likelihood criteria. Comparisons amongst morphological character types suggest that although many characters at every scale are homoplastic, some to a greater extent than others, several can aid in distinguishing genus‐level clades. Our resulting trees and character analyses form the basis of a revised classification that spans a total of 139 species contained within 24 genera. The tree topologies necessitate the synonymization of Barabattoia as Dipsastraea, and Phymastrea as Favites. Furthermore, Astrea and Coelastrea are resurrected, and one new genus, Paramontastraea Huang & Budd gen. nov., is described. All the genera in Merulinidae, along with the monotypic Montastraeidae and Diploastraeidae, are diagnosed based on the characters examined. The integrative classification system proposed here will form the framework for more accurate biodiversity estimates and guide the taxonomic placement of extinct species. © 2014 The Linnean Society of London

The New Systematics of Scleractinia: Integrating Molecular and Morphological Evidence

“…The recent recognition that the scleractinian skeleton is biologically controlled and not easily perturbed by environmental factors at the microstructural level (Janiszewska et al 2011(Janiszewska et al , 2013) has led to more detailed subcorallite observations (Cuif et al 2003;Budd et al 2012;Kitahara et al 2012Kitahara et al , 2013Arrigoni et al 2014a;Huang et al 2014b;Janiszewska et al 2015). Indeed, greater attention has been given to previously overlooked micromorphological and microstructural characters.…”

“…Dai and Horng (2009b) transferred Plesiastrea into Plesiastreidae (clade XIV sensu Fukami et al 2008), although only the move of the type species P. versipora has been validated since P. devantieri is in Astrea, Merulinidae (Huang et al 2014b). Blastomussa was also transferred into Plesiastreidae (Dai and Horng 2009b), but it has been considered incertae sedis more recently Benzoni et al 2014) as Plesiastrea is more closely related to the azooxanthellate species Cyathelia axillaris, Trochocyathus efateensis and Tethocyathus virgatus (Kitahara et al 2010b;Benzoni et al 2011;Huang 2012;Huang andRoy 2013, 2015).…”

Physiological integration of coral colonies is correlated with bleaching resistance

“…Evidence of physiological integration in corals has historically been inferred from skeletal features that reflect pathways of (or barriers to) communication between polyps and indicate a degree of reliance upon, or coordination between, other polyps within the colony for basic life functions (Coates & Oliver 1973, Coates & Jackson 1987, Soong & Lang 1992. Communication pathways include skeletal features that allow the gastrovascular cavities of neighboring polyps to be continuous, such as skeletal voids (perforate skeleton, commonly found in genera such as Acropora, Montipora, and Porites; van Woesik et al 2013) that allow tissue to transverse through the skeleton (Yost et al 2013), or inter-polyp alignment of septa (continuity of costosepta, such as the confluent costosepta of Favites abdita or Favites halicora; Huang et al 2014) that demonstrate alignment of mesenteries and may allow tissue connections to continue above the surface of the skeleton (Coates & Oliver 1973, Coates & Jackson 1987. Inferences of reliance and coordination among polyps include polymorphic calices that reflect differential functions of polyps and division of labor among colonial modules (polymorphic polyps, such as the apical polyps of Acropora at the growing tips of branches that are larger, have fewer tentacles, lower Symbiodinium density, and no gonads compared to the axial polyps; Oliver 1984, Hemond et al 2014) and complex colony morphologies that require coordinated skeletal construction to maintain colony dimensions, symmetry, and balance (growth form, such as branching Acropora palmata or Seriatopora caliendrum; Madin et al 2016) (Coates & Oliver 1973, Coates & Jackson 1987.…”

Calcium Carbonate Production, Coral Cover and Diversity along a Distance Gradient from Stone Town: A Case Study from Zanzibar, Tanzania

“…In total 33 hard coral taxa were observed when all transects were pooled ( Figure S1). At Chapwani Reef 10 hard coral taxa were observed, whereas in Prison, Bawe and Chumbe reefs a total of 20, 21, and 27 taxa were observed, respectively following the most recent taxonomic revision (Huang et al, 2014). Biodiversity and richness increased southwards from Chapwani Reef to Chumbe Reef (Table 1).…”

“…By convention, six 10-m transects were randomly placed and independently recorded by SCUBA divers on the reef slope of each study site at shallow (5 ± 2 m) and deep (10 ± 2 m) areas, with the exception of Chapwani Reef, where transects were only recorded at 5 m, as the reef slope was bathymetrically constrained to approx. 7 m. The identification of corals was made to the genus and species level where possible, following taxonomic references (Veron, 2000(Veron, , 2002Huang et al, 2014) We also recorded the following benthic categories: coralline algae, sponge, corallimorph, others (e.g., seagrass, zoanthids, clams etc. ), sub-category 1 (i.e., dead coral and rubble) and sub-category 2 (i.e., sand, mud and silt).…”