Clarifying Phylogenetic Relationships and the Evolutionary History of the Bivalve Order Arcida (Mollusca: Bivalvia: Pteriomorphia) Q ⇑ David J
Total Page：16
File Type：pdf, Size：1020Kb
Molecular Phylogenetics and Evolution 94 (2016) 298–312 Contents lists available at ScienceDirect Molecular Phylogenetics and Evolution journal homepage: www.elsevier.com/locate/ympev Clarifying phylogenetic relationships and the evolutionary history of the bivalve order Arcida (Mollusca: Bivalvia: Pteriomorphia) q ⇑ David J. Combosch , Gonzalo Giribet Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA article info abstract Article history: The systematics of the bivalve order Arcida constitutes an unresolved conundrum in bivalve systematics. Received 6 July 2015 The current definition of Arcida encompasses two superfamilies: Limopsoidea, which includes the recent Revised 16 September 2015 families Philobryidae and Limopsidae, and Arcoidea, which encompasses the families Arcidae, Accepted 18 September 2015 Cucullaeidae, Noetiidae, Glycymerididae and Parallelodontidae. This classification, however, is controver- Available online 28 September 2015 sial particularly with respect to the position and taxonomic status of Glycymerididae. Previous molecular phylogenies were limited either by the use of only a single molecular marker or by including only a few Keywords: limopsoid and glycymeridid taxa. The challenging nature of Arcida taxonomy and the controversial Molecular phylogeny results of some of the previous studies, prompted us to use a broad range of taxa (55 species), three Cretaceous Molecular dating nuclear markers (18S rRNA, 28S rRNA and histone H3) and a wide range of algorithmic approaches. Bivalve evolution This broad but stringent approach led to a number of results that differ significantly from previous stud- ies. We provide the first molecular evidence that supports the separation of Arcoidea from Limopsoidea, although the exact position of Glycymerididae remains unresolved, and the monophyly of Limopsoidea is algorithm-dependent. In addition, we present the first time-calibrated evolutionary tree of Arcida rela- tionships, indicating a significant increase in the diversification of arcidan lineages at the beginning of the Cretaceous, around 140 Ma. The monophyly of Arcida, which has been supported previously, was con- firmed in all our analyses. Although relationships among families remain somehow unresolved we found support for the monophyly of most arcidan families, at least under some analytical conditions (i.e., Glycymerididae, Noetiidae, Philobryidae, and Limopsidae). However, Arcidae, and particularly Arcinae, remain a major source of inconsistency in the current system of Arcida classification and are in dire need of taxonomic revision. Ó 2015 Elsevier Inc. All rights reserved. 1. Introduction including some of the most economically important marine taxa, like oysters, mussels and scallops. Bivalvia is the second most speciose class of Mollusca (after A well-known, economically-important group of pteriomorphs Gastropoda) with approximately 10,000 described species are the ark clams or ark shells (order Arcida Gray, 1854). Ark shells (Huber, 2010; Bieler et al., 2013). While Bivalvia is clearly mono- are amongst the oldest bivalve lineages, reaching back to the lower phyletic, its internal classification has been and continues to be Ordovician (450 Mya; Morton et al., 1998). Today, species of subject of debate and controversy. Morphological and recent Arcida are globally distributed, predominantly in shallow tropical molecular phylogenetic research has clarified relationships among marine and brackish waters, where they are often abundant. Sev- most high-level bivalve lineages and clades (e.g., Campbell et al., eral species have significant economic value. For example, Tegillarca 1998; Waller, 1998; Carter et al., 2000; Steiner and Hammer, granosa is cultivated on mudflats in South-East Asia (China, Taiwan, 2000; Giribet, 2008; Giribet and Wheeler, 2002; Sharma et al., Korea, Malaysia and Thailand) and has been consumed by humans 2012; Bieler et al., 2014; González et al., 2015). Amongst the least for centuries (Beesley et al., 1998); Scapharca species are harvested controversial is the monophyly of the subclass Pteriomorphia in Japan and China; Senilia senilis in West Africa; and Glycymeris Beurlen 1944, which comprises approximately 20% of all bivalves, glycymeris and G. violascens in Europe and the Mediterranean region (Oliver and Holmes, 2006). Their common name, blood cockles, refers to the presence of intracellular hemoglobin, a rare, albeit q This paper was edited by the Associate Editor Marcos Perez-Losada. homoplastic trait among bivalves, which distinguishes members ⇑ Corresponding author. E-mail address: [email protected] (D.J. Combosch). of the families Arcidae and Glycymerididae (Boyd, 1998). http://dx.doi.org/10.1016/j.ympev.2015.09.016 1055-7903/Ó 2015 Elsevier Inc. All rights reserved. D.J. Combosch, G. Giribet / Molecular Phylogenetics and Evolution 94 (2016) 298–312 299 Although several ark shells display highly unusual shell mor- subdivided in two subfamilies, Anadarinae and Arcinae, based on phologies, they share a straight hinge, which gives the order its the strength of the byssus (Newell, 1969). Arcinae contains some common name, since the remainder of the shell now resembles of the best-known and most widely distributed genera, like Arca the hull of a boat or an ark. Both shells and adductor muscles are Linnaeus, 1758 and Barbatia Gray, 1842. usually of sub-equal size (isomyarian), equivalved and have a Another particularly controversial family is Noetiidae, which characteristic inner and outer crossed-lamellar microstructure was originally described as a glycymeridid subfamily, Noetiinae (Taylor et al., 1969). At the same time, arcidans share several ple- Stewart, 1930. Soon after, the subfamily was transferred to siomorphic characteristic like the taxodont dentition, or homoplas- Arcoidea (Reinhardt, 1935), a classification followed in several tic ones, like the presence of hemoglobin, which occurs as well in recent catalogues (e.g., Bouchet and Rocroi, 2010; Carter et al., the thermal vent clam Calyptogena magnifica (Terwilliger et al., 2011). Today, it is most commonly considered to be a family 1983) and in several members of the families Carditidae and of Arcoidea, with the subfamilies Noetiinae and Striarcinae Crassatellidae (Slack-Smith, 1998a,b; Taylor et al., 2005). The MacNeil, 1937 (Frizzell, 1946; Newell, 1969). The family is straight hinge line can be somewhat curved among members of defined by their unique noetiid ligament, which has particular the superfamily Limopsidae. vertical strips instead of the V-shaped chevron strips of other Today, the order Arcida Gray, 1854 encompasses approximately duplivincular ligaments (MacNeil, 1937). The synapomorphic 250–350 extant species of ark shells (e.g., Coan et al., 2000; Oliver value of this prominent character, however, has recently been and Holmes, 2006). It is monophyletic (e.g., Steiner and Hammer, questioned, and due to the absence of other synapomorphies, 2000; Giribet and Wheeler, 2002; Matsumoto, 2003; Bieler et al., the validity of Noetiidae has been challenged (Thomas et al., 2014) but its internal relationships remain poorly understood 2000). and represent a conundrum in bivalve systematics (Giribet and The glycymeridids are distinguished by their strongly arched Distel, 2003; Giribet, 2008; Bieler et al., 2014). hinge line and large anterior adductor muscles (Oliver and The current definition of Arcida encompasses two superfami- Holmes, 2006). Their internal taxonomy is as complicated as their lies: Limopsoidea Dall, 1895, which include the recent families superfamily affiliation. No subfamilies are currently recognized Philobryidae Bernard, 1897 and Limopsidae Dall, 1895, and and the 100 species are organized in five genera, dominated by Arcoidea Lamarck, 1809, which encompass the families Arcidae Glycymeris and Tucetona. Lamarck, 1809, Cucullaeidae Stewart, 1930, Noetiidae Stewart, The other two arcid families, Parallelodontidae and Cucullaei- 1930, Glycymerididae Dall, 1908 and Parallelodontidae Dall, dae, are represented today by a single extant species each 1898 (e.g., WoRMS Editorial Board, 2015). This classification is (WoRMS Editorial Board, 2015). In fact, Parallelodontidae is consid- controversial and particularly the position and taxonomic status ered extinct by several authors (e.g., Oliver and Holmes, 2006; of Glycymerididae is contentious. Their orbicular (ovate) shell Bieler et al., 2014), while others content that Porterius dalli from form is characteristic of Limopsoidea (Arcoidea are usually trape- Japan is the last living parallelodontiid (Newell, 1969; WoRMS zoidal, elongate or quadratic), and lead several authors to Editorial Board, 2015). Both families have a rich fossil record in consider glycymeridids as part of the superfamily Limopsoidea the Paleozoic/Mesozoic (Amler, 1989) and in the Jurassic/ (e.g., Vokes, 1968; Newell, 1969; Tevesz, 1977; Oliver, 1981; Cretaceous, respectively (Nicol, 1950). Beesley et al., 1998; WoRMS Editorial Board, 2015). On the other In order to evaluate the monophyly of the above-mentioned hand, glycymeridids have duplivincular ligaments, an important taxa and to reassess the troubled systematics of Arcida, we assem- synapomorphy of Arcoidea (Limopsoidea have alivincular liga- bled a multi-locus dataset including a broad sample of Arcida spe- ments), which testifies to their current status as supported by cies. Our dataset encompasses representatives of all Arcida families most recent