Molecular phylogeny of the highly disjunct cliff water beetles from South Africa and China (Coleoptera: Aspidytidae)

Abstract

The superfamily Dytiscoidea contains six families with an aquatic lifestyle, with most of its extant diversity in two families: the burrowing water beetles (Noteridae) and the diving beetles (Dytiscidae). The other families have few species (up to six) and generally highly disjunct extant distributions. Aspidytidae currently contains one genus with two species, one in China and one in South Africa. Here we provide the first molecular data for the Chinese species, allowing us to explore the phylogenetic relationships and position of both species of this small family for the first time. Based on a matrix of 11 genes we inferred a phylogenetic hypothesis for Dytiscoidea including all extant families. Unexpectedly, Aspidytidae were consistently recovered as paraphyletic relative to Amphizoidae, despite being well characterized by apparently synapomorphic adult features. A re-examination of larval characters in the two aspidytid species revealed that the larva of the Chinese species is strikingly similar to that of Amphizoidae. Both share a series of plesiomorphic features but also some potential synapomorphies, including a dense vestiture of short setae on the head capsule, anteriorly shifted posterior tentorial grooves and widely separated labial palps. Arguably these features may belong to the groundplan of the clade Aspidytidae + Amphizoidae, with far-reaching secondary modifications (including reversals) in the South African Aspidytes niobe. At present we retain the family Aspidytidae, however, due to the strong adult morphological synapomorphies of the two extant species, and the fact that the molecular paraphyly of the family may result from the highly divergent nature of the two extant species. This long evolutionary separation and strong divergence, in terms of gene sequences and Zoological Journal of the Linnean Society, 2016, 176, 537-546. With 11 figures. larval features, is undeniable, substantial levels of saturation in third codon positions of protein-coding genes being present between the two taxa. We address this issue taxonomically by introducing the new genus Sinaspidytes gen. nov. for the Chinese Aspidytes wrasei. The continued contentious relationships amongst Dytiscidae, Hygrobiidae, Aspidytidae and Amphizoidae highlight the need for more data to address dytiscoid phylogenetics, possibly involving a genomic approach.

Phylogenomics of the superfamily Dytiscoidea (Coleoptera: Adephaga) with an evaluation of phylogenetic conflict and systematic error

“…A sister group relationship between Amphizoidae and Aspidytidae has been suggested in previous studies analyzing molecular data (Balke et al, , 2005Hawlitschek et al, 2012;Toussaint et al, 2015), but Toussaint et al (2015) recovered paraphyletic Aspidytidae (in relation to Amphizoidae). Specifically, in a multigene analysis of nucleotide sequence data, and after excluding the highly saturated third codon positions, A. niobe was placed as a sister taxon of Amphizoidae (Fig.…”

“…Meruidae, with the single species Meru phyllisae Spangler and Steiner, 2005, is known only from the Guiana Shield region of Venezuela (Spangler and Steiner, 2005). Aspidytidae contain two species, Sinaspidytes wrasei (Balke, Ribera, Beutel, 2003) from China (Balke et al, 2003;Toussaint et al, 2015) and Aspidytes niobe Ribera, Beutel, Balke, Vogler, 2002 from the Cape region of South Africa (Beutel et al, 2010;Ribera et al, 2002a). Phylogenetic analyses have placed these two families in the superfamily Dytiscoidea (Beutel et al, 2006;Ribera et al, 2002a), along with the Dytiscidae (diving beetles, 4,489 species; Nilsson and Hájek, 2019), Noteridae (burrowing water beetles, 258 species; Nilsson, 2011), Hygrobiidae (squeak beetles, six species) and Amphizoidae (trout stream beetles, five species).…”

“…The phylogenetic relationships of dytiscoid beetles have been addressed in numerous studies investigating morphology, chemical gland compounds, fossil data, and DNA sequences (Alarie et al, 2011(Alarie et al, , 2004Alarie and Bilton, 2005;Baca et al, 2017;Balke et al, 2008Balke et al, , 2005Beutel et al, 2006;Beutel, 1993;Beutel et al, 2013Beutel et al, , 2008Beutel and Haas, 1996;Burmeister, 1976;Dettner, 1985;Kavanaugh, 1986;López-López and Vogler, 2017;McKenna et al, 2015;Ribera et al, 2002b;Toussaint et al, 2015). Analyses of these different data have not yielded congruent topologies (see Fig.…”

“…A clade consisting of Dytiscidae and Hygrobiidae is supported by some morphological features (Balke et al, 2005;Beutel et al, 2006;Dressler and Beutel, 2010), such as the presence of prothoracic glands (Beutel, 1988(Beutel, , 1986bForsyth, 1970) but molecular and total evidence analyses have yielded incongruent topologies (e.g. Baca et al, 2017;Balke et al, 2005;Ribera et al, 2002a;Toussaint et al, 2015).…”

Systematics of aquatic beetles (Coleoptera): current state and future directions

“…Most morphology-based studies in the last 10 years suggest Gryinidae Beutel et al (1999) Morphology (I) Myxophaga Beutel (1999) Morphology (A + I) Myxophaga (Lepicerus) Short et al (2015) Molecular (6 genes) Hydroscaphidae Hydradephaga (selected) Beutel & Roughley (1988) Morphology (A + I) Hydradephaga (Gyrinidae focused) Ribera et al (2002a) Molecular (1 gene) Adephaga Ribera et al (2002b) Molecular (3 genes) Hydradephaga (Aspidytidae focused) Morphology (I) Hydradephaga (Hygrobiia focused) Balke et al (2005) Molecular (6 genes) + Morphology (A + I) Dytiscoidea Beutel et al (2008) Morphology (A + I) Adephaga Alarie et al (2011a) Morphology (I) Hydradephaga (Meru focused) Toussaint et al (2016b) Molecular (11 genes) Dytiscoidea López-López & Vogler (2017) Phylogenomics (Mitogenomes) Adephaga Baca et al (2017b) Phylogenomics (UCEs) Adephaga Noteridae + Meruidae Beutel & Roughley (1987) Morphology (A) Noteridae Belkaceme (1991) Morphology (A) Noteridae Beutel et al (2006) Morphology (A + I) Noteridae + Meruidae Balke et al (2008b) Molecular (6 genes) Noteridae + Meruidae Miller (2009) Morphology (A) Noteridae Kato et al (2010) Molecular (6 genes) Noteridae (Phreatodytes) Dressler et al (2011) Morphology (A + I) Noteridae + Meruidae Gómez & Miller (2013) Morphology (A) Noteridae (Prionohydrus) Baca et al (2017a) Molecular (5 genes) Noteridae Haliplidae Beutel & Ruhnau (1990) Morphology (A) Haliplidae Mousseau & Roughley (2007) Morphology (A + I) Brychius Hygrobiidae Morphology (I) Hygrobiidae Hawlitschek et al (2012a) Molecular (5 genes) Hygrobiidae Michat et al (2014) Morphology (A + I) Hygrobiidae Gyrinidae Beutel (1989a) Morphology (A: head) Gyrinidae (Spanglerogyrus) Beutel (1989b) Morphology (A) Gyrinidae (Spanglerogyrus) Beutel (1990) Morphology (A: thorax) Gyrinidae Burmeister (1990) Morphology (A) Gyrinidae (Spanglerogyrus) Oygur & Wolfe (1991) Morphology (A) Gyrin...…”