ABSTRACT
The New World species of the minute aquatic beetle genus Notomicrus Sharp compose a much greater diversity than their Old World congeners, with 14 of the 17 known Notomicrus species occurring in the Neotropics. A recent phylogenetic study recovered four primary New World species groups and found that there are a number of undescribed species across all of these main lineages. Here, we provide a taxonomic key to these New World species groups, including two described species that we currently do not place in any group ("incertae sedis" species), complete with images and illustrations of diagnostic characters and taxonomic notes including a list of known species in each group. This work provides a scaffold for further planned taxonomic revisions within the genus. In addition, we review the first of the four New World groups, the josiahi species group and describe one new taxon, N. interstinctus sp. nov. from northern Brazil. Provided are descriptions, habitus images and illustrations of diagnostic characters.
ABSTRACT
Suphisellus grossoi sp. n. is described from the Reserva Natural del Bosque de Mbaracayú, Canindeyú department, Paraguay. Diagnostic characters are described and illustrated in detail. New records are provided for S. flavolineatus (Régimbart, 1889) and S. grammicus (Sharp, 1882), which are also briefly diagnosed. Suphisellus melzeri Zimmermann, 1925 is proposed as a junior subjective synonym of S. flavolineatus (syn. n.), and lectotypes are designated for both taxa.
Subject(s)
Coleoptera , Animals , South America , WaterABSTRACT
Notomicrus petrareptans sp. n. is described from an inselberg seepage in southwestern Suriname. This species is diagnosable by a combination of its weakly punctate elytra, respective shapes of the pro- and mesotarsal claws (males), and long and slender median lobe of the aedeagus. This is the first member of the subfamily Notomicrinae to be described from hygropetric seep habitats and only the second known seep-dwelling species of the family Noteridae. Diagnostic characters are illustrated and habitat images are provided.
Subject(s)
Coleoptera , Animals , Ecosystem , Male , SurinameABSTRACT
The first molecular phylogenetic hypothesis for the aquatic beetle family Noteridae is inferred using DNA sequence data from five gene fragments (mitochondrial and nuclear): COI, H3, 16S, 18S, and 28S. Our analysis is the most comprehensive phylogenetic reconstruction of Noteridae to date, and includes 53 species representing all subfamilies, tribes and 16 of the 17 genera within the family. We examine the impact of data partitioning on phylogenetic inference by comparing two different algorithm-based partitioning strategies: one using predefined subsets of the dataset, and another recently introduced method, which uses the k-means algorithm to iteratively divide the dataset into clusters of sites evolving at similar rates across sampled loci. We conducted both maximum likelihood and Bayesian inference analyses using these different partitioning schemes. Resulting trees are strongly incongruent with prior classifications of Noteridae. We recover variant tree topologies and support values among the implemented partitioning schemes. Bayes factors calculated with marginal likelihoods of Bayesian analyses support a priori partitioning over k-means and unpartitioned data strategies. Our study substantiates the importance of data partitioning in phylogenetic inference, and underscores the use of comparative analyses to determine optimal analytical strategies. Our analyses recover Noterini Thomson to be paraphyletic with respect to three other tribes. The genera Suphisellus Crotch and Hydrocanthus Say are also recovered as paraphyletic. Following the results of the preferred partitioning scheme, we here propose a revised classification of Noteridae, comprising two subfamilies, three tribes and 18 genera. The following taxonomic changes are made: Notomicrinae sensu n. (= Phreatodytinae syn. n.) is expanded to include the tribe Phreatodytini; Noterini sensu n. (= Neohydrocoptini syn. n., Pronoterini syn. n., Tonerini syn. n.) is expanded to include all genera of the Noterinae; The genus Suphisellus Crotch is expanded to include species of Pronoterus Sharp syn. n.; and the former subgenus Sternocanthus Guignot stat. rev. is resurrected from synonymy and elevated to genus rank.
Subject(s)
Aquatic Organisms/genetics , Coleoptera/classification , Coleoptera/genetics , Phylogeny , Animals , Bayes Theorem , Likelihood Functions , Models, TheoreticalABSTRACT
The burrowing water beetle genus Liocanthydrus Guignot, 1957 is redefined and its species are revised. Of the four current species, three are recognized as belonging to the genus and redescribed: L. angustus (Guignot, 1957), L. octoguttatus (Zimmermann, 1921) and L. uniformis (Zimmermann, 1921). The fourth species, L. buqueti (Laporte, 1835) is found to not be a member of Liocanthydrus, but of an undescribed genus. The noterid genus Siolius J. Balfour-Browne, 1969, is synonymized with Liocanthydrus (new synonymy) based on comparison of type specimens in both groups. Two of the three species described in Siolius, S. bicolor J. Balfour-Browne, 1969 and S. clayae J. Balfour-Browne, 1969, are recognized as valid, transferred to Liocanthydrus, and redescribed. The third, S. amazonicus J. Balfour- Browne, 1969, is synonymized with L. uniformis (new synonymy). Two new species from South America, L. armulatus sp. n. and L. nanops sp. n. are also recognized and described. A lectotype is designated for Canthydrus octoguttatus Zimmermann, 1921. After this revision, there are seven valid species of Liocanthydrus. Habitus photos are provided, diagnostic characters of all recognized species are illustrated, distributions are provided, and a key to the species is included.