Phylogenetic systematics and historical biogeography of the Neotropical electric fish Gymnotus (Teleostei: Gymnotidae)

Phylogenetic interrelationships of the Neotropical electric fish genus Gymnotus are documented from comparative study of phenotypic data. A data matrix was compiled of 113 phenotypic characters for 40 taxa, including 31 recognized Gymnotus species, six allopatric populations of G. carapo, two allopatric populations of G. coropinae, and three gymno‐tiform outgroups. MP analysis yielded 15 trees of equal length, the strict consensus of which is presented as a working hypothesis of Gymnotus interrelationships. Diagnoses are presented for 26 clades, including three species groups; the G. cylindricus group with two species restricted to Middle America, the G. pantherinus group with 12 species in South America, and the G. carapo group with 16 species in South America. The basal division of Gymnotus is between clades endemic to Middle and South America. Both the G. pantherinus and G. carapo groups include trans‐Andean sister‐taxon pairs, suggesting a minimum date for the origins of these groups in the late Middle Miocene (c. 12 Ma.). The geographically widespread species G. carapo is paraphyletic. Analysis of character state evolution shows characters of external morphology are more phylogenetically plastic and provide more phylogenetic information in recent branches than do characters of internal morphology, which themselves provide the more information in deeper branches. Nine regional species assemblages of Gymnotus are recognized, none of which is monophyletic. There are at least two independent origins of Gymnotus species in sediment rich, high conductivity, perennially hypoxic whitewater floodplains (varzea´) derived from an ancestral condition of being restricted to low conductivity non‐floodplain (terra firme) black and clearwater rivers and streams. These phylogenetic, biogeographic and ecological patterns suggest a lengthy and complex history involving numerous instances of speciation, extinction, migration and coexistence in sympatry. Evolution in Gymnotus has been a continent‐wide phenomenon; i.e. Amazonian species richness is not a consequence of strictly Amazonian processes. These patterns are similar to those of other highly diverse groups of Neotropical fishes and do not resemble those of monophyletic, rapidly generated species flocks.     

Comparative morphology,phylogenetic relationships,and historical biogeography of plesiolebiasine seasonal killifishes (Teleostei: Cyprinodontiformes: Rivulidae)

Phylogenetic and biogeographical analyses were performed for the Plesiolebiasini, a group of 20 small and rare species of South American annual killifishes, some threatened with extinction, occurring in river basins of Brazil, Bolivia, Paraguay, and Argentina. The results of a maximum parsimony analysis of 142 morphological characters highly corroborate monophyly of the Plesiolebiasini. Monophyly of each plesiolebiasine genus is supported and Plesiolebias is hypothesized to be the sister group to a clade comprising the remaining plesiolebiasine genera (Papiliolebias, Pituna, Maratecoara, and Stenolebias), corroborating studies based on mitochondrial genes. The phylogenetic analysis supports sister group relationships between Papiliolebias and the clade containing Pituna, Maratecoara, and Stenolebias, and between Maratecoara and Stenolebias. The biogeographical analysis indicates a complex historical biogeographical scenario for plesiolebiasines. A vicariance event between the western Paraguay area and northern river basins may be related to the isolation of the Chaco region from the Amazon between the Late Oligocene and Early Miocene. A vicariance event involving the Paraguay River basin and northern rivers, and the multiple occurrence of area hybridism along the Araguaia depression are tentatively identified as a consequence of tectonic subsidence events occurring during the Pleistocene. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 131–148.     

A new species of electric knifefish,genus Compsaraia (Gymnotiformes: Apteronotidae) from the Amazon River,with extreme sexual dimorphism in snout and jaw length

Abstract

A new species of the neotropical electric fish genus Compsaraia is described from the western Amazon of Peru and Brazil. Compsaraia samueli is distinguishable from all other apteronotids by sexual dimorphism in which mature males exhibit extreme elongation and slenderness of the snout and jaws. Compsaraia samueli is readily distinguishable from its only congener, C. compsa, by more caudal‐fin rays (17–18 vs. 13–16), a shorter caudal peduncle (mean length 9% vs. 34% body length to end of anal fin), a less tapering body shape in lateral profile (mean ratio of body depth at origins of anal fin and dorsal organ 93% vs. 75%), and a smaller maximum adult body size (230 vs. 305 mm). The genus Compsaraia is readily separated from other apteronotids by a pale antorbital stripe and a pale L‐shaped patch over the supra‐temporal canal. The phylogenetic position of C. samueliis estimated by inclusion in a previously published data matrixof osteological and other morphological characters. Comparisons of the cranial bones in apteronotids shows the derived morphology of C. samueli to be a composite of three developmentally and phylogenetically discrete characters: (1) positive allometric growth before sexual maturity in both sexes of the pre‐orbital region of the neurocranium, (2) positive allometric growth of the (oral) jaws, and (3) secondary sexual dimorphism of snout and jaw morphology. The genus Compsaraia represents one of at least three phylogenetically independent cases of snout elongation and one of at least four cases of jaw elongation within the Apteronotidae. Compsaraia samueli also represents one of at least four cases of secondary sexual dimorphism in snout and jaw length within the Apteronotidae. The phylogenetic distribution of snout and jaw characters within the Apteronotidae suggests the influence of both sexual and trophic functional influences on the evolution of head morphology.     

Sternopygus castroi,a new species of Neotropical freshwater electric fish,with new synapomorphies to the genus (Sternopygidae: Gymnotiformes: Teleostei)

Sternopygus castroi n. sp. is described as a new species of sternopygid Neotropical freshwater fish from the Rio Cuieiras, tributary of Rio Negro, Amazonas State, Brazil. It differs from the other species of the genus by a combination of characters. Three new synapomorphies for Sternopygus are reported. Only Sternopygus species present a membranous integumental subopercular fold originating postero-ventrally in the opercular region, running anteriorly to the isthmus region. In Sternopygus, the membranous opercular opening is wide and S-shaped (wide but fleshy in Gymnotus). In Sternopygus there is also a medial cephalic fleshy fold at the ventral margin of the opercular membrane, directed forward and ventrally to the isthmus, surrounding the anal pore anteriorly, just behind the subopercular flap.     

Phylogenetic relationships within the South American fish family Anostomidae (Teleostei,Ostariophysi, Characiformes)

Analysis of a morphological dataset containing 152 parsimony‐informative characters yielded the first phylogenetic reconstruction spanning the South American characiform family Anostomidae. The reconstruction included 46 ingroup species representing all anostomid genera and subgenera. Outgroup comparisons included members of the sister group to the Anostomidae (the Chilodontidae) as well as members of the families Curimatidae, Characidae, Citharinidae, Distichodontidae, Hemiodontidae, Parodontidae and Prochilodontidae. The results supported a clade containing Anostomus, Gnathodolus, Pseudanos, Sartor and Synaptolaemus (the subfamily Anostominae sensu Winterbottom) albeit with a somewhat different set of relationships among the species within these genera. Anostomus as previously recognized was found to be paraphyletic and is split herein into two monophyletic components, a restricted Anostomus and the new genus Petulanos gen. nov. , described herein. Laemolyta appeared as sister to the clade containing Anostomus, Gnathodolus, Petulanos, Pseudanos, Sartor and Synaptolaemus. Rhytiodus and Schizodon together formed a well‐supported clade that was, in turn, sister to the clade containing Anostomus, Gnathodolus, Laemolyta, Petulanos, Pseudanos, Sartor and Synaptolaemus. Anostomoides was sister to the clade formed by these nine genera. Leporinus as currently defined was not found to be monophyletic, although certain clades within that genus were supported, including the species with subterminal mouths in the former subgenus Hypomasticus which we recognize herein as a genus. Abramites nested in Leporinus, and Leporellus was found to be the most basal anostomid genus. The presence of cis‐ and trans‐Andean species in Abramites, Leporellus, Leporinus and Schizodon, all relatively basal genera, suggests that much of the diversification of anostomid species pre‐dates the uplift of the Andean Cordilleras circa 11.8 million years ago. Several important morphological shifts in anostomid evolution are illustrated and discussed, including instances of convergence and reversal. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 70–210.     

Phylogenetic interrelationships,taxonomy, and reductive evolution in the Neotropical electric fish genus Hypopygus (Teleostei,Ostariophysi, Gymnotiformes)

A phylogenetic reconstruction of the Neotropical electric fish genus Hypopygus based on 47 parsimony‐informative morphological characters is presented. A series of synapomorphies support the hypothesis of monophyly of Hypopygus, and partially resolve species‐level relationships within the genus. Hypopygus species are recognized here as miniaturized fishes based on two criteria; first, a derived condition of diminutive body size, and; second, the presence of a suite of reductive morphological characters, including partial or total losses, simplifications, and reductions of the anal‐fin rays, scales, cranial bones, and laterosensory canal system. Reductive characters associated with miniaturization comprise 45% of the total number of characters in the phylogenetic reconstruction of the genus. Miniaturization and reductive morphological evolution in Hypopygus are discussed here in the phylogenetic context. A taxonomic revision of Hypopygus is presented, in which five new species are described, two species previously assigned to the genus are redescribed, and a single known species of Stegostenopos is redescribed and included in Hypopygus as a junior synonym. Distribution maps and a key for all eight valid species of Hypopygus are provided, based on the examination of 5014 catalogued museum specimens. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 1096–1156.     

Electric fishes of the genus Sternarchorhynchus (Teleostei,Ostariophysi, Gymnotiformes); phylogenetic and revisionary studies

Analysis of 88 characters of external and internal body systems yielded a phylogenetic reconstruction of the Neotropical electric knifefish genus Sternarchorhynchus (Apteronotidae; Gymnotiformes). The results support a hypothesis of Sternarchorhynchus as the sister group to Platyurosternarchus. A series of synapomorphies, many involving major innovations of the neurocranium, jaws, suspensorium, and associated systems that permit an unusual mode of grasp‐suction feeding, support the monophyly of both genera. Synapomorphies largely resolve relationships within Sternarchorhynchus with basal nodes strongly supported by characters pertinent to prey capture and initial processing of food items. These possible key innovations may provide Sternarchorhynchus with a competitive advantage over other clades of the Apteronotidae and account for the species diversity of the genus in Neotropical rivers. Adaptive radiation in Sternarchorhynchus was analysed. Habitat preference transitions repeatedly occurred in the genus between deep‐river channel dwelling species and rheophilic species with preferences for higher energy setting including rapids and swift‐flowing fluviatile settings. Twenty‐two species of Sternarchorhynchus are described as new based on samples that originated in the smaller rivers draining into the Golfo de Paria, the Marowijne and Essequibo River basins, the Río Orinoco and in particular the Amazon River basin. The 32 species in Sternarchorhynchus make it the most speciose genus in the Apteronotidae. No claim to original US government works. Journal compilation © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 159 , 223–371.     

Nine polymorphic microsatellite loci in the Neotropical electric eel Eigenmannia (Teleostei: Gymnotiformes)

Ten microsatellite loci were isolated from a species of the Neotropical electric eel, Eigenmannia, a genus of freshwater fish characterized by small populations and low vagility. Nine microsatellites were polymorphic, the number of alleles ranging from seven to 27, and values of observed heterozygosity ranging from 0.327 to 0.741. These loci were developed for population genetic studies of Eigenmannia sp. 2, however, cross‐amplification carried out with other species of this genus as well as other Gymnotiformes genera indicate that these molecular markers are also potentially useful for population‐level studies in closely related species.     

The pseudotympanum in the Gymnotiformes (Teleostei,Ostariophysi, Otophysi): homology and evolution of a previously unexplored system in Neotropical electric fishes

The pseudotympanum, a reduction of the hypaxialis muscle in the body wall lateral to the anterior portion of the swim bladder, is unique to some members of the Otophysi, the largest clade of primarily freshwater fishes. Prior studies documented the presence of the pseudotympanum in a number of groups within the Characiformes, to a lesser extent in subunits of the Siluriformes, and in a few taxa of the Cypriniformes, but with only one record of the aperture in the Gymnotiformes – the Neotropical electric fishes. Surveys across the five families and c. two‐thirds of the genera in the Gymnotiformes revealed the occurrence of a pseudotympanum in all examined taxa. Pronounced variation in the expanse and details of the morphology of the opening and its relationship to the anterior elements of the axial skeleton was documented amongst Neotropical electric fish. Details of pseudotympanal morphology in the different families of the Gymnotiformes are described and the variation evaluated within the context of the two alternative hypotheses of higher‐level phylogenetic relationships within the order. © 2015 The Linnean Society of London     

Phylogenetic relationships and biogeography of midwife toads (Discoglossidae: Alytes)

Aim To devise a robust phylogenetic hypothesis for midwife toads (Alytes: Anura: Discoglossidae) and to discuss its implications for the reconstruction of the biogeographical history of the group. Location Western Palearctic. Methods Analysis of sequences of mitochondrial DNA (cytochrome b and 16S RNA, 861 bp) and 29 characters of cranial osteology of all species and subspecies within Alytes. Results Phylogenetic analyses support a sister group relationship between Alytes dickhilleni and A. muletensis, and of this clade with A. maurus. The monophyly of A. obstetricans is controversial; in particular, the phylogenetic position of A. obstetricans almogavarii is uncertain. The estimated dates for the cladogenetic events within Alytes are congruent with those derived from independent analyses (allozymes), except for the differentiation of A. o. almogavarii and the split between A. dickhilleni and A. muletensis. Main conclusions The phylogeny based on the analysis of morphological and mtDNA data differs from previous hypotheses in the positions of A. o. almogavarii and A. maurus. Events associated with the radiation of Alytes are the formation of large inland saline lakes in Iberia c. 16 Ma and the 11 ° C dramatic decrease in average annual temperature during the Middle–Late Badenian transition c. 14–13.5 Ma (A.cisternasii vs. the ancestor of the remaining clades), the structuring of the Neo‐Pyrenees and the reopening of the Betic Strait c. 10–8 Ma(A. o. almogavarii vs. A. obstetricans and vs. the subgenus Baleaphryne), the opening of the Gibraltar Strait at the end of the Messinian Salinity Crisis at c. 5.3 Ma (A. maurus vs. the ancestor of the A. dickhilleni A. muletensis clade) and a transmarine colonization event at c. 3 Ma (the ancestor of A. muletensis vs. A. dickhilleni). Following the new hypothesis, A. maurus, previously considered a subspecies of A. obstetricans, deserves species status. Second, A. o. almogavarii is a well‐differentiated lineage that was isolated from other A. obstetricans more than c. 5 Ma, but later lost its genetic and specific identity following secondary contact, hybridization and introgression with the main stock. The presence of a marked morphological and genetic diversity within A. obstetricans renders reconstruction of the evolutionary history of the genus more complicated than previously appreciated.     

Phylogenetic relationships, diversification and biogeography in Neotropical Brotogeris parakeets

Aim We present a molecular phylogenetic analysis of Brotogeris (Psittacidae) using several distinct and complementary approaches: we test the monophyly of the genus, delineate the basal taxa within it, uncover their phylogenetic relationships, and finally, based on these results, we perform temporal and spatial comparative analyses to help elucidate the historical biogeography of the Neotropical region. Location Neotropical lowlands, including dry and humid forests. Methods Phylogenetic relationships within Brotogeris were investigated using the complete sequences of the mitochondrial genes cyt b and ND2, and partial sequences of the nuclear intron 7 of the gene for Beta Fibrinogen for all eight species and 12 of the 17 taxa recognized within the genus (total of 63 individuals). In order to delinetae the basal taxa within the genus we used both molecular and plumage variation, the latter being based on the examination of 597 skin specimens. Dates of divergence and confidence intervals were estimated using penalized likelihood. Spatial and temporal comparative analyses were performed including several closely related parrot genera. Results Brotogeris was found to be a monophyletic genus, sister to Myiopsitta. The phylogenetic analyses recovered eight well‐supported clades representing the recognized biological species. Although some described subspecies are diagnosably distinct based on morphology, there was generally little intraspecific mtDNA variation. The Amazonian species had different phylogenetic affinities and did not group in a monophyletic clade. Brotogeris diversification took place during the last 6 Myr, the same time‐frame as previously found for Pionus and Pyrilia. Main conclusions The biogeographical history of Brotogeris implies a dynamic history for South American biomes since the Pliocene. It corroborates the idea that the geological evolution of Amazonia has been important in shaping its biodiversity, argues against the idea that the region has been environmentally stable during the Quaternary, and suggests dynamic interactions between wet and dry forest habitats in South America, with representatives of the Amazonian biota having several independent close relationships with taxa endemic to other biomes.     

Molecular systematics,taxonomy and biogeography of the genus Cavia (Rodentia: Caviidae)

Phylogenetic analyses were conducted on cytochrome b sequence data of the most geographically and taxonomically broad sampling of Cavia taxa to date. Primary objectives included providing the first extensive molecular phylogenetic framework for the genus, testing the taxonomic and systematic hypotheses of previous authors and providing insight into the evolutionary and biogeographic history of the genus. Support was found for the morphologically defined species C. aperea, C. tschudii, C. magna and C. fulgida and the taxonomic placement of taxa previously subject to conflicting taxonomic opinions (e.g. C. nana, C. anolaimae and C. guianae) was further resolved. Additionally, we elevate the Ecuadorian C. a. patzelti to species status, restrict the distributional limits and suggest taxonomic affiliations of some C. tschudii subspecies, and provide strong evidence for the geographic origin of guinea pig domestication. Finally, we provide an estimated evolutionary timeline for the genus Cavia, which appears to extend well into the late Miocene.     

Historical biogeography and molecular systematics of the Indo-Pacific genus Dascyllus (Teleostei: Pomacentridae)

The phylogeographical and systematic relationships among species in the tropical marine fish genus Dascyllus were inferred using mitochondrial DNA (mtDNA) sequence data. Although our results were generally consistent with previously published phylogenies based on both morphological and mitochondrial data, our broad taxonomic and geographical sampling design revealed novel insights into the phylogenetic history of Dascyllus that had escaped previous notice. These results include: (a) the polyphyletic nature of D. reticulatus mtDNAs, representing two divergent and geographically separated lineages, one shared with D. flavicaudus and the second forming the sister lineage of D. carneus; (b) the paraphyly of D. trimaculatus relative to the closely related D. abisella; and (c) phylogeographical structure within the widespread taxa D. aruanus and D. trimaculatus. Application of a molecular clock permits us to posit a causative role for tectonic and oceanic changes regarding some Dascyllus speciation events. Finally, we mapped body size and the presence or absence of protogynous sex change on the mtDNA tree, and tested published hypotheses regarding determinants of the evolution of mating system and protogyny in the genus. Our data rejected a model based on body size but not one based on phylogenetic inertia. The ability to change sex arose once in the ancestor to the entire genus, and was lost once in the ancestor of the D. trimaculatus complex. For taxa that are as geographically widespread as many Indo-Pacific genera, this study highlights the importance of adequate geographical sampling when inferring patterns of species diversification and life history evolution.     

Molecular phylogeny and biogeography of the Neotropical cichlid fish tribe Cichlasomatini (Teleostei: Cichlidae: Cichlasomatinae)

We have conducted the first comprehensive molecular phylogeny of the tribe Cichlasomatini including all valid genera as well as important species of questionable generic status. To recover the relationships among cichlasomatine genera and to test their monophyly we analyzed sequences from two mitochondrial (16S rRNA, cytochrome b) and one nuclear marker (first intron of S7 ribosomal gene) totalling 2236 bp. Our data suggest that all genera except Aequidens are monophyletic, but we found important disagreements between the traditional morphological relationships and the phylogeny based on our molecular data. Our analyses support the following conclusions: (a) Aequidens sensu stricto is paraphyletic, including also Cichlasoma (CA clade); (b) Krobia is not closely related to Bujurquina and includes also the Guyanan Aequidens species A. potaroensis and probably A. paloemeuensis (KA clade). (c) Bujurquina and Tahuantinsuyoa are sister groups, closely related to an undescribed genus formed by the 'Aequidens'pulcher-'Aequidens'rivulatus groups (BTA clade). (d) Nannacara (plus Ivanacara) and Cleithracara are found as sister groups (NIC clade). Acaronia is most probably the sister group of the BTA clade, and Laetacara may be the sister group of this clade. Estimation of divergence times suggests that the divergence of Cichlasomatini started around 44Mya with the vicariance between coastal rivers of the Guyanas (KA and NIC clades) and remaining cis-andean South America, followed by evolution of the Acaronia-Laetacara-BTA clade in Western Amazon, and the CA clade in the Eastern Amazon. Vicariant divergence has played importantly in evolution of cichlasomatine genera, with dispersal limited to later range extension of species within genera.     

Notograptidae, sister to Acanthoplesiops Regan (Teleostei: Plesiopidae: Acanthoclininae), with comments on biogeography, diet and morphological convergence with Congrogadinae (Teleostei: Pseudochromidae)

The Notograptidae contains one genus, Notograptus Günther, and five nominal species from northern Australia and southern New Guinea. Morphological evidence places Notograptus among acanthoclinine plesiopids (continuous free margin of lower lip; head naked; dorsal and anal fins with many spines and few segmented rays; no extensor proprius; reduced number of caudal-fin rays) and supports a sister relationship with Acanthoplesiops (symphyseal flap on lower lip; reduced hypural 5; reduced hypurapophysis). This hypothesis resolves the relationships within Acanthoplesiops , clarifying the polarity of autogenous middle radials of dorsal- and anal-fin pterygiophores. The proposed relationships among acanthoclinines are: Acanthoclinus ( Belonepterygion ( Beliops ( Notograptus ( Acanthoplesiops hiatti ( A. indicus ( A. psilogaster ( A. echinatus ))))))). The distribution of Notograptus compliments that of its proposed sister clade in that Acanthoplesiops is unknown from northern Australia or southern New Guinea. There are repeated geographical patterns among several groups suggesting that Australia is a basal area to a broader Indo-Pacific region. Similarity between the Congrogadinae (Pseudochromidae) and Notograptus has long been noted, both having a loosely connected suspensorium and elongate body which were mistakenly considered indicators of relationship; we add reduced branchial arches, straight, tube-like gut and highly expandable anus. We examine these similarities as an indication of a shared specialized feeding habit. Notograptus is an alpheid shrimp predator, able to swallow its large prey whole. Most species of congrogadines eat whole, large crustaceans. This is probably an example of convergent adaptation to a particular selective regime.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 141 , 179–205.     

Chromosomal diversity in three species of electric fish (Apteronotidae,Gymnotiformes) from the Amazon Basin

Cytogenetic studies were carried out on samples of Parapteronotus hasemani, Sternarchogiton preto and Sternarchorhamphus muelleri (Apteronotidae, Gymnotiformes) from the Amazon basin. The first two species exhibited both a 2n = 52 karyotype, but differed in their karyotypic formulae, distribution of constitutive heterochromatin, and chromosomal location of the NOR. The third species, Sternarchorhamphus muelleri, was found to have a 2n = 32 karyotype. In all three species the DAPI and chromomycin A3 staining results were consistent with the C-banding results and nucleolar organizer region (NOR) localization. The 18S rDNA probe confirmed that there was only one pair of ribosomal DNA cistron bearers per species. The telomeric probe did not reveal interstitial telomeric sequences (ITS). The karyotypic differences among these species can be used for taxonomic identification. These data will be useful in future studies of these fishes and help understanding the phylogenetic relationships and chromosomal evolution of the Apteronotidae.     

Phylogenetic study of the Characinae (Teleostei: Characiformes: Characidae)

The Characinae is a subunit of the Characidae of special significance in including Charax, the type genus of the family and the order Characiformes. Twelve genera and 79 species have been traditionally assigned to the Characinae, but the subfamily still lacks a phylogenetic diagnosis. Herein, a data matrix including 150 morphological characters and 64 taxa (35 species representing all genera of the Characinae and 29 included in other lineages within the Characiformes) was submitted to two cladistic analyses that differ in the inclusion/exclusion of Priocharax due to the difficulty of coding most of the character states in the miniature species of this genus. Both analyses resulted in a non‐monophyletic Characinae and this subfamily is herein restricted to only seven of the original 12 genera forming the clade (Phenacogaster((Charax Roeboides)(Acanthocharax(Cynopotamus(Acestrocephalus Galeocharax))))), which is supported by ten non‐ambiguous synapomorphies and is more closely related to other genera of the Characidae than those traditionally placed in the subfamily. A second clade includes the members of the tribe Heterocharacini (Lonchogenys(Heterocharax Hoplocharax)) as the sister‐group of Gnathocharax, supported by seven non‐ambiguous synapomorphies. This clade is more closely related to a taxon formed by Roestes and Gilbertolus based on seven non‐ambiguous synapomorphies. Results do not corroborate a close relationship between Roestes–Gilbertolus and the Cynodontinae. Inclusion of the genus Priocharax suggests that it is related more closely to the Heterocharacini, but the profound modifications in its anatomy possibly related to ontogenetic truncations obscure a better understanding of its relationships. A new classification of the Characinae and the Heterocharacinae is proposed. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 809–915.     

Phylogenetic systematics of leaffishes (Teleostei: Polycentridae,Nandidae)

The Asian (nandid) and Afro‐Neotropical (polycentrid) leaffishes represent two superficially similar, but historically poorly diagnosed families – a situation resulting in a convoluted systematic history. Here, and including for the first time in a molecular study all leaffish genera, we generate a hypothesis of the phylogenetic history of both groups. We analyse a multilocus molecular data set encompassing 257 acanthomorph taxa, carry out a survey and assessment of selected osteological characters for the polycentrid leaffishes and also provide a reanalysis of previously published morphological data. Our results confirm: (1) that the Polycentridae and Nandidae are only remotely related, and hence, the classic leaffishes are diphyletic; (2) that the Polycentridae is monophyletic, with new skeletal synapomorphies being congruent with molecular data in placing the enigmatic Afronandus – a taxon that thus far has never been included in any molecular study – as sistergroup to the remaining genera; (3) the monophyly of the Nandidae + Badidae and their inclusion into a larger monophyletic group – along with the Pristolepididae, Anabantoidei and Channoidei – comprising the Labyrinthici sensu Rosen & Patterson. We also review the morphological and molecular evidence for both the conflicting placement of Pristolepis and the putative sistergroup relationship between the labyrinth fishes (Anabantoidei) and snakeheads (Channoidei).     

Reinterpreting recapitulation: systematics of needlefishes and their allies (Teleostei: Beloniformes)

Abstract. As needlefishes (Belonidae) grow, their jaws pass through a "halfbeak" stage that resembles the adult jaw condition of the closely related family of halfbeaks (Hemiramphidae). Based on this pattern, some authors have suggested that halfbeaks are "developmentally arrested" or paedomorphic needlefish derivatives, whereas others have supported the notion that needlefishes are descended from halfbeak-like ancestors and that needlefish ontogeny thereby recapitulates phylogeny. To test these ideas and to better understand evolutionary changes in jaw ontogeny, phylogenetic relationships among genera of needlefishes, sauries (Scomberesocidae), halfbeaks, and flyingfishes (Exocoetidae) were assessed using mitochondrial (cytochrome b and 16S), nuclear (Tmo-4C4), and morphological characters. The resultant tree provides several novel taxonomic findings: (1) flyingfishes appear to be nested within halfbeaks; (2) sauries appear to be nested within needlefishes; and (3) the Indo-West Pacific freshwater halfbeaks appear to be most closely related to the needlefish/saury clade. The structure of the tree falsifies the idea that halfbeaks are paedomorphic needlefishes. Instead, halfbeaks are basal relative to needlefishes, fitting the pattern predicted by the hypothesis of recapitulation. I discuss limitations to phylogenetic perspectives on recapitulation based on discrete character data by comparing aspects of von Baerian and Haeckelian views of the relation between ontogeny and phylogeny.