A new species of ponyfish (Teleostei: Leiognathidae: Photoplagios) from the Philippines

A new species of ponyfish in the genus Photoplagios is described from material collected in the Philippines. Photoplagios laterofenestra, new species, is distinguished from congeners by the presence in males of an expansive translucent flank patch in the shape of a cornucopia. Additionally, both sexes of the new species can be distinguished from congeners by body shape, pigmentation pattern on the upper flank, and length of the second dorsal-fin spine. © 2007 by the American Society of Ichthyologists and Herpetologists

The ariid catfishes (Teleostei: Siluriformes: Ariidae) of Madagascar, with the description of two new species

http://deepblue.lib.umich.edu/bitstream/2027.42/57171/1/OP735.pd

Paretroplus maromandia, a new cichlid fish from the northwest of Madagascar

http://deepblue.lib.umich.edu/bitstream/2027.42/57163/1/OP727.pd

Phylogeny, taxonomy, and evolution of Neotropical cichlids (Teleostei: Cichlidae: Cichlinae)

Despite recent progress on the higher-level relationships of Cichlidae and its Indian, Malagasy, and Greater Antillean components, conflict and uncertainty remain within the species-rich African, South American, and Middle American assemblages. Herein, we combine morphological and nucleotide characters from the mitochondrial large ribosomal subunit, cytochrome c oxidase subunit I, NADH dehydrogenase four, and cytochrome b genes and from the nuclear histone H3, recombination activating gene two, Tmo-4C4, Tmo-M27, and ribosomal S7 loci to analyse relationships within the Neotropical cichlid subfamily Cichlinae. The simultaneous analysis of 6309 characters for 90 terminals, including representatives of all major cichlid lineages and all Neotropical genera, resulted in the first well-supported and resolved generic-level phylogeny for Neotropical cichlids. The Neotropical subfamily Cichlinae was recovered as monophyletic and partitioned into seven tribes: Astronotini, Chaetobranchini, Cichlasomatini, Cichlini, Geophagini, Heroini, and Retroculini. Chaetobranchini + Geophagini (including the crenicichlines ) was resolved as the sister group of Heroini + Cichlasomatini (including Acaronia). The monogeneric Astronotini was recovered as the sister group of these four tribes. Finally, a clade composed of Cichlini + Retroculini was resolved as the sister group to all other cichlines. The analysis included the recently described †Proterocara argentina, the oldest known cichlid fossil (Eocene), which was placed in an apical position within Geophagini, further supporting a Gondwanan origin for Cichlidae. These phylogenetic results were used as the basis for generating a monophyletic cichline taxonomy. © The Willi Hennig Society 2008

Phylogeny and revision of Paretroplus

151 p. : ill. (1 col.) ; 26 cm.Includes bibliographical references (p. 135-139).A species-level phylogeny for Etroplinae is presented, based on the simultaneous analysis of morphological and nucleotide characters, and species of the endemic Malagasy genus Paretroplus are taxonomically revised, including the description of two new species. Relative to most other cichlid genera, Paretroplus is diagnosed by numerous anatomical features, including morphology of the gas bladder, neurocranium, oral jaws and dentition, and suspensorium. Keys to the genera of Malagasy-South Asian cichlids and to the species of Paretroplus are provided. Paretroplus is endemic to Madagascar and is the sister genus to Etroplus, endemic to southern India and Sri Lanka. Together these two genera comprise the subfamily Etroplinae. Paretroplus comprises 12 species, two of which are described herein as new. Three morphologically distinct clades are recovered within Paretroplus, one comprising the comparatively elongate, primarily riverine and rheophilic species P. damii, P. nourissati, P. tsimoly, and P. lamenabe, new species, the second comprising the deep-bodied, primarily lacustrine species P. polyactis, P. petiti, P. kieneri, P. maculatus, P. menarambo, P. maromandia, and P. dambabe, and the third comprising the shallow-bodied and highly mottled species P. kieneri and P. gymnopreopercularis, new species, which occur in both lentic and lotic habitats. Monophyly of Etroplinae and Etroplus are also discussed and diagnostic anatomical features are presented for both clades. The sister-group relationship between Etroplus and Paretroplus represents a well-corroborated transoceanic link within Cichlidae, a pattern congruent with the Mesozoic fragmentation of Gondwana. The anterior of the gas bladder is highly modified in Etroplinae, reaching its most derived configuration in Paretroplus, in which multiple, structurally complex and rigid anterior bullae expand into large exoccipital recesses, forming a mechanical (5 otophysic) connection between the gas bladder and inner ear. Evolution of the gas bladder, and its function in conferring increased hearing ability, is discussed in terms of the phylogenetic information this structure provides for reconstructing hypotheses of relationships within Cichlidae

The First Record of a Trans-Oceanic Sister-Group Relationship between Obligate Vertebrate Troglobites

We show using the most complete phylogeny of one of the most species-rich orders of vertebrates (Gobiiformes), and calibrations from the rich fossil record of teleost fishes, that the genus Typhleotris, endemic to subterranean karst habitats in southwestern Madagascar, is the sister group to Milyeringa, endemic to similar subterranean systems in northwestern Australia. Both groups are eyeless, and our phylogenetic and biogeographic results show that these obligate cave fishes now found on opposite ends of the Indian Ocean (separated by nearly 7,000 km) are each others closest relatives and owe their origins to the break up of the southern supercontinent, Gondwana, at the end of the Cretaceous period. Trans-oceanic sister-group relationships are otherwise unknown between blind, cave-adapted vertebrates and our results provide an extraordinary case of Gondwanan vicariance. © 2012 Chakrabarty et al

Evolution and diversification of a sexually dimorphic luminescent system in ponyfishes (Teleostei: Leiognathidae), including diagnoses for two new genera

A phylogeny was generated for Leiognathidae, an assemblage of bioluminescent, Indo-Pacific schooling fishes, using 6175 characters derived from seven mitochondrial genes ( 16S , COI , ND4 , ND5 , tRNA-His , tRNA-Ser , tRNA-Leu ), two nuclear genes ( 28S , histone H3 ), and 15 morphological transformations corresponding to features of the fishes' sexually dimorphic light-organ system (LOS; e.g., circumesophageal light organ, lateral lining of the gas bladder, transparent flank and opercular patches). Leiognathidae comprises three genera, Gazza , Leiognathus , and Secutor . Our results demonstrate that Leiognathidae, Gazza , and Secutor are monophyletic, whereas Leiognathus is not. The recovered pattern of relationships reveals that a structurally complex, strongly sexually dimorphic and highly variable species-specific light organ is derived from a comparatively simple non-dimorphic structure, and that evolution of other sexually dimorphic internal and external features of the male LOS are closely linked with these light-organ modifications. Our results demonstrate the utility of LOS features, both for recovering phylogeny and resolving taxonomic issues in a clade whose members otherwise exhibit little morphological variation. We diagnose two new leiognathid genera, Photopectoralis and Photoplagios , on the basis of these apomorphic LOS features and also present derived features of the LOS to diagnose several additional leiognathid clades, including Gazza and Secutor . Furthermore, we show that five distinct and highly specialized morphologies for male-specific lateral luminescence signaling, which exhibit species-specific variation in structure, have evolved in these otherwise outwardly conservative fishes. Leiognathids inhabit turbid coastal waters with poor visibility and are often captured in mixed assemblages of several species. We hypothesize that the species-specific, sexually dimorphic internal and external modifications of the leiognathid LOS provide compelling evidence for an assortative mating scheme in which males use species-specific patterns of lateral luminescence signaling to attract mates, and that this system functions to maintain reproductive isolation in these turbid coastal environments. © The Willi Hennig Society 2005.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72092/1/j.1096-0031.2005.00067.x.pd

New species of ponyfish.

14 pages : color illustrations ; 26 cm.A new species belonging to the leiognathid genus Photolateralis, collected from the coastal waters of Oman, is described herein. Photolateralis is unique among leiognathid genera in possessing a species-specific translucent midlateral flank stripe that may be comprised of either multiple independent translucent windows (P. stercorarius, P. moretoniensis, and the new species) or a continuous translucent lateral band (P. antongil). Photolateralis polyfenestrus, new species, is distinguished from congeners by the presence of a short, composite midlateral stripe comprised of three small, rounded translucent windows (vs. numerous windows in both P. stercorarius and P. moretoniensis, or a continuous translucent stripe in P. antongil), and that is confined to the midflank (vs. extending a majority of the length of the flank in congeners). The new species is further distinguished from both P. moretoniensis and P. antongil by a shallower body, and from both P. stercorarius and P. moretoniensis by a pigmentation pattern above the lateral midline comprised primarily of larger rounded blotches (vs. smaller sinuous lines and markings comprising a vermiculated pattern). Photolateralis polyfenestrus is characterized by a lower jaw that is deep and convex in lateral view (vs. mostly straight in congeners, excluding P. antongil), and that forms an angle of between 60°-70° to horizontal (vs. less than 45° in congeners, excluding P. antongil). The only other species of Photolateralis reported from the western Indian Ocean is P. antongil, to date only known from the coastal waters of Madagascar, whereas both P. stercorarius and P. moretoniensis have ranges restricted to the western Pacific and extending into the eastern Indian Ocean

Non-sexually dimorphic ponyfishes

21 p. : ill. (some col.) ; 26 cm.Electronic version available in portable document format (PDF).Includes bibliographical references (p. 18-20).A phylogeny was generated for Leiognathidae, commonly known as ponyfishes, using nucleotide characters from two mitochondrial genes. Results indicate that Leiognathidae comprises two major clades, one consisting of species that exhibit internally sexually dimorphic light-organ systems (LOS), and the Leiognathus equulus species complex, whose members exhibit neither internal nor external sexual dimorphism of the LOS. Species with internally sexually dimorphic LOS generally also exhibit associated male-specific external modifications in the form of transparent patches on the margin of the opercle, the midlateral flank, or behindthe pectoral fin axil. The L. equulus species complex is the sister group to all other leiognathids, and a new species, L. robustus, recovered within this clade is described herein. Results demonstrate that Leiognathus is paraphyletic, whereas Gazza and Secutor are each monophyletic and are nested within the sexually dimorphic clade. The morphology of the LOS of nonsexually dimorphic leiognathids is compared to the more common sexually dimorphic state, and differences in these systems are discussed and illustrated. In the context of a family-level phylogeny, we can trace the evolution of the leiognathid LOS from a 'simple' non-sexually dimorphic circumesophageal light organ to a complex and species-specific luminescence system involving not only major structural modifications of the light organ itself but also numerous associated tissues