MtDNA species-level phylogeny and delimitation support significantly underestimated diversity and endemism in the largest Neotropical cichlid genus (Cichlidae: Crenicichla)

Crenicichla is the largest and most widely distributed genus of Neotropical cichlids. Here, we analyze a mtDNA dataset comprising 681 specimens (including Teleocichla, a putative ingroup of Crenicichla) and 77 out of 105 presently recognized valid species (plus 10 out of 36 nominal synonyms plus over 50 putatively new species) from 129 locations in 31 major river drainages throughout the whole distribution of the genus in South America. Based on these data we make an inventory of diversity and highlight taxa and biogeographic areas worthy of further sampling effort and conservation protection. Using three methods of molecular species delimitation, we find between 126 and 168 species-like clusters, i.e., an average increase of species diversity of 65–121% with a range of increase between species groups. The increase ranges from 0% in the Missioneira and Macrophthama groups, through 25–40% (Lacustris group), 50–87% (Reticulata group, Teleocichla), 68–168% (Saxatilis group), 125–200% (Wallacii group), and 158–241% in the Lugubris group. We found a high degree of congruence between clusters derived from the three used methods of species delimitation. Overall, our results recognize substantially underestimated diversity in Crenicichla including Teleocichla. Most of the newly delimited putative species are from the Amazon-Orinoco-Guiana (AOG) core area (Greater Amazonia) of the Neotropical region, especially from the Brazilian and Guiana shield areas of which the former is under the largest threat and largest degree of environmental degradation of all the Amazon.

First Records of Freckled Madtom (Noturus nocturnus) in Ohio, USA

Two new Ohio localities for the Freckled Madtom (Noturus nocturnus Jordan and Gilbert, 1886) were recently discovered. These are the first, and currently only, Freckled Madtom collected in Ohio waters. A single individual was collected in the Scioto River in Scioto County by the Midwest Biodiversity Institute (MBI) and a previously misidentified specimen was collected in the Ohio River at the Hannibal Locks and Dam by the Ohio River Valley Water Sanitation Commission (ORSANCO). The closest historical records are from the Little Sandy River and Big Sandy River drainages in eastern Kentucky. Other Ohio River collections have been made near the border of Kentucky and Indiana. The origins of the recent Ohio specimens are unknown; whether they emanate from other known populations or have been overlooked altogether is unclear.

Provenance of Pleistocene Sediments in West Sarawak and Evidence for Pliocene Acid Magmatism in Central Borneo

Quaternary deposits in Borneo are commonly not assigned to any formation or group and are usually not studied in great detail but are important for understanding of the Pleistocene to Holocene climate and drainage evolution. This study presents a detrital zircon provenance analysis of two possible (Plio-) Pleistocene fluvial deposits in West Sarawak, indicating two very different source areas and paleo-river drainages. Those paleo-rivers resemble the present-day drainage but show much higher energy level deposits associated with higher sedimentation rates possibly as a function of (Plio-) Pleistocene climate and hinterland exposure. The deposits at Kampung Jangkar in western West Sarawak were entirely sourced by the uplifted Pueh batholith. In contrast, sediments in Petra Jaya district (northern Kuching city) were sourced by recycling of the Kayan Sandstone near the Bungo Range in the area of the town Bau. The Petra Jaya sediments have abundant Pliocene and some Late Miocene zircons. The Niut Volcanics south of West Sarawak are of this age, but are basic and could not yield significant zircons. It is therefore concluded that zircons came from acid igneous rocks of Pliocene age, as well as the Kayan Sandstone and Middle Miocene Bau Suite igneous rocks, where they formed a highland in the Bau-Bungo Range region which has been entirely removed by erosion.

Oxynoemacheilus phasicus, a new nemacheilid loach from the eastern Black Sea basin with some remarks on other Caucasian Oxynoemacheilus (Teleostei: Nemacheilidae)

Oxynoemacheilus phasicus, new species, is described from the Rioni and Enguri River drainages in Georgia. It is distinguished from other Oxynoemacheilus species in the O. brandtii group by a mottled or marbled flank pattern in adults, a slightly emarginate caudal fin, and a deep caudal peduncle. Molecular data suggest that the new species is characterized by a minimum K2P distance of 7.5% from O. brandtii from the Kura drainage in the mtDNA COI barcode region. Oxynoemacheilus brandtii and O. elsae are re-diagnosed. A very slender Oxynoemacheilus from the Aras drainage clusters as sister to O. elsae in our molecular analysis and not with O. brandtii from the Kura River. However, it is identified as O. brandtii as it is indistinguishable from this species in morphological characters.

Cryptic speciation in populations of the genus Aphyocharax (Characiformes: Characidae) from eastern Amazon coastal river drainages and surroundings revealed by single locus species delimitation methods

Recent studies in eastern Amazon coastal drainages and their surroundings have revealed new fish species that sometimes exhibit little morphological differentiation (cryptic species). Thus, we used a DNA-based species delimitation approach to test if populations showing the morphotype and typical character states of the Aphyocharax avary holotype correspond either to A. avary or A. brevicaudatus, two known species from the region, or if they form independent lineages, indicating cryptic speciation. WP and GMYC analyses recovered five lineages (species) in the ingroup, while a bPTP analysis delimited three lineages. ABGD analyses produced two possible results: one corroborating the WP and GMYC methods and another corroborating the bPTP method. All methods indicate undescribed cryptic species in the region and show variation from at least 1 to 4 species in the ingroup, depending on the approach, corroborating previous studies, and revealing this region as a possible hotspot for discovering undescribed fish species.

Distribution and diversity of fish from Seyhan, Ceyhan and Orontes river systems

In this study, the current ichthyofauna of the Seyhan, Ceyhan and Orontes River drainages were presented and actual taxonomic positions of the species were assessed. Sixty-seven species belonging to 32 genera and 17 families of fishes were reported from these river drainages in Turkey and Syria. Acanthobrama centisquama and Tinca tinca could not be observed in the study area and Alburnus sellal and Esox lucius are recorded for the first time respectively in the Lake Gölbaşı (connected to the Ceyhan River) and Seyhan River.

Andean uplift, drainage basin formation, and the evolution of riverweeds (Marathrum, Podostemaceae) in northern South America

SummaryNorthern South America is a geologically dynamic and species-rich region. While fossil and stratigraphic data show that reconfiguration of river drainages resulted from mountain uplift in the tropical Andes, investigations of the impact of landscape change on the evolution of the flora in the region have been restricted to terrestrial taxa.We explore the role of landscape change on the evolution of plants living strictly in rivers across drainage basins in northern South America by conducting population structure, phylogenomic, phylogenetic networks, and divergence-dating analyses for populations of riverweeds (Marathrum, Podostemaceae).We show that mountain uplift and drainage basin formation isolated populations of Marathrum and created barriers to gene flow across rivers drainages. Sympatric species hybridize and the hybrids show the phenotype of one parental line. We propose that the pattern of divergence of populations reflect the formation of river drainages, which was not complete until <4 MaOur study provides a clear picture of the role of landscape change in shaping the evolution of riverweeds in northern South America, advances our understanding of the reproductive biology of this remarkable group of plants, and spotlights the impact of hybridization in phylogenetic inference.

Rhodeus caspius, a new bitterling from Iran (Teleostei: Cypriniformes: Acheilognathidae)

A new bitterling from the Rhodeus amarus group is described based on morphological and molecular data. Rhodeus caspius sp. nov. from the Caspian Sea, Urmia Lake and the upper Tigris River drainages in Iran, is distinguished from its closest congeners (R. amarus and R. colchicus) by having short post-dorsal distance and caudal peduncle length and long head length. It is also characterized by one fixed diagnostic nucleotide substitutions and a K2P nearest neighbor distance of 1% to R. amarus and R. colchicus in the mtDNA COI barcode region.