Phylogeography of Cuban Rivulus: Evidence for allopatric speciation and secondary dispersal across a marine barrier

In biogeography, vicariance and long-distance dispersal are often characterised as competing scenarios. However, they are related concepts, both relying on collective geological, ecological, and phylogenetic evidence. This is illustrated by freshwater fishes, which may immigrate to islands either when freshwater connections are temporarily present and later severed (vicariance), or by unusual means when ocean gaps are crossed (long-distance dispersal). Marine barriers have a strong filtering effect on freshwater fishes, limiting immigrants to those most capable of oceanic dispersal. The roles of vicariance and dispersal are debated for freshwater fishes of the Greater Antilles. We review three active hypotheses [Cretaceous vicariance, Greater Antilles-Aves Ridge (GAARlandia), long-distance dispersal] and propose long-distance dispersal to be an appropriate model due to limited support for freshwater fish use of landspans. Greater Antillean freshwater fishes have six potential source bioregions (defined from faunal similarity): Northern Gulf of México, Western Gulf of México, Maya Terrane, Chortís Block, Eastern Panamá, and Northern South America. Faunas of the Greater Antilles are composed of taxa immigrating from many of these bioregions, but there is strong compositional disharmony between island and mainland fish faunas (>90% of Antillean species are cyprinodontiforms, compared to <10% in Northern Gulf of México and Northern South America, and ≤50% elsewhere), consistent with a hypothesis of long-distance dispersal. Ancestral-area reconstruction analysis indicates there were 16 or 17 immigration events over the last 51 million years, 14 or 15 of these by cyprinodontiforms. Published divergence estimates and evidence available for each immigration event suggests they occurred at different times and by different pathways, possibly with rafts of vegetation discharged from rivers or washed to sea during storms. If so, ocean currents likely provide critical pathways for immigration when flowing from one landmass to another. On the other hand, currents create dispersal barriers when flowing perpendicularly between landmasses. In addition to high salinity tolerance, cyprinodontiforms collectively display a variety of adaptations that could enhance their ability to live with rafts (small body size, viviparity, low metabolism, amphibiousness, diapause, self-fertilisation). These adaptations likely also helped immigrants establish island populations after arrival and to persist long term thereafter. Cichlids may have used a pseudo bridge (Nicaragua Rise) to reach the Greater Antilles. Gars (Lepisosteidae) may have crossed the Straits of Florida to Cuba, a relatively short crossing that is not a barrier to gene flow for several cyprinodontiform immigrants. Indeed, widespread distributions of Quaternary migrants (Cyprinodon, Gambusia, Kryptolebias), within the Greater Antilles and among neighbouring bioregions, imply that long-distance dispersal is not necessarily inhibitory for well-adapted species, even though it appears to be virtually impossible for all other freshwater fishes.

In South Africa, freshwater habitats are among the most threatened ecosystems, and freshwater fishes are the most threatened species group. Understanding patterns in freshwater fish diversity, threat, invasion, and protection status are vital for their management. However, few studies have undertaken such analyses at ecologically and politically appropriate spatial scales, largely because of limited access to comprehensive biodiversity data sets. Access to freshwater fish data for South Africa has recently improved through the advent of the Freshwater Biodiversity Information System (FBIS). We used occurrence records downloaded from the FBIS to evaluate spatial patterns in distribution, diversity, threat, invasion, and protection status of freshwater fishes in South Africa. Results show that record density varies spatially, at both primary catchment and provincial scales. The diversity of freshwater fishes also varied spatially: native species hotspots were identified at a provincial level in the Limpopo, Mpumalanga, and KwaZulu-Natal provinces; endemic species hotspots were identified in the Western Cape; and threatened species hotspots in the Western Cape, Mpumalanga, Eastern Cape, and KwaZulu-Natal. Non-native species distributions mirrored threatened species hotspots in the Western Cape, Mpumalanga, Eastern Cape, and KwaZulu-Natal. Some 47% of threatened species records fell outside of protected areas, and 38% of non-native species records fell within protected areas. Concerningly, 58% of the distribution ranges of threatened species were invaded by non-native species.

We assessed dispersal and vicariant events in four species of Japanese moles in the genera Mogera and Euroscaptor to better understand the factors shaping intra- and interspecific differentiation in Japanese moles. We used the combined viewpoints of molecular phylogeny and historical geology using nucleotide sequences of mitochondrial (cytochrome b; Cytb) and nuclear (A2ab, Bmp4, Tcf25, vWf) genes. The divergence times estimated from the molecular data were verified with available geological data on the chronology of fluctuations in sea level in the Korea Strait, assuming sequential migration and speciation events. This produced possible migration times of 5.6, 3.5, 2.4, and 1.3 million years ago for four species of Japanese moles, Euroscaptor mizura, Mogera tokudae, M. imaizumii, and M. wogura, respectively. For the western Japanese mole M. wogura, Cytb sequences revealed four major phylogroups with strong geographic affinities in southwestern Central Honshu (I), western Honshu/Shikoku (II), Kyushu/westernmost Honshu (III), and Korea/Russian Primorye (IV). The nuclear gene sequences supported the distinctiveness of phylogroups I and IV, indicating long, independent evolutionary histories. In contrast, phylogroups II and III were merged into a single geographic group based on the nuclear gene data. Intraspecific divergences in M. imaizumii and M. tokudae were rather apparent in Cytb but not in nuclear gene sequences. The results suggest that repeated dispersal events have occurred between the Asian continent and the Japanese Islands, and intensive vicariant events associated with abiotic and biotic factors have created higher levels of species and genetic diversities in moles occurring on the Japanese Islands.

Hydropower plants represent one of the greatest threats for freshwater fish by fragmenting the habitat and avoiding the species dispersal. This type of dispersal barrier is often disregarded when predicting freshwater species distribution due to the complexity in inserting the species dispersal routes, and thus the barriers, into the models. Here, we evaluate the impact of including hydroelectric dams into species distribution models through asymmetrical dispersal predictors on the predicted geographic distribution of freshwater fish species. For this, we used asymmetrical dispersal (i.e., AEM) as predictors for modeling the distribution of 29 native fish species of Tocantins-Araguaia River basin. After that, we included the hydropower power plant (HPP) location into the asymmetrical binary matrix for the AEM construction by removing the connections where the HPP is located, representing the downstream disconnection a dam causes in the fish species dispersal route. Besides having higher predicted accuracy, the models using the HPP information generated more realistic predictions, avoiding overpredictions to areas suitable but limited to the species dispersal due to an anthropic barrier. Furthermore, the predictions including HPPs showed higher loss of species richness and nestedness (i.e., loss of species instead of replacement), especially for the southeastern area which concentrates most planned and built HPPs. Therefore, using dispersal constraints in species distribution models increases the reliability of the predictions by avoiding overpredictions based on premise of complete access by the species to any area that is climatically suitable regardless of dispersal barriers or capacity. In conclusion, in this study, we use a novel method of including dispersal constraints into distribution models through a priori insertion of their location within the asymmetrical dispersal predictors, avoiding a posteriori adjustment of the predicted distribution.

The seeds of most plant species are dispersed by multiple mechanisms. Whether functional traits mediate positive correlations or negative correlations (trade-offs) between different dispersal mechanisms has important consequences for ecological and evolutionary dynamics. We investigate how traits affect wind-driven seed dispersal through the air and across the ground (primary and secondary wind dispersal, respectively). We hypothesized that primary and secondary wind dispersal were positively correlated because they should both decrease with the wing loading of seeds. We test this hypothesis with wind-tunnel experiments using different seed morphologies of Zygophyllum xanthoxylon (heterocarpous) and Calligonum species. We measured primary dispersal distance at varying wind speeds and release heights, and quantified secondary dispersal potential as the threshold wind speed for seed movement on four ground surfaces. Contrary to our expectation, we found a context-dependent trade-off between primary and secondary wind dispersal. The smoother the ground surface, the stronger this trade-off becomes. The trade-off results from a positive relationship between wing loading and the ratio of vertical to horizontal seed projection (v/h-ratio): an increasing v/h-ratio not only promotes secondary dispersal on smooth surfaces by increasing wind interception of seeds, but also decreases primary dispersal distance by increasing wing loading and terminal velocity of seeds. The trade-off contradicts the widespread assumption of a positive correlation between primary and secondary dispersal. A simple classification into poorly and well-dispersed seeds is thus not possible. The trade-off may affect dynamics of succession and the expansion of pioneer vegetation, while potentially slowing down evolutionary responses to selection on seed dispersal.

Mims MC, Olden JD, Shattuck ZR, Poff NL. Life history trait diversity of native freshwater fishes in North America. Ecology of Freshwater Fish 2010: 19: 390–400. © 2010 John Wiley &amp; Sons A/SAbstract – Freshwater fish diversity is shaped by phylogenetic constraints acting on related taxa and biogeographic constraints operating on regional species pools. In the present study, we use a trait‐based approach to examine taxonomic and biogeographic patterns of life history diversity of freshwater fishes in North America (exclusive of Mexico). Multivariate analysis revealed strong support for a tri‐lateral continuum model with three end‐point strategies defining the equilibrium (low fecundity, high juvenile survivorship), opportunistic (early maturation, low juvenile survivorship), and periodic (late maturation, high fecundity, low juvenile survivorship) life histories. Trait composition and diversity varied greatly between and within major families. Finally, we used occurrence data for large watersheds (n = 350) throughout the United States and Canada to examine geographic patterns of life history variation. Distinct patterns of life history strategies were discernible and deemed congruent with biogeographic processes and selection pressures acting on life history strategies of freshwater fishes throughout North America.

The Southeastern Fishes Council Technical Advisory Committee reviewed the diversity, distribution, and status of all native freshwater and diadromous fishes across 51 major drainage units of the southern United States. The southern United States supports more native fishes than any area of comparable size on the North American continent north of Mexico, but also has a high proportion of its fishes in need of conservation action. The review included 662 native freshwater and diadromous fishes and 24 marine fishes that are significant components of freshwater ecosystems. Of this total, 560 described, freshwater fish species are documented, and 49 undescribed species are included provisionally pending formal description. Described subspecies (86) are recognized within 43 species, 6 fishes have undescribed subspecies, and 9 others are recognized as complexes of undescribed taxa. Extinct, endangered, threatened, or vulnerable status is recognized for 28% (187 taxa) of southern freshwater and diadromou...

The insular radiation of hutias is remarkable among mammals for its high rate of extinction during the Holocene (~58% of species), yet fragments of intact habitat throughout the West Indies retain a critical portion of endemic diversity needing assessment. Cuba contains 8 of the 11 recognized living species of hutias, with surviving forms also on Hispaniola, Jamaica, and the Bahamas. Herein, we performed molecular phylogenetic analyses across populations of Cuban hutias in the genera Capromys, Mesocapromys, and Mysateles to address major gaps in our understanding of their species limits, phylogenetic structure, and geographic distributions. Comparing sequences of mitochondrial genes (cyt-b, COI, 12S rRNA) from 41 individuals and 21 sites across the archipelago, we found evidence that Capromys pilorides contains a major species-level subdivision from western to eastern Cuba, spanning a greater geographic region than previously hypothesized. Populations of Capromys in each clade last shared a common ancestor ~1.1 million years ago (Ma; 5.2% cyt-b divergence). The western clade is further subdivided between mainland hutias (C. p. pilorides) and those on Isla de la Juventud plus Cayo Cantiles (C. p. relictus has priority). The eastern clade contains all Capromys east of Sierra del Escambray in central Cuba, including mainland and insular forms. However, without paired analyses of morphology and genetics or data from type localities, we cannot assign a name to the eastern Capromys sp. nov. at this time. Divergence-time analyses across 9 named species of hutias (plus 1 extinct), including nuclear genes (GHR, vWF, RAG1), dates the Capromyidae split from their South American relatives (Echimyidae) at 15.5 Ma. The crown radiation of hutias was 8.8 Ma, with successive divergences at 5.4 Ma (Geocapromys), 3.1 Ma (Capromys), and 2.2 Ma (Mysateles–Mesocapromys). Detailed surveys are needed to assess the conservation status of these evolutionarily distinct Cuban taxa. La radiación insular de jutias es notable entre los mamíferos por su alta tasa de extinción durante el Holoceno (~ 58% de las especies). Sin embargo, fragmentos de hábitat intacto en las Antillas conservan una porción de diversidad endémica que necesita evaluación. Cuba contiene 8 de las 11 especies vivas de jutias reconocidas, con especies sobrevivientes también en Hispaniola, Jamaica y las Bahamas. Aquí realizamos un análisis filogenético molecular usando poblaciones de jutias cubanas de losgéneros Capromys, Mesocapromys y Mysateles para definir los límites de sus especies, la estructura filogenética y las distribuciones geográficas. Comparando secuencias de genes mitocondriales (cyt-b, COI, ARNr 12S) de 41 individuos recogidos en 21 sitios a través del archipiélago, encontramos evidencia que sugiere que Capromys pilorides contiene una subdivisión mayor a nivel de especie del oeste al este de Cuba, pero que abarca una región geográfica mayor que la hipotetizada anteriormente. Poblaciones de Capromys en cada clado compartieron por última vez un antepasado común hace ~1,1 millones de años (Ma, 5,2% de divergencia de cyt-b). El clado occidental está subdividido entre las jutias de la isla de Cuba (C. p. pilorides) y las de la Isla de la Juventud y Cayo Cantiles (C. p. relictus tiene prioridad). El clado oriental contiene todos Capromys al este de la Sierra del Escambray, en el centro de Cuba, incluyendo la parte de la isla principal (Cuba) y formas insulares. Sin embargo, sin un análisis conjunto de morfología y genética o datos de localidades tipo, no podemos asignar un nombre al Capromys sp. nov. oriental en este momento. Los análisis de divergencia temporal para 9 especies nombradas de jutias (más 1 extinto), incluyendo genes nucleares (GHR, vWF, RAG1), datan la separación de Capromyidae de sus parientes sudamericanos (Echimyidae) en 15.5 Ma, la corona evolutiva de jutias en 8.8 Ma y las divergencias sucesivas en 5.4 Ma (Geocapromys), 3.1 Ma (Capromys) y 2.2 Ma (Mysateles–Mesocapromys). Estudios geográficos detallados son necesarios para evaluar el estado de conservación de estos taxones cubanos evolutivamente distintos.

We resurrected Typhlops cubae Bibron, 1843, a species considered as a nomen dubium for the past 55 years. Based on a designated lectotype and nearly 80 additional specimens, we redescribed the species and compare it with other congeners from the Bahamas, Cuba, and Hispaniola Islands. We found that Typhlops cubae is related to the Typhlops lumbricalis species group, restricting its distribution to western Cuba and Isla de la Juventud, and overlapping with Typhlops pachyrhinus along the Pinar del Río and Artemisa provinces. We also provided additional comments about the taxonomy of other Cuban Typhlops updating their geographical distribution.

Abstract. Roesma DI, Tjong DH, Aidil DR, Prawira FDL, Saputra A. 2024. Freshwater fish diversity from Siberut Island, a small island in the western part of Sumatra, Indonesia. Biodiversitas 25: 836-845. Indonesia is an archipelagic country with thousands of islands, including small islands with a variety of biodiversity, such as freshwater fish. Data and information on the fish biodiversity of small islands in the western part of Sumatra are limited, including Siberut Island. A study on freshwater fish diversity in Siberut Island was carried out using morphological and molecular methods. The study was conducted on seven rivers in the North and South Siberut Districts, Siberut Island. The study obtained 676 individuals, including 34 species, 26 genera, 16 families, and 10 orders. Oxudecidae is the family with the largest species (8), and Rasbora jacobsoni has the highest number of individuals (341). Species richness ranged from 2 to 18 species per site and was highest in the Srilanggai River. Siberut Island has low-moderate freshwater fish diversity. As many as 90 DNA barcodes of individuals from 34 species have been submitted to the Barcode of Life Data System. Freshwater fish groups do not receive enough attention from local communities and the government because of the richness of marine fish on Siberut Island. Apart from functioning as evidence of species richness, the results of this study are also useful for local communities' education.

Ohee HL. 2016. Freshwater fish diversity in an oil palm concession area in Mimika, Papua. Biodiversitas 17: 665-672. New Guinea’s freshwater fish diversity may reach 400 species, twice the number of fish recorded in Australia. However, New Guinea’s freshwater fishes are facing rapid and poorly-planned social and economic developments, which have accelerated both habitat loss and degradation, impacting its unique biodiversity and threatening natural ecosystems. This study documents freshwater fish diversity and threats due to habitat conservation from oil palm development in the Timika Region, Papua. Fishes were sampled in canals, creeks, streams and rivers in the concession area of Pusaka Agro Lestari Company (PT. PAL) using seine and hand nets and a spear gun. Twenty two freshwater fish species in 15 families and 15 genera were recorded from the area. One of them is an endemic species ofTimika (Glossamia timika), one rainbowfish species with a restricted Southern New Guinea distribution, and 12 other native fishes. Land clearing leads to increase water turbidity and sedimentation, water temperature, and pollution which are potential threats to native fishes and their habitats. The fact that PAL’s concession is part of distribution area of known distribution of G. timika in Timika vicinity, habitat conversion to palm oil elevates the threat to this species. Hopefully, PT. PAL will adopt necessary conservation measures to mitigate the potential impact during the land clearing, especially, if they leave riparian buffer regions intact to protect aquatic habitats when clearing land.

BackgroundThe interplay of animal dispersal and environmental heterogeneity is fundamental for the distribution of biodiversity on earth. In the ocean, the interaction of physical barriers and dispersal has primarily been examined for organisms with planktonic larvae. Animals that lack a planktonic life stage and depend on active dispersal are however likely to produce distinctive patterns.MethodsWe used available literature on population genetics and phylogeography of elasmobranchs (sharks, rays and skates) to examine how marine barriers and dispersal ecology shape genetic connectivity in animals with active dispersal. We provide a global geographical overview of barriers extracted from the literature and synthesize the geographical and hydrological factors, spatial and temporal scales to characterize different types of barriers. The three most studied barriers were used to analyse the effect of elasmobranch dispersal potential and barrier type on genetic connectivity.ResultsWe characterized nine broad types of marine barriers, with the three most common barriers being related to ocean bathymetry. Themaximum depth of occurrence,maximum body sizeandhabitatof each species were used as proxies for dispersal potential, and were important predictors of genetic connectivity with varying effect depending on barrier type. Environmental tolerance and reproductive behaviour may also play a crucial role in population connectivity in animals with active dispersal. However, we find that studies commonly lack appropriate study designs based on a priori hypotheses to test the effect of physical barriers while accounting for animal behaviour.Main conclusionsOur synthesis highlights the relative contribution of different barrier types in shaping elasmobranch populations. We provide a new perspective on how barriers and dispersal ecology interact to rearrange genetic variation of marine animals with active dispersal. We illustrate methodological sources that can bias the detection of barriers and provide potential solutions for future research in the field.

Drainage rearrangements, either headwater captures or coastal paleodrainages formed when sea level was low, are often invoked to explain connectivity and isolation among fish populations. Unravelling these events is crucial for understanding the evolutionary processes that have shaped the genetic diversity and differentiation in freshwater fishes, which is especially relevant in regions with high endemism and species richness. Here, we analyse mitochondrial (cytochrome c oxidase subunit I) and genomic (restriction site‐associated DNA) data to test the putative effects of the current configuration of basins and historical drainage rearrangements on the genetic structuring of a characid fish (Nematocharax) endemic to a largely overlooked Neotropical freshwater ecoregion—the North‐eastern Mata Atlantica. Bathymetric and geomorphological data were also used to generate hypotheses for two potential routes of dispersal (headwater captures and coastal paleodrainages). We found that the divergence between lineages from the highlands of the Brazilian shield and the lowlands occurred during the Mio‐Pliocene (i.e., divergence between Nematocharax varii and Nematocharax venustus), followed by divergence events within N. venustus in lowland basins during the Pleistocene. The general distribution of genetic variation in N. venustus seems to reflect the current configuration of basins, suggesting long‐term isolation, but a subset of the inferred drainage rearrangements have facilitated movement among these catchments, which is supported by both mitochondrial DNA and genomic data. Our results suggest that the North‐eastern Mata Atlantica river basins have had their own independent histories, except for some past temporary connections that allowed dispersal events and multiple independent colonisation of basins, as seen in the Contas and Cachoeira river systems. Estimating when and where connections between river basins may have occurred is fundamental to understand the role of different historical processes structuring divergence in freshwater fish species.

Freshwater fish diversity is the number of fish species found in freshwater areas. This research is an exploratory study aimed at the diversity of freshwater fish in the Sanenrejo and Wonoasri Resort’s Rivers of Meru Betiri National Park. Fishes were caught using gill nets with mesh sizes 0.5 inch and handnet The level of diversity of freshwater fish in the Sanenrejo and Wonoasri Resorts is classified as being moderate with the diversity index values in the Sanenrejo and Wonoasri Resorts respectively 1.5902 and 2.2323 while the overall index value is 2.4102. Freshwater fish found consisted of 15 species, namely: Barbodes binotatus, Trichopodus trichopterus, Neovespicula depressifrons, Rasbora lateristriata, Planiliza subviridis, Orechromis niloticus, Eleotris melanosoma, Dermogenys pusilla, Periopthalmus argentilineatus, Pterygoplichthys pardalis, Channa gachua, Butis butis, Nemacheilus fasciatus, Siycopterus cyanocephalus, and Monopterus albus.

Abstract. Suryaningsih S, Bhagawati D, Sukmaningrum S, Sugiharto, Puspitasari IGAAR. 2020. Freshwater fish diversity in three tributary streams in Serayu Basin, Central Java, Indonesia. Biodiversitas 21: 5811-5817. Determining the diversity of freshwater fish species in Central Java, Indonesia has been confounded by temporal and spatial limitations in past studies. The Serayu Basin is a large watershed in Central Java that is believed to have high freshwater fish diversity. We aimed to determine the diversity and community structure of freshwater fish species in three tributaries of the Serayu, elucidate the factors influencing this diversity, and determine the extent to which these tributaries contribute to the total freshwater fish species richness for southwest Central Java. We conducted gill net sampling from May to August 2018 on the Tulis, Mrawu, and Kali Sapi Rivers located at Banjanegara district Sampling followed a random group technique in upstream, midstream, and downstream river sections of each tributary. In total, we observed 21 freshwater fish species. Broadly, fish species diversity was relatively low in the study area, and water temperature and dissolved oxygen were important in maintaining fish diversity. These three tributaries house 27–46% of the freshwater fish species reported for southern Central Java.