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Enigmatic armoured catfishes (Siluriformes: Callichthyidae and Loricariidae) in ornamental aquaculture: A new insight into Neotropical fish diversity
Abstract
Globally, ornamental aquaculture is a multi-million-dollar industry and popular hobby. There are circa 6700 fish taxa being exploited and traded. Various species are traded under commercial names or codes such as certain armoured catfish of families Callichthyidae (C and CW codes or numbers) and Loricariidae (L and LDA codes). Many of these species are imported, reared and multiplied in captivity without their species identification. Here we present a detailed survey of this group of armoured catfish with a special focus on pairing of commercial codes with scientific names. In this context, both species with valid names and scientifically undescribed taxa contributed significantly to the total number of ornamental fish species by circa 25%. In total, 176 species of loricariids and 47 species of small callichthyids were paired with codes used in ornamental aquaculture. The total number of loricariids introduced as ornamentals was estimated to be more than 1000 taxa while more than 500 in small callichthyids. We recommend present findings to all stakeholders and especially taxonomists, conservationists and wildlife managers who are focused on this group of Neotropical fishes. Moreover, formal descriptions of unidentified taxa are required for feasible future monitoring and appropriate management measures of wild populations.
... in the artisanal fishery and the ornamental fish trade (Novák et al., 2022). Despite their great diversity in morphology, ecology, and habitats, Loricariidae is recovered as a monophyletic group in both morphological and molecular phylogenetic reconstructions, though the relationships between the tribes and genera have not been fully resolved so far (Covain et al., 2016;Londoño-Burbano and Reis, 2021). ...
The remarkable fish biodiversity encompasses also great sex chromosome variability. Harttia catfish belong to Neotropical models for karyotype and sex chromosome research. Some species possess one of the three male-heterogametic sex chromosome systems, XY, X1X2Y or XY1Y2, while other members of the genus have yet uncharacterized modes of sex determination. Particularly the XY1Y2 multiple sex chromosome system shows a relatively low incidence among vertebrates, and it has not been yet thoroughly investigated. Previous research suggested two independent X-autosome fusions in Harttia which led to the emergence of XY1Y2 sex chromosome system in three of its species. In this study, we investigated evolutionary trajectories of synteny blocks involved in this XY1Y2 system by probing six Harttia species with whole chromosome painting (WCP) probes derived from the X (HCA-X) and the chromosome 9 (HCA-9) of H. carvalhoi. We found that both painting probes hybridize to two distinct chromosome pairs in Amazonian species, whereas the HCA-9 probe paints three chromosome pairs in H. guianensis, endemic to Guyanese drainages. These findings demonstrate distinct evolutionary fates of mapped synteny blocks and thereby elevated karyotype dynamics in Harttia among the three evolutionary clades.
... Considerable effort is therefore required to keep abreast of hobbyist naming conventions, particularly if future taxonomic resolution occurs. To this end, the work conducted by Novák et al. (2022) provides a useful template of how hobbyist pseudo-taxonomic units such as Lnumbers can be matched (in some cases) to current taxonomy. ...
The wildlife (animal and plant) trade has moved online, which presents researchers and enforcement agencies with an unprecedented opportunity to monitor trade activity to manage environmental biosecurity and combat illegal activities. The invasion risk posed by ecommerce was previously identified by the Environment and Invasives Committee Scoping Study on “E-commerce in invasive species”. There was broad acknowledgment that existing ad hoc monitoring of wildlife trade on the internet was insufficient to fully quantify risk and aid prevention. This report can assist Australian biosecurity practitioners and decision-makers to establish their own surveillance systems to enable early preventative action to protect Australia’s economy, environment, and social wellbeing from the burgeoning costs of the illegal wildlife trade. In this report we detail the internet surveillance project we established to monitor the alien vertebrate pet trade and declared ornamental plant trade. This project contributes to Australia’s implementation of Convention on Biological Diversity Aichi Target 9: By 2020, invasive alien species and pathways are identified and prioritized, priority species are controlled or eradicated, and measures are in place to manage pathways to prevent their introduction and establishment. We constructed automated monitoring systems for about 90 ‘open-web’ websites (e.g. ecommerce, stores, forums) across four continents. To date, we have collected over seven million unique, online wildlife advertisements at a rate of about 2.5 million advertisements per year. With feedback and communication from government practitioners and stakeholders, we constructed a user-friendly website that can be used to query our database and receive email alerts. We named this website DIWT: Digital surveillance for Illegal Wildlife Trade. DIWT is different from any other surveillance platform currently being used to survey and detect online wildlife trade in Australia (Appendix S5). We use several case studies to demonstrate how we used our dataset of online advertisements. These case studies include the illegal plant and animal trade in Australia, as well as exploring the burgeoning trade in live invertebrates as pets. In particular, we have greatly expanded knowledge of the ecommerce pathway in Australia and implemented a more strategic and coordinated approach to ecommerce surveillance. DIWT will enable government biosecurity agencies to better manage this pathway, while future research will be required to extend our work to other ecommerce trading platforms (including user-groups and forums) and include automated approaches for combating illicit behaviour (e.g., incorporating image recognition plug-ins and machine learning).
... "Tapajos Red head" as Geophagus pyrocephalus (Chuctaya et al., 2022)). To this end, the work conducted by Novák et al. (2022) provides a useful template of how hobbyist pseudo-taxonomic units such as L numbers can be matched (in some cases) to current taxonomy. ...
The international trade of non-domesticated pets impacts both conservation and biosecurity via the harvest and release of live animals beyond their native distributions. The extent to which individual countries mitigate these impacts via regulation of trade is inconsistent, as is their capacity to monitor internet facilitated trade. We investigated the online trade of vertebrate pets within Australia, a country with a reputation for relatively stringent pet-importation regulations and world-class border biosecurity. Using semi-automated data mining (i. e., webscraping) techniques, we collected online pet trade data over the course of 14 weeks from 12 Australian e-commerce platforms selected using an a priori set of search terms. We analysed spatial, temporal and taxonomic biases in trade and identified instances of high rates of trade in: (i) threatened species, (ii) non-native species, (iii) and species not permissible for live import. We identified over 100,000 individual live animals across 1192 species, including: 667 non-native species for sale within Australia from 03/12/2019 to 20/03/2020 (mammals were excluded from our analysis). Our findings constitute a much greater scale (in terms of abundance and richness) of non-native species trade than previously recorded in Australia. Substantial changes to legislative control of domestically traded pets are needed at the national level to reduce the volume of non-native pets that may contribute to the establishment of invasive species in Australia. We suggest that contemporary examples of permit systems applied to native taxa may provide a valuable template for the implementation of such changes.
... Although there are many studies of fish pigmentation and its impact on the social structure of a shoal, data regarding the effects of pigmentation on fish welfare in aquaculture are rare. Additionally, in recent years, production aquaculture and the ornamental fish trade have exhibited rapid increases (FAO, 2020;Novák et al., 2020Novák et al., , 2022; hence, we focused on the welfare of differently pigmented fish in a shoal and the possible consequences for aquaculture. ...
Pigmentation is an important factor for the survival of organisms in different environments; in fish, it plays a key role in social communication and shoal formation. Pigmentation mediates communication among colour phenotypes, as fish may temporarily change colouring to indicate their position in a social hierarchy. Although some colour phenotypes may be more common, less frequent colourations do not appear to significantly impact fish welfare, as aggression is directed more towards common, typically pigmented phenotypes than rare phenotypes. The relationship between pigmentation and fish behaviour can be clearly observed with extremely coloured phenotypes, i.e., albino and melanistic individuals. The melanocortin hypothesis states that phenotypes with more pigmentation are more aggressive, reproductively active, and resistant to stress as well as having better overall health. However, the high levels of aggression expressed by melanistic phenotypes may reduce the well-being of less intensely pigmented phenotypes if these individuals are kept together. In contrast, albino individuals are more sensitive to stress, less aggressive, and, as they are prone to physiological constraints such as impaired vision, are unable to effectively defend resources compared to pigmented phenotypes. Moreover, both these extremely coloured phenotypes are unable to signal their position in the social hierarchy by changing colours, which can result in conflict between their mental state and position in a social hierarchy and/or attempt to change their social rank. In summary, colour variation is a consequence of physiological conditions, especially stress, rather than a cause of such conditions. The breeding and propagation of albino and melanistic fish is generally unethical and should not be considered in aquaculture unless these phenotypes are bred separately under specific conditions, i.e., not kept with typically pigmented conspecifics.
... Species endemic to the restricted area are more at risk from stressors like pollution, habitat destruction, invasive alien species, pathogens, and overharvesting. It is not surprising that certain freshwater species traded as ornamentals are also endangered (Raghavan et al., 2013), e.g., giant arapaima (Arapaima gigas; Marková et al., 2020), zebra loach (Botia striata; Tapkir et al., 2021), Asian arowana (Scleropages formosus; Rowley et al., 2008;Voigt, 2017), European minnow (Phoxinus phoxinus; Patoka et al., 2017a), and Mexican dwarf crayfish (Cambarellus patzcuarensis; Weiperth et al., 2017), bala shark (Balantiocheilos melanopterus; Ng and Tan, 1997) or even species unknown to science such as armoured catfish known as "L", "LDA", "C", and "CW" numbers (Dignall et al., 1999;Evers and Schaefer, 2004;Glaser and Schaefer, 1996;Novák et al., 2022;Schraml and Schaefer, 2004) and New Guinean Cherax crayfish (Parenti and Hadiaty, 2010;Patoka, 2020). Even if policymakers tend to protect endangered species (Voigt, 2017) and regulate the invasive ones, the efficiency of this effort is at least disputable in many cases (Faulkes, 2018;Patoka et al., 2018a) and improved management and conservation practices should be established to protect the endangered species effectively. ...
Ornamental aquaculture is an economically important industry with many enthusiasts worldwide. Much of the supply for the industry is provided by individuals and businesses in tropical countries because many ornamental species originated in the tropics. But Czechia, a temperate region in Central Europe, is an exception. Czech suppliers have significantly influenced the global freshwater ornamental aquaculture market for decades. Here we present and discuss the history of ornamental aquaculture in Czechia considering its geopolitical background, social status and history, pet-trade trends, overlapping to research activities, public education, and related risks and threads. We list the most traded and exported species, and list species that rarely reproduce in captivity, but that are successfully bred for commercial purposes by Czech producers globally, we introduce the term “Czech aquarium phenomenon” to describe the substantial economic and scientific importance of Czechia in ornamental aquaculture. Given that the diversity and volume of species traded are vast, we suggest the importance of this phenomenon for consideration to key stakeholders who design aquaculture policies, including the management of invasive alien species and ex-situ conservation programs for endangered species.
The ornamental pet trade is a biologically diverse multi-billion-dollar industry that transports various exotic pets worldwide. Among aquarium pets, Anentome helena is a carnivorous snail sold widely for its high aesthetic value and aquarium pest snail control ability. The present study documents the differences in prey consumption, selectivity, and predation-derived potential impacts of the exotic predator, A. helena, and native predators, the leech Glossiphonia weberi and the waterbug Diplonychus rusticus, on selected native and invasive snails of West Bengal, India, through laboratory-based prey-choice experiments. Maximum prey consumption was observed in case of D. rusticus, but A. helena consumed a significantly (p < 0.05) higher number of operculate snails. Both native predators preferred non-operculate snails, Racesina luteola and Physella acuta, whereas A. helena preferred R. luteola and an operculate snail, Filopaludina bengalensis, as prey. Proximately, P. acuta faced more apparent competition from other prey snails following the predation of native predators. However, F. bengalensis might face higher apparent competition following the predation of A. helena. Considering the differential predation pattern and higher vulnerability of operculate snails from A. helena predation, awareness should be raised among aquarium enthusiasts to reduce the risk of chance dispersal of such exotic predators.
To understand how Neotropical freshwater fishes (NFF) benefit society, we conducted a broad literature survey to (i) map and list the ecosystem services (ES) generated by these organisms, and (ii) investigate how human activities have affected the ecosystem service chain. We found sound evidence that NFF contribute directly and indirectly to the generation of several provisioning, regulating, supporting, and cultural services. Provisioning services have been widely recognized, especially those related to fisheries, but this class also included ornamental fish, genetic pools, medicines, aquaculture, and bioindicators. Other services remain less understood and largely ignored by society. Regulating services included seed dispersal, decomposition, and top-down control, while supporting services included nutrient cycling, habitat quality, and ecosystem engineering. Cultural services associated with NFF included recreational fishing, tourism, fishkeeping, education, production of scientific knowledge, in addition to values linked to traditional communities, such as local knowledge, cosmology, and existential foundations. Human activities have negatively impacted the generation of ES, especially those related to fishing and food provisioning. This review indicates that Neotropical fishes benefit society in multiple ways, but it is imperative to improve our understanding about those benefits, and to increase conservation efforts directed to this important component of global biodiversity.
Focusing on extreme climatic events in India’s Western Ghats Biodiversity Hotspot, we demonstrate that unmanaged aquaculture and unregulated fisheries can often combine with ECE in exacerbating biological invasions through the unexpected introduction and escape of novel alien species. High magnitude flooding events in August 2018 and 2019 resulted in the escape of at least ten alien fish species that were recorded for the first time, from the natural waters of the Western Ghats. Illegal farming systems, aqua-tourism destinations and amusement parks, as well as reservoirs, facilitated the escape of alien species during the ECE. Despite expanding invasions, unmanaged stocking and aquaculture using alien species continue in the Western Ghats, necessitating urgent management and policy interventions.
Cherax quadricarinatus is a parastacid crayfish native to parts of northeastern Australia and southern New Guinea. It is a relatively large and highly fecund species in comparison with other crayfish of this genus. Since C. quadricarinatus was previously assessed as an invasive species in Indonesia, further monitoring of this species in this region was recommended. Detailed understanding of its spatial behaviour can be the basis for further research aimed at improved management. Field sampling was performed outside its native range in Java, Indonesia from 2019-2020, resulting in data useful for modelling the species' spatial distribution. The occurrence of the species was confirmed in 66 of 70 surveyed localities with 51 new records for Indonesia. Future investigations focused on the relationship between the spatial distribution and dispersal pattern of C. quadricarinatus and its interactions with native biota and entire ecosystems were recommended.
Hypancistrus zebra, also known as the zebra pleco, is a small sucker-mouth catfish endemic to the Xingu River in Brazil where its survival in the wild is threatened by habitat modification and overfishing for the ornamental fish industry. It is a highly sought-after freshwater ornamental species and one of the most commonly trafficked from Brazil. To date, little is known about its global legal and illicit supply chains within the ornamental fish trade. Through a mixed methods approach (i.e., online survey, key informant interviews and web scraping), we examined the trade and trafficking of this species as well as the awareness of the international aquarist community and local and international stakeholders regarding its conservation. We also establish the historical timeline of zebra pleco keeping and breeding in captivity and assess whether commercial captive breeding can play an important role in the conservation of this species. The retail price of the zebra pleco increased worldwide after an export ban in 2004 but have since decreased to an average of $US 155 (+/- $US 23 based on geographical location) per fish. Fishermen have been consistently paid relatively little ($US 7-60) for each specimen compared to the average wholesale price of $US 100 (+/- $US 94 over time). We conservatively estimate ~100,000 specimens are trafficked out of Brazil annually, of which half or more die in transport, and only a small fraction is seized by law enforcement in Brazil or internationally. The fishes are primarily smuggled from Brazil to Peru and Colombia and then exported internationally with the majority sent to China. The majority of aquarists (representing 35 countries) are aware the zebra pleco is both endangered and highly endemic. There was less awareness that buying wild caught specimens shipped from Peru, Colombia or elsewhere implies supporting wildlife trafficking. Nevertheless, nearly three quarters of respondents preferred aquarium bred specimens, if available. The zebra pleco is being bred in captivity in high numbers in several countries, yet in Brazil it remains illegal to keep in private aquaria or to commercially breed them. Given the large success of hobby and commercial breeders around the world, H. zebra is well suited for indoor breeding facilities. We argue that implementing regulated local breeding facilities in Brazil, to increase the already large numbers reproduced in captivity worldwide, could decrease the demand for trafficked specimens, one of the primary factors threatening its survival. Given its iconic status among freshwater fishes it should be recognised as a flagship species of the Xingu River’s conservation.
The updated status of the ornamental fish trade from the Amazonas state was analyzed between the years of 2006-2015 (IBAMA database). The trade of ornamental fish from Amazonas state mainly consists of species extracted from nature. A total of 142,552,253 specimens were exported during the studied period. Sales plummeted since 2006, from 26,075,241 specimens exported then to 2,729,846 specimens in 2015 (Jan-Jul). Between 2006 and 2015, a total of US$ 23.0 million in revenue was generated from fish exports destined to 35 countries. Germany, Taiwan, USA and Japan accounted for 75.5% of the volume and 76.7% of the value exported. During this time, 375 species were exported, included Paracheirodon axelrodi, P. simulans, Hemigrammus bleheri, Otociclus affinis and O. hoppei that together represented 84.5% of exports. Thirty are not on the list of IBAMA species released for export, and six are currently on the list of endangered fauna of Brazil, being them: Hopliancistrus tricornis, Leporacanthicus joselimai, Parancistrus nudiventris, Peckoltia compta, Scobinancistrus auratus and S. pariolispos. These results are an additional tool for managers, environmentalists and decision makers to establish regulations to govern the trade.
Trade with marine species as ornamentals is an important sector of the international pet trade. The vast majority of these species are collected from the wild and one of the top supplying countries is Indonesia. Detailed evidence on trade with marine resources in Indonesia is lacking or it is hardly accessible. Moreover, the exploitation of ornamental species seems to be mostly uncontrolled. This study presents detailed characteristics of such trade for Indonesia, including the offered species, their sizes, prices, and conservation status, based on data and information obtained from wholesalers in 2018. The main provinces of marine wildlife collecting are also identified. In total, 777 marine vertebrate and invertebrate species were traded, belonging to 174 families including two species classified as endangered: Banggai cardinal fish ( Pterapogon kauderni ) and zebra shark ( Stegostoma fasciatum ). Commonly traded was red lionfish ( Pterois volitans ), known to be a successful invader. The volume of ornamental marine fish exported from Indonesia in period 2015–2019 was 3 353 983 kgs sold for 33 123 218 USD. The province of Bali was identified as the main exporter of ornamental marine fish within Indonesia. These findings should help to establish sustainable exploitation of marine resources in relation to conservation and wildlife management.
Ornamental aquaculture is known to be one of the main sources of non-native species and Indonesia has been identified as one of the leading suppliers of these organisms worldwide. Released or escaped ornamental aquatic animals can establish new populations and become invasive. On the other hand, some invasive species can be also endangered in their native range, which is called the "Biodiversity Conservation Paradox". This is true for Arapaima gigas, one of the popular ornamental creatures and the largest bony fish of all, which is threatened in its native range in parts of Amazonia and which has been found to occur in various localities in Java and Sumatra in Indonesia. Based on climate matching we found the vast majority of Indonesian territory to be suitable for this species establishment. Keeping in mind the size and predatory behaviour of A. gigas, we discussed possible consequences of its spread and impacts on native biota in Indonesia.
There is a long history of crayfish introductions in Europe and numbers keep increasing. In Hungary, spiny-cheek crayfish Faxonius limosus, signal crayfish Pacifastacus leniusculus, red swamp crayfish Procambarus clarkii, marbled crayfish P. virginalis and Mexican dwarf crayfish Cambarellus patzcuarensis have become established. Here we report on monitoring at two localities with novel crayfish assemblages closely linked to releases associated with the pet trade. Florida crayfish Procambarus alleni were recorded from the Gombás brook near Vác living in syntopy with the established spiny-cheek crayfish. Dozens of Florida crayfish individuals including egg-carrying females have been detected. The short lifespan of this species and its documented presence including two overwintering in at least two years suggests possible establishment. However, the lack of juvenile records calls for further monitoring as long-term propagule pressure cannot be ruled out. We also identified a single marbled crayfish in the Danube floodplain at the end of the monitoring campaign. The second locality (Városliget thermal pond in Budapest) harbours an even more diverse crayfish assemblage. Here, we identified numerous red swamp and marbled crayfish in syntopy with dozens of monitored redclaws Cherax quadricarinatus and seven individuals of New Guinean Cherax species À C. holthuisi, C. snowden, as well as two scientifically undescribed species. These findings clearly indicate the attractiveness of urban and, especially, thermal waters for the release of even expensive aquatic pets and highlight the hitherto poorly known biodiversity of New Guinean crayfish species.
Dwarf suckermouth catfish are preferred especially for small aquariums. They are usually referred to as tank cleaners and commonly traded in the ornamental fish sector. Since these fish are nocturnal, it is difficult to observe their reproductive behavior and larval development. This study was carried out to determine the reproductive variables of bushymouth catfish (Ancistrus dolichopterus) under aquarium conditions. Three broodstocks bushymouth catfish with an average initial weight and a total length of 10.5±0.3 g and 9.5±0.2 cm were stocked in three 240-L aquariums with the ratio of 1:2 (male: female). The observations were made in triplicate tanks for six months. Females laid an average of 39.78±0.41 eggs and fertilization and hatching rates were 75.05% and 62.94%, respectively. It was found that the transition time from egg to apparently larval stage was 105.28 h, and bushymouth catfish showed an indistinguishable development from the hatching to juvenile stage without a real larval transition stage. The results of the study provide basic information on the reproductive performance and early development of bushymouth catfish.
Sailfin catfish indigenous to South America are very popular ornamental fish, having previously been introduced to many regions outside their native range. Two species, namely Pterygoplichthys disjunctivus and P. pardalis, are illegal but widespread in Indonesia. They have formed self-sustaining populations, exploited for feeding of domestic animals and locally for human consumption. Also possible hybrids of the two mentioned species were recorded. The surveyed populations were considered established which perfectly fits with the climate matching analysis. Further monitoring and inspection of regions highlighted to be suitable for sailfin catfish is recommended.
Non-native freshwater fish introduced via the aquarium trade can cause major changes at the community level over time and space, resulting in dynamics context dependencies within homogenization process. We investigated fish biodiversity in anthropogenically impacted headwater creeks (i.e., under elevated propagule pressure) located in southeastern Brazil, through a standardized sampling program. We assessed ichthyological community composition with the aim of quantifying spatio-temporal dynamics across creeks. We divided the sampling period according to decades, in which “2000s” represented 2003, 2004, 2005, and 2006, while “2010s” represented 2015. Changes in pairwise community similarity indicated biotic homogenization in the 2000s (i.e., communities became more similar over time). In contrast, changes in pairwise similarity in the 2010s indicated biotic differentiation. We suggest that these changes are caused by the extirpation of both native and non-native species due to environmental degradation and the occurrence of six new non-native species. The beta-diversity increased between sampling seasons and creeks across decades, also indicating biotic differentiation. Our study provides strong evidence for a transition phase from biotic homogenization to differentiation of fish communities over time, caused by interaction between older environmental degradation and more recent impacts from the Brazilian aquarium trade, reinforcing the importance of simple, practical, and inexpensive long-term studies to understand biodiversity-related processes.
Modern ornamental fishkeeping is one of the most popular hobbies in the world, with various known positive and also negative aspects including the introduction of non-native species. Despite this fact, the history of the first imports of freshwater tropical fish species for ornamental purposes has never been deeply studied and is usually simplified. Here, we present the first comprehensive review of reported imports in the period of the early history of this sector of aquaculture, ending with the end of the First World War. Moreover, the total number of kept species has been updated, with a forecast for the future. We present the sum-marised information in a wide context of both historical and current connections and viewpoints, highlighting the crucial role of German importers at this time. In this regard, the term 'German aquarium phenomenon' is proposed.
The suckermouth armored catfish genus Panaque contains seven valid species, including the Royal Pleco, Panaque nigrolineatus, which has long been popular as an ornamental aquarium fish and was originally described from the Apure River basin in Venezuela. We examine a phenotypically distinct population of P. nigrolineatus from the Guaviare River in southern Colombia at the southwesternmost corner of the Orinoco River basin. In contrast to typically boldly striped populations from closer to the type locality of P. nigrolineatus, the Guaviare River basin population is usually boldly spotted, earning them the common name Watermelon Pleco in the aquarium fish trade. Because of the commercial popularity of this distinctive color morph, it is heavily exploited for export to the global ornamental fish trade. We find that the Guaviare River P. nigrolineatus laurafabianae is not only distinct geographically and in color pattern, but is also morphometrically diagnosable from P. nigrolineatus individuals from outside the Guaviare River basin. However, relatively subtle phenotypic differences, invariance in nuclear DNA markers, < 0.5% divergence in mitochondrial DNA markers 16S, cytb, and ND2, and the non-monophyly of Guaviare River populations prevent us from robustly inferring species-level distinctiveness of the Watermelon Pleco. We therefore propose to recognize this population as a distinct subspecies.
After 80 years of misidentifications, the analysis of the holotype of Corydoras arcuatus plus several non-type specimens attributed to this species allowed its recognition and also revealed a new species, both sharing the following diagnostic features: a long, arched, continuous black stripe that runs parallel to the dorsal profile of the body and extends at least from the anterior margin of the first dorsolateral body
plate to the posterior portion of caudal peduncle; absence of transverse black bars on caudal fin; infraorbital 2 in contact with sphenotic and compound pterotic. In addition to these features, C. arcuatus can be distinguished from congeners by having the posterior margin of both dorsal and pectoral spines with laminar serrations directed towards their origins. The new species can be additionally distinguished from its congeners by presenting the following combination of features: ventral surface of trunk entirely or partially covered by relatively large and coalescent platelets; absence of spots or blotches on dorsal fin; and posterior margin of both dorsal and pectoral spines with serrations directed towards their tips. Finally, an identification key to all arc-striped species of Corydoras is provided.
The global trade in ornamental fish involves c. 125 countries worldwide and is worth c. US $15–30 billion each year. This total is dominated (90%) by freshwater fishes, most of which are sourced from breeding facilities located in developing countries, typically in Asia or South America, but also in Israel, USA and Europe. Some fish are obtained from natural (wild) sources in Asia and South America, but the exact percentage of wild‐caught fish is difficult to quantify given a lack of reliable data. Although c. 1000 species of freshwater fishes are widely available (from a total of > 5300 on sale), the most dominant freshwater fishes in the market comprise only 30 species from the orders Cyprinodontiformes, Perciformes, Characiformes and Siluriformes. In this perspectives review, illustrative example case studies of wild‐fish collecting (Barcelos and Rio Xingu, Brazil) and breeding projects (Java, Indonesia) are described. In addition, wild‐collecting expeditions to West Papua, Indonesia are discussed, focused on discovering novel species of rainbowfish (Melanotaeniidae) for breeding in captivity. Sustainability of the aquarium industry is considered in its broadest sense. The aquarium industry has been portrayed as both a major threat to natural ecosystems, but also as being part of the solution in terms of helping to maintain species when they have gone extinct in the wild or offering an income to impoverished citizens who might otherwise engage in much more destructive practices.
The aim of this study was to characterize the haematological profile of four Amazonian ornamental freshwater armoured catfish: acari-bola (Peckoltia oligospila - L06), acari-pleco (Cochliodon sp. - L145), acari-canoa (Lasiancistrus saetiger - L323) and acari-assacu (Pseudocanthicus spinosus - L160). The highest blood glucose levels (72.47 ± 28.7 mg dL-1) and erythrocyte counts (0.51 ± 0.2 x 106 cel. μL-1) were recorded for acari-canoa. The acari-bola and acari-pleco presented similar concentrations of total plasma protein (TPP) (7.96 ± 1.8 and 7.93 ± 1.8 g dL-1, respectively) against lower TPP concentrations observed in acari-canoa (4.87 ± 1.5 g dL-1) and acari-assacu (6.55 ± 1.5 g dL-1). The acari-assacu had lower total haemoglobin concentration (5.88 ± 1.7 g dL-1) and haematocrit (12.66 ± 4.6%). No interspecific differences were observed in mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC). The acari-pleco and acari-assacu presented the highest counts for neutrophils (4142.42 ± 3280.1 cel. μL-1) and thrombocytes (4778.33 ± 1224.8 cel. μL-1), respectively. The haematological profiles were similar to those reported in the literature for freshwater fish and the interspecific differences observed were discussed.
• The freshwater aquarium trade provides economic and livelihood opportunities to the rural poor, but has been implicated in biodiversity loss through population declines and local extirpation of high‐value endemic species. Previous observations on population declines are largely based on anecdotal data, however, and there are no studies on the population dynamics or stock assessment of freshwater fish species collected for the aquarium pet trade.
• To understand how wild collection of endemic and threatened species for the aquarium trade could affect their populations, the sustainability of collecting the endangered redline torpedo barb (Sahyadria denisonii), and its evolutionarily distinct lineages (henceforth RLTBs), from the Western Ghats region (part of the Western Ghats–Sri Lanka biodiversity hot spot) for the aquarium trade was studied to provide baseline data to inform conservation action.
• Local populations of RLTBs at the five commercial collection sites showed high mortality rates, and fish were exploited before they attained sexual maturity. The unmanaged fishery has led to unsustainable levels of exploitation, and populations of RLTBs at three sites are vulnerable to an impending collapse.
• Endemic and threatened freshwater fish species used in the aquarium pet trade are exposed to local extirpations and global extinctions unless management plans and legislative controls are implemented and strictly enforced. Management plans and conservation actions to help guide the responsible fisheries of RLTBs are suggested, and the wider implications of unmanaged exploitation of endemic aquarium fisheries are discussed.
The rio Ivaí flows through the left margin of the upper rio Paraná basin with 798 km of extension, being one of its largest tributaries. In this study, we analyzed 586 specimens of Hypostomus Lacépède, 1803 from the rio Ivaí basin deposited in the Coleção de Peixes do Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura da Universidade Estadual de Maringá (NUP) and Coleção Ictiológica do Grupo de Pesquisas em Limnologia e Recursos Pesqueiros (CIG). Herein, 14 species of Hypostomus were recorded from the rio Ivaí basin (10 already described and 4 possible new). The most representative species was H. ancistroides , corresponding to 23.5% of all the specimens, followed by Hypostomus sp. 3, with 15.2%, and Hypostomus sp. 2, with 13.8%. Considering Hypostomus , this study suggests that the rio Ivaí has high species richness compared with adjacent basins, such as rio Paranapanema, rio Tibagi, rio Piquiri and rio Iguaçu. Knowing the difficulties founded by many ichthyologists and researchers in identifying species within this genus, we also present here an identification key for its species present in the rio Ivaí basin.
During a survey of loricariid catfishes from Colombia, specimens that match the original description of Chaetostomus setosus Boulenger, 1887 were found. This is the first record after the original description. A redescription and a precise capture locality of the species are provided. The analysis of external characters indicate that the species belongs within the Chaetostoma group; however, specimens of C. setosus possess a mixture of external characters that make generic identification difficult. Tentatively, the species is allocated to the genus Cordylancistrus. External morphology of the known species that belong to the Chaetostoma group (mainly type specimens) was analyzed to find diagnostic characters that may be used for appropriate generic assignment. The results of this analysis are presented herein.
Informal sales of large-bodied non-native aquarium fishes (known as “tankbusters”) is increasing among Brazilian hobbyists. In this study, we surveyed this non-regulated trade on Facebook® from May 2012 to September 2016, systematically collecting information about the fishes available for trading: species, family, common/scientific names, native range, juvenile length, behavior, number of specimens available in five geographical regions from Brazil. We also assessed the invasion risk of the most frequently sold species using the Fish Invasiveness Screening Test (FIST). We found 93 taxa belonging to 35 families. Cichlidae was the dominant family, and most species were native to South America. All species are sold at very small sizes (< 10.0 cm), and most display aggressive behavior. The hybrid Amphilophus trimaculatus × Amphilophus citrinellus, Astronotus ocellatus, Uaru amphiacanthoides, Osteoglossum bicirrhosum, Cichla piquiti, Pangasianodon hypophthalmus, Datnioides microlepis and Cichla kelberi were the main species available. The southeast region showed the greatest trading activity. Based on biological traits, the FIST indicated that Arapaima gigas, C. kelberi and C. temensis are high-risk species in terms of biological invasions via aquarium dumping. We suggest management strategies such as trade regulations, monitoring, euthanasia and educational programs to prevent further introductions via aquarium dumping.
Only one species of armored catfish, Ancistrus cirrhosus Valenciennes 1836, has been historically described in the basin of the Paraná River, from Misiones (Argentina). However, the ample variation found in the morphology and coloration of the populations sampled in the tributaries of the Brazilian state of Paraná makes it difficult to establish the real taxonomic status and evolutionary history of the Ancistrus specimens, suggesting that A. cirrhosus is not the only species found in this basin. By combining data on mitochondrial DNA (COI gene) and chromosomal markers from different Ancistrus populations, totaling 144 specimens, in the tributaries of the Paraná, and specimens from Misiones (type-locality of A. cirrhosus), we detected five distinct evolutionary lineages. All the specimens were 2n = 50, but had four distinct karyotype formulae. The results of the Generalized Mixed Yule Coalescent (GYMC) and the genetic distances (uncorrected P-values) between lineages ranged from 3 to 5%. Clusters of 18S rDNA were observed in a single chromosome pair in seven populations of Ancistrus, but at different positions, in some cases, in synteny with the 5S rDNA sites. Multiple 5S sites were observed in all populations. Overall, the cytogenetic data reinforce the genetic evidence of the diversification of lineages, and indicate the existence of candidate species in the study region. The evidence indicates that at least four candidate species of the Ancistrus may coexist in the Paraná basin besides A. cirrhosus. Overall, our results provide a comprehensive scenario for the genetic variation among Ancistrus populations and reinforce the conclusion that the true diversity of the freshwater fish of the Neotropical regions has been underestimated.
Araichthys loro, a new genus and species of the suckermouth armored catfish family Loricariidae, is described from the rio Papagaio and tributaries, rio Tapajós basin, Mato Grosso State, central Brazil. Araichthys is distinguished from all other genera of the Ancistrini by features of body and head plates, odontodes of breeding males, and osteology, and by the absence of an adipose fin. A phylogenetic analysis of morphological characters obtained Araichthys as part of a monophyletic group that also includes Pseudolithoxus, Ancistrus and Lasiancistrus based on the presence of a large gap with a strut between the anterior process of the pterotic-supracleithrum and its main body, three rows of plates at thinnest part of caudal peduncle, fleshy tentacles on snout with a sheath partially detached from odontodes, and small tentacles on pectoral fins partially detached from odontodes.
Incidental observations of aquatic exotic species may represent important early indicators of established populations. Herein we report ecologically significant observations of 2 exotic fish taxa in southern Alabama-Pterygoplichthys disjunctivus x pardalis (Amazon Sailfin Catfish) and Oreochromis niloticus (Nile Tilapia). Our observations establish the presence and confirm reproduction, respectively, of these species in the state.
The aquarium hobby is popular worldwide, but it has positives and negatives for freshwater fish conservation. The most damaging impacts of the aquarium trade on ecosystems are overharvesting and invasive species. Consequently, many conserva-tionists and academics have the perception that aquarium hobbyists are generally harmful to species conservation. Without overlooking these major drawbacks of the aquarium hobby, we aim to establish common ground between hobbyists and con-servationists by correcting some misconceptions and showing the benefits of serious aquarium hobbyists in the conservation of freshwater fishes and their habitats. Our overview illustrates that the aquarium hobby is not insensitive to the pernicious effects of this enduring hobby on natural systems and that serious aquarists and their associations can directly assist and fund scientific research, increase conservation awareness among the general public and even participate in ex situ and in situ conservation programmes for native fish species at national or international levels. Whilst the relationship between conservationists and the aquarium hobby has often been antagonistic in recent years, ultimately most biologists and aquarists share a love of the species they study or maintain, and this common interest could be the basis for a more positive and productive relationship.
Aquarium fish trade has strongly increased in the past decades to become one of the most popular hobbies globally. Historically, all aquarium fish traded were wild-caught. Then, an increasing number of fish species
have been produced in captivity. The main goal of the present study is to apply the concept of domestication
level to the hundred most popular aquarium fish species in Europe and North America. The levels of domestication
of freshwater aquarium fish species (n = 50) ranged from 0 to 5, with 20 species classified at the level 5
(selective breeding programmes are used focusing on specific goals) and only three species at the level 0 (capture
fisheries) and 1 (first trials of acclimatization to the culture environment). In contrast, the levels of domestication
of marine fish species (n = 50) ranged from 0 to 3, implying that the production of all marine aquarium fish species
is based either entirely or partly on the capture of wild-caught specimens. Based on this new classification,
the main advantages and drawbacks of fisheries and aquaculture are discussed.
Distribuição espacial, locais favoráveis è desova e dimorfismo sexual foram estudados no cascudo Neoplecostomus microps no rio Macaé de março 2004 a março 2005. Espécimes de N. microps estiveram restritos a trechos de águas rápidas, e sua distribuição foi relacionada ao desenvolvimento ontogenético. Larvas em pós-flexão ocorreram somente na vegetação marginal e adultos somente em frestas entre rochas e pedras no canal do rio. Juvenis ocorreram em ambos ambientes. Desovas foram encontradas no ambiente natural em trechos de corredeira, com os ovos aderidos a superfície ventral de rochas em aberturas formadas com o leito do rio. O número de ovos/pedra variou de 62 a 375, com diferenças significativas entre os valores médios dos ovos. Dimorfismo sexual foi verificado em N. microps. As papilas anal e urogenital são separadas em machos e colabadas em fêmeas, e há uma projeção epidérmica na nadadeira peitoral de machos.
The diversity of Hypancistrus species in the Xingu River is remarkable and the variation in color morphs represents a real challenge to taxonomists to delimit species boundaries. One of the most recognizable Hypancistrus complexes is the worm-lined species, known in the aquarium trade as King Tiger Plec in English, Hypancistrus “pão” in Portuguese or under the L-numbers L066 and L333 that represent two melanic pigment pattern phenotypes. To assess the identity of these two phenotypes, we described their karyotypes and sequenced part of the mitochondrial cytochrome oxidase I gene (DNA barcode). These fishes have 52 chromosomes (40 meta-submetacentric and 12 subtelo-acrocentric) and a strong heteromorphism in chromosome pair 21 was observed, which does not correlate with the two phenotypes or sex. DNA barcodes separated the samples analyzed from Hypancistrus zebra and other publicly available sequences of Loricariidae showing no divergence between the two phenotypes. The data set indicates that worm-lined Hypancistrus from the Xingu form a single species with clear chromosomal and melanic pigment pattern polymorphisms.
Worldwide biodiversity assessments have mainly focused on species richness but little is known about the diversity of species roles, i.e. functional diversity, while this is a key facet to understanding the consequences of global changes on the ecosystem services to human societies. Here, we report the world pattern of functional diversity of freshwater fish using a database encompassing morphological characteristics of more than 9,000 species. The Neotropical realm hosts more than 75% of global functional diversity while other realms each host less than 25%. This discrepancy is mediated by high functional uniqueness in some diversified Neotropical fish orders. Surprisingly, functional diversity patterns were weakly related to functional vulnerability. In the Neotropics the loss of threatened species will cause a limited loss of functional diversity (<10%) whereas in the Nearctic and Palearctic realms, decline of the functional diversity will reach 43% and 33%, respectively, conferring a high functional vulnerability to these realms. Conservation of the Neotropical fish diversity is a key target to maintain world fish functional diversity, but this should not hide the pressing need to conserve the vulnerable fish faunas of the rest of the world, in which functional diversity is to a large extent supported by threatened species.
We review the complex history of those species included in the Hypostomus emarginatus species complex and recognize them in Isorineloricaria and Aphanotorulus. Isorineloricaria consists of four valid species: I. acuarius n. sp., I. spinosis-sima, I. tenuicauda, and I. villarsi. Aphanotorulus consists of six valid species: A. ammophilus, A, emarginatus, A. gomesi, A. horridus, A. phrixosoma, and A. unicolor. Plecostomus annae and Hypostoma squalinum are placed in the synonymy of A. emarginatus; Plecostomus biseriatus, P. scopularius, and P. virescens are placed in the synonymy of A. horridus; Plecostomus winzi is placed in the synonymy of I. tenuicauda, and one new species, I. acuarius is described from the Apure River basin of Venezuela. Aphanotoroulus can be distinguished from Isorineloricaria by having caudal peduncles that do not become greatly lengthed with size and that are oval in cross section (vs. caudal peduncle proportions that get proportionately longer with size and that become round in cross-section), and by having small dark spots (less than half plate diameter) on a light tan background (vs. spots almost as large as lateral plates on a nearly white background.
Two new species, Hypancistrus phantasma and Hypancistrus margaritatus, are described based on material from the Rio Negro drainage. Both species are distinguished from congeners by unique color patterns. Hypancistrus phantasma is described from the Rio Uaupes and differs from congeners by having a tan body with small dark spots (vs. dark with light spots or with saddles or stripes). Hypancistrus margaritatus is described from the Takutu River and differs from congeners by having densely-packed light spots on a dark brown background, with spots about the size of the nasal aperture (vs. sparse light spots either smaller or larger than the nasal aperture, or brown to black spots, saddles, or stripes).
Hypostomus fonchii sp. n. is described. Diagnostic characters are the unicuspid premaxillary and dentary teeth, present in subadults as well as in adults, and the elongated and broad tooth crown. Because these tooth characters are intermediate between Hypostomus and Cochliodon, and because dentition traits are the only characters diagnosing Cochliodon, the discovery of H. fonchii provides evidences for questioning the generic status of Cochliodon. We conclude that Cochliodon is a subjective junior synonym of Hypostomus. This work is the first part of our joint investigations on Hypostomus based on both morphological and molecular characters.
Countless animals, including threatened species from invertebrates to vertebrates, are the victims of the world's largest illegitimate business—illicit sales of wildlife. Botia striata (zebra loach) is an endangered freshwater fish endemic to the Western Ghats of India. Because of its distinctive stripes, it is heavily exported and ranks second in the volume of trade in aquarium pets from India. However, maintaining a sustainable aquarium trade is a complex task which depends on the availability of authentic data on the volume of trade, trade routes and the supply chain of the species involved. In this study, therefore, we collected five years of trade data including daily exports of zebra loach from India's international airports to identify the global centers for its trade, its exact traded volume and trade routes. To support artificial breeding programs of zebra loach, the breeding season and size at first maturity were also determined. Using reproductive biology data, the number of individuals traded during the breeding season and the total contribution of immature individuals to the trade were also determined. Results revealed that 265,610 zebra loach were exported from five exit points in India to sixteen different countries (global centers in Asian countries). The greatest number of consignments was from Kolkata, which makes it the top exit point for the zebra loach trade. Singapore is the top importer (73.05 %) of zebra loach and thus probably acts as a transit hub for the distribution of zebra loach individuals across the globe. About 60% of the zebra fish were exported during the breeding season suggesting that the global aquarium pet trade may increase the fish’s risk of extinction. Our global maps of trade centers of the study species would serve as “The past as a guide to the future”. The present study indicates that sustainable trade in wildlife can be achieved if laws are enacted and enforced to require information on traded species, support functional artificial breeding programs, include species of conservation concern into CITES appendices and ensure strict enforcement of laws to preserve biodiversity.
Despite its social and economic benefits, the ornamental trade has become a major source of non-native fish introductions into freshwater ecosystems. However, the ornamental trade as a vector for introductions of non-native freshwater fishes is not well defined. We developed a framework incorporating elements of biological invasion processes and a typical ornamental fish trade supply chain to fill this gap. Records of non-native ornamental fishes introduced to freshwater environments of Australia, Belgium (Flanders), Canada (British Columbia), China (Guangdong), the Philippines, Poland, Singapore, the United Kingdom (England), and the United States of America (Florida) were reviewed to explore the pervasiveness of these introduced fishes in the wild. These regional case studies confirmed the prominence of the ornamental trade as a global vector for freshwater fish introductions beyond their natural range. Additionally, we examined freshwater fishes associated with the ornamental trade to identify ‘risky’ species that could establish in recipient regions based on climate match. All regions assessed were at risk of new fish introductions via the ornamental trade, with the number of ‘risky’ species ranging from seven to 256. Further, there appears to be taxonomic bias in the freshwater ornamental fish trade, with 74% of the species belonging to just 10 families (of 67). Current prevention and management approaches and associated polices, regulations and legislation on aquatic non-native species within assessed regions fit five general categories: import controls, risk assessment, whitelist, blacklist, and release ban. However, these prevention/management efforts may not be sufficient to reduce the invasion risk associated with the ornamental fish trade. Recommendations including species- and vector-based risk assessments, better recording of species import consignments, increased public education and industry engagement, early detection and rapid response are each discussed in this review.
Two new species of the suckermouth armored catfish genus Baryancistrus are described from the Jari River basin, at the border of Pará and Amapá states, Brazil. The new species are the first representatives of the genus described from rivers draining the Guiana shield, and can be distinguished from their congeners by color pattern and a combination of non- exclusive characters. Baryancistrus micropunctatus, new species, has a color pattern similar to B. longipinnis from the Tocantins River, whereas Baryancistrus hadrostomus, new species, has a color pattern that is unique for the genus, with a gray to black body covered by small and widely spaced white points. The first exemplars of the two new species were collected in the late 1980s by INPA ichthyological staff, and in 2007 additional materials were collected by the Museu de Zoologia da Universidade de São Paulo (MZUSP), providing a foundation for this description of the new species.
One of the primary functions of animal aggregations is defence against predators. Many social animals enjoy reduced predation risk as a result of grouping, and individuals within groups can benefit from information transferred by their group‐mates about a potential predator. We present evidence that a tactile interaction behaviour we term “nudging” substantially modified group responses to a potential threat in a highly social catfish, Corydoras aeneus. These catfish deployed nudges during flight responses, and these nudges were associated with a greater likelihood of group cohesion following a threat event. Increased nudging behaviour also resulted in longer flight responses, a potentially costly outcome in natural contexts. In addition, individuals that perceived the threat first were more likely to initiate nudges, implying that nudges could be used to alert group‐mates to the presence of a threat. Taken together, our results suggest that tactile communication plays an important role in mediating anti‐predator benefits from sociality in these fish.
Neotropical freshwaters host more than 6000 fish species, of which 983 are suckermouth armored catfishes of the family Loricariidae – the most-diverse catfish family and fifth most species-rich vertebrate family on Earth. Given their diversity and ubiquitous distribution across many habitat types, loricariids are an excellent system in which to investigate factors that create and maintain Neotropical fish diversity, yet robust phylogenies needed to support such ecological and evolutionary studies are lacking. We sought to buttress the systematic understanding of loricariid catfishes by generating a genome-scale data set (1041 loci, 328,330 bp) for 140 species spanning 75 genera and five of six previously proposed subfamilies. Both maximum likelihood and Bayesian analyses strongly supported the monophyly of Loricariidae. Our results also reinforced the established backbone of loricariid interrelationships: Delturinae as sister to all other analyzed loricariids, with subfamily Rhinelepinae diverging next, followed by Loricariinae sister to Hypostominae + Hypoptopomatinae. Previous DNA-based relationships within Hypostominae and Loricariinae were strongly supported. However, we evaluated for the first time DNA-based relationships among many Hypoptopomatinae genera and found significant differences with this subfamily's current genus-level classification, prompting several taxonomic changes. Finally, we placed our topological results within a fossil-calibrated temporal context indicating that early Loricariidae diversification occurred across the Cretaceous-Paleogene boundary ∼65 million years ago (Ma). Our study lays a strong foundation for future research to focus on relationships among species and the macroevolutionary processes affecting loricariid diversification rates and patterns.
Ancistrus is one of the most diverse genera in the Ancistrini tribe, with 64 nominal species. The group is characterized by high cytogenetic variability; the diploid number of chromosomes ranges from 2n = 34 to 2n = 54. Ancistrus is widely distributed in the basins of the Uruguay, Paraguay, and Amazonian rivers; the latter two regions show the greatest diversity of Ancistrus species and karyotypes. Despite these characteristics, the group includes species for which taxonomic identification is difficult, and phylogenetic relationships and phylogeographic patterns, especially in the Paraguay and Amazon basins, have not yet been revealed. In this study, we determined the phylogenetic and phylogeographic relationships among the Ancistrus lineages in these regions. In particular, 93 concatenated sequences of mitochondrial ATPase 6/8 and COI as well as nuclear Rag2 were used for a phylogenetic analysis, and ATPase 6/8 were used for a phylogeographic analysis. The topology generated by the Bayesian method included three distinct clades subdivided into 21 groups. The clades indicated a monophyletic relationship among the lineages from the Amazon and Paraguay basins. The 21 groups had a high average genetic distance (8.4%) and were structured genetically. In the haplotype network, eight large groups were observed, seven belonging to the Paraguay basin and one corresponding to the Amazon basin, and no haplotypes were shared between the two basins. These results indicate that Ancistrus lineages form a monophyletic unit in the Paraguay and Amazon basins, and these lineages have a high level of divergence and genetic isolation. These results corroborate the existence of cryptic species in the region and emphasize the need for a taxonomic revision of the genus in these basins.
Hypostomus latirostris was originally described by Regan (1904) from "River Jungada [= rio Jangada], Matto Grosso and Goyaz"; however, the species is rarely mentioned in taxonomic works on Hypostomus from Paraguay. Herein, the two syntypes of Plecostomus latirostris were examined showing critical differences between them. After the analysis of a large sample of recently collected specimens from the upper rio Paraguay basin we concluded that the two syntypes from the rio Jangada indeed belong to different species. Hypostomus latirostris is redescribed and a lectotype is designated herein. The other syntype (now a paralectotype of H. latirostris) is designated as paratype of Hypostomus renestoi, new species. Hypostomus renestoi can be differentiated from H. latirostris by having robust teeth (vs. slender); by having 28-77 teeth on the premaxilla (vs. 79-111) and 25-64 on the dentary (vs. 79-109); by having small and more conspicuous dark spots (vs. larger and less conspicuous dark spots); by having dorsal and mid-dorsal series of plates with moderate hypertrophied odontodes (vs. lacking hypertrophied odontodes on lateral series of plates); and usually by attaining a smaller size.
The aim of this study was to characterize the haematological profile of four Amazonian ornamental freshwater armoured catfish: acari-bola (Peckoltia oligospila-L06), acari-pleco (Cochliodon sp.-L145), acari-canoa (Lasiancistrus saetiger-L323) and acari-assacu (Pseudocanthicus spinosus-L160). The highest blood glucose levels (72.47 ± 28.7 mg dL⁻¹) and erythrocyte counts (0.51 ± 0.2 x 10⁶ cel. μL⁻¹) were recorded for acari-canoa. The acari-bola and acari-pleco presented similar concentrations of total plasma protein (TPP) (7.96 ± 1.8 and 7.93 ± 1.8 g dL⁻¹, respectively) against lower TPP concentrations observed in acari-canoa (4.87 ± 1.5 g dL⁻¹) and acari-assacu (6.55 ± 1.5 g dL⁻¹). The acari-assacu had lower total haemoglobin concentration (5.88 ± 1.7 g dL⁻¹) and haematocrit (12.66 ± 4.6%). No interspecific differences were observed in mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC). The acari-pleco and acari-assacu presented the highest counts for neutrophils (4142.42 ± 3280.1 cel. μL⁻¹) and thrombocytes (4778.33 ± 1224.8 cel. μL⁻¹), respectively. The haematological profiles were similar to those reported in the literature for freshwater fish and the interspecific differences observed were discussed. © 2018, Eduem - Editora da Universidade Estadual de Maringa. All rights reserved.
Approximately two-dozen species in three genera of the Neotropical suckermouth armored catfish family Loricariidae are the only described fishes known to specialize on diets consisting largely of wood. We conducted a molecular phylogenetic analysis of 10 described species and 14 undescribed species or morphotypes assigned to the wood-eating catfish genus Panaqolus, and four described species and three undescribed species or morphotypes assigned to the distantly related wood-eating catfish genus Panaque. Our analyses included individuals and species from both genera that are broadly distributed throughout tropical South America east of the Andes Mountains and 13 additional genera hypothesized to have also descended from the most recent common ancestor of Panaqolus and Panaque. Bayesian and maximum likelihood analyses of two mitochondrial and three nuclear loci totaling 4293 bp confirmed respective monophyly of Panaqolus, exclusive of the putative congener 'Panaqolus' koko, and Panaque. Members of Panaqolus sensu stricto were distributed across three strongly monophyletic clades: a clade of 10 generally darkly colored, lyretail species distributed across western headwaters of the Amazon Basin, a clade of three irregularly and narrowly banded species from the western Orinoco Basin, and a clade of 11 generally brown, broadly banded species that are widely distributed throughout the Amazon Basin. We erect new subgenera for each of these clades and a new genus for the morphologically, biogeographically and ecologically distinct species 'Panaqolus' koko. Our finding that perhaps half of the species-level diversity in the widespread genus Panaqolus remains undescribed illustrates the extent to which total taxonomic diversity of small and philopatric, yet apparently widely distributed, Amazonian fishes may remain underestimated. Ranges for two Panaqolus subgenera and the genus Panaque overlap with the wood-eating genus Cochliodon in central Andean tributaries of the upper Amazon Basin, which appear to be a global epicenter of wood-eating catfish diversity.
Ecological opportunity is often proposed as a driver of accelerated diversification, but evidence has been largely derived from either contemporary island radiations or the fossil record. Here, we investigate the potential influence of ecological opportunity on a transcontinental radiation of South American freshwater fishes. We generate a species-dense, time-calibrated molecular phylogeny for the suckermouth armored catfish subfamily Hypostominae, with a focus on the species-rich and geographically widespread genus Hypostomus. We use the resulting chronogram to estimate ancestral geographic ranges, infer historical rates of cladogenesis and diversification in habitat and body size and shape, and test the hypothesis that invasions of previously unoccupied river drainages accelerated evolution and contributed to adaptive radiation. Both the subfamily Hypostominae and the included genus Hypostomus originated in the Amazon/Orinoco ecoregion. Hypostomus subsequently dispersed throughout tropical South America east of the Andes Mountains. Consequent to invasion of the peripheral, low-diversity Paraná River basin in southeastern Brazil approximately 12.5 Mya, Paraná lineages of Hypostomus experienced increased rates of cladogenesis and ecological and morphological diversification. Contemporary lineages of Paraná Hypostomus are less species rich but more phenotypically diverse than their congeners elsewhere. Accelerated speciation and morphological diversification rates within Paraná basin Hypostomus are consistent with adaptive radiation. The geographical remoteness of the Paraná River basin, its recent history of marine incursion, and its continuing exclusion of many species that are widespread in other tropical South American rivers suggest that ecological opportunity played an important role in facilitating the observed accelerations in diversification. This article is protected by copyright. All rights reserved.
Hydrological connectivity regulates the structure and function of Amazonian freshwater ecosystems and the provisioning of services that sustain local populations. This connectivity is increasingly being disrupted by the construction of dams, mining, land-cover changes, and global climate change. This review analyzes these drivers of degradation, evaluates their impacts on hydrological connectivity, and identifies policy deficiencies that hinder freshwater ecosystem protection. There are 154 large hydroelectric dams in operation today, and 21 dams under construction. The current trajectory of dam construction will leave only three free-flowing tributaries in the next few decades if all 277 planned dams are completed. Land-cover changes driven by mining, dam and road construction, agriculture and cattle ranching have already affected ~20% of the Basin and up to ~50% of riparian forests in some regions. Global climate change will likely exacerbate these impacts by creating warmer and dryer conditions, with less predictable rainfall and more extreme events (e.g., droughts and floods). The resulting hydrological alterations are rapidly degrading freshwater ecosystems, both independently and via complex feedbacks and synergistic interactions. The ecosystem impacts include biodiversity loss, warmer stream temperatures, stronger and more frequent floodplain fires, and changes to biogeochemical cycles, transport of organic and inorganic materials, and freshwater community structure and function. The impacts also include reductions in water quality, fish yields, and availability of water for navigation, power generation, and human use. This degradation of Amazonian freshwater ecosystems cannot be curbed presently because existing policies are inconsistent across the Basin, ignore cumulative effects, and overlook the hydrological connectivity of freshwater ecosystems. Maintaining the integrity of these freshwater ecosystems requires a basinwide research and policy framework to understand and manage hydrological connectivity across multiple spatial scales and jurisdictional boundaries.