Tropical Aquarium Research Articles

Thermal tolerance for three ornamental tankbuster catfishes

Pet abandonment is an important introduction vector for freshwater aquarium fishes, as unwanted pets become too large for tank dimensions and are released into the environment. Concerns over pet abandonment may be particularly important for the U.S. state of Florida, which exhibits abundant access to freshwater habitats and a climate more favorable to tropical aquarium fishes than other continental U.S. states. Numerous studies have examined the factors affecting establishment for non-native species, including the importance of propagule pressure and climate suitability. For freshwater aquarium species, maximum body size can increase pet abandonment because they grow too large for the tank dimensions (i.e., “tankbusters”). Thus, large maximum body size may increase propagule pressure due to intentional release. In addition to being introduced in sufficient numbers, a match between the thermal tolerance of a species and the thermal habitat is necessary for establishment. Several large-bodied catfishes are found in the aquarium trade, including the goonch Bagarius spp., redtail catfish Phractocephalus hemioliopterus, and tiger sorubim Pseudoplatystoma tigrinum. Here, we experimentally determined the chronic lethal minimum temperature (CLmin) for the three catfishes. CLMin estimates for these three species were higher than many other ornamental species, highest for the redtail catfish (14.3 °C), lower for the tiger sorubim (11.0 °C), and lowest (9.9 °C) for the goonch. Given these lethal temperatures, the distribution of redtail catfish would be limited to South Florida while the tiger sorubim and goonch could live, provided other habitat characteristics are suitable, up to ~28°N Latitude in Florida.

The environmental impact of keeping a tropical aquarium in Northern Europe.

Tropical fishkeeping is a popular practice in societies across the globe and involves recreating and sustaining an entire ecosystem in an aquarium within a domestic setting. The process invariably has an environmental impact, yet an assessment of this impact has previously been limited to the ecological consequences of harvesting fish from the wild or the release of non-native fish species. Provided here are the first estimates of carbon dioxide equivalent (CO2 eq) emissions produced from running a tropical aquarium across multiple countries in Northern Europe (France, Poland and the UK), along with water consumption. Estimates were produced in silico and are discussed in the context of freshwater and marine aquariums, calculated using example aquarium sizes of 50, 200 and 400 l. Using estimates from the UK, depending on size and running conditions, a tropical aquarium produces an estimated 85.3-635.2 kg of CO2 eq per year, equating to 1.6%-12.4% of the UK annual average household CO2 emissions, and uses 156-31,200 l of water per year, equating to 0.2%-30.1% of the UK annual average household water usage. Despite this, comparison with the CO2 eq of an average-size dog (127-1592 kg of CO2 eq per year) or cat (121-251 kg of CO2 eq per year), estimated from meat consumption alone, demonstrates that ornamental fishkeeping can be a more environmentally conscious pet choice. In addition, the majority of CO2 eq produced from tropical fishkeeping is generated from the energy consumption of aquarium equipment and as more national electricity grids begin to decarbonize, this estimate should decrease.

海南热带水族现状及热带水族技术课程教学建设的思考——以海南大学为例

海南热带水族现状及热带水族技术课程教学建设的思考——以海南大学为例

Accurate long-read eDNA metabarcoding of North Sea fish using Oxford Nanopore sequencing

To halt North Sea ecosystem degradation, accurate and intensive monitoring of the North Sea ecosystem and its fish is vital to correctly inform management decisions. DNA based techniques and especially the use of environmental (e)DNA from seawater can become a powerful monitoring tool. However, current eDNA based metabarcoding approaches are based on genetic target regions of <500 nucleotides which offers only limited taxonomic resolution. We tested sensitivity and applicability for field samples of newly designed universal fish primer targeting a 2kb region covering mitochondrial 12S and 16S genes in eDNA samples. Samples were processed using long read nanopore sequencing in combination with the consensus builder Decona and retrieved accurate read identities of up to 99.9%. To test accuracy of the primer, eDNA was analyzed from a tropical aquarium with a known species composition of bony fish and elasmobranchs. This showed that over 50% of species present can be identified. The majority of remaining reads are identified as -in aquarium present- genera and can be explained by an incomplete reference database for the fish present in the aquarium. Primers were also applied in North sea eDNA field samples. Distinct species compositions between different locations could be observed and consisted of ecological relevant species and shows the applicability for long-read eDNA metabarcoding in field studies. Incomplete reference databases currently form the main bottleneck to further develop high resolution nanopore based long read sequencing as metabarcoding strategy. Nevertheless, this study shows that long read nanopore sequencing of eDNA can be used to obtain accurate information on the fish and elasmobranch species composition in the North Sea and beyond.

Four new species of Heteromysis (Crustacea: Mysida) from public aquaria in Hawaii, Florida, and Western to Central Europe

Four new species of the subgenus Heteromysis (Olivemysis) were detected in material from (sub)-tropical aquaria in six public aquarium institutions around the globe. Modifications of pleopods by spines represent the strongest structural complex used for differentiation within this subgenus: male pleopods 1–4 modified in H. smithsoniana sp. nov., male pleopods 2–4 plus female pleopod 2 in H. hornimani sp. nov. and H. waikikensis sp. nov. Additional important diagnostic characters are provided by the antennulae, uropods, and telson. The male of H. sixi sp. nov. represents a very rare case within the genus Heteromysis by having only pleopod 2 modified by flagellate spines. The definition of the subgenus Olivemysis is modified in order to include H. sixi sp. nov. A summary of pleopod modifications in the genus Heteromysis and a key to the species of the subgenus Olivemysis are given. The here described new taxa more than double the number of Heteromysis species known from aquaria yet unknown in nature from three to seven.

Diseño de un control difuso tipo Mamdani para regular la temperatura de una Acuario tipo tropical

In the present research work, an automatic control technique based on fuzzy logic is shown to regulate the temperature conditions in a tropical aquarium with a capacity of 100 liters. To analyze the effectiveness of the technique, the design and implementation of a fuzzy logic controller type Mamdani was carried out. Subsequently, the diffuse controller was integrated into an electrical system using a 100-watt resistor. The regulation is carried out from the acquisition of the water temperature, thus varying the current of the resistance, a temperature sensor, and a heater as actuators were used. The functionality of the system is verified through the Artix-7 FPGA platform, using the VHDL hardware description language. The controller design was developed using the fuzzy logic tool in Matlab in order to compare experimental results of the FPGA, obtaining an error of 2.94% accuracy between both designs.

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OPINION Reactions ShareShare onFacebookTwitterWechatLinked InRedditEmail C&EN, 2018, 96 (9), p 2February 26, 2018Cite this:C&EN 96, 9, 2Letters to the editor Palytoxin We read with interest Emma Hiolski’s article entitled “Palytoxin: The danger hidden in tropical aquariums” that described palytoxin as the Mount Everest of chemistry due to its remarkable chemical complexity (Jan. 8, page 12). As detailed, professor Kishi’s synthesis in the ’90s was in no doubt a tremendous accomplishment in assembling its structure, having a backbone of 115 carbon atoms! What was overlooked by the author was an equally important history that is sadly often downplayed in the chemical literature in favor of chemical synthesis, and that has to do with the discovery and characterization of the natural product itself; palytoxin in this case during the ’70s and early ’80s. That work was led by the late Richard E. Moore of the University of Hawaii, who reported its structure and stereochemistry in two [Journal of the American Chemical Society] articles in 1981 and 1982 (DOI: 10.1021/ja00399a093 and DOI: 10.1021/ja00377a064). That work was the culmination of over a decade of research of incredible ingenuity at a time when chromatography, NMR, and other modern conveniences that we take for granted today were nonexistent or in their infancy. Additional discovery work by professor Daisuke Uemura from Shizuoka University at the time amplified the structure of palytoxin and its derivatives (Tetrahedron Lett. 1981, DOI: 10.1016/S0040-4039(01)90551-9). It was this collection of discovery work that made it possible for Kishi and others to finally assign a chemical structure to the name and fascinating history of palytoxin.So let’s not forget about the incredible chemists who illuminate for us the chemical faces of nature’s molecules that continue to inspire us in many scientific disciplines.Bradley Moore (son of Richard E. Moore)La Jolla, Calif.William FenicalDel Mar, Calif. Corrections Jan. 29, page 10: In the science brief on a possible technique to search for extraterrestrial life, the pair of gases given as the atmospheric disequilibrium on Earth was incorrect. They should be methane and oxygen.Feb. 12, page 14: In a news story about NIGMS’s decision to stop funding a predoctoral fellowship, the number of fellowships should have been 85 since 2015, not per year. The NSF fellowships mentioned in the story are also available in the early years of graduate school, not just before students enter graduate school.Feb. 19, page 20: In the feature story on vaccines against drugs of abuse, the reference for the oxycodone vaccine entry in the table is incorrect. It is PLOS One 2014, DOI: 10.1371/journal.pone.0096547.

Tranquilisation, anaesthesia and euthanasia in pet fish

Many commonly used veterinary anaesthetics for small animals can also be used with pet fish. Treating tropical aquarium fish is not as hard as one might think, and tranquilising them prior to handling them for physical examinations and diagnostic tests makes the process easier. A number of surgical procedures have been performed on anaesthetised fish, especially with large species such as koi or fish on display in a public aquarium. Anaesthetising the fish prior to any surgical procedure is essential. Euthanasia of aquarium fish is sometimes necessary, and using an overdose of anaesthetic agents can make this process quick and painless. Anaesthetic agents can be added to the water, given orally or injected into the fish. This paper reviews the drugs, dosages and routes of administration used for tranquilisation, anaesthesia and euthanasia in aquatic veterinary medicine.

The tropical South American cichlid, Geophagus brasiliensis in Mediterranean climatic south-western Australia

The highly endemic (82%) freshwater fishes of south-western Australia are imperiled due to severe habitat and water quality declines and impacts of introduced species. As a case study of the recent tropical aquarium fish introductions, the biology and ecology of the pearl cichlid Geophagus brasiliensis was determined in the Swan River catchment south-western Australia. Unlike endemic freshwater fish species of this Mediterranean climatic region, Geophagus brasiliensis underwent a protracted spawning period during the warmer period from December to May. It appeared that recruitment only occurred in lentic habitats; however the species also persists in downstream lotic habitats. Growth rate and maximum size (245 mm TL) of the species exceed all but one of the region's native freshwater fishes. Whilst minimum water temperature may help limit its establishment in many aquatic ecosystems, its salinity tolerance and omnivorous diet would facilitate its colonisation in this region, including freshwaters and estuaries. Past and future habitat and climatic change is predicted to continue to favour species from sub-tropical and tropical regions.

Offsetting the impact of the marine ornamental trade: a case study of two temperate top shells (Osilinus lineatus and Gibbula umbilicalis) as potential clean‐up crew

Abstract It is estimated that several million tropical gastropods are exported each year for the marine ornamental trade to become part of a clean‐up crew (those species that have a beneficial function such as controlling nuisance algae) in an aquarium. Collecting non‐tropical species could offset exploitation impacts, reduce shipping costs and increase survival rates due to shorter transport distances. However, these species must be able to survive and function at tropical marine tank temperatures (25 °C). Two species of intertidal temperate top shell (Osilinus lineatus) and (Gibbula umbilicalis) were acclimated to 25 °C, 27 °C and 29 °C and survivorship compared with ambient (UK summer) conditions for 55 days. Virtually all G. umbilicalis died during the experiment in all elevated temperatures. In contrast, O. lineatus had minimal mortality in all treatments except the 29 °C, which reached 46.7% ±3.3 by day 55. Locomotor activity and position in relation to the air/water interface were assessed at 25 °C and ambient conditions. All individuals from both species were active and the mean activity score did not differ between treatments. The majority (63–85%) of the individuals of both species also spent their time either submerged or at the air–water interface and those held at 25 °C spent less time on average out of the water. Nitrocellulose plates impregnated with an algal extract were used to assess grazing of both species at 25 °C compared with ambient temperature. Over 24 h both consumed significant quantities, and no differences in levels were observed between temperatures or species. Together this evidence shows that O. lineatus survives equally well at standard tropical aquarium temperatures and also continues to function as a clean‐up crew. Collection of this and other non‐tropical species may be an important alternative conservation approach to tropical collection if ethical and management issues are addressed. Copyright © 2012 John Wiley & Sons, Ltd.

Thanks be to Zebrafish

During the last 10–15 years, the tiny, tropical, freshwater zebrafish has become one of the most powerful and versatile models for studying vertebrate heart development. Three recent reports in Nature remind us of just how much we owe to this fishy friend of research. The zebrafish was first developed for use as a model organism by George Streisinger at the University of Oregon in the 1970s. A common resident of household tropical aquariums, the fish soon became a common laboratory resident thanks to its hardiness and many other research-friendly characteristics. The zebrafish is small, easy to keep, and produces large numbers of offspring on a regular basis—female zebrafish can produce up to 200 eggs per week. Such features make it perfect for genetic analysis. Its genome has been fully sequenced, large-scale mutation screenings have been carried out, and countless transgenic strains and human disease models are available. In addition, the zebrafish embryo is transparent, develops rapidly, and grows externally from the mother, allowing for easy experimental manipulation and observation. The zebrafish is, thus, close to being the ideal model organism for studying vertebrate development. In the field of cardiovascular biology, studies of zebrafish heart development have revealed a large number of genes and pathways that are conserved with higher vertebrates and mammals. Thus, although the zebrafish is coldblooded and its heart has just a single ventricle, it serves as a great tool and starting point for comparative analysis. One feature of the zebrafish heart that differs dramatically from that of mammals is the capacity for regeneration. In 2002, Kenneth Poss (Duke University, Durham, NC) and colleagues reported in the journal Science that after removing up to 20% of the fish's ventricle, the heart could regrow fully.1 This led to the exciting idea that if scientists could discover how the …

Marine Ornamental Trade in Brazil

Brazil is one of the five leading exporting countries of tropical aquarium fishes in the world, and the interest in marine ornamental organisms has increased substantially there from the mid to the late 1990s. About 120 reef fish species are currently harvested in Brazil's ornamental trade. Among the 75 most harvested species, 26 (34.7%) are endemic, eight (10.7%) are rare, and six (8.2%) are estuarine-dependent species. Fifty-five species (75.3%) have complex reproductive strategies and/or parental care. In quantitative terms, the top 10 species comprises 62% of the species exported from Brazil to the USA and the European Community. The most harvested reef invertebrates include about 65 species. The most representative groups are crustaceans with 15 species (23%), and molluscs and stony corals with 10 species (15.4%) each. Among these, 15 (23%) are endemics, nine (13.8%) are rare species, and seven (10.8%) are important reef builders. A case of local extinction of the giant anemone Condylactis gigantea is reported. To alleviate ecological impacts a series of urgent measures is suggested, including the creation of specific laws for marine ornamental harvesting and improving law enforcement to prevent illegal trade in Brazil.

Aliens on the shores.

In the early 1980s, a biologist at the tropical aquarium in Stuttgart, Germany, noticed that the beautiful green alga Caulerpa taxifolia (Fig. 1) would make an ideal aquarium decoration. It does not wither, it is fast growing and it withstands cool temperatures. In the following years, many aquariums acquired Caulerpa plants from Stuttgart, among them the Oceanographic Museum of Monaco, from which it escaped into the Mediterranean Sea. In 1984, the alga covered an area of around 1 m2 on the coast of Monaco. Since then, it has invaded large areas of the French and Italian coasts and has spread as far as the coasts of Spain, Croatia and North Africa. The alga grows everywhere, from the surface to the lower limits of underwater vegetation, forming huge monocultures that displace other plant species and, being highly toxic to many fish species, also threatens aquatic fauna wherever it roots. > Invasive species are the second biggest cause of loss of biodiversity after habitat destruction Figure 1. The green alga Caulerpa taxifolia In the summer of 1999, New York City witnessed an unusual spate of bird deaths, particularly of crows. During the same summer, on August 23, a physician from a hospital in northern Queens reported two encephalitis patients to the New York City Department of Health, and further surveillance identified other cases. A month later, scientists from the Centers for Disease Control and Prevention (CDC) in Atlanta, GA, USA, identified the link between these seemingly unrelated events. They discovered that the causative agent was the West Nile virus, which had never before been seen in North America. To contain the outbreak and prevent transmission of the virus by mosquitoes, New York's mayor, Rudy Giuliani, ordered the spraying of whole neighbourhoods in New York with pesticides. It was in vain. During 2001, 149 cases …

Laboratory evaluation of crude oil biodegradation with commercial or natural microbial inocula

Experiments have been performed to screen eight microbial commercial products that, according to the manufacturers, are able to degrade crude oil. This study compared the crude oil biodegradation activity of commercial inocula with that of natural inocula (activated sludge and tropical aquarium water). Some of the latter were previously adapted to the crude oil as the only carbon source. Nutrients and sorbents in the commercial formulations were eliminated, and each inoculum was precultured on marine yeast extract medium. Crude oil biodegradability tests were conducted with close initial substrate concentration to initial bacterial concentration ratios (S0/X0) of 0.94 g of crude oil/10(9) CFU, which allowed a comparison of biodegradation activity. The inocula oxidized the crude oil after a short lag time of less than 3-18 days. After that time, the rate of oxidation varied between 45 and 244 mg O2/(L.day). Crude oil biodegradation after a 28-day test was effective only for 10 out of 12 inocula (from 0.1 to 25% in weight). Biodegradation mainly corresponded to the saturated fraction of the crude oil; the asphaltene fraction was never significantly biodegraded. Our results led to the conclusion that natural inocula, either adapted or not adapted to crude oil, were the most active (from 16 to 25% of loss in crude oil weight) and only one commercial inoculum was able to degrade 18% of the crude oil. Other inocula had a biodegradation activity ranging from 0.1 to 14%.

Characterization of four Flavobacterium columnare ( Flexibacter columnaris) strains isolated from tropical fish

Four Flavobacterium columnare strains (AJS 1–4) were isolated from black mollies ( Poecilia sphenops) and platies ( Xiphophorus maculatus), showing white spots on the back, head and skin ulcers. The isolates developed characteristic rhizoid yellow pigmented colonies on Shieh agar and typical growth in Shieh broth. They were Gram-negative, filamentous bacteria exhibiting flexing movements. When compared to F. columnare strains isolated from temperate fish, it was noted that the four strains originating from tropical aquarium fish are more capable of growing at higher temperatures, the opposite being true for the strains isolated from temperate fish. Biochemical characterization and agglutination tests proved that the isolated strains could be classified as F. columnare. Low minimal inhibitory concentration (MIC) values were found for chloramphenicol, erythromycin, furazolidone, kanamycin, lincomycin, nalidixic acid, oxytetracycline and streptomycin. MIC values were high for colistin, sulfamethoxazole and neomycin. Pathogenicity studies were performed on black mollies. When these animals were submersed in an infective solution of the F. columnare strains, a marked difference in virulence was noted among the four isolated strains, strain AJS 1 being the most virulent one and strain AJS 4 being of low virulence.

Spread of the introduced tropical green alga Caulerpa taxifolia in northern Mediterranean waters

The first report of Caulerpa taxifolia in the Mediterranean is from 1984. The alga was found on the rocky shore at Monaco, below the Oceanographic Museum, where it had been on display in tropical aquaria. Within five years, there was an abundance of C. taxifolia on the shores around the first point of observation. In 1987, C. taxifolia appeared on the French coast, 3 km east of Monaco, at Cap Martin. By late 1991, 30 ha of shore in the vicinity of Monaco was covered with the alga. New points of colonization were in Livorno, Italy, 240 km east of Monaco, and to the west at Agay, Le Lavandou, Hyeres, Toulon, Les Lecques, Saint Cyprien, 50 to 370 km from Monaco. The westernmost point of colonization, noted in September 1992, was 600 km from Monaco, at Majorca (Balearic island, Spain). Most types of substrata, between 0 and 50 m depth, are susceptible to colonization by C. taxifolia. Seaweed and seagrass populations on the coasts of Monaco and Cap Martin have been significantly reduced or destroyed because of invasion by C. taxifolia.

Technical Notes: Multiple-Tank Aquarium System with Recirculating Water for Laboratory Studies of Freshwater Fishes

Abstract A recirculating-water aquarium system for laboratory studies of freshwater fishes is described. The system consists of 216 glass tanks (3.5 gal each), two particle filters, a multistage biofilter, two ultraviolet-light sterilizers, and a regenerative blower for auxiliary aeration. Each tank is connected separately to the recirculating-water supply through inflow and outflow manifold pipes. Water flow to individual tanks is adjustable and can be varied from 0 to 10 gal/h (0–3 water exchanges/ h). The system was designed to minimize environmental variation among tanks and families in genetic studies of tropical aquarium fishes but would be useful for other studies in which replicated treatments or experimental units are required.

A Note on the Typification of Vallisneria spiralis (Hydrocharitaceae)

Vallisneria spiralis L. is an aquatic species which is common and widespread in the tropics and warm temperate regions. It is also well-known in cultivation and is frequently planted as an oxygenator in tropical aquaria. While preparing an account of Hydrocharitaceae for Flora of Tropical East Africa, I was unable to find any reference to a type for this species, and since it is such a well-known plant it seemed desirable to investigate this further. In LINN there are two specimens (Savage Catalogue nos. 1157-1 and 1157-2) which, without doubt, can be assigned to V. spiralis. However these appear to have been collected after 1753, and as there is no reference to them in any of Linnaeus' work they must be discounted as possible type material. Before 1758, Vallisneria was described in Linnaeus' Hortus Cliffortianus (1738), Flora Lapponica (1737) and Genera Plantarum (1738). However there are no specimens of Vallisneria in Linnaeus' Lapland Herbarium at the Institut de France, Paris, nor in other herbaria containing Linnaean material (C. Jarvis pers. comm.). There is also a mention of it in van Royen's Florae Leydensis prodromus (1740) but, again, no specimen can be found in van Royen's herbarium at L. In Species Plantarum three polynomials are cited in synonymy. The first and third of these are taken from Micheli's Nova plantarum genera (1729), where they are accompanied by detailed and accurate illustrations in Plate 10, Figs. 1 & 2 of the book. Although Micheli believed that these polynomials described separate taxa, they do in fact refer respectively to the female and male plants of V. spiralis and this was correctly acknowledged by Linnaeus in Species Plantarum. Unfortunately there are no specimens corresponding to V. spiralis in Micheli's herbarium at FI. The second polynomial is quoted as being taken from Boccone's "Museo di piante rare della Sicilia", p. 289 (1697). However this would appear to be incorrect as Boccone's work only has 196 pages and there is no mention of any such polynomial in the index. The same polynomial and reference are given by Micheli, and therefore it is probable that Linnaeus obtained them from this source, and as a result the error was perpetuated in his own work. The correct source of this polynomial cannot be traced.

Anesthesia in Fish

1. Before using anesthesia in fish, check water quality parameters for tropical fish aquariums in the locality. 2. Monitor any changes in water quality that result from anesthetic administration, especially pH and alkalinity. Have adequate buffering agents available to counter these changes. 3. Use one or two preferred agents, and become familiar with the effects they produce. 4. Where possible, withhold food from fish for 24 hours prior to administration of the anesthetic agent. 5. Try to anesthetize a few fish in a group first as a test batch. Wait 12 to 24 hours for signs of delayed mortality before proceeding to anesthetize the rest of the fish. 6. Always provide adequate aeration in holding vessels. 7. Where practical, use water that the fish has come from in the anesthetic tank. 8. Always have a container of the same water for the fish to recover in.

Enteric pathogens in tropical aquaria.

A total of 100 tropical aquaria from six pet shops were sampled for the presence of Salmonella, Campylobacter and Aeromonas species. Eight fish tanks contained unusual serotypes of salmonella. None had been used to house terrapins. One hundred and three isolates of Aeromonas species were obtained from 98 tanks. One tank contained Plesiomonas shigelloides. No Campylobacter species were isolated. It is suggested that a tropical aquarium may constitute an infection hazard.