Aquarium Fish Research Articles

Occurrence of Mycobacterium spp. in ornamental fish in Italy

The occurrence of Mycobacterium spp. in freshwater and marine ornamental fish was studied in Italy from June 2002 to May 2005. Two surveys were carried out, one of aquarium fish sent to the Laboratory for diagnosis, and the other of prevalence of infection by mycobacteria in ornamental fish imported into Italy. Bacterial isolation was carried out from the spleen, kidney and liver, and the isolates were subsequently identified by biochemical tests. In the first survey, 387 fish were examined and Mycobacterium spp. were isolated from 181 (46.8%) fish. In the second survey 127 batches of ornamental fish from different countries were examined. Mycobacterium spp. were isolated from 38 (29.9%) batches. The following species were found: M. fortuitum, M. peregrinum, M. chelonae, M. abscessus, M. marinum, M. gordonae, M. nonchromogenicum and M. interjectum. There was a high prevalence of infection independent of the presence of macroscopic lesions. Mycobacterium fortuitum and M. chelonae were more prevalent than M. marinum in the samples examined.

Detecting the transport of toxic pesticides from golf courses into watersheds in the precambrian shield region of ontario, canada

Golf courses impact the environment through alterations to habitat and through the release of nutrients and pesticides. The Precambrian Shield region of central Ontario, Canada, which is a major recreational area, is especially susceptible to the impacts of golf courses as a result of the geology and hydrology of the region. In a monitoring program at two golf courses in the Muskoka region conducted during the spring, summer, and fall of 2002, semipermeable membrane devices (SPMDs) were deployed into streams that drain the golf courses. The extracts from the SPMDs were tested for toxicity using bioassays with early life stages of an aquarium fish, the Japanese medaka (Oryzias latipes). Toxicity was assessed using a scoring system developed for the present study. The bioassays with medaka indicated that toxicity was highest in extracts from SPMDs deployed during the spring and the fall. The peaks in toxicity for the SPMDs deployed at the two golf courses corresponded with the presence in the SPMD extracts of pentachloronitrobenzene (PCNB) at concentrations up to 334 ng/SPMD. Quintozene is the turfgrass fungicide in which PCNB is the active ingredient. Pentachlorothioanisole, an anaerobic degradation product of PCNB, also was detected in the SPMDs deployed during the spring. Extracts prepared from SPMDs with high toxicity contained residues of a surfactant used in pesticide formulations, nonylphenol, at concentrations up to approximately 20 microg/SPMD. Overall, these data indicate that some pesticides applied to golf courses in the Precambrian Shield of central Ontario may have the potential to cause toxic impacts to aquatic organisms in adjacent watersheds.

Harvest, trade and conservation of the Asian arowana Scleropages formosus in Cambodia

Abstract The worldwide trade in aquarium fish is a multi‐billion dollar industry. One of the most popular and expensive species traded is the Asian arowana Scleropages formosus. As a result of over‐harvesting for the aquarium fish trade, S. formosus is now endangered and commercial international trade in the species is prohibited under CITES. Despite this, very little is known about S. formosus in the wild. Interviews were conducted with 62 local villagers at four sites in Koh Kong province, south‐west Cambodia, to obtain information on the reproduction, historical and current harvest and trade, and population trends of S. formosus. The spawning season of S. formosus in Cambodia begins towards the end of the dry season (March–April) and is approximately 3 months in duration. Each male mouth‐broods an average of 30 juveniles. Harvesters target S. formosus fry and juveniles, and typically kill or frighten brooding males into releasing their offspring in order to harvest them. The prices obtained by harvesters for S. formosus has been increasing since collection began, and currently averages $US11–13 per juvenile. After collection, fish are transported through a series of larger towns, most ultimately bound for Thailand. The current number of S. formosus harvested from the wild in Cambodia is almost certainly highly unsustainable, with all respondents indicating that local S. formosus population abundance had declined dramatically in recent years. It is also likely that a number of populations have already become locally extinct. Strengthening legislation to protect the species within Cambodia, increasing enforcement of cross‐border trade, and an investigation into alternative low‐impact income generation opportunities for local communities is vital. There is also an urgent need to gather detailed information on the distribution, population abundance and threats facing S. formosus in Cambodia, and in other countries throughout its range. Copyright © 2008 John Wiley & Sons, Ltd.

Genetic Analysis of Betanodaviruses in Subclinically Infected Aquarium Fish and Invertebrates

Betanodaviruses causing viral nervous necrosis (VNN) have been detected and isolated from several species of cultured marine fish worldwide. In Korea, VNN was identified in several species of cultured marine fish. This study presents data on the amplified nested PCR product (420 bp) of 11 nodavirus strains from different species of apparently healthy aquarium fish and invertebrates collected in one private commercial aquarium in Korea. Phylogenetic analyses based on the partial nucleotide sequence (177 bases) of the RNA2 coat protein gene were identical to the redspotted grouper nervous necrosis virus (RGNNV) genotype (96%-100%). The presence of the RGNNV type of betanodaviruses in these subclinically infected aquarium fish and invertebrates imported from different countries probably indicates that the samples were contaminated inside the aquarium and represents a serious challenge for its management of viral nervous necrosis. These positive samples can be an inoculum source of betanodavirus infection to other susceptible fish species inside the aquarium.

Importation of mycobacteriosis with ornamental fish: Medico-legal implications

Mycobacterium fortuitum, as well as Mycobacterium marinum and Mycobacterium chelonae, are the etiological agents of fish Mycobacterioses. Mycobacteriosis has been reported to affect a wide range of freshwater and marine fish species, suggesting an ubiquitous distribution, and can cause zoonotic infections (known as "fish tank granuloma" or "swimming pool granuloma") in humans exposed to fish and contaminated water. Infection in human consists of nodular cutaneous lesions that can progress to tenosynovitis, arthritis, and osteomyelitis, depending on the immunological status. Authors describe some cases observed during routinary diagnostic activity in aquarium fish. Fish were sampled and histopathological, microbiological, and biomolecular exams were carried out. Histopathology showed systemic granulomatosis. Microbiological and biomolecular exams allowed us to identify the M. fortuitum as a main species. Finally, some considerations on the legal aspects of such disease are discussed.

Pumpkinseed sunfish (Lepomis gibbosus) invasions facilitated by introductions and nature management strongly reduce macroinvertebrate abundance in isolated water bodies

The pumpkinseed sunfish, Lepomis gibbosus, originates from Eastern North America and was introduced to the Netherlands in 1902 as an aquarium and garden pond fish. At present the pumpkinseed is widely spread throughout the Netherlands and occurs in a variety of aquatic habitats. It is especially abundant in moorland pools, fishing ponds and urban waters. Strong population development of the pumpkinseed appears to be facilitated by nature management practices in existing ponds (the removal of accumulated organic matter and macrophytes) and by creating new ponds. These measures enhance suitable breeding habitats that are free of competitors and predators. Isolated waters harbouring pumpkinseed were more often situated close to human habitation and infrastructure than could be expected based on the distribution of randomly selected isolated waters, identifying introductions as an important dispersal mechanism. In order to minimize the chances of introductions, planning of nature management practices should be done at distances over 250 m from human habitation and 100 m from infrastructure. Macroinvertebrate abundance in pools populated by pumpkinseed was eighty three percent lower than in pools without pumpkinseed, probably due to opportunistic feeding and high pumpkinseed abundances. Currently there is little experience with pumpkinseed control. However, options to be explored include: decreasing depth of colonized waters by filling them with soil allowing them to occasionally dry up, introducing native competitors and predators and the use of biodegradable piscicides. In addition, limitation of the sale of pumpkinseed is required as well as public education on the consequences of introducing exotic species.

Description of a new cichlid fish species of the genus Benthochromis (Perciformes: Cichlidae) from Lake Tanganyika

Benthochromis horii, a new cichlid species is described based on 19 type specimens from the deep waters of Lake Tanganyika. It differs from its congeners by having smaller eyes and longer snout (eye length usually shorter than snout length v. equal to or longer than snout length in Benthochromis tricoti and Benthochromis melanoides), and more dorsal fin rays (total number of spines and soft rays in dorsal fin usually 30 or 31 v. usually 28 or 29 in B. tricoti and B. melanoides). Large males of the new species differ from those of congeneric species in terms of their body colour pattern and long pelvic fins. This species has been confused with B. tricoti and has been traded as an aquarium fish.

Structure and Organisation of Small-Scale Freshwater Fisheries: Aquarium Fish Collection in Western Amazonia

Small-scale fisheries in developing countries are often vital to the livelihoods of the rural poor, yet the dynamic and variable nature of household engagement in local fisheries remains poorly understood. This paper describes a small-scale fishery for aquarium fish in two proximate villages of the Peruvian Amazon, and explains observed differences within and between villages in participation, reliance and organisation of the fishery. A framework is developed to guide the systematic description and characterisation of small-scale fisheries organisation in Amazonia and beyond. An improved understanding of the socioeconomic factors that shape the organisation of artisanal freshwater fisheries promises to better inform research and management initiatives aimed at promoting sustainable local fisheries and poverty reduction among fishers.

Short- and long-term dietary effects on disease and mortality in American lobster Homarus americanus

The American lobster Homarus americanus fishery is heavily dependent on the use of fish as bait to entice lobsters into traps. There is concern that this food supplementation is nutritionally insufficient for lobsters, but previous experiments reported conflicting results. We conducted a long-term feeding experiment in which 1 yr old American lobsters were fed one of 7 diets for a period of 352 d, a time that allowed the lobsters to molt thrice. The diets consisted of fresh frozen herring, a 'wild' diet (rock crab, mussel, and Spirulina algae), a formulated artificial diet for shrimp, paired combinations of these 3 diets or a diet formulated at the New England Aquarium (Artemia, fish and krill meal, Spirulina algae, soy lecithin, vitamins and minerals). The lobsters fed the diet of 100% fish had higher initial molting rates, but within the period of this experiment all either contracted shell disease or died. Mixed diets resulted in higher survival and a lower probability of mortality. This research demonstrated a critical time component to diet studies in lobsters. Short- and long-term impacts of diet differ. In the long term, continual high consumption rates of fish by the lobsters promote poor health in all lobsters, not just those of market size. The use of fish as bait may make lobsters more susceptible to the stress associated with environmental fluctuation, thereby leading to increased disease and mortality. This nutritional stress can be used to develop a laboratory model of shell disease in American lobsters.

Isoenzyme electrophoretic patterns in discus fish (Symphysodon aequifasciatus Pellegrin, 1904 and Symphysodon discus Heckel, 1840) from the Central Amazon

The discus is a very popular and expensive aquarium fish belonging to the family Cichlidae, genus Symphysodon, formed by three Amazon basin endemic species: Symphysodon aequifasciatus, S. discus and S. tarzoo. The taxonomic status of these fish is very controversial, with a paucity of molecular research on their population genetic structure and species identification. Information on molecular genetic markers, especially isoenzymes, in search of a better understanding of the population genetic structure and correct identification of fish species, has been receiving more attention when elaborating and implementing commercial fishery management programs. Aiming to contribute to a better understanding of the species taxonomic status, the present study describes the isoenzymatic patterns of 6 enzymes: esterase (Est - EC 3.1.1.1), lactate dehydrogenase (Ldh - EC 1.1.1.27), malate dehydrogenase (Mdh - EC 1.1.1.37), phosphoglucomutase (Pgm - EC 5.4.2.2), phosphoglucose isomerase (Pgi - EC 5.3.1.9), and super oxide dismutase (Sod - EC 1.15.1.1) extracted from skeletal muscle specimens and analyzed by starch gel electrophoresis. Monomorphic patterns, presumably controlled by 11 loci: Est-1, Est-2, Est-3, Ldh-1, Ldh-2, Mdh-1, Mdh-2, Pgi-1, Pgi-2, Pgm-1, and Sod-1 were fixed for the same alleles: Est-1(1), Est-2(1), Est-3(1), Ldh-1(1), Ldh-2(1), Mdh-1(1), Mdh-2(1), Pgi-1(1), Pgi-2(1), Pgm-1(1), and Sod-1(1), respectively, and detected in all 60 specimens examined (27 S. aequifasciatus from Manacapuru and 33 S. discus from Novo Airão, Central Amazon). The failure in the present study to detect diagnostic loci, which could be very useful for differentiating S. aequifasciatus from S. discus species, and polymorphic loci, which could also be applied for possible identification and delimitation of their stocks, does not rule out the possibility of there existing in other isoenzyme gene loci to be analyzed in the future.

Nitrite Toxicity to Danio rerio: Effects of Subchronic Exposure on Fish Growth

The aim of this study was to investigate the long-term effects of subchronic exposure to sublethal levels of nitrite, ranging from 15 to 130 mg l-1 NO2-, on growth in aquarium fish Danio rerio. The juvenile growth test according to OECD 215 was used in the experiments. Fish weight was measured at the beginning of the experiment and then using the same method, fish weight was observed 28 days after fish stocking. Compared to the control, growth suppression was detected from the concentration of 73 mg l-1 NO2- (P < 0.05) and a significant inhibition of fish body growth was shown from 130 mg l-1 NO2- (P < 0.01). An exponential relationship between nitrite concentrations and specific growth rate (R2 = 0.896) was detected.

RAPD fingerprinting of the ornamental fish Badis badis (Hamilton 1822) and Dario dario (Kullander and Britz 2002) (Perciformes, Badidae) from West Bengal, India

We used random amplification of polymorphic DNA (RAPD) to generate species-specific diagnostic fragment patterns for the molecular identification of the ornamental aquarium fish species Badis badis and Dario dario. Seven arbitrary oligodecamer primers produced a total of 116 bands of which 98.23% were polymorphic. The size of the amplified products was in the range 340 bp to 2170 bp. Intraspecies genetic similarity was 0.879 ± 0.023 for B. badis and 0.840 ± 0.014 for D. dario while interspecies genetic similarity was 0.602 ± 0.017, with cluster analysis displaying separate taxonomic and evolutionary status for these fish. The results show that RAPD was useful for the molecular identification of aquarium fish species, with morphological traits also being important.

Preface

Preface

Establishment, characterization, and viral susceptibility of two cell lines derived from goldfish Carassius auratus muscle and swim bladder

Goldfish Carassius auratus are common aquarium fish and have a significant economic and research value, having considerable worth to fisheries as a baitfish and the ability to adapt to a range of habitats. Two cell lines were established from goldfish muscle and swim bladder tissue, in order to create a biological monitoring tool for viral diseases. Cell lines were optimally maintained at 30 degrees C in Leibovitz-15 medium supplemented with 20% fetal bovine serum. Propagation of goldfish cells was serum dependent, with a low plating efficiency (>16%). Karyotyping analysis indicated that both cell lines remained diploid, with a mean chromosomal count of 104. Results of viral challenge assays revealed that both cell lines shared similar patterns of viral susceptibility and production to infectious hematopoietic necrosis virus, infectious pancreatic necrosis virus, snakehead rhabdovirus, and spring viremia carp virus. Both cell lines demonstrated a higher sensitivity and significantly larger viral production than control brown bullhead cells for channel catfish virus. These newly established cell lines will be used as a diagnostic tool for viral diseases in this fish species and also for the isolation and study of goldfish viruses in the future.

Ornamental Fish Trade: An Introduction with Perspectives for Responsible Aquarium Fish Ownership

FA-124, an 8-page illustrated fact sheet by E. J. Livengood and F.A. Chapman, aims inform aquarium owners about the ornamental fish industry so that they can make conscientious decisions about their purchases, and help protect the wild species and safeguard the natural environments. It describes how aquarium fish are collected or cultured, ecological considerations, and things a potential aquarist should know. Includes resource list. Published by the UF Department of Fisheries and Aquatic Sciences, May 2007. FA124/FA124: The Ornamental Fish Trade: An Introduction with Perspectives for Responsible Aquarium Fish Ownership (ufl.edu)

Global survey of diversity among environmental saltwater Bacteriovoracaceae

Halophilic Bacteriovorax (Bx), formerly known as the marine Bdellovibrio, are Gram-negative, predatory bacteria found in saltwater systems. To assess their genetic diversity and geographical occurrence, the small subunit rRNA (ssu-rRNA) gene sequences were analysed from 111 marine, salt lake and estuarine isolates recovered from 27 locations around the world. Phylogenetic analysis of these isolates using Geobacter as the outgroup revealed eight distinct ribotype clusters each with at least two isolates. Each cluster was composed of isolates with >or= 96.5% similarity in ssu-rRNA sequences. Three single isolate outliers were observed. Many of the Bx ribotypes were widely dispersed among different types of ecosystems (e.g. cluster III was recovered from the Great Salt Lake, the Atlantic Ocean, Pacific Ocean, Chesapeake Bay and gills of aquarium fish). However, cluster V was only recovered from a single ecosystem, estuaries. Cluster V was originally detected in the Chesapeake Bay and subsequently in the Pamlico Sound/Neuse River system. Principal coordinate analysis revealed that the sequences of the isolates from different environments were distinct from each other. The results of this study reveal the saltwater Bx to be phylogenetically and environmentally more diverse than was previously known.

Infección cutánea esporotricoide por Mycobacterium haemophilum en un paciente con sida

We report a case of primary cutaneous infection by Mycobacterium haemophilum after the bite of an aquarium fish in a severely immunodepressed AIDS patient. Clinical features consisted in nodular and ulcerative lesions that followed a sporotrichoid pattern. Histological study of nodular lesions showed a granulomatous dermatitis with numerous acid-fast bacilli. The mycobacterium was identified 3 months later by genetic hybridization from a cultive in solid medium. Combined therapy with isoniazid, rifampin, clarithromycin, ethambutol, amikacin and ciprofloxacin resulted in complete resolution of the lesions. Infection by Mycobacterium haemophilum is a rare mycobacteriosis that usually affects immunodepressed patients. The most common clinical manifestations are cutaneous lesions but the development of sporotrichoid nodular lymphangitis is exceptional.

Aquarium fish exploitation in western Amazonia: conservation issues in Peru

The Amazon basin is a key supplier of wild freshwater fishes to the multi-billion US$ global aquarium market, yet limited information exists on the organization of the regional trade, its importance to local economies or conservation impacts. Through field interviews and review of government statistics, this paper describes the state of the industry in Peru, reporting on the scale and value of the trade, the nature of the fishery and the characteristics and roles of key actors in regional supply networks. An economically important industry is revealed, with 28 firms officially exporting over nine million fishes worth US$ 2.5 million to 24 countries in 2001, and involving fish species from 36 families transported from rainforest catchments up to 1100 km distant from the export centre of Iquitos. Most fish are however collected close to the city, with 10 species representing >70% of trade volume. Some 10 000 people earn income from the trade, among them many rural poor who depend on aquarium fish collection as a primary or supplementary source of cash income. The industry is currently undergoing an important transition towards supplying new Asian and European markets, increasing exports of species biologically unsuited to heavy exploitation as a result, and highlighting the conservation need for improved knowledge and management of the trade in Amazonia.

What Characterizes House Dust Mite Sensitive Individuals in a House Dust Mite Free Community in Reykjavik, Iceland?

Previous studies show that 6-9% of young adults in Reykjavik are sensitised to the house dust mite (HDM) Dermatophagoides pteronyssinus (D. pteronyssinus). However, only negligible amounts of HDM and HDM allergens were detected in their homes. The study investigates what characterizes these individuals. We investigated all participants in the European Community Respiratory Health Surveys I and II (ECRHS I and II) with D. pteronyssinus specific IgE, in the years 1991-92. A grass positive but D. pteronyssinus negative control group was recruited from the same cohort. A detailed questionnaire was administered and the specific IgE (Pharmacia CAP system) against six D. pteronyssinus cross-reactive allergens was measured. Of 601 ECRHS I participants with available IgE results, 88% returned for ECRHS II, 8.4 years later. Of 49 individuals with D. pteronyssinus specific IgE in ECRHS I, 24 had become negative in ECRHS II. Compared with controls, HDM sensitive subjects were more often men who had lived on farms or kept aquaria fish in childhood. Of those with specific IgE against D. pteronyssinus in ECRHS I and II, 75% had detectable IgE antibodies (>or=0.35 kU/l) to cross-reactive allergens compared with none in the control group (p<0.0001): Lepidoglyphus destructor (L. destructor) (67%), shrimp (58%), cockroach (33%), mosquito (17%), tropomyosin (17%) and blood worm (4%). Icelanders with specific IgE to D. pteronyssinus are more often men who spent time on farms in childhood and today have high prevalence of IgE antibodies cross-reactive to D. pteronyssinus.

The Ocean at Home: An Illustrated History of the Aquarium (review)

Reviewed by: The Ocean at Home: An Illustrated History of the Aquarium Harriet Ritvo (bio) The Ocean at Home: An Illustrated History of the Aquarium. By Bernd Brunner . New York: Princeton Architectural Press, 2005. Pp. 144. $24.95. The nineteenth-century aquarium served several paradoxical purposes. Most obviously, it allowed water animals and plants to live (more or less) on land. It opened the most mysterious and inaccessible environment to casual inspection. It appealed to—and sometimes appeased—the divergent curiosities of scientific investigators, amateur collectors, and observers simply in search of entertainment. It could enhance cozy domesticity or offer a thrilling glimpse of the sublime perils of the oceanic deeps. Aquariums continue to fulfill most of these functions, and they have also maintained the Victorian trajectory of technical improvement. The most elaborate modern aquariums are enormous and can be modified to simulate a variety of freshwater and marine environments. (The fragile and artificial nature of these environments, no matter how realistic they seem to human observers, was demonstrated by the mass death of the inhabitants of the [End Page 186] Aquarium of the Americas in New Orleans after Hurricane Katrina.) In The Ocean at Home, Bernd Brunner tells how these elaborate devices for storage and display evolved. Most of Brunner's account focuses on the nineteenth century, the period when workable aquarium technology was developed and when aquariums enjoyed their first flush of popularity. But he traces their origins to several earlier periods. In the eighteenth century, he claims, superstitious dread of the sea began to give way to sublime appreciation and scientific investigation (although he acknowledges that some mystery and dread persisted, as evidenced by the popularity of books such as Jules Verne's 20,000 Leagues under the Sea). Brunner links the desire to possess and display aquatic organisms to the passion for collecting that derived from early modern cabinets of curiosity. Finally, he places aquarium fish in a tradition of pet-keeping that echoes practices recorded as long ago as classical antiquity and as far away as medieval China. Few of these early piscine captives survived long, and, beginning in the late seventeenth century, European naturalists searched for ways to enhance their survival. A series of improvements, including the adaptation of the simple but effective technology of the Wardian case (devised for transporting plants) and the use of industrially manufactured glass, meant that, by the mid-Victorian period, even relatively modest homes could display small but well-stocked aquariums. One reason that many inhabitants of such homes desired to maintain these fascinating yet time-consuming devices resulted from another widespread Victorian phenomenon: the craze for examining and collecting the plants and animals that lived on the margins of the sea. This enthusiasm was stoked by popular natural-history writing, especially that of Philip Henry Gosse (to whom Brunner devotes an entire chapter), and it led to several further ichthyological developments. Serious amateur aquarists formed societies and founded specialist magazines, following the pattern of amateurs in other branches of natural history. They joined professional naturalists in debating the relative merits of freshwater fish as opposed to marine fish, or (once the transportation of tropical fish became fairly reliable) of exotics as opposed to indigenous European or American species. The general public in Europe and North America also showed persistent interest in viewing captive live fish. By the late nineteenth century, large aquariums had been constructed in many major cities, either as part of established zoos or as free-standing tourist attractions. In addition to telling its story, The Ocean at Home offers readers a chance to understand why Victorian observers found fish so appealing. The book is attractively designed, with numerous illustrations, some in color, and a lot of white space on each page. The presentation also signals that its target audience does not consist primarily of professional historians, a signal that is amplified by the text. Brunner's account is descriptive and anecdotal [End Page 187] rather than analytic. He slips easily from time to time and place to place without much regard for chronology or cultural context. There is an extensive bibliography, but no index. The author draws on an impressive range of material, but...