Public Aquarium Research Articles

Aquariums as Research Platforms: Characterizing Fish Sounds in Controlled Settings with Preliminary Insights from the Blackbar Soldierfish Myripristis jacobus

This study highlights the potential of aquariums as research platforms for bioacoustic research. Aquariums provide access to a wide variety of fish species, offering unique opportunities to characterize their acoustic features in controlled settings. In particular, we present a preliminary description of the acoustic characteristics of Myripristis jacobus, a soniferous species in the Holocentridae family, within a controlled environment at a zoological facility in the Canary Islands, Spain. Using two HydroMoth 1.0 hydrophones, we recorded vocalizations of the blackbar soldierfish in a glass tank, revealing a pulsed sound type with a peak frequency around 355 Hz (DS 64), offering a more precise characterization than previously available. The vocalizations exhibit two distinct patterns: short sequences with long pulse intervals and fast pulse trains with short inter-pulse intervals. Despite some limitations, this experimental setup highlights the efficacy of cost-effective methodologies in public aquariums for initial bioacoustic research. These findings contribute to the early stages of acoustic characterization of coastal fishes in the western central Atlantic, emphasizing the value of passive acoustic monitoring for ecological assessments and conservation efforts. Moreover, this study opens new avenues for considering the acoustic environment as a crucial factor in the welfare of captive fish, an aspect that has largely been overlooked in aquarium management.

Submissions of diagnostic samples of two critically endangered species of handfish (Branchionichthys hirsutus and Thymichthys politus) from a public aquarium from 2018 to 2024.

Handfish (Family Brachionichthyidae) is the most threatened marine teleost fish family, however, there is little information on handfish health. We reviewed the results of submissions of mortalities from captive and captive bred spotted handfish (Branchionichthys hirsutus (Lacepède, 1804)) and red handfish (Thymichthys politus (Richardson, 1844)) from a public aquarium from January 2018 to February 2024. Seventeen cases for spotted handfish (comprising 33 individuals) and five cases for red handfish (one individual each) were submitted for mortality investigation. In 2018-2019, six of seven cases were diagnosed with scuticociliatosis. Other conditions included epitheliocystis (1 of 17), infections with metazoan parasites (2 of 17 for spotted handfish and 2 of 5 for red handfish) and hepatic lipidosis (4 of 17). Most submissions were fixed samples for histology with only one fish suitable for microbiology. We recommend development of a coordinated health program for all captive breeders and aquaria, which should include sampling protocols, collection, and preservation in a range of fixatives of all the dying or dead handfish and adapting sublethal sampling, including tank water to assess presence of pathogens and other microorganisms. Risk factors for handfish health in captivity should be assessed. Handfish health database should be established to avoid loss of corporate knowledge in this area.

Deep Dive Into Noninvasive Biometrics: A Pilot Journey Using Stereo-Video in a Public Aquarium.

Accurate collection of biometric data is important for understanding the biology and conservation of marine organisms, including elasmobranch and teleost fish, both in nature and controlled environments where monitoring marine specimens' health is mandatory. Traditional methods involving specimen capture and handling are invasive, stressful, and disruptive. Some techniques like underwater visual census or laser photogrammetry have been used for noninvasive data collection, but they have limitations and biases. The application of stereo-video photogrammetry through the use of diver-operated stereo-video systems (stereo-DOV) is a noninvasive method that overcomes these challenges, providing highly accurate measurements. It has become popular for species monitoring, studying anthropogenic impacts, and assessing length distributions. However, this technique is still uncommon and barely reported in aquarium settings. This study describes an innovative pilot study targeting multiple species carried out in a Public Aquarium, using a low-cost house-made device. The results revealed that measuring more than 100 individuals in approximately 1 day's work is possible. Total and fork lengths were estimated using specific software for 31 teleost and 16 elasmobranch species and compared with real measurements for the available species. Despite technical limitations that must be reviewed for application in future studies that resulted in high root mean square (RMS) values (> 20 mm), differences between methodological approaches revealed a minimal discrepancy (1.37%-5% in large sharks and rays and 1.8%-5.5% in teleost fish). This technique has time and cost requirements, but might represent a major advance in husbandry and in the contribution to conservation that ex situ studies can provide.

From wild to captive: Understanding the main nutritional diseases of sharks in public aquariums.

The establishment of a well-adapted and accurate feeding regimen is a fundamental determining factor in the maintenance of shark species in captivity. Replicating the natural diet in captivity is commonly accepted and recommended. Given the diverse nutritional composition of prey, supplementation may become necessary. The captive environment poses unique challenges, making sharks susceptible to an array of health issues, including numerous diseases. Mitigating these risks demands detailed husbandry practices, an appropriate physical environment and a balanced diet. Supplementation, encompassing vitamins and minerals, becomes imperative for the provision of essential nutrients. This complexity has rendered the formulation of an adapted feeding plan for aquarists exceptionally challenging. The scarcity of information in these species adds to the issue, mandating extrapolation from various shark groups and to species with analogous characteristics. This literature review concentrates predominantly on benthic and pelagic shark species prevalent in contemporary aquariums. The central argument posits that dietary choices in captivity rely on factors such as availability, quality and consistency of supply. The advocated approach highlights the importance of a balanced, diverse feeding that closely mirrors natural diets. It is then crucial to emphasize that these are general guidelines, and the specific dietary requisites may diverge between shark species. Collaborating with experts in marine biology, shark husbandry and veterinary care is imperative for the formulation and perpetuation of an adapted diet for captive sharks.

Cesarian section and long-term outcomes for cownose rays (Rhinoptera bonasus).

Cownose rays (Rhinoptera bonasus) are schooling rays commonly displayed in large groups in public aquariums. They are long-lived, have an annual reproductive cycle, and readily breed in managed care with most pregnancies culminating with the unaided and successful birth of a single neonate. Occasionally, females are observed to have prolonged pregnancies or suffer dystocia during parturition and intervention via a cesarian section (C-section) is required to deliver the neonate. Monthly reproductive monitoring at Ripley's Aquarium of the Smokies using ultrasound to stage pregnancies allows for the prediction of anticipated due dates and guides the decision to assist with delivery. Recognizing when to assist birth and best practices for performing C-section are important for the reproductive health, sustainability, and longevity of this species in managed care. This report describes a surgical technique for C-section in cownose rays and includes short-term complications and long-term outcomes for females.

HEMATOLOGIC AND PLASMA BIOCHEMICAL REFERENCE VALUES FOR CAPTIVE LEOPARD SHARKS (TRIAKIS SEMIFASCIATA).

Leopard sharks (Triakis semifasciata) are temperate, Eastern Pacific elasmobranchs popular in public aquariums. Blood analysis is commonly used for assessing animal health, yet reference values have not been established for this species. This study analyzed T. semifasciata population data to characterize blood reference values for a collection of T. semifasciata housed at a public aquarium. Twenty-one captive leopard sharks were sampled. Blood was collected during annual health examinations from sedated animals. After collection, blood samples were anticoagulated with lithium heparin, and hematocrit and plasma biochemistry values were analyzed. The minimum-maximum ranges were hematocrit 11-31%, buffy coat 1-2%, glucose 4.94-9.38 mM/L, sodium 244-272 mM/L, potassium 3.7-5.5 mM/L, chloride 214-246 mM/L, aspartate aminotransferase 5-31 U/L, creatine kinase 36-1,136 U/L, calcium 3.65-3.95 mM/L, phosphorus 1.13-2.23 mM/L, total protein 21-38 g/L, and total CO2 12-18 mM/L. The values identified will contribute to a better understanding of captive leopard shark physiology and to improved veterinary care for captive leopard sharks. Further research can examine the validity of machines like the Vetscan VS2, which will expand the resources available to care professionals.

Current disease treatments for the ornamental pet fish trade and their associated problems

AbstractThe trade in live ornamental fishes to be held as companion animals or displayed in public aquaria has an estimated global annual value of US$15–20 billion. Supply chains for ornamental pet fishes often involve many more parties than for fish farmed as food fishes, and at each stage, fishes are exposed to stressors including handling, confinement, crowding, mechanical disturbance, and poor water quality. If chronic, these stressors can compromise their immune system, making fishes more susceptible to pathogens. Mortality and morbidity from infectious disease can result in considerable welfare impacts and massive economic losses for the industry, and the range of infective agents seen in ornamental species is well documented. However, treating these diseases is not straightforward with practices varying greatly across the trade and with several approaches having unintended consequences, such as the emergence of resistant strains of pathogens. While disease treatments for a handful of fish species (e.g., koi, goldfish) have received focused research attention, for the home aquarium owner, there is an increasing reliance on products based on natural compounds which have received far less scientific attention. This review aims to highlight the gaps in our knowledge surrounding the range of disease treatments used across the ornamental pet fish trade, with a particular focus on freshwater tropical species destined for home aquaria. Consideration is given to the potential problems arising from these treatments, including microbial resistance and effects of treatments themselves on fish health and welfare.

Surgical outcomes and complications associated with ovariectomy in the southern stingray Hypanus americanus.

Southern stingrays (Hypanus americanus) are relatively large rays that are common and popular in public aquariums because of their size and gentle nature. In aquariums, as well as in the wild, female southern stingrays are fecund. They have a short gestation cycle and can sustain multiple pregnancies each year, each culminating with 2-10 young. This reproductive rate could quickly outpace capacity in managed care and result in a ray surplus. To prevent overpopulation, many aquaria have resorted to single sex groups with a preference for female-only populations. This is an effective way to control population growth, but forces the maintenance of two separated populations of rays; for females this interrupts normal reproductive cycling and replaces it with a protracted non-pregnant condition. An additional consideration is development of reproductive disease in females which is recognized by an enlarged, misshapen, and congested ovary with an abundance of cystic structures and an enlarged uterus with a thickened wall that is often filled with histotroph despite a non-pregnant status. There are no effective long-lasting medical treatments for this type of reproductive disease and mortality is often the result. This report describes a surgical technique for ovariectomy in southern stingrays including outcomes and complications. Ovariectomy as a surgical method prevents unwanted reproduction and has the benefit of reducing reproductive pathologies commonly observed in southern stingrays as they age. Seven stingrays 1-5.2 years old and 42-83.5 cm disc width underwent ovariectomy. After anesthesia, the ovary and a small amount of epigonal was excised via a left para-lumbar incision. Four of the seven rays survived five or more years post-procedure. Two rays died acutely of coelomitis and one ray died of complications unrelated to the procedure. This report details a surgical procedure for ovariectomy in southern stingrays including outcomes, complications, and recommendations.

A novel protocol for three-dimensional mapping of sand tiger shark (Carcharias taurus) enclosure use in aquaria: Implications for management.

This study investigated sand tiger shark (STS; Carcharias taurus) spatial use and exclusion in public aquarium enclosures using a novel protocol for three-dimensional mapping. Fifty-one STS were observed in 14 enclosures, and swimming pattern, depth, and location were recorded in ZooMonitor. Data were converted into quantitative, three-dimensional representations using ArcGIS® Pro v. 2.9. All observed STS except one swam in circular patterns, and 80% (n = 41) showed a directional swimming bias. Most STS (80%; n = 41) predominantly utilized the top two-thirds of the enclosures, though 83% (n = 34) of those had swimming obstructions in the bottom of the enclosure. Avoidance of obstructed areas, sections <7 m wide, as well as behavioral spatial separation, resulted in utilization of between 27% and 66% of available enclosure space. STS underutilized corners, pinch-points, and obstructed areas requiring abrupt directional changes and instead exhibited continual, unimpeded swimming patterns. In addition, this study found no relationship between directional swimming bias or use of smaller enclosure volumes and spinal deformity, a health issue affecting 26% of STS 10 years ago but now with an incidence of 6%. Using novel protocols for three-dimensional mapping and volume estimation, this study demonstrated that enclosures facilitating unimpeded, continuous swimming are most usable for STS and provides important information that will be useful for future enclosure design.

Complete genome of Vibrio harveyi isolate K2014767 from the hepatopancreas of captive Caribbean spiny lobster (Panulirus argus).

The complete genome sequence is reported for Vibrio harveyi isolate K2014767, isolated from a captive Caribbean spiny lobster (Panulirus argus) during a species-specific mortality event in a public display aquarium in the United States.

Review of neoplasia in fish at a large display aquarium, 2005-2021.

Fish maintained in managed care may have longer lifespans as a result of advances in veterinary medicine and husbandry and reduced risk of predation. Neoplasia is of increasing interest in managed aquarium populations. However, few studies have systematically evaluated neoplasia in managed fish populations. Our objective in this retrospective study was to review and describe neoplasia diagnosed in fish at a large public display aquarium between 2005 and 2021. Any fish diagnosed with neoplasia on either antemortem or postmortem evaluation during the study period was included, and all medical records, biopsy, and autopsy reports were reviewed. Sixty-two fish met the inclusion criteria; 37 species were included in the study population, most of which were tropical freshwater fish (n = 34 fish). Thirty-two types of neoplasia were identified. Ten fish had benign neoplasms, and 53 fish had malignant neoplasms. The most common neoplasms were of epithelial and neuroectodermal origin. The most common site of tumor origin was the skin. Our data suggest that mesenchymal neoplasms may be more common in cold saltwater fish than in tropical freshwater and saltwater fish. Malignant neoplasms were most commonly diagnosed in the study population and should be a top differential when neoplasms are identified in fish managed under human care. Our study contributes to the overall knowledge of the health of aquarium fish and may aid clinicians in characterizing neoplasia that may be present in fish under human care.

The effects of anthropogenic noise on frogs housed on exhibit at a public aquarium.

Anuran behavior and reproduction are dominated by vocalizations, rendering them vulnerable to the effects of signal masking. For anurans on display in zoos and aquaria, a major source of ambient noise is visitors, which pose a unique source of potential anthropogenic signal masking. Call characteristics (total call duration, and minimum and maximum call frequencies) of three populations of dendrobatids (Dendrobates leucomelas, Epipedobates tricolor, and Ranitomeya imitator) on public display were investigated at time periods of increasing visitor-related noise (closed, off-peak, and peak aquarium visiting hours) to determine if there were changes in call characteristics that correlated with changes in visitor noise levels. The data revealed that call length increased with more visitor noise for D. leucomelas and E. tricolor, with their longest calls during peak hours, and all three species had their shortest calls during closed hours. Both minimum and maximum call frequencies increased with more visitor noise for E. tricolor and R. imitator, with their highest frequencies during peak hours, and lowest frequencies during closed hours. This study found evidence that anurans on public display adjust their vocalizations in the presence of visitor noise. These findings support expanded monitoring of ambient noise for animals on public display to determine if noise poses significant effects that might influence well-being or reproduction.

A Review of Two Decades of In Situ Conservation Powered by Public Aquaria

The European Union of Aquarium Curators (EUAC) boasts a membership of 150 dedicated individuals, standing as a vital cornerstone within the European public aquarium community. Since 2004, the EUAC Conservation Fund has granted over a quarter of a million euros to approximately 50 conservation projects spanning the globe. These initiatives, diverse in nature and scale, have yielded tangible impacts on local populations and their focal species. This paper delves into the outcomes of these conservation endeavors and proposes enhancements to ensure that the funding is unequivocally channeled towards conservation efforts. One resounding observation gleaned from the array of projects spotlighted in this study is the profound community engagement that emerges, irrespective of the final project outcomes. These endeavors serve as a catalyst for local communities, shedding light on subjects that would otherwise remain shrouded in obscurity. Furthermore, the EUAC-backed projects illuminate the expansive reach of public aquarium initiatives, transcending the confines of acrylic tank walls and institutional boundaries to resonate globally, heightening local awareness about the imperative to safeguard biodiversity. These findings underscore a prospective trajectory for both the EUAC and the public aquaria it comprises: an intensified advocacy and collaboration with legislative bodies to fortify in situ conservation measures. In essence, it is imperative that the public comprehends the pivotal role played by aquaria in preserving a multitude of species and acknowledges that their visits directly contribute to funding projects aimed at safeguarding species within their natural habitats.

Application of a One Welfare‐Based Ecosystem Model to assess wild collection for public aquariums

Abstract1. Public aquariums are organizations that offer their visitors an opportunity to engage with, gain knowledge of, and contribute to the conservation of species and ecosystems. Unfortunately, the ways many aquariums maintain their populations include primarily sourcing marine species from the wild. This creates the potential for negative impacts to stressed aquatic environments and a need for a holistic approach to quantify the impacts of aquarium population management. 2. The objective of this study was to implement a developed One Welfare‐Based Ecosystem Model to predict impacts of aquarium population management on humans, animals, and the environment. Ecosystem indicators were selected and grouped into physical–chemical, biological, and socio‐economic categories. Data included measurements of environmental and animal indicators at field sites frequently visited by aquariums to collect animals from, aquarium visitor surveys, and publicly available data. Model development included comparing field data to reference information and then adding weightings based on indicator significance and alpha‐testing of the model. 3. At model completion, each institution was allocated a One Welfare status. Confidence ratings of measured indicators and reference data occurred for each field site to determine the appropriateness of use of the model for each aquarium. 4. Findings included a positive One Welfare status, with collaborating institutions scoring in the good and excellent categories (81.92/100 and 92.51/100). Confidence ratings showed positive results (62/100 and 78/100) for model applicability for the field sites studied as well as future use by other institutions assessing similar parameters. 5. To maintain their recognition as leaders in conservation, public aquariums must objectively assess their direct and indirect influence on marine ecosystems moving forward.

Traumatic telson avulsion and attempted external stabilization in Atlantic horseshoe crabs (Limulus polyphemus).

Atlantic horseshoe crabs (Limulus polyphemus) are prevalent in public aquarium touch pools. Despite their popularity, the literature concerning medical management under managed care is sparse. Noninfectious conditions include trauma to the exoskeleton and compound eyes; however, injury to the soft tissue connecting the telson and opisthosoma has not been previously reported. This report describes telson avulsion in three Atlantic horseshoe crabs at a public aquarium and attempted external stabilization with a vascular silicone tie in two of three affected animals. The horseshoe crab that received no veterinary intervention suffered a complete telson amputation 1 month after the initial injury. Although the two other horseshoe crabs did well postoperatively, and external stabilization prevented further avulsion or amputation, they still could not right themselves if flipped into dorsal recumbency. All three horseshoe crabs were ultimately euthanized due to animal welfare concerns. To avoid potentially serious telson ligament injury, horseshoe crabs should never be picked up by the telson. The authors recommend that telson ligament injuries be addressed promptly, any inciting cause be mitigated, and external stabilization be considered earlier.

Pyrethroid-associated nephrotoxicity in channel catfish, Ictalurus punctatus, and blue catfish, I. furcatus, at a public aquarium.

Over the course of an approximately 11-month period, an outdoor, freshwater, mixed species, recirculating, display system at a public aquarium experienced intermittent mortalities of channel catfish (Ictalurus punctatus) and blue catfish (I. furcatus). Catfish acutely presented for abnormal buoyancy, coelomic distention, and protein-rich coelomic effusion. Gross lesions typically involved massive coelomic distension with protein-rich effusion, generalized edema, and gastric hemorrhage and edema. Microscopically, primary lesions included renal tubular necrosis, gastric edema with mucosal hemorrhages, and generalized edema. Aerobic culture and virus isolation could not recover a consistent infectious agent. Intracoelomic injection of coelomic effusion and aspirated retrobulbar fluid from a catfish into naïve zebrafish (bioassay) produced peracute mortality in 3 of 4 fish and nervous signs in the fourth compared with 2 saline-injected control zebrafish that had - no mortality or clinical signs. Kidney tissue and coelomic effusion were submitted for gas chromatography tandem mass spectrometry by multiple reaction monitoring against laboratory standards, which detected the presence of multiple pyrethroid toxins, including bioallethrin, bifenthrin, trans-permethrin, phenothrin, and deltamethrin. Detection of multiple pyrethroids presumably reflects multiple exposures with several products. As such, the contributions of each pyrethroid toward clinical presentation, lesion development, and disease pathogenesis cannot be determined, but they are suspected to have collectively resulted in disrupted osmoregulation and fluid overload due to renal injury. Pesticide-induced toxicoses involving aquarium fish are rarely reported with this being the first description of pyrethroid-induced lesions and mortality in public aquarium-held fish.

Polycystic ovarian disease in aquarium-managed cownose rays Rhinoptera bonasus.

Significant knowledge gaps remain in our understanding of the reproductive physiology and diseases of elasmobranchs. The objective of this work is to describe the clinical, imaging, and pathologic findings associated with polycystic ovaries in cownose rays housed in public aquariums. Ten adult female cownose rays Rhinoptera bonasus housed in 4 public aquariums presented with variable nonspecific (lethargy, anorexia, cutaneous discoloration) or no clinical signs. Clinical antemortem examination revealed a large, heterogeneously hyperechoic mass with many variably sized and shaped anechoic cavitations within the coelom on ultrasound in 2 animals. Necropsies of 10 animals revealed polycystic, fluid-filled ovarian masses filling approximately 65-75% of the coelomic cavity in severe cases along with substantial liver atrophy. Microscopically, the masses were composed of delicate connective tissue supporting a combination of cysts lined by attenuated squamous to foamy columnar epithelium, hemorrhage, embedded anovulatory follicles, and oocytes along the periphery. Polycystic ovarian disease is understudied in elasmobranchs and presumptively resulted from failure of follicular ovulation in these cases. Along with southern stingrays, cownose rays appear to be at heightened risk for developing polycystic ovaries under human care. Further study into disease prevalence, epidemiologic factors, etiopathogenesis, and treatment modalities are needed in order to prevent and medically manage this condition in cownose rays under human care.

Apseudes ranma sp. nov. (Tanaidacea: Apseudidae) found in a public aquarium, with notes on phylogeny and a presumptive stridulatory organ

We describe Apseudes ranma sp. nov. from the Port of Nagoya Public Aquarium, Nagoya, Japan. It resembles two congeners, Apseudes curtiramus (Guţu, 2007) and Apseudes orghidani Guţu and Iliffe, 1989, in having the rostrum triangular, wider than long, the carapace without lateral spines, distinct and round eye lobes, pereonites 3–6 with a pair of tongue-shaped anterolateral projections, and the pleotelson with two pairs of lateral projections, but differs from them in having lateral setae on the anterolateral margin of the carapace and a ventro-subproximal spine on the pereopod-1 basis, and in the number of spiniform setae on articles of pereopods 2–4. We determined partial nucleotide sequences for the cytochrome c oxidase subunit I (COI) and 18S rRNA (18S) genes in A. ranma sp. nov. for future DNA barcoding and phylogeny reconstruction. In an 18S tree, A. ranma sp. nov. was the sister taxon to Apseudes nipponicus Shiino, 1937, and this clade was the sister group to moderately supported Carpoapseudes clade. We discovered a presumptive stridulatory organ in A. ranma sp. nov. consisting of a cylindrical protrusion and knobbly area on the inner surface of each of the left and right chelipedal bases. The location of the protrusion and knobbly area suggests that these may be a plectrum and pars stridens, respectively.

Techniques and Poetics of the Submarine in Film

Water, whether surface or depths, recurrently appears in cinema as a motif and a material. The great symbolic importance this recurrence of the aquatic bears within film leads to calling its different uses into question, especially when it comes to the subaquatic. Addressing the question of the submarine allows going beyond water as a simple surface, and thus to move towards a real habitability of water. Making a history of underwater cinema that includes precinematic devices such as the public aquariums of the late 19th century enables the identification of an aesthetic community, as well as that of a common desire to stage a totalizing perceptive experience of the aquatic element and, in that way, of the image materiality. In line with the various cinematic underwater devices conceived to that end during the 20th century, virtual reality, as a total experience generator, also resorts to the subaquatic as a pretext to immerse the user in the work of art. The recurring fascination for the subaquatic throughout the ages, even more so with the rise of new media, demonstrates how water is a central feature to better define and archeologize the concept of immersion.

Invisible Invertebrates: The Welfare of Invertebrates in Public Aquaria

Invisible Invertebrates: The Welfare of Invertebrates in Public Aquaria