Water Quality and Idiopathic Diseases of Laboratory Zebrafish

Targeting in zebrafish fast growth, high survival rates and improved reproductive performance has led over the last years in variable feeding regimes between different facilities. Despite its significance on fish function and welfare, normal skeletal development has rarely been evaluated in establishing the best feeding practices for zebrafish. The aim of this study was to establish a protocol for normal skeletal development, growth and survival of zebrafish larvae through live feed‐to‐microdiet transition at an appropriate rate. Four feeding regimes including feeding exclusively on Artemia nauplii (A) or dry microdiet (D), and feeding on both Artemia and microdiet at two different transition rates (slow (B) or fast (C)) were applied from 5 to 24 dpf (days post‐fertilization). Results demonstrated a significant effect of feeding regimes on the incidence of skeletal abnormalities (gill cover, fins and vertebral column, p < .05) in zebrafish larvae. The A and B experimental groups presented the highest (88 ± 3 and 84 ± 17%, respectively), but the C and D the lowest (18 ± 14 and 11 ± 2%, respectively), rates of normal fish (fish without any abnormality). Similarly, growth rate was comparatively elevated in A and B groups. No significant differences were observed in fish survival between A, B and C groups. However, D group presented a significantly lower survival rate. To our knowledge, this is the first study to show that the live feed‐to‐microdiet transition rate influences larval growth, survival and abnormality rates in a non‐homogenous pattern.

“…Skeletal abnormalities are common in zebrafish laboratory stocks (Murray et al., 2020). In their recent review, with 12‐year data from 752 cases (involving 10,121 fish), Kent et al.…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Balancing between Artemia and microdiet usage for normal skeletal development in zebrafish (Danio rerio)

Printzi

Kourkouta

Fragkoulis

et al. 2021

“…Gas supersaturation, also known as gas bubble disease (GBD), is a common problem in zebrafish facilities (Murray et al, 2020), and this disease occurred in some tanks a few days after the experiment was initiated. Consistent with GBD, which has been an intermittent problem in our vivarium, moribund fish accumulated at the bottom of the tanks and were listless and respired rapidly.…”

Section: Resultsmentioning

confidence: 99%

Early detection of Pseudocapillaria tomentosa by qPCR in four lines of zebrafish, Danio rerio (Hamilton 1882)

Schuster

Leong

Kasschau

et al. 2023

The intestinal nematode Pseudocapillaria tomentosa in zebrafish (Danio rerio) causes profound intestinal lesions, emaciation and death and is a promoter of a common intestinal cancer in zebrafish. This nematode has been detected in zebrafish from about 15% of the laboratories. Adult worms are readily detected about 3 weeks after exposure by either histology or wet mount preparations of the intestine, and larval worms are inconsistently observed in fish before this time. A quantitative PCR (qPCR) test was recently developed to detect the worm in fish and water, and here we determined that the test on zebrafish intestines was effective for earlier detection. Four lines of zebrafish (AB, TU, 5D and Casper) were experimentally infected and evaluated by wet mounts and qPCR at 8, 15‐, 22‐, 31‐ and 44‐day post‐exposure (dpe). At the first two time points, only 8% of the wet mounts from exposed fish were identified as infected, while the same intestines screened by qPCR showed 78% positivity, with low and consistent cycle threshold (Ct) values at these times. Wet mounts at later time points showed a high prevalence of infection, but this was still surpassed by qPCR.

“…Zebrafish are subject to most of the same water quality concerns as other fishes reared in intensive recirculating systems, including gas supersaturation, metal toxicities in new systems, ammonia and nitrite toxicity in crowded systems or when biological filters fail (Murray, Lains, & Spagnoli, 2020) (Table 2). Gill epithelial hypertrophy and hyperplasia is not an uncommon finding in routine screening of sump or sentinel zebrafish.…”

Section: Overview Of Diseasesmentioning

confidence: 99%

“…In addition to neoplasms, a few idiopathic diseases or lesions are somewhat common (Matthews, 2009; Murray et al, 2020). Hepatic megalocytosis is frequently observed in fish of various ages, but is often not associated with clinical disease.…”

Section: Overview Of Diseasesmentioning

confidence: 99%

Review of diseases and health management in zebrafish Danio rerio (Hamilton 1822) in research facilities

Kent

Sanders

Spagnoli

et al. 2020

The use of zebrafish (Danio rerio) in biomedical research has expanded at a tremendous rate over the last two decades. Along with increases in laboratories using this model, we are discovering new and important diseases. We review here the important pathogens and diseases based on some 20 years of research and findings from our diagnostic service at the NIH-funded Zebrafish International Resource Center. Descriptions of the present status of biosecurity programmes and diagnostic and treatment approaches are included. The most common and important diseases and pathogens are two parasites, Pseudoloma neurophilia and Pseudocapillaria tomentosa, and mycobacteriosis caused by Mycobacterium chelonae, M. marinum and M. haemophilum. Less common but deadly diseases are caused by Edwardsiella ictaluri and infectious spleen and kidney necrosis virus (ISKNV). Hepatic megalocytosis and eggassociated inflammation and fibroplasia are common, apparently non-infectious, in zebrafish laboratories. Water quality diseases include supersaturation and nephrocalcinosis. Common neoplasms are spindle cell sarcomas, ultimobranchial tumours, spermatocytic seminomas and a small-cell carcinoma that is caused by a transmissible agent. Despite the clear biosecurity risk, researchers continue to use fish from pet stores, and here, we document two novel coccidia associated with significant lesions in zebrafish from one of these stores. K E Y W O R D S biosecurity, Danio rerio, diagnostics, fish diseases, treatment